1
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Kirk R, He H, Wahome PG, Wu S, Carter GT, Bertin MJ. New Micropeptins with Anti-Neuroinflammatory Activity Isolated from a Cyanobacterial Bloom. ACS Omega 2021; 6:15472-15478. [PMID: 34151125 PMCID: PMC8210450 DOI: 10.1021/acsomega.1c02025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 05/21/2021] [Indexed: 06/13/2023]
Abstract
Metabolite mining of environmentally collected aquatic and marine microbiomes offers a platform for the discovery of new therapeutic lead molecules. Combining a prefractionated chromatography library with liquid chromatography tandem mass spectrometry (LC-MS/MS)-based molecular networking and biological assays, we isolated and characterized two new micropeptins (1 and 2) along with the previously characterized micropeptin 996. These metabolites showed potency in anti-neuroinflammatory assays using BV-2 mouse microglial cells, showing a 50% reduction in inflammation in a range from 1 to 10 μM. These results show promise for cyanobacterial peptides in the therapeutic realm apart from their impact on environmental health and provide another example of the utility of large prefractionated natural product libraries for therapeutic hit and lead identification.
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Affiliation(s)
- Riley
D. Kirk
- Department
of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, Rhode Island 02881, United States
| | - Haiyin He
- Biosortia
Pharmaceuticals Hollings Marine Laboratory, Charleston, South Carolina 29412, United States
| | - Paul G. Wahome
- Biosortia
Pharmaceuticals Hollings Marine Laboratory, Charleston, South Carolina 29412, United States
| | - ShiBiao Wu
- Biosortia
Pharmaceuticals Hollings Marine Laboratory, Charleston, South Carolina 29412, United States
| | - Guy T. Carter
- Biosortia
Pharmaceuticals Hollings Marine Laboratory, Charleston, South Carolina 29412, United States
| | - Matthew J. Bertin
- Department
of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, Rhode Island 02881, United States
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2
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He H, Bertin MJ, Wu S, Wahome PG, Beauchesne KR, Youngs RO, Zimba PV, Moeller PDR, Sauri J, Carter GT. Cyanobufalins: Cardioactive Toxins from Cyanobacterial Blooms. J Nat Prod 2018; 81:2576-2581. [PMID: 30369239 DOI: 10.1021/acs.jnatprod.8b00736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cyanobufalins A-C (1-3), a new series of cardiotoxic steroids, have been discovered from cyanobacterial blooms in Buckeye Lake and Grand Lake St. Marys in Ohio. Compounds 1-3 contain distinctive structural features, including geminal methyl groups at C-4, a 7,8 double bond, and a C-16 chlorine substituent that distinguish them from plant- or animal-derived congeners. Despite these structural differences, the compounds are qualitatively identical to bufalin in their cytotoxic profiles versus cell lines in tissue culture and cardiac activity, as demonstrated in an impedance-based cellular assay conducted with IPSC-derived cardiomyocytes. Cyanobufalins are nonselectively toxic to human cells in the single-digit nanomolar range and show stimulation of contractility in cardiomyocytes at sub-nanomolar concentrations. The estimated combined concentration of 1-3 in the environment is in the same nanomolar range, and consequently more precise quantitative analyses are recommended along with more detailed cardiotoxicity studies. This is the first time that cardioactive steroid toxins have been found associated with microorganisms in an aquatic environment. Several factors point to a microbial biosynthetic origin for the cyanobufalins.
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Affiliation(s)
- Haiyin He
- Biosortia Pharmaceuticals , Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Matthew J Bertin
- Biosortia Pharmaceuticals , Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy , University of Rhode Island , Kingston , Rhode Island 02881 , United States
| | - ShiBiao Wu
- Biosortia Pharmaceuticals , Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Paul G Wahome
- Biosortia Pharmaceuticals , Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Kevin R Beauchesne
- Biosortia Pharmaceuticals , Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Ross O Youngs
- Biosortia Pharmaceuticals , Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Paul V Zimba
- Center for Coastal Studies , Texas A & M University Corpus Christi , 6300 Ocean Drive , Corpus Christi , Texas 78412 , United States
| | - Peter D R Moeller
- National Oceanic and Atmospheric Administration , Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Josep Sauri
- Structure Elucidation, Analytical Research & Development , Merck & Co., Inc. , 126 E. Lincoln Avenue , Rahway , New Jersey 07735 , United States
| | - Guy T Carter
- Biosortia Pharmaceuticals , Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
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3
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He H, Wu S, Wahome PG, Bertin MJ, Pedone AC, Beauchesne KR, Moeller PDR, Carter GT. Microcystins Containing Doubly Homologated Tyrosine Residues from a Microcystis aeruginosa Bloom: Structures and Cytotoxicity. J Nat Prod 2018; 81:1368-1375. [PMID: 29847132 DOI: 10.1021/acs.jnatprod.7b00986] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Four new microcystin congeners are described including the first three examples of microcystins containing the rare doubly homologated tyrosine residue 2-amino-5-(4-hydroxyphenyl)pentanoic acid (Ahppa) (1-4). Large-scale harvesting and biomass processing allowed the isolation of substantial quantities of these compounds, thus enabling complete structure determination by NMR as well as cytotoxicity evaluation against selected cancer cell lines. The new Ahppa-toxins all incorporate Ahppa residues at the 2-position, and one of these also has a second Ahppa at position 4. The two most lipophilic Ahppa-containing microcystins showed 10-fold greater cytotoxic potency against human tumor cell lines (A549 and HCT-116) compared to microcystin-LR (5). The presence of an Ahppa residue in microcystin congeners is difficult to ascertain by MS methods alone, due to the lack of characteristic fragment ions derived from the doubly homologated side chain. Owing to their unexpected cytotoxic potency, the potential impact of the compounds on human health should be further evaluated.
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Affiliation(s)
- Haiyin He
- Biosortia Pharmaceuticals, Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - ShiBiao Wu
- Biosortia Pharmaceuticals, Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Paul G Wahome
- Biosortia Pharmaceuticals, Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Matthew J Bertin
- Biosortia Pharmaceuticals, Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Anna C Pedone
- Biosortia Pharmaceuticals, Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Kevin R Beauchesne
- Biosortia Pharmaceuticals, Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Peter D R Moeller
- National Oceanic and Atmospheric Administration, Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
| | - Guy T Carter
- Biosortia Pharmaceuticals, Hollings Marine Laboratory , 331 Ft. Johnson Road , Charleston , South Carolina 29412 , United States
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4
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Wlodek A, Kendrew SG, Coates NJ, Hold A, Pogwizd J, Rudder S, Sheehan LS, Higginbotham SJ, Stanley-Smith AE, Warneck T, Nur-E-Alam M, Radzom M, Martin CJ, Overvoorde L, Samborskyy M, Alt S, Heine D, Carter GT, Graziani EI, Koehn FE, McDonald L, Alanine A, Rodríguez Sarmiento RM, Chao SK, Ratni H, Steward L, Norville IH, Sarkar-Tyson M, Moss SJ, Leadlay PF, Wilkinson B, Gregory MA. Diversity oriented biosynthesis via accelerated evolution of modular gene clusters. Nat Commun 2017; 8:1206. [PMID: 29089518 PMCID: PMC5663706 DOI: 10.1038/s41467-017-01344-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 09/08/2017] [Indexed: 11/09/2022] Open
Abstract
Erythromycin, avermectin and rapamycin are clinically useful polyketide natural products produced on modular polyketide synthase multienzymes by an assembly-line process in which each module of enzymes in turn specifies attachment of a particular chemical unit. Although polyketide synthase encoding genes have been successfully engineered to produce novel analogues, the process can be relatively slow, inefficient, and frequently low-yielding. We now describe a method for rapidly recombining polyketide synthase gene clusters to replace, add or remove modules that, with high frequency, generates diverse and highly productive assembly lines. The method is exemplified in the rapamycin biosynthetic gene cluster where, in a single experiment, multiple strains were isolated producing new members of a rapamycin-related family of polyketides. The process mimics, but significantly accelerates, a plausible mechanism of natural evolution for modular polyketide synthases. Detailed sequence analysis of the recombinant genes provides unique insight into the design principles for constructing useful synthetic assembly-line multienzymes. Reengineering polyketide synthase encoding genes to produce analogues of natural products can be slow and low-yielding. Here the authors use accelerated evolution to recombine the gene cluster for rapid production of rapamycin-related products.
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Affiliation(s)
- Aleksandra Wlodek
- Isomerase Therapeutics Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK
| | - Steve G Kendrew
- Biotica Technology Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK.,Engineered Biodesign Limited, Cambridge, CB22 3GN, UK
| | - Nigel J Coates
- Isomerase Therapeutics Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK.,Biotica Technology Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK
| | - Adam Hold
- Isomerase Therapeutics Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK
| | - Joanna Pogwizd
- Isomerase Therapeutics Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK
| | - Steven Rudder
- Isomerase Therapeutics Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK
| | - Lesley S Sheehan
- Isomerase Therapeutics Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK.,Biotica Technology Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK
| | | | - Anna E Stanley-Smith
- Isomerase Therapeutics Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK.,Biotica Technology Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK
| | - Tony Warneck
- Biotica Technology Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK
| | - Mohammad Nur-E-Alam
- Biotica Technology Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK.,Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, 12372, Saudi Arabia
| | - Markus Radzom
- Biotica Technology Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK.,BASF SE, Speyerer Str. 2, Limburgerhof, 67117, Germany
| | - Christine J Martin
- Biotica Technology Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK
| | - Lois Overvoorde
- Isomerase Therapeutics Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK
| | - Markiyan Samborskyy
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Silke Alt
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Daniel Heine
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Guy T Carter
- Chemical and Screening Sciences, Wyeth Pharmaceuticals, 401 North Middletown Road, Pearl River, NY, 10965, USA
| | - Edmund I Graziani
- Chemical and Screening Sciences, Wyeth Pharmaceuticals, 401 North Middletown Road, Pearl River, NY, 10965, USA.,Medicine Discovery Network-Synthetic Biology, Pfizer Worldwide R&D, 445 Eastern Point Rd., Groton, CT, 06340, USA
| | - Frank E Koehn
- Chemical and Screening Sciences, Wyeth Pharmaceuticals, 401 North Middletown Road, Pearl River, NY, 10965, USA
| | - Leonard McDonald
- Chemical and Screening Sciences, Wyeth Pharmaceuticals, 401 North Middletown Road, Pearl River, NY, 10965, USA
| | - Alexander Alanine
- Roche Innovation Center Basel, Pharmaceutical Research and Early Development (PRED), Basel, CH-4070, Switzerland
| | | | - Suzan Keen Chao
- Roche Innovation Center Basel, Pharmaceutical Research and Early Development (PRED), Basel, CH-4070, Switzerland
| | - Hasane Ratni
- Roche Innovation Center Basel, Pharmaceutical Research and Early Development (PRED), Basel, CH-4070, Switzerland
| | - Lucinda Steward
- Roche Innovation Center Basel, Pharmaceutical Research and Early Development (PRED), Basel, CH-4070, Switzerland
| | - Isobel H Norville
- Defence Science and Technology Laboratory, Porton Down, PO17 6AD, UK
| | - Mitali Sarkar-Tyson
- Defence Science and Technology Laboratory, Porton Down, PO17 6AD, UK.,Marshall Centre for Infectious Diseases, School of Biomedical Sciences, University of Western Australia, Monash Avenue, Nedlands, WA, 6009, Australia
| | - Steven J Moss
- Isomerase Therapeutics Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK.,Biotica Technology Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK
| | - Peter F Leadlay
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Barrie Wilkinson
- Isomerase Therapeutics Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK. .,Biotica Technology Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK. .,Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
| | - Matthew A Gregory
- Isomerase Therapeutics Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK. .,Biotica Technology Ltd., Chesterford Research Park, Cambridge, CB10 1XL, UK.
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5
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Affiliation(s)
- Bradley S Moore
- Scripps Institution of Oceanography and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, California 92093-0204, USA.
| | - Guy T Carter
- Carter-Bernan Consulting, 350 Phillips Hill Road, New City, New York 10956, United States.
| | - Mark Brönstrup
- Department for Chemical Biology, Helmholtz Centre for Infection Research and German Centre for Infection Research (DZIF), Inhoffenstraße 7, 38124 Braunschweig, Germany and Centre of Biomolecular Drug Research (BMWZ), Schneiderberg 38, 30167 Hannover, Germany.
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6
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Jadulco R, Koch M, Kakule T, Schmidt EW, Orendt A, He H, Janso JE, Carter GT, Larson EC, Pond C, Matainaho T, Barrows LR. Isolation of pyrrolocins A-C: cis- and trans-decalin tetramic acid antibiotics from an endophytic fungal-derived pathway. J Nat Prod 2014; 77:2537-2544. [PMID: 25351193 PMCID: PMC4251065 DOI: 10.1021/np500617u] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Indexed: 06/04/2023]
Abstract
Three new decalin-type tetramic acid analogues, pyrrolocins A (1), B (2), and C (3), were defined as products of a metabolic pathway from a fern endophyte, NRRL 50135, from Papua New Guinea. NRRL 50135 initially produced 1 but ceased its production before chemical or biological evaluation could be completed. Upon transfer of the biosynthetic pathway to a model host, 1-3 were produced. All three compounds are structurally related to equisetin-type compounds, with 1 and 3 having a trans-decalin ring system, while 2 has a cis-fused decalin. All were active against Mycobacterium tuberculosis, with the trans-decalin analogues 1 and 3 exhibiting lower MICs than the cis-decalin analogue 2. Here we report the isolation, structure elucidation, and antimycobacterial activities of 1-3 from the recombinant expression as well as the isolation of 1 from the wild-type fungus NRRL 50135.
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Affiliation(s)
- Raquel
C. Jadulco
- Department of Pharmacology and
Toxicology, Department of Medicinal Chemistry, and Center for High
Performance Computing, University of Utah, Salt Lake City, Utah United States
| | - Michael Koch
- Department of Pharmacology and
Toxicology, Department of Medicinal Chemistry, and Center for High
Performance Computing, University of Utah, Salt Lake City, Utah United States
| | - Thomas
B. Kakule
- Department of Pharmacology and
Toxicology, Department of Medicinal Chemistry, and Center for High
Performance Computing, University of Utah, Salt Lake City, Utah United States
| | - Eric W. Schmidt
- Department of Pharmacology and
Toxicology, Department of Medicinal Chemistry, and Center for High
Performance Computing, University of Utah, Salt Lake City, Utah United States
| | - Anita Orendt
- Department of Pharmacology and
Toxicology, Department of Medicinal Chemistry, and Center for High
Performance Computing, University of Utah, Salt Lake City, Utah United States
| | - Haiyin He
- Natural
Products − Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Jeffrey E. Janso
- Natural
Products − Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 445 Eastern Point Road, Groton, Connecticut 06340, United States
| | - Guy T. Carter
- Carter-Bernan
Consulting, 350 Phillips
Hill Road, New City, New
York 10956, United
States
| | - Erica C. Larson
- Department of Pharmacology and
Toxicology, Department of Medicinal Chemistry, and Center for High
Performance Computing, University of Utah, Salt Lake City, Utah United States
| | - Christopher Pond
- Department of Pharmacology and
Toxicology, Department of Medicinal Chemistry, and Center for High
Performance Computing, University of Utah, Salt Lake City, Utah United States
| | - Teatulohi
K. Matainaho
- School
of Medicine and Health Sciences, University
of Papua New Guinea, Boroko, NCD, Papua New Guinea
| | - Louis R. Barrows
- Department of Pharmacology and
Toxicology, Department of Medicinal Chemistry, and Center for High
Performance Computing, University of Utah, Salt Lake City, Utah United States
- School
of Medicine and Health Sciences, University
of Papua New Guinea, Boroko, NCD, Papua New Guinea
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7
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Abstract
This Highlight explores the evolution of applications of mass spectrometric technologies in the context of natural products research since the 1970's. The central themes are the analysis of mixtures, dereplication (identification) and structure determination. The ascension of HPLC as the method of choice for the analysis of pharmaceuticals was a driving force for the development of interfaces for coupling of HPLC and MS. An example of sequential analysis of fragment ions or MS/MS or MS(n) methods to provide detailed structural information on muraymycins, a family of uridyl-peptide antibiotics, is presented.
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Affiliation(s)
- Guy T Carter
- Carter-Bernan Consulting, 350 Phillips Hill Road, New City, New York 10956, United States.
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8
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Janso JE, Haltli BA, Eustáquio AS, Kulowski K, Waldman AJ, Zha L, Nakamura H, Bernan VS, He H, Carter GT, Koehn FE, Balskus EP. Discovery of the lomaiviticin biosynthetic gene cluster in Salinispora pacifica.. Tetrahedron 2014; 70:4156-4164. [PMID: 25045187 PMCID: PMC4101813 DOI: 10.1016/j.tet.2014.03.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The lomaiviticins are a family of cytotoxic marine natural products that have captured the attention of both synthetic and biological chemists due to their intricate molecular scaffolds and potent biological activities. Here we describe the identification of the gene cluster responsible for lomaiviticin biosynthesis in Salinispora pacifica strains DPJ-0016 and DPJ-0019 using a combination of molecular approaches and genome sequencing. The link between the lom gene cluster and lomaiviticin production was confirmed using bacterial genetics, and subsequent analysis and annotation of this cluster revealed the biosynthetic basis for the core polyketide scaffold. Additionally, we have used comparative genomics to identify candidate enzymes for several unusual tailoring events, including diazo formation and oxidative dimerization. These findings will allow further elucidation of the biosynthetic logic of lomaiviticin assembly and provide useful molecular tools for application in biocatalysis and synthetic biology.
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Affiliation(s)
- Jeffrey E. Janso
- Natural Products, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, Groton, CT 06355, United States
| | - Brad A. Haltli
- Natural Products, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, Groton, CT 06355, United States
| | - Alessandra S. Eustáquio
- Natural Products, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, Groton, CT 06355, United States
| | - Kerry Kulowski
- Natural Products, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, Groton, CT 06355, United States
| | - Abraham J. Waldman
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States
| | - Li Zha
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States
| | - Hitomi Nakamura
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States
| | - Valerie S. Bernan
- Natural Products, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, Groton, CT 06355, United States
| | - Haiyin He
- Natural Products, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, Groton, CT 06355, United States
| | - Guy T. Carter
- Natural Products, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, Groton, CT 06355, United States
| | - Frank E. Koehn
- Natural Products, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, Groton, CT 06355, United States
| | - Emily P. Balskus
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, United States
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9
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Abstract
BACKGROUND The principles and screening strategies for brain penetration in drug discovery are important in identifying drug candidates with desirable CNS properties. OBJECTIVE Define key variables and assays that are essential for determining brain penetration. METHODS This review covers issues, methods, and strategies for assessing brain penetration of small molecules in drug discovery. RESULTS/CONCLUSION Brain penetration is assessed using both initial rate and extent at steady-state. Unbound drug is the active species that exerts pharmacological effects. Low brain penetration can be due to low blood-brain barrier (BBB) permeability, P-glycoprotein (Pgp) efflux, or high plasma protein binding. Successful methods include: parallel artificial membrane permeability assay (PAMPA)-BBB permeability, MDR1-MDCKII for Pgp efflux, B-P dialysis for fraction unbound, and in vivo B/P ratio to extrapolate unbound brain drug concentration.
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Affiliation(s)
- Li Di
- Principal Research Scientist II Wyeth Research, 865 Ridge Road, Monmouth Jct., Princeton, NJ 08852, USA +1 732 274 4489 ; +1 732 274 4505 ;
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10
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Kendrew SG, Petkovic H, Gaisser S, Ready SJ, Gregory MA, Coates NJ, Nur-e-Alam M, Warneck T, Suthar D, Foster TA, McDonald L, Schlingman G, Koehn FE, Skotnicki JS, Carter GT, Moss SJ, Zhang MQ, Martin CJ, Sheridan RM, Wilkinson B. Recombinant strains for the enhanced production of bioengineered rapalogs. Metab Eng 2013; 15:167-73. [DOI: 10.1016/j.ymben.2012.11.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 10/16/2012] [Accepted: 11/03/2012] [Indexed: 10/27/2022]
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11
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12
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13
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Miyanaga A, Janso JE, McDonald L, He M, Liu H, Barbieri L, Eustáquio AS, Fielding EN, Carter GT, Jensen PR, Feng X, Leighton M, Koehn FE, Moore BS. Discovery and assembly-line biosynthesis of the lymphostin pyrroloquinoline alkaloid family of mTOR inhibitors in Salinispora bacteria. J Am Chem Soc 2011; 133:13311-3. [PMID: 21815669 PMCID: PMC3161154 DOI: 10.1021/ja205655w] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The pyrroloquinoline alkaloid family of natural products, which includes the immunosuppressant lymphostin, has long been postulated to arise from tryptophan. We now report the molecular basis of lymphostin biosynthesis in three marine Salinispora species that maintain conserved biosynthetic gene clusters harboring a hybrid nonribosomal peptide synthetase-polyketide synthase that is central to lymphostin assembly. Through a series of experiments involving gene mutations, stable isotope profiling, and natural product discovery, we report the assembly-line biosynthesis of lymphostin and nine new analogues that exhibit potent mTOR inhibitory activity.
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Affiliation(s)
- Akimasa Miyanaga
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California 92093-0204
| | - Jeffrey E. Janso
- Natural Products Laboratory, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 558 Eastern Point Road, Groton, Connecticut 06340
| | - Leonard McDonald
- Natural Products Laboratory, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 558 Eastern Point Road, Groton, Connecticut 06340
| | - Min He
- Natural Products Laboratory, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 558 Eastern Point Road, Groton, Connecticut 06340
| | - Hongbo Liu
- Natural Products Laboratory, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 558 Eastern Point Road, Groton, Connecticut 06340
| | - Laurel Barbieri
- Natural Products Laboratory, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 558 Eastern Point Road, Groton, Connecticut 06340
| | - Alessandra S. Eustáquio
- Natural Products Laboratory, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 558 Eastern Point Road, Groton, Connecticut 06340
| | - Elisha N. Fielding
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California 92093-0204
| | - Guy T. Carter
- Natural Products Laboratory, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 558 Eastern Point Road, Groton, Connecticut 06340
| | - Paul R. Jensen
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California 92093-0204
| | - Xidong Feng
- Natural Products Laboratory, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 558 Eastern Point Road, Groton, Connecticut 06340
| | - Margaret Leighton
- Natural Products Laboratory, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 558 Eastern Point Road, Groton, Connecticut 06340
| | - Frank E. Koehn
- Natural Products Laboratory, Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, 558 Eastern Point Road, Groton, Connecticut 06340
| | - Bradley S. Moore
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California 92093-0204
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, California 92093
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14
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15
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Siegel MM, Kong F, Carter GT. Aspartocin cyclic lipopeptide antibiotics: mass spectral structural confirmations and the diagnostic role played by the alpha,beta-diaminobutyric acid residue. J Mass Spectrom 2010; 45:820-823. [PMID: 20623487 DOI: 10.1002/jms.1755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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16
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Janso JE, Carter GT. Biosynthetic potential of phylogenetically unique endophytic actinomycetes from tropical plants. Appl Environ Microbiol 2010; 76:4377-86. [PMID: 20472734 PMCID: PMC2897433 DOI: 10.1128/aem.02959-09] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Accepted: 05/06/2010] [Indexed: 11/20/2022] Open
Abstract
The culturable diversity of endophytic actinomycetes associated with tropical, native plants is essentially unexplored. In this study, 123 endophytic actinomycetes were isolated from tropical plants collected from several locations in Papua New Guinea and Mborokua Island, Solomon Islands. Isolates were found to be prevalent in roots but uncommon in leaves. Initially, isolates were dereplicated to the strain level by ribotyping. Subsequent characterization of 105 unique strains by 16S rRNA gene sequence analysis revealed that 17 different genera were represented, and rare genera, such as Sphaerisporangium and Planotetraspora, which have never been previously reported to be endophytic, were quite prevalent. Phylogenetic analyses grouped many of the strains into clades distinct from known genera within Thermomonosporaceae and Micromonosporaceae, indicating that they may be unique genera. Bioactivity testing and liquid chromatography-mass spectrometry (LC-MS) profiling of crude fermentation extracts were performed on 91 strains. About 60% of the extracts exhibited bioactivity or displayed LC-MS profiles with spectra indicative of secondary metabolites. The biosynthetic potential of 29 nonproductive strains was further investigated by the detection of putative polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes. Despite their lack of detectable secondary metabolite production in fermentation, most were positive for type I (66%) and type II (79%) PKS genes, and all were positive for NRPS genes. These results suggest that tropical plants from New Guinea and the adjacent archipelago are hosts to unique endophytic actinomycetes that possess significant biosynthetic potential.
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17
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Siegel MM, Kong F, Feng X, Carter GT. Structure characterization of lipocyclopeptide antibiotics, aspartocins A, B & C, by ESI-MSMS and ESI-nozzle-skimmer-MSMS. J Mass Spectrom 2009; 44:1684-1697. [PMID: 19839028 DOI: 10.1002/jms.1677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Three lipocyclopeptide antibiotics, aspartocins A (1), B (2), and C (3), were obtained from the aspartocin complex by HPLC separation methodology. Their structures were elucidated using previously published chemical degradation results coupled with spectroscopic studies including ESI-MS, ESI-Nozzle Skimmer-MSMS and NMR. All three aspartocin compounds share the same cyclic decapeptide core of cyclo [Dab2 (Asp1-FA)-Pip3-MeAsp4-Asp5-Gly6-Asp7-Gly8-Dab9-Val10-Pro11]. They differ only in the fatty acid side chain moiety (FA) corresponding to (Z)-13-methyltetradec-3-ene-carbonyl, (+,Z)-12-methyltetradec-3-ene-carbonyl and (Z)-12-methyltridec-3-ene-carbonyl for aspartocins A (1), B (2), and C (3), respectively. All of the sequence ions were observed by ESI-MSMS of the doubly charged parent ions. However, a number of the sequence ions observed were of low abundance. To fully sequence the lipocyclopeptide antibiotic structures, these low abundance sequence ions together with complementary sequence ions were confirmed by ESI-Nozzle-Skimmer-MSMS of the singly charged linear peptide parent fragment ions H-Asp5-Gly6-Asp7-Gly8-Dab9-Val10-Pro11-Dab2(1+)-Asp1-FA. Cyclization of the aspartocins was demonstrated to occur via the beta-amino group of Dab2 from ions of moderate intensity in the ESI-MSMS spectra. As the fatty acid moieties do not undergo internal fragmentations under the experimental ESI mass spectral conditions used, the 14 Da mass difference between the fatty acid moieties of aspartocins A (1) and B (2) versus aspartocin C (3) was used as an internal mass tag to differentiate fragment ions containing fatty acid moieties and those not containing the fatty acid moieties. The most numerous and abundant fragment ions observed in the tandem mass spectra are due to the cleavage of the tertiary nitrogen amide of the pipecolic acid residue-3 (16 fragment ions) and the proline residue-11 (7 fragment ions). In addition, the neutral loss of ethanimine from alpha,beta-diaminobutyric acid residue 9 was observed for the parent molecular ion and for 7 fragment ions.
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Affiliation(s)
- Marshall M Siegel
- Wyeth Research, Chemical Technologies Section, Chemical Sciences Division, 401 N. Middletown Road, Pearl River, NY 10965, USA.
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18
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England JD, Gronseth GS, Franklin G, Carter GT, Kinsella LJ, Cohen JA, Asbury AK, Szigeti K, Lupski JR, Latov N, Lewis RA, Low PA, Fisher MA, Herrmann D, Howard JF, Lauria G, Miller RG, Polydefkis M, Sumner AJ. Practice parameter: the evaluation of distal symmetric polyneuropathy: the role of autonomic testing, nerve biopsy, and skin biopsy (an evidence-based review). Report of the American Academy of Neurology, the American Association of Neuromuscular and Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation. PM R 2009; 1:14-22. [PMID: 19627868 DOI: 10.1016/j.pmrj.2008.11.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Accepted: 11/24/2008] [Indexed: 11/17/2022]
Abstract
BACKGROUND Distal symmetric polyneuropathy (DSP) is the most common variety of neuropathy. Since the evaluation of this disorder is not standardized, the available literature was reviewed to provide evidence-based guidelines regarding the role of autonomic testing, nerve biopsy and skin biopsy for the assessment of polyneuropathy. METHODS A literature review using MEDLINE, EMBASE, Science Citation Index and Current Contents was performed to identify the best evidence regarding the evaluation of polyneuropathy published between 1980 and March 2007. Articles were classified according to a four-tiered level of evidence scheme and recommendations were based upon the level of evidence. RESULTS AND CONCLUSIONS 1. Autonomic testing may be considered in the evaluation of patients with polyneuropathy to document autonomic nervous system dysfunction (Level B). Such testing should be considered especially for the evaluation of suspected autonomic neuropathy (Level B) and distal small fiber sensory polyneuropathy (SFSN) (Level C). A battery of validated tests is recommended to achieve the highest diagnostic accuracy (Level B). 2. Nerve biopsy is generally accepted as useful in the evaluation of certain neuropathies as in patients with suspected amyloid neuropathy, mononeuropathy multiplex due to vasculitis, or with atypical forms of chronic inflammatory demyelinating polyneuropathy (CIDP). However, the literature is insufficient to provide a recommendation regarding when a nerve biopsy may be useful in the evaluation of DSP (Level U). 3. Skin biopsy is a validated technique for determining intraepidermal nerve fiber (IENF) density and may be considered for the diagnosis of DSP, particularly SFSN (Level C). There is a need for additional prospective studies to define more exact guidelines for the evaluation of polyneuropathy.
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Affiliation(s)
- J D England
- Louisiana State University Health Sciences Center, New Orleans, USA
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19
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England JD, Gronseth GS, Franklin G, Carter GT, Kinsella LJ, Cohen JA, Asbury AK, Szigeti K, Lupski JR, Latov N, Lewis RA, Low PA, Fisher MA, Herrmann DN, Howard JF, Lauria G, Miller RG, Polydefkis M, Sumner AJ. Practice parameter: the evaluation of distal symmetric polyneuropathy: the role of laboratory and genetic testing (an evidence-based review). Report of the American Academy of Neurology, the American Association of Neuromuscular and Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation. PM R 2009. [PMID: 19627867 DOI: 10.1212/01.wnl.0000336370.51010.al] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Distal symmetric polyneuropathy (DSP) is the most common variety of neuropathy. Since the evaluation of this disorder is not standardized, the available literature was reviewed to provide evidence-based guidelines regarding the role of laboratory and genetic tests for the assessment of DSP. METHODS A literature review using MEDLINE, EMBASE, Science Citation Index and Current Contents was performed to identify the best evidence regarding the evaluation of polyneuropathy published between 1980 and March 2007. Articles were classified according to a four-tiered level of evidence scheme and recommendations were based upon the level of evidence. RESULTS AND CONCLUSIONS 1. Screening laboratory tests may be considered for all patients with polyneuropathy (Level C). Those tests that provide the highest yield of abnormality are blood glucose, serum B12 with metabolites (methylmalonic acid with or without homocysteine) and serum protein immunofixation electrophoresis (Level C). If there is no definite evidence of diabetes mellitus by routine testing of blood glucose, testing for impaired glucose tolerance may be considered in distal symmetric sensory polyneuropathy (Level C). 2. Genetic testing is established as useful for the accurate diagnosis and classification of hereditary neuropathies (Level A). Genetic testing may be considered in patients with cryptogenic polyneuropathy who exhibit a hereditary neuropathy phenotype (Level C). Initial genetic testing should be guided by the clinical phenotype, inheritance pattern, and electrodiagnostic (EDX) features and should focus on the most common abnormalities which are CMT1A duplication/HNPP deletion, Cx32 (GJB1), and MFN2 mutation screening. There is insufficient evidence to determine the usefulness of routine genetic testing in patients with cryptogenic polyneuropathy who do not exhibit a hereditary neuropathy phenotype (Level U).
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Affiliation(s)
- J D England
- Louisiana State University Health Sciences Center, New Orleans, USA
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Abstract
We report a case of apparently sporadic amyotrophic lateral sclerosis (ALS) in a young pregnant woman presenting subacutely with severe left shoulder pain followed by progressive weakness and wasting of the left arm, mimicking neuralgic amyotrophy. She was later found electrophysiologically to have widespread denervation involving more than just the arm and an alanine for valine substitution in codon 4 (A4V) in the gene for Cu/Zn superoxide dismutase 1 (SOD1). Her case illustrates that pain on initial presentation, though uncommon, does not exclude a diagnosis of ALS.
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Affiliation(s)
- M D Weiss
- Department of Neurology, University of Washington Medical Center, Seattle 98195, USA.
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21
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Caccamese S, Bianca S, Carter GT. Direct high-performance liquid chromatographic separation of the enantiomers of venlafaxine and 11 analogs using amylose-derived chiral stationary phases. Chirality 2009; 21:569-77. [DOI: 10.1002/chir.20633] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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22
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Liu H, Jiang H, Haltli B, Kulowski K, Muszynska E, Feng X, Summers M, Young M, Graziani E, Koehn F, Carter GT, He M. Rapid cloning and heterologous expression of the meridamycin biosynthetic gene cluster using a versatile Escherichia coli-streptomyces artificial chromosome vector, pSBAC. J Nat Prod 2009; 72:389-395. [PMID: 19191550 DOI: 10.1021/np8006149] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Expression of biosynthetic pathways in heterologous hosts is an emerging approach to expedite production improvement and biosynthetic modification of natural products derived from microbial secondary metabolites. Herein we describe the development of a versatile Escherichia coli-Streptomyces shuttle Bacterial Artificial Chromosomal (BAC) conjugation vector, pSBAC, to facilitate the cloning, genetic manipulation, and heterologous expression of actinomycetes secondary metabolite biosynthetic gene clusters. The utility of pSBAC was demonstrated through the rapid cloning and heterologous expression of one of the largest polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) biosynthetic pathways: the meridamycin biosynthesis gene cluster (mer). The entire mer gene cluster ( approximately 90 kb) was captured in a single pSBAC clone through a straightforward restriction enzyme digestion and cloning approach and transferred into Streptomyces lividans. The production of meridamycin (1) in the heterologous host was achieved after replacement of the original promoter with an ermE* promoter and was enhanced by feeding with a biosynthetic precursor. The success of heterologous expression of such a giant gene cluster demonstrates the versatility of BAC cloning technology and paves the road for future exploration of expression of the meridamycin biosynthetic pathway in various hosts, including strains that have been optimized for polyketide production.
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Affiliation(s)
- Hongbo Liu
- Chemical and Screening Science, Wyeth Research, Pearl River, New York 10965, USA
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23
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Ratnayake AS, Janso JE, Feng X, Schlingmann G, Goljer I, Carter GT. Evaluating indole-related derivatives as precursors in the directed biosynthesis of diazepinomicin analogues. J Nat Prod 2009; 72:496-499. [PMID: 19199816 DOI: 10.1021/np800664u] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The effectiveness of precursor-directed biosynthesis to generate diazepinomicin (1) analogues with varied ring-A substitutents was investigated by feeding commercially available, potential ring-A precursors such as fluorinated tryptophans, halogenated anthranilates, and various substituted indoles into growing actinomycete culture DPJ15 (genus Micromonospora). Two new monofluorinated diazepinomicin analogues (2 and 3) were identified and characterized by spectroscopic methods. Both derivatives showed modest antibacterial activity against the Gram-positive coccus Staphylococcus aureus with MIC values in the range 8-32 microg/mL.
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Affiliation(s)
- Anokha S Ratnayake
- Chemical and Screening Sciences, Wyeth Research, 401 North Middletown Road, Pearl River, New York 10965, USA.
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24
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England JD, Gronseth GS, Franklin G, Carter GT, Kinsella LJ, Cohen JA, Asbury AK, Szigeti K, Lupski JR, Latov N, Lewis RA, Low PA, Fisher MA, Herrmann D, Howard JF, Lauria G, Miller RG, Polydefkis M, Sumner AJ. Evaluation of distal symmetric polyneuropathy: the role of laboratory and genetic testing (an evidence-based review). Muscle Nerve 2009; 39:116-25. [PMID: 19086068 DOI: 10.1002/mus.21226] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Distal symmetric polyneuropathy (DSP) is the most common variety of neuropathy. Since the evaluation of this disorder is not standardized, the available literature was reviewed to provide evidence-based guidelines regarding the role of laboratory and genetic tests for the assessment of DSP. A literature review using MEDLINE, EMBASE, Science Citation Index, and Current Contents was performed to identify the best evidence regarding the evaluation of polyneuropathy published between 1980 and March 2007. Articles were classified according to a four-tiered level of evidence scheme and recommendations were based on the level of evidence. (1) Screening laboratory tests may be considered for all patients with polyneuropathy (Level C). Those tests that provide the highest yield of abnormality are blood glucose, serum B(12) with metabolites (methylmalonic acid with or without homocysteine), and serum protein immunofixation electrophoresis (Level C). If there is no definite evidence of diabetes mellitus by routine testing of blood glucose, testing for impaired glucose tolerance may be considered in distal symmetric sensory polyneuropathy (Level C). (2) Genetic testing is established as useful for the accurate diagnosis and classification of hereditary neuropathies (Level A). Genetic testing may be considered in patients with cryptogenic polyneuropathy who exhibit a hereditary neuropathy phenotype (Level C). Initial genetic testing should be guided by the clinical phenotype, inheritance pattern, and electrodiagnostic (EDX) features and should focus on the most common abnormalities, which are CMT1A duplication/HNPP deletion, Cx32 (GJB1), and MFN2 mutation screening. There is insufficient evidence to determine the usefulness of routine genetic testing in patients with cryptogenic polyneuropathy who do not exhibit a hereditary neuropathy phenotype (Level U).
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Affiliation(s)
- J D England
- Louisiana State University Health Sciences Center, Baton Rouge, Louisiana, USA
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25
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England JD, Gronseth GS, Franklin G, Carter GT, Kinsella LJ, Cohen JA, Asbury AK, Szigeti K, Lupski JR, Latov N, Lewis RA, Low PA, Fisher MA, Herrmann D, Howard JF, Lauria G, Miller RG, Polydefkis M, Sumner AJ. Evaluation of distal symmetric polyneuropathy: the role of autonomic testing, nerve biopsy, and skin biopsy (an evidence-based review). Muscle Nerve 2009; 39:106-15. [PMID: 19086069 DOI: 10.1002/mus.21227] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Distal symmetric polyneuropathy (DSP) is the most common variety of neuropathy. Since the evaluation of this disorder is not standardized, the available literature was reviewed to provide evidence-based guidelines regarding the role of autonomic testing, nerve biopsy, and skin biopsy for the assessment of polyneuropathy. A literature review using MEDLINE, EMBASE, Science Citation Index, and Current Contents was performed to identify the best evidence regarding the evaluation of polyneuropathy published between 1980 and March 2007. Articles were classified according to a four-tiered level of evidence scheme and recommendations were based on the level of evidence. (1) Autonomic testing may be considered in the evaluation of patients with polyneuropathy to document autonomic nervous system dysfunction (Level B). Such testing should be considered especially for the evaluation of suspected autonomic neuropathy (Level B) and distal small fiber sensory polyneuropathy (SFSN) (Level C). A battery of validated tests is recommended to achieve the highest diagnostic accuracy (Level B). (2) Nerve biopsy is generally accepted as useful in the evaluation of certain neuropathies as in patients with suspected amyloid neuropathy, mononeuropathy multiplex due to vasculitis, or with atypical forms of chronic inflammatory demyelinating polyneuropathy (CIDP). However, the literature is insufficient to provide a recommendation regarding when a nerve biopsy may be useful in the evaluation of DSP (Level U). (3) Skin biopsy is a validated technique for determining intraepidermal nerve fiber (IENF) density and may be considered for the diagnosis of DSP, particularly SFSN (Level C). There is a need for additional prospective studies to define more exact guidelines for the evaluation of polyneuropathy.
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Affiliation(s)
- J D England
- Louisiana State University Health Sciences Center, Baton Rouge, Louisiana, USA
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26
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Feng X, Ratnayake AS, Charan RD, Janso JE, Bernan VS, Schlingmann G, He H, Tischler M, Koehn FE, Carter GT. Probing natural product biosynthetic pathways using Fourier transform ion cyclotron resonance mass spectrometry. Bioorg Med Chem 2009; 17:2154-61. [DOI: 10.1016/j.bmc.2008.10.073] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Revised: 09/26/2008] [Accepted: 10/31/2008] [Indexed: 10/21/2022]
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Abstract
The solubility of a compound depends on its structure and solution conditions. Structure determines the lipophilicity, hydrogen bonding, molecular volume, crystal energy and ionizability, which determine solubility. Solution conditions are affected by pH, co-solvents, additives, ionic strength, time and temperature. Many drug discovery experiments are conducted under "kinetic" solubility conditions. In drug discovery, solubility has a major impact on bioassays, formulation for in vivo dosing, and intestinal absorption. A good goal for the solubility of drug discovery compounds is >60 ug/mL. Equilibrium solubility assays can be conducted in moderate throughput, by incubating excess solid with buffer and agitating for several days, prior to filtration and HPLC quantitation. Kinetic solubility assays are performed in high throughput with shorter incubation times and high throughput analyses using plate readers. The most frequently used of these are the nephelometric assay and direct UV assay, which begin by adding a small volume of DMSO stock solution of each test compound to buffer. In nephelometry, this solution is serially diluted across a microtitre plate and undissolved particles are detected via light scattering. In direct UV, undissolved particles are separated by filtration, after which the dissolved material is quantitated using UV absorption. Equilibrium solubility is useful for preformulation. Kinetic solubility is useful for rapid compound assessment, guiding optimization via structure modification, and diagnosing bioassays. It is often useful to customize solubility experiments using conditions that answer specific research questions of drug discovery teams, such as compound selection and vehicle development for pharmacology and PK studies.
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28
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England JD, Gronseth GS, Franklin G, Carter GT, Kinsella LJ, Cohen JA, Asbury AK, Szigeti K, Lupski JR, Latov N, Lewis RA, Low PA, Fisher MA, Herrmann DN, Howard JF, Lauria G, Miller RG, Polydefkis M, Sumner AJ. Practice Parameter: evaluation of distal symmetric polyneuropathy: role of autonomic testing, nerve biopsy, and skin biopsy (an evidence-based review). Report of the American Academy of Neurology, American Association of Neuromuscular and Electrodiagnostic Medicine, and American Academy of Physical Medicine and Rehabilitation. Neurology 2008; 72:177-84. [PMID: 19056667 DOI: 10.1212/01.wnl.0000336345.70511.0f] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Distal symmetric polyneuropathy (DSP) is the most common variety of neuropathy. Since the evaluation of this disorder is not standardized, the available literature was reviewed to provide evidence-based guidelines regarding the role of autonomic testing, nerve biopsy, and skin biopsy for the assessment of polyneuropathy. METHODS A literature review using MEDLINE, EMBASE, and Current Contents was performed to identify the best evidence regarding the evaluation of polyneuropathy published between 1980 and March 2007. Articles were classified according to a four-tiered level of evidence scheme and recommendations were based upon the level of evidence. RESULTS AND RECOMMENDATIONS 1) Autonomic testing should be considered in the evaluation of patients with polyneuropathy to document autonomic nervous system dysfunction (Level B). Such testing should be considered especially for the evaluation of suspected autonomic neuropathy (Level B) and distal small fiber sensory polyneuropathy (SFSN) (Level C). A battery of validated tests is recommended to achieve the highest diagnostic accuracy (Level B). 2) Nerve biopsy is generally accepted as useful in the evaluation of certain neuropathies as in patients with suspected amyloid neuropathy, mononeuropathy multiplex due to vasculitis, or with atypical forms of chronic inflammatory demyelinating polyneuropathy (CIDP). However, the literature is insufficient to provide a recommendation regarding when a nerve biopsy may be useful in the evaluation of DSP (Level U). 3) Skin biopsy is a validated technique for determining intraepidermal nerve fiber density and may be considered for the diagnosis of DSP, particularly SFSN (Level C). There is a need for additional prospective studies to define more exact guidelines for the evaluation of polyneuropathy.
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Affiliation(s)
- J D England
- American Academy of Neurology, St Paul, MN 55116, USA.
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29
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Ratnayake AS, Haltli B, Feng X, Bernan VS, Singh MP, He H, Carter GT. Investigating the biosynthetic origin of the nitro group in pyrrolomycins. J Nat Prod 2008; 71:1923-1926. [PMID: 18986197 DOI: 10.1021/np800401h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Feasible modes of introducing the nitro group into pyrrolomycin antibiotics were investigated based on incorporation of (15)N-labeled arginine and proline into dioxapyrrolomycin, produced by the actinomycete culture LL-F42248. Biosynthesis of nitrated pyrrolomycins was unaffected by the presence of nitric oxide synthase (NOS) inhibitors. The culture was able to grow in nitrogen-free (minimal) media and produce nitrated secondary metabolites. These results indicate that LL-F42248 is capable of fixing nitrogen.
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Affiliation(s)
- Anokha S Ratnayake
- Chemical and Screening Sciences, Wyeth Research, 401 North Middletown Road, Pearl River, New York 10965, USA.
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McAlpine JB, Banskota AH, Charan RD, Schlingmann G, Zazopoulos E, Piraee M, Janso J, Bernan VS, Aouidate M, Farnet CM, Feng X, Zhao Z, Carter GT. Biosynthesis of diazepinomicin/ECO-4601, a Micromonospora secondary metabolite with a novel ring system. J Nat Prod 2008; 71:1585-1590. [PMID: 18722414 DOI: 10.1021/np800376n] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The novel microbial metabolite diazepinomicin/ECO-4601 (1) has a unique tricyclic dibenzodiazepinone core, which was unprecedented among microbial metabolites. Labeled feeding experiments indicated that the carbocyclic ring and the ring nitrogen of tryptophan could be incorporated via degradation to the 3-hydroxyanthranilic acid, forming ring A and the nonamide nitrogen of 1. Genomic analysis of the biosynthetic locus indicated that the farnesyl side chain was mevalonate derived, the 3-hydroxyanthranilic acid moiety could be formed directly from chorismate, and the third ring was constructed via 3-amino-5-hydroxybenzoic acid. Successful incorporation of 4,6-D2-3-hydroxyanthranilic acid into ring A of 1 via feeding experiments supports the genetic analysis and the allocation of the locus to this biosynthesis. These studies highlight the enzymatic complexity needed to produce this structural type, which is rare in nature.
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Affiliation(s)
- James B McAlpine
- Thallion Pharmaceuticals Inc., 7150 Alexander-Fleming, Montréal, Québec, H4S 2C8, Canada.
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31
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Bennett CL, Lawson VH, Brickell KL, Isaacs K, Seltzer W, Lipe HP, Weiss MD, Carter GT, Flanigan KM, Chance PF, Bird TD. Late-onset hereditary axonal neuropathies. Neurology 2008; 71:14-20. [PMID: 18495953 DOI: 10.1212/01.wnl.0000304048.94023.73] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Hereditary motor-sensory neuropathy or the Charcot-Marie-Tooth syndrome is known to represent considerable genetic heterogeneity. Onset is usually in childhood, adolescence, or young adulthood. The objective of this study was to define late-onset forms of the disorder. METHODS A clinical and genetic study of families with uniformly late onset of peripheral neuropathy was performed in a university neurogenetics setting. RESULTS Six families were identified with consistently late onset of a primarily axonal neuropathy. Median age at symptom onset was 57 years (range 35-85 years) of a mixed motor and sensory neuropathy with electrophysiologic characteristics of an axonal rather than demyelinating condition. There was a possible association with deafness. Two families showed autosomal dominant inheritance whereas four families had only one affected generation with an excess of males. An extensive mutation screen of nine genes known to cause Charcot-Marie-Tooth was negative. CONCLUSIONS There are late-onset forms of hereditary axonal neuropathies. The genetic causes remain unknown and genetic heterogeneity within this entity is likely.
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Affiliation(s)
- C L Bennett
- Department of Pediatrics, University of Washington Medical School, Children's Hospital and Regional Medical Center, Seattle, WA, USA
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Schlingmann G, Taniguchi T, He H, Bigelis R, Yang HY, Koehn FE, Carter GT, Berova N. Reassessing the structure of pyranonigrin. J Nat Prod 2007; 70:1180-7. [PMID: 17604395 DOI: 10.1021/np070175n] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Fermentation extracts of the marine fungus Aspergillus niger LL-LV3020 were found to have relevant activity in a number of assays. Chemical screening of the extracts revealed that this organism produced numerous secondary metabolites in addition to its principal metabolite, citric acid. The compound with the most significant UV peak was isolated and its structure elucidated. Physical data suggested that this compound is identical with pyranonigrin A (1); however, our structure elucidation led to a different assignment than previously reported. On the basis of analysis of all data, we propose a correction to the structure of pyranonigrin A. Its absolute configuration was determined by electronic circular dichroism measurements in comparison with theoretical values calculated via ab initio time-dependent density functional theory and assigned as (7R)-3,7-dihydroxy-2-[(1E)-prop-1-enyl]-6,7-dihydropyrano[2,3-c]pyrrole-4,5-dione.
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Affiliation(s)
- Gerhard Schlingmann
- Department of Natural Products, Chemical and Screening Sciences, Wyeth Research, 401 North Middletown Road, Pearl River, New York 10965, USA.
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Di L, Kerns EH, Li SQ, Carter GT. Comparison of cytochrome P450 inhibition assays for drug discovery using human liver microsomes with LC–MS, rhCYP450 isozymes with fluorescence, and double cocktail with LC–MS. Int J Pharm 2007; 335:1-11. [PMID: 17137735 DOI: 10.1016/j.ijpharm.2006.10.039] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2006] [Revised: 10/20/2006] [Accepted: 10/20/2006] [Indexed: 11/25/2022]
Abstract
The disparity of IC(50)s from CYP450 inhibition assays used to assess drug-drug interaction potential was investigated, in order to have evidence for selecting a reliable in vitro CYP450 inhibition assay to support drug discovery. Three assays were studied: individual rhCYP isozymes and corresponding coumarin derivative-probe substrates with fluorescent detection, human liver microsomes (HLM) and cocktail drug-probe substrates with LC-MS detection, and double cocktail rhCYP isozymes mix and drug-probe mix with LC-MS detection. Data comparisons showed that the rhCYP-fluorescent assay and the cocktail assay with HLM-LC-MS had weak correlation. Detection method and probe substrates were shown to not be the major cause of the disparity in IC(50)s. However, the enzyme source and composition (HLM versus, rhCYP) caused disparity in IC(50)s. Specifically, the high concentrations of CYP isozymes often used with HLM-based assays produced high probe substrate conversion and test compound metabolism, which should both contribute to artificially higher IC(50)s. Non-specific binding of substrate to higher concentration proteins and lipids in the HLM-based assays should also contribute to higher IC(50)s. The modified double cocktail assay was found to overcome limitations of the other two assays. It uses an rhCYP isozymes mix, drug-probe substrate mix, low protein concentration, and LC-MS detection. The double cocktail assay is sensitive, selective, and high throughout for use in drug discovery to provide an early alert to potential toxicity with regard to drug-drug interaction, prioritize chemical series, and guide structural modification to circumvent CYP450 inhibition.
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Affiliation(s)
- Li Di
- Wyeth Research, P.O. Box CN 8000, Princeton, NJ 08543-8000, United States.
| | - Edward H Kerns
- Wyeth Research, P.O. Box CN 8000, Princeton, NJ 08543-8000, United States
| | - Susan Q Li
- Wyeth Research, P.O. Box CN 8000, Princeton, NJ 08543-8000, United States
| | - Guy T Carter
- Wyeth Research, P.O. Box CN 8000, Princeton, NJ 08543-8000, United States
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Carter GT, Gloer JB, Kobayashi J, Pearce C. Special issue in honor of Professor Kenneth L. Rinehart. J Nat Prod 2007; 70:329-31. [PMID: 17286430 DOI: 10.1021/np070041+] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
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Abstract
21-Hydroxyoligomycin A (1) was isolated from Streptomyces cyaneogriseus ssp. noncyanogenus (LL-F28249) and fully characterized by NMR and single-crystal X-ray diffraction methods. The complete 1H and 13C NMR chemical shift assignments for 1 were made using 2D NMR experiments, and the chirality at C-21 was deduced to be R from a J-based configuration analysis. The absolute configuration at C-21 and at the other 18 chiral centers in the molecule were independently confirmed by anomalous dispersion measurements on a crystal of the chloroform methanol solvate of 21-hydroxyoligomycin A (1).
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36
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Summers MY, Kong F, Feng X, Siegel MM, Janso JE, Graziani EI, Carter GT. Septocylindrins A and B: peptaibols produced by the terrestrial fungus Septocylindrium sp. LL-Z1518. J Nat Prod 2007; 70:391-6. [PMID: 17288478 DOI: 10.1021/np060571q] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Two new peptaibols, septocylindrin A (1) and septocylindrin B (2), related to the well-studied membrane-channel-forming peptaibol alamethicin, were obtained from a terrestrial isolate of the fungus Septocylindrium sp. Both 1 and 2 are linear 19-amino acid peptides with a modified phenylalanine C-terminus. Analysis of the HRMS data indicated that they differ only in the 18th residue, where 1 contains Glu and 2 contains Gln. The structures of these two peptaibols were determined by extensive NMR and HRMS analysis. The absolute configurations of amino acids present in 1 were determined using Marfey's methodology. Both compounds were isolated through bioassay-guided fractionation and exhibited significant antibacterial and antifungal activity.
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Affiliation(s)
- Mia Y Summers
- Department of Chemical and Screening Sciences, Wyeth Research, 401 N. Middletown Road, Pearl River, NY 10965, USA.
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Caccamese S, Bianca S, Carter GT. Direct high-performance liquid chromatographic separation of the enantiomers of an aromatic amine and four aminoalcohols using polysaccharide chiral stationary phases and acidic additive. Chirality 2007; 19:647-53. [PMID: 17568428 DOI: 10.1002/chir.20438] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The HPLC enantiomeric separation of N-benzyl-alpha-methyl-benzylamine, phenylalaninol, tryptophanol, 2 (diphenylhydroxymethyl)pyrrolidine, and isoproterenol was accomplished in the normal-phase mode using two polysaccharide-derived chiral stationary phases (CSPs) and various n-hexane/2-propanol mobile phases with acidic (TFA) or basic (DEA) additive. The compounds were separated without any derivatization and separation factor range between 2.09 and 1.09 with resolution factor 3.4 and 0.4, respectively. The best separation of the enantiomers of the amine was achieved on amylose tris (3, 5-dimethylphenylcarbamate) CSP with TFA additive in the mobile phase; in acidic conditions, instead, the best enantioseparation of the aminoalcohols was achieved on cellulose tris (3, 5-dimethylphenilcarbamate). A long equilibration time of the CSP when switching from an undoped mobile phase to a doped one is required to obtain reproducible results.
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Affiliation(s)
- Salvatore Caccamese
- Dipartimento di Scienze Chimiche, Università di Catania, Viale A. Doria 6, Catania, Italy.
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Abstract
Streptomyces fumanus, intramurally coded as culture LL-F42248, produces a series of pyrrolomycins including dioxapyrrolomycin (1) as the principal component. Our biosynthetic studies revealed that feeding labeled acetate to growing cultures of S. fumanus yielded pyrrolomycins labeled in the phenyl ring only. When l-[methyl-13C]methionine was fed, the labeled carbon atom was found in the methoxy group of pyrrolomycins H-J and in the methylenedioxy bridge of dioxapyrrolomycin. A Na15NO3-enriched medium was employed to produce 15N-labeled pyrrolomycins in which both nitrogen atoms were highly enriched, whereas feeding of 15N-labeled l-proline furnished pyrrolomycins labeled in the pyrrole moiety. Thus, S. fumanus elaborates the pyrrolomycin skeleton from proline and a polyketide precursor. Since the organism readily converted 13C- or 15N-labeled pyrrolomycin C, G, or H into the correspondingly labeled dioxapyrrolomycin, these minor pyrrolomycins are actually precursors of the ultimate product, dioxapyrrolomycin.
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Affiliation(s)
- Romila D Charan
- Chemical and Screening Sciences, Wyeth Research, 401 N. Middletown Road, Pearl River, New York 10965, USA
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Abstract
Two new naphthoquinone macrolides, hygrocins A (1) and B (2), were isolated from the fermentation broth of Streptomyces hygroscopicus. Hygrocin A is not stable due to the presence of an active methylene group (C-22), which undergoes intramolecular aldol condensation with the quinone ring to yield a gamma-lactam derivative, 6. Its structural elucidation was achieved by chemical conversion to 3, an unusual diazomethane derivative, and confirmed by its alkaline hydrolysis product 4, hydrogenation derivative 5, and "degradation" product 6. The structure of hygrocin B was determined by combined chemical and spectroscopic methods.
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Affiliation(s)
- Ping Cai
- Chemical and Pharmaceutical Development, and Chemical and Screening Sciences, Wyeth Research, 401 N. Middletown Road, Pearl River, New York 10965, USA.
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England JD, Gronseth GS, Franklin G, Miller RG, Asbury AK, Carter GT, Cohen JA, Fisher MA, Howard JF, Kinsella LJ, Latov N, Lewis RA, Low PA, Sumner AJ. Distal symmetric polyneuropathy: a definition for clinical research: report of the American Academy of Neurology, the American Association of Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation. Neurology 2005; 64:199-207. [PMID: 15668414 DOI: 10.1212/01.wnl.0000149522.32823.ea] [Citation(s) in RCA: 513] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The objective of this report was to develop a case definition of distal symmetric polyneuropathy to standardize and facilitate clinical research and epidemiologic studies. A formalized consensus process was employed to reach agreement after a systematic review and classification of evidence from the literature. The literature indicates that symptoms alone have relatively poor diagnostic accuracy in predicting the presence of polyneuropathy; signs are better predictors of polyneuropathy than symptoms; and single abnormalities on examination are less sensitive than multiple abnormalities in predicting the presence of polyneuropathy. The combination of neuropathic symptoms, signs, and electrodiagnostic findings provides the most accurate diagnosis of distal symmetric polyneuropathy. A set of case definitions was rank ordered by likelihood of disease. The highest likelihood of polyneuropathy (useful for clinical trials) occurs with a combination of multiple symptoms, multiple signs, and abnormal electrodiagnostic studies. A modest likelihood of polyneuropathy (useful for field or epidemiologic studies) occurs with a combination of multiple symptoms and multiple signs when the results of electrodiagnostic studies are not available. A lower likelihood of polyneuropathy occurs when electrodiagnostic studies and signs are discordant. For research purposes, the best approach to defining distal symmetric polyneuropathy is a set of case definitions rank ordered by estimated likelihood of disease. The inclusion of this formalized case definition in clinical and epidemiologic research studies will ensure greater consistency of case selection.
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Ritacco FV, Graziani EI, Summers MY, Zabriskie TM, Yu K, Bernan VS, Carter GT, Greenstein M. Production of novel rapamycin analogs by precursor-directed biosynthesis. Appl Environ Microbiol 2005; 71:1971-6. [PMID: 15812028 PMCID: PMC1082568 DOI: 10.1128/aem.71.4.1971-1976.2005] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The natural product rapamycin, produced during fermentation by Streptomyces hygroscopicus, is known for its potent antifungal, immunosuppressive, and anticancer activities. During rapamycin biosynthesis, the amino acid l-pipecolate is incorporated into the rapamycin molecule. We investigated the use of precursor-directed biosynthesis to create new rapamycin analogs by substitution of unusual l-pipecolate analogs in place of the normal amino acid. Our results suggest that the l-pipecolate analog (+/-)-nipecotic acid inhibits the biosynthesis of l-pipecolate, thereby limiting the availability of this molecule for rapamycin biosynthesis. We used (+/-)-nipecotic acid in our precursor-directed biosynthesis studies to reduce l-pipecolate availability and thereby enhance the incorporation of other pipecolate analogs into the rapamycin molecule. We describe here the use of this method for production of two new sulfur-containing rapamycin analogs, 20-thiarapamycin and 15-deoxo-19-sulfoxylrapamycin, and report measurement of their binding to FKBP12.
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Affiliation(s)
- Frank V Ritacco
- Natural Products, Wyeth Research, 401 North Middletown Road, Building 205, Room 465, Pearl River, NY 10965, USA.
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42
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Kong F, Singh MP, Carter GT. Pseudopyronines A and B, alpha-pyrones produced by a marine Pseudomonas sp. F92S91, and evidence for the conversion of 4-hydroxy-alpha-pyrone to 3-furanone. J Nat Prod 2005; 68:920-3. [PMID: 15974619 DOI: 10.1021/np050038v] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In our search for inhibitors of bacterial fatty acid biosynthesis, two new alpha-pyrones, pseudopyronines A (1) and B (2), were isolated from a marine Pseudomonas sp. F92S91. The naturally occurring alpha-pyrones appeared to be unstable, evidenced by the conversion of pseudopyronine B into an oxidation product, 3-furanone (3). Structural elucidations were made by spectroscopic analyses including 2D-NMR data.
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Affiliation(s)
- Fangming Kong
- Chemical and Screening Sciences, Wyeth Research, Pearl River, New York 10965, USA.
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43
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Abstract
A new prenylated naphthoquinone antibiotic, fumaquinone (5,7-dihydroxy-2-methoxy-3-methyl-6-(3-methyl-but-2-enyl)[1,4]naphthoquinone) was isolated from cultures of Streptomyces fumanus (LL-F42248). Its chemical structure was determined primarily by NMR spectroscopy. Preliminary feeding experiments indicated the naphthoquinone is of polyketide origin, while the O-methyl and aromatic C-methyl groups are derived from methionine.
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Affiliation(s)
- Romila D Charan
- Chemical and Screening Sciences, Wyeth Research, 401 N. Middletown Road, Pearl River, New York 10965, USA
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44
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Koehn FE, Carter GT. Rediscovering natural products as a source of new drugs. Discov Med 2005; 5:159-164. [PMID: 20704903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Extract: Since the very beginnings of human medicine, physicians have relied on chemical compounds produced by animals, plants and microorganisms, so-called natural products, to treat diseases. Natural products are directly or indirectly responsible for roughly one-half of all drugs currently in use. Of the 877 small-molecule new drug molecules introduced between 1981 and 2002, 49% were natural products or natural product analogs. Despite the great success of the 70s and 80s, the pharmaceutical industry de-emphasized natural products research during the following decade. In this article, we examine the underlying reasons for the decline, and assess future prospects for natural products research in drug discovery. In the 1990s, major pharmaceutical companies moved to a lead-finding strategy based on High Throughput Screening (HTS) of very large collections (libraries) of synthetic compounds. The move arose from the belief that techniques such as combinatorial chemistry could produce larger, more cost-effective libraries with improved hit rates and quality. Additionally, advances in molecular biology, cellular biology and genomics dramatically increased the number of molecular targets, prompting shorter drug discovery timelines. In today's drug discovery environment, rapid screening and identification of potential drug molecules is essential for success. This puts traditional natural products-based programs, with their reliance on the lengthy processes of the screening of extracts library, bioassay-guided isolation of the active components, structure elucidation and subsequent production scale-up, at a competitive disadvantage.
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Affiliation(s)
- Frank E Koehn
- Chemical and Screening Sciences, Wyeth Research, 401 North Middletown Road, Pearl River, NY 10965, USA
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45
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Abstract
Natural products and their derivatives have historically been invaluable as a source of therapeutic agents. However, in the past decade, research into natural products in the pharmaceutical industry has declined, owing to issues such as the lack of compatibility of traditional natural-product extract libraries with high-throughput screening. However, as discussed in this review, recent technological advances that help to address these issues, coupled with unrealized expectations from current lead-generation strategies, have led to a renewed interest in natural products in drug discovery.
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Affiliation(s)
- Frank E Koehn
- Wyeth Research, 401 North Middletown Road, Pearl River, New York 10965, USA.
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46
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Abstract
Along with dioxapyrrolomycin (1), four new pyrrolomycin antibiotics, namely, pyrrolomycin G (3), pyrrolomycin H (4), pyrrolomycin I (5), and pyrrolomycin J (6), were produced in cultures of Streptomyces fumanus. Apart from dioxapyrrolomycin, pyrrolomycin G and pyrrolomycin H are the only other chiral members of the pyrrolomycin family of antibiotics, and their absolute stereochemistry was deduced to be 13S. Here, we report the isolation, structure elucidation, and antimicrobial activity of these new pyrrolomycins.
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Affiliation(s)
- Romila D Charan
- Chemical and Screening Sciences, Wyeth Research, 401 N. Middletown Road, Pearl River, NY 10965, USA
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47
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McDonald LA, Barbieri LR, Bernan VS, Janso J, Lassota P, Carter GT. 07H239-A, a new cytotoxic eremophilane sesquiterpene from the marine-derived Xylariaceous fungus LL-07H239. J Nat Prod 2004; 67:1565-1567. [PMID: 15387660 DOI: 10.1021/np049924g] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
07H239-A (1), a new eremophilane sesquiterpene from a marine-derived xylariaceous fungus, was isolated, characterized, and shown to be cytotoxic toward a variety of cancer cell lines, with some selectivity for a CCRFCEM leukemia line (IC(50) = 0.9 microg/mL).
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Affiliation(s)
- Leonard A McDonald
- Wyeth-Research, 401 North Middletown Road, Pearl River, New York 10965, USA.
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48
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Charan RD, Schlingmann G, Janso J, Bernan V, Feng X, Carter GT. Diazepinomicin, a new antimicrobial alkaloid from a marine Micromonospora sp. J Nat Prod 2004; 67:1431-1433. [PMID: 15332871 DOI: 10.1021/np040042r] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The structure of a new dibenzodiazepine alkaloid, diazepinomicin (1), isolated from the culture of a marine actinomycete of the genus Micromonospora was characterized using spectroscopic methods. Diazepinomicin represents a unique molecular class composed of a dibenzodiazepine core linked to a farnesyl side chain.
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Affiliation(s)
- Romila D Charan
- Chemical and Screening Sciences, Wyeth Research, 401 N. Middletown Road, Pearl River, New York 10965, USA.
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49
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Bugni TS, Janso JE, Williamson RT, Feng X, Bernan VS, Greenstein M, Carter GT, Maiese WM, Ireland CM. Dictyosphaeric acids A and B: new decalactones from an undescribed Penicillium sp. obtained from the alga Dictyosphaeria versluyii. J Nat Prod 2004; 67:1396-1399. [PMID: 15332862 DOI: 10.1021/np049973t] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Fungal isolate F01V25 was obtained from the alga Dictyosphaeria versluyii collected near Dravuni, Fiji, in 2001 and represented a previously undescribed Penicillium sp. Fermentation of isolate F01V25 resulted in the production of two new polyketides, dictyosphaeric acids A and B, along with the known anthraquinone carviolin. The relative stereochemistry of dictyosphaeric acids A and B was determined using the J-based configuration analysis method in conjunction with ROE and NOE correlations.
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Affiliation(s)
- Tim S Bugni
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
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50
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Davis RA, Mangalindan GC, Bojo ZP, Antemano RR, Rodriguez NO, Concepcion GP, Samson SC, de Guzman D, Cruz LJ, Tasdemir D, Harper MK, Feng X, Carter GT, Ireland CM. Microcionamides A and B, Bioactive Peptides from the Philippine Sponge Clathria (Thalysias) abietina. J Org Chem 2004; 69:4170-6. [PMID: 15176844 DOI: 10.1021/jo040129h] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Microcionamides A (1) and B (2) have been isolated from the Philippine marine sponge Clathria (Thalysias) abietina. These new linear peptides are cyclized via a cystine moiety and have their C-terminus blocked by a 2-phenylethylenamine group. Their total structures, including absolute stereochemistry, were determined by a combination of spectral and chemical methods. Compound 1 was shown to slowly isomerize about the C-36/C-37 double bond when stored in DMSO. Microcionamides A (1) and B (2) exhibited significant cytotoxicity against the human breast tumor cells lines MCF-7 and SKBR-3 and displayed inhibitory activity against Mycobacterium tuberculosis H(37)Ra.
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Affiliation(s)
- Rohan A Davis
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
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