401
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Bagwell CL, Moloney MG, Yaqoob M. Oxazolomycins: Natural product lead structures for novel antibacterials by click fragment conjugation. Bioorg Med Chem Lett 2010; 20:2090-4. [DOI: 10.1016/j.bmcl.2010.02.066] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 02/17/2010] [Accepted: 02/17/2010] [Indexed: 12/25/2022]
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402
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Zeng X, Yin B, Hu Z, Liao C, Liu J, Li S, Li Z, Nicklaus MC, Zhou G, Jiang S. Total synthesis and biological evaluation of largazole and derivatives with promising selectivity for cancers cells. Org Lett 2010; 12:1368-71. [PMID: 20184338 PMCID: PMC7386434 DOI: 10.1021/ol100308a] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The efficient total synthesis of the natural substance largazole is described. Using this strategy, a small library of largazole analogs was developed. Structure-activity relationship studies suggested that the geometry of the alkene in the side chain is critical. While the largazole's analogues with trans-alkene are potent for the antiproliferative effect, those with cis-alkene are completely inactive. Most importantly, replacement of valine with tyrosine in largazole increased selectivity toward human cancer cells over human normal cells more than 100-fold.
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Affiliation(s)
- Xin Zeng
- Guangzhou Institute of Biomedicine and Health, CAS, Guangzhou 510663, PR China
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403
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Kirst HA. The spinosyn family of insecticides: realizing the potential of natural products research. J Antibiot (Tokyo) 2010; 63:101-11. [DOI: 10.1038/ja.2010.5] [Citation(s) in RCA: 209] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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404
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Tanino T, Ichikawa S, Shiro M, Matsuda A. Total Synthesis of (−)-Muraymycin D2 and Its Epimer. J Org Chem 2010; 75:1366-77. [DOI: 10.1021/jo9027193] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tetsuya Tanino
- Faculty of Pharmaceutical Sciences, Hokkaido University Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Rigaku Corporation, 3-9-12 Matsubara, Akishima, Tokyo 196-0003, Japan
| | - Satoshi Ichikawa
- Faculty of Pharmaceutical Sciences, Hokkaido University Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Rigaku Corporation, 3-9-12 Matsubara, Akishima, Tokyo 196-0003, Japan
| | - Motoo Shiro
- Faculty of Pharmaceutical Sciences, Hokkaido University Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Rigaku Corporation, 3-9-12 Matsubara, Akishima, Tokyo 196-0003, Japan
| | - Akira Matsuda
- Faculty of Pharmaceutical Sciences, Hokkaido University Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, Rigaku Corporation, 3-9-12 Matsubara, Akishima, Tokyo 196-0003, Japan
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405
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Ravindran J, Nair HB, Sung B, Prasad S, Tekmal RR, Aggarwal BB. Thymoquinone poly (lactide-co-glycolide) nanoparticles exhibit enhanced anti-proliferative, anti-inflammatory, and chemosensitization potential. Biochem Pharmacol 2010; 79:1640-7. [PMID: 20105430 DOI: 10.1016/j.bcp.2010.01.023] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2009] [Revised: 01/19/2010] [Accepted: 01/20/2010] [Indexed: 12/23/2022]
Abstract
Thymoquinone (TQ), derived from the medicinal spice Nigella sativa (also called black cumin), has been shown to exhibit anti-inflammatory and anti-cancer activities. In this report we employed polymer-based nanoparticle approach to improve upon its effectiveness and bioavailability. TQ was encapsulated with 97.5% efficiency in biodegradable nanoparticulate formulation based on poly (lactide-co-glycolide) (PLGA) and the stabilizer polyethylene glycol (PEG)-5000. Dynamic laser light scattering and transmission electron microscopy confirmed particle diameter between 150 and 200nm. Electrophoretic gel shift mobility assay showed that TQ nanoparticles (NP) were more active than TQ in inhibiting NF-kappaB activation and in suppressing the expression of cyclin D1, matrix metalloproteinase (MMP)-9, vascular endothelial growth factor (VEGF), those are markers of cell proliferation, metastasis and angiogenesis, respectively. TQ-NP were also more potent than TQ in suppressing proliferation of colon cancer, breast cancer, prostate cancer, and multiple myeloma cells. Esterase staining for plasma membrane integrity revealed that TQ-NP were more potent than TQ in sensitizing leukemic cells to TNF- and paclitaxel-induced apoptosis. Overall our results demonstrate that encapsulation of TQ into nanoparticles enhances its anti-proliferative, anti-inflammatory, and chemosensitizing effects.
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Affiliation(s)
- Jayaraj Ravindran
- Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, Houston, 77030, United States
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406
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Abstract
Apoptosis is important for normal development and removal of damaged cells. Evasion of apoptosis by cancer cells is one of the key characteristics of many tumor types. Thus, discovering agents that promote apoptosis in tumor cells could have great therapeutic value. Marine natural products have demonstrated great potential as anticancer agents, and the proapoptotic activity of some of these products is emerging as a potentially useful property for cancer treatments. Using a tumor xenograft assay in rodents, we previously found that the marine alkaloid naamidine A is a potent antitumor agent. In this study, we further characterize the mechanism of action of naamidine A. In cultured tumor cells, we find that naamidine A induces cell death, which is accompanied with annexin V staining, disruption of the mitochondrial membrane potential, and cleavage and activation of caspases 3, 8, and 9, all of which are hallmarks of apoptosis. Furthermore, naamidine A-induced cell death is caspase dependent. We also find that under conditions where naamidine A inhibits tumor xenograft growth, it induces activation of caspase 3, suggesting that apoptosis is part of its antitumorigenic activity in vivo. Apoptosis is not dependent on extracellular signal-regulated kinase 1/2, previously characterized molecular targets of naamidine A, nor does it require functional p53. Our studies support the continued study of naamidine A and its target(s) for the potential development of better clinical treatments for cancer.
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407
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Li F, Fernandez PP, Rajendran P, Hui KM, Sethi G. Diosgenin, a steroidal saponin, inhibits STAT3 signaling pathway leading to suppression of proliferation and chemosensitization of human hepatocellular carcinoma cells. Cancer Lett 2010; 292:197-207. [PMID: 20053498 DOI: 10.1016/j.canlet.2009.12.003] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 12/07/2009] [Accepted: 12/07/2009] [Indexed: 11/18/2022]
Abstract
Constitutive activation of STAT3 has been shown in several human cancers and transformed cell lines including hepatocellular carcinoma (HCC). In the present report, we investigated whether diosgenin, a steroidal saponin isolated from fenugreek can modulate the STAT3 signaling pathway. We found that diosgenin inhibited both constitutive and inducible activation of STAT3 with no effect on STAT5. The activation of c-Src, JAK1 and JAK2 implicated in STAT3 activation, were also suppressed by this saponin. Pervanadate reversed the diosgenin-induced downregulation of STAT3, suggesting the involvement of a protein tyrosine phosphatase. Indeed, we found that diosgenin can induce the expression of Src homology 2 phosphatase 2 (SH-PTP2) that correlated with downregulation of constitutive STAT3 activation. Diosgenin also downregulated the expression of various STAT3-regulated gene products, inhibited proliferation and potentiated the apoptotic effects of paclitaxel and doxorubicin. Overall, these results suggest that diosgenin is a novel blocker of the STAT3 activation pathway, with a potential role in the treatment of HCC and other cancers.
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Affiliation(s)
- Feng Li
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore
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408
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Yan LC, Bi EG, Lou YT, Wu XD, Liu ZD, Zhou J, Wang Y, Ma Z, Lin GM, Sun SH, Bian C, Chen AZ, Yao ZJ, Sun B. Novel sinomenine derivative 1032 improves immune suppression in experimental autoimmune encephalomyelitis. Biochem Biophys Res Commun 2010; 391:1093-8. [DOI: 10.1016/j.bbrc.2009.12.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 12/05/2009] [Indexed: 11/26/2022]
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409
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Computational analysis of phenotypic space in heterologous polyketide biosynthesis—Applications to Escherichia coli, Bacillus subtilis, and Saccharomyces cerevisiae. J Theor Biol 2010; 262:197-207. [DOI: 10.1016/j.jtbi.2009.10.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Revised: 10/05/2009] [Accepted: 10/06/2009] [Indexed: 11/21/2022]
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410
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Abstract
Agelasines, asmarines and related compounds are natural products with a hybrid terpene-purine structure isolated from numerous genera of sponges (Agela sp., Raspailia sp.). Some agelasine analogs and related structures have displayed high general toxicity towards protozoa, and have exhibited broad-spectrum antimicrobial activity against a variety of species, including Mycobacterium tuberculosis, and also an important cytotoxic activity against several cancer cell lines, including multidrug-resistant ones. Of particular interest in this context are the asmarines (tetrahydro[1,4]diazepino[1,2,3-g,h]purines), which have shown potent antiproliferative activity against several types of human cancer cell lines. This review summarizes the sources of isolation, chemistry and bioactivity of marine alkylpurines and their bioactive derivatives.
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411
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Hueso-Falcón I, Girón N, Velasco P, Amaro-Luis JM, Ravelo AG, de las Heras B, Hortelano S, Estevez-Braun A. Synthesis and induction of apoptosis signaling pathway of ent-kaurane derivatives. Bioorg Med Chem 2009; 18:1724-35. [PMID: 20116261 DOI: 10.1016/j.bmc.2009.11.064] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 11/11/2009] [Accepted: 11/27/2009] [Indexed: 01/09/2023]
Abstract
Thirty one ent-kaurane derivatives were prepared from kaurenoic acid (1), grandiflorenic acid (16), 15alpha-acetoxy-kaurenoic acid (26) and 16alpha-hydroxy-kaurenoic acid (31). They were tested for their ability to inhibit cell viability in the mouse leukemic macrophagic RAW 264.7 cell line. The most effective compounds were 12, 20, 21, and 23. These were selected for further evaluation in other human cancer cell lines such as Hela, HepG2, and HT-29. Similar effects were obtained although RAW 264.7 cells were more sensitive. In addition, these compounds were significantly less cytotoxic in non-transformed cells. The apoptotic potential of the most active compounds was investigated and they were able to induce apoptosis with compound 12 being the best inducer. The caspase-3, -8 and -9 activities were measured. The results obtained showed that compounds 12, 21, and 23 induce apoptosis via the activation of caspase-8, whereas compound 20 induces apoptosis via caspase-9. Immunoblot analysis of the expression of p53, Bax, Bcl-2, Bcl-xl, and IAPs in RAW 264.7 cells was also carried out. When cells were exposed to 5 microM of the different compounds, expression levels of p53 and Bax increased whereas levels of antiapoptotic proteins such as Bc1-2, Bc1-x1, and IAPs decreased. In conclusion, kaurane derivatives (12, 20, 21, and 23) induce apoptosis via both the mitochondrial and membrane death receptor pathways, involving the Bcl-2 family proteins. Taken together these results provide a role of kaurane derivatives as apoptotic inducers in tumor cells.
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Affiliation(s)
- Idaira Hueso-Falcón
- Instituto Universitario de Bio-Orgánica 'Antonio González', Universidad de La Laguna, La Laguna, Tenerife, Spain
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412
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Keiser MJ, Setola V, Irwin JJ, Laggner C, Abbas AI, Hufeisen SJ, Jensen NH, Kuijer MB, Matos RC, Tran TB, Whaley R, Glennon RA, Hert J, Thomas KLH, Edwards DD, Shoichet BK, Roth BL. Predicting new molecular targets for known drugs. Nature 2009; 462:175-81. [PMID: 19881490 PMCID: PMC2784146 DOI: 10.1038/nature08506] [Citation(s) in RCA: 1124] [Impact Index Per Article: 74.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Accepted: 09/14/2009] [Indexed: 12/18/2022]
Abstract
Whereas drugs are intended to be selective, at least some bind to several physiologic targets, explaining both side effects and efficacy. As many drug-target combinations exist, it would be useful to explore possible interactions computationally. Here, we compared 3,665 FDA-approved and investigational drugs against hundreds of targets, defining each target by its ligands. Chemical similarities between drugs and ligand sets predicted thousands of unanticipated associations. Thirty were tested experimentally, including the antagonism of the β1 receptor by the transporter inhibitor Prozac, the inhibition of the 5-HT transporter by the ion channel drug Vadilex, and antagonism of the histamine H4 receptor by the enzyme inhibitor Rescriptor. Overall, 23 new drug-target associations were confirmed, five of which were potent (< 100 nM). The physiological relevance of one such, the drug DMT on serotonergic receptors, was confirmed in a knock-out mouse. The chemical similarity approach is systematic and comprehensive, and may suggest side-effects and new indications for many drugs.
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Affiliation(s)
- Michael J Keiser
- Department of Pharmaceutical Chemistry, University of California San Francisco, 1700 4th Street, San Francisco, California 94143-2550, USA
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413
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Abstract
Numerous ‘scaffolds’ that have been identified in natural product structures have led to very significant numbers of approved drugs and drug candidates for a multiplicity of diseases over the years. In this mini-review, we discuss the base scaffolds (chemical skeletons) that we feel have produced very significant numbers of agents as drugs or drug leads and, in a number of cases, compounds that can be used as chemical synthons or that present activities in biological areas that were not obvious from their earlier history.
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414
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Porwal S, Chauhan SS, Chauhan PMS, Shakya N, Verma A, Gupta S. Discovery of Novel Antileishmanial Agents in an Attempt to Synthesize Pentamidine−Aplysinopsin Hybrid Molecule. J Med Chem 2009; 52:5793-802. [DOI: 10.1021/jm900564x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sharad Porwal
- Division of Medicinal & Process Chemistry, Central Drug Research Institute, Lucknow 226001, India
| | - Shikha S. Chauhan
- Division of Medicinal & Process Chemistry, Central Drug Research Institute, Lucknow 226001, India
| | - Prem M. S. Chauhan
- Division of Medicinal & Process Chemistry, Central Drug Research Institute, Lucknow 226001, India
| | - Nishi Shakya
- Division of Parasitology, Central Drug Research Institute, Lucknow 226001, India
| | - Aditya Verma
- Division of Parasitology, Central Drug Research Institute, Lucknow 226001, India
| | - Suman Gupta
- Division of Parasitology, Central Drug Research Institute, Lucknow 226001, India
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415
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Beutler JA. Natural Products as a Foundation for Drug Discovery. CURRENT PROTOCOLS IN PHARMACOLOGY 2009; 46:9.11.1-9.11.21. [PMID: 20161632 PMCID: PMC2813068 DOI: 10.1002/0471141755.ph0911s46] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Natural products have contributed to the development of many drugs for diverse indications. While most U.S. pharmaceutical companies have reduced or eliminated their in-house natural product groups, new paradigms and new enterprises have evolved to carry on a role for natural products in the pharmaceutical industry. Many of the reasons for the decline in popularity of natural products are being addressed by the development of new techniques for screening and production. This overview aims to inform pharmacologists of current strategies and techniques that make natural products a viable strategic choice for inclusion in drug discovery programs.
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Affiliation(s)
- John A Beutler
- Molecular Targets Development Program Center for Cancer Research National Cancer Institute Frederick, MD 21702 USA 301-846-1942 (ph.) 301-846-6177 (fax)
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416
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Cao S, Kingston DGI. Biodiversity conservation and drug discovery: Can they be combined? The Suriname and Madagascar experiences. PHARMACEUTICAL BIOLOGY 2009; 47:809-823. [PMID: 20161050 PMCID: PMC2746688 DOI: 10.1080/13880200902988629] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The approach to new drugs through natural products has proved to be the single most successful strategy for the discovery of new drugs, but in recent years its use has been deemphasized by many pharmaceutical companies in favor of approaches based on combinatorial chemistry and genomics, among others.Drug discovery from natural sources requires continued access to plant, marine, and microbial biomass, and so the preservation of tropical rainforests is an important part of our drug discovery program. Sadly, many of the tropical forests of the world are under severe environmental pressure, and deforestation is a serious problem in most tropical countries. One way to combat this loss is to demonstrate their value as potential sources of new pharmaceutical or agrochemical products.As part of an effort to integrate biodiversity conservation and drug discovery with economic development, we initiated an International Cooperative biodiversity Group (ICBG) to discover potential pharmaceuticals from the plant biodiversity of Suriname and Madagascar. The Group, established with funding from agencies of the United States government, involved participants from the USA, Suriname, and Madagascar. The basic approach was to search for bioactive plants in the Suriname and Malagasy flora, and to isolate their bioactive constituents by the best available methods, but the work included capacity building as well as research. Progress on this project will be reported, drawing on results obtained from the isolation of bioactive natural products from Suriname and Madagascar. The benefits of this general approach to biodiversity and drug discovery will also be discussed.
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Affiliation(s)
| | - David G. I. Kingston
- Address for correspondence: David G. I. Kingston, Virginia Polytechnic Institute and State University. Tel: (540) 231-6570. Fax: (540) 231-3255.
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417
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Li JWH, Vederas JC. Drug discovery and natural products: end of an era or an endless frontier? Science 2009; 325:161-5. [PMID: 19589993 DOI: 10.1126/science.1168243] [Citation(s) in RCA: 1277] [Impact Index Per Article: 85.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Historically, the majority of new drugs have been generated from natural products (secondary metabolites) and from compounds derived from natural products. During the past 15 years, pharmaceutical industry research into natural products has declined, in part because of an emphasis on high-throughput screening of synthetic libraries. Currently there is substantial decline in new drug approvals and impending loss of patent protection for important medicines. However, untapped biological resources, "smart screening" methods, robotic separation with structural analysis, metabolic engineering, and synthetic biology offer exciting technologies for new natural product drug discovery. Advances in rapid genetic sequencing, coupled with manipulation of biosynthetic pathways, may provide a vast resource for the future discovery of pharmaceutical agents.
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Affiliation(s)
- Jesse W-H Li
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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418
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Walther T, Renner S, Waldmann H, Arndt HD. Synthesis and structure-activity correlation of a brunsvicamide-inspired cyclopeptide collection. Chembiochem 2009; 10:1153-62. [PMID: 19360807 DOI: 10.1002/cbic.200900035] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cyanobacterial cyclopeptides: A series of analogues of the cyanobacterial cyclopeptide brunsvicamide A was prepared by effective solid-support-based total synthesis. Variations in stereochemistry revealed the importance of the D-lysine and the L-isoleucine residues for the substrate-competitive inhibitory activity of brunsvicamide A against carboxypeptidase A. The brunsvicamides are modified cyclopeptides from cyanobacteria, cyclised through the epsilon-amino group of a D-lysine unit. They are functionalised with urea groups and show potent carboxypeptidase inhibitory activities. In order to unravel the structural parameters that determine their activities, a collection of brunsvicamide analogues with varied amino acid structures and stereochemistries was synthesised by a combined solution- and solid-phase approach. Biochemical investigation of the compound collection for carboxypeptidase A inhibition revealed that the presence of D-lysine and L-isoleucine in the urea section is important for inhibition. It was found that brunsvicamide A is a substrate-competitive inhibitor of carboxypeptidase A. These findings are in agreement with the substrate specificity of the enzyme and were rationalised by computational studies, which showed the high relevance of the lysine stereochemistry for inhibitory activity.
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Affiliation(s)
- Thilo Walther
- Technische Universität Dortmund, Fakultät Chemie, Otto-Hahn-Strasse 6, 44221 Dortmund, Germany
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419
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Salazar MO, Ramallo IA, Micheloni O, Sierra MG, Furlan RLE. Chemically engineered extracts: bioactivity alteration through sulfonylation. Bioorg Med Chem Lett 2009; 19:5067-70. [PMID: 19635668 DOI: 10.1016/j.bmcl.2009.07.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 07/03/2009] [Accepted: 07/07/2009] [Indexed: 12/16/2022]
Abstract
The chemical composition and the biomolecular properties of a series of crude plant extracts were altered without previous knowledge of their detailed chemical composition.
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Affiliation(s)
- Mario O Salazar
- Farmacognosia, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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420
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From fragment to clinical candidate—a historical perspective. Drug Discov Today 2009; 14:668-75. [DOI: 10.1016/j.drudis.2009.04.007] [Citation(s) in RCA: 171] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 04/01/2009] [Accepted: 04/23/2009] [Indexed: 11/21/2022]
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421
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De Wael F, Jeanjot P, Moens C, Verbeuren T, Cordi A, Bouskela E, Rees JF, Marchand-Brynaert J. In vitro and in vivo studies of 6,8-(diaryl)imidazo[1,2-a]pyrazin-3(7H)-ones as new antioxidants. Bioorg Med Chem 2009; 17:4336-44. [DOI: 10.1016/j.bmc.2009.05.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2009] [Revised: 05/06/2009] [Accepted: 05/11/2009] [Indexed: 10/20/2022]
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422
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Liu Y, Law BK, Luesch H. Apratoxin a reversibly inhibits the secretory pathway by preventing cotranslational translocation. Mol Pharmacol 2009; 76:91-104. [PMID: 19403701 DOI: 10.1124/mol.109.056085] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Apratoxin A is a potent cytotoxic marine natural product that rapidly inhibits signal transducer and activator of transcription (STAT) 3 phosphorylation by an undefined mechanism. We have used biochemical and proteomics approaches to illuminate upstream molecular events. Apratoxin A inhibits Janus kinase (JAK)/STAT signaling through rapid down-regulation of interleukin 6 signal transducer (gp130). Apratoxin A also depletes cancer cells of several cancer-associated receptor tyrosine kinases by preventing their N-glycosylation, leading to their rapid proteasomal degradation. A proteomics approach revealed that several proteins in the endoplasmic reticulum, the site of N-glycoprotein synthesis, are down-regulated upon apratoxin A exposure. Using in vitro cell free systems, we demonstrated that apratoxin A prevents cotranslational translocation of proteins destined for the secretory pathway. This process is reversible in living cells. Our study indicates that apratoxins are new tools to study the secretory pathway and raises the possibility that inhibition of cotranslational translocation may be exploited for anticancer drug development.
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Affiliation(s)
- Yanxia Liu
- Department of Medicinal Chemistry, University of Florida, Gainesville, FL 32610, USA
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423
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Targeting protein–protein interactions for therapeutic intervention: a challenge for the future. Future Med Chem 2009; 1:65-93. [DOI: 10.4155/fmc.09.12] [Citation(s) in RCA: 187] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Background: Over the last two decades, an increasing research effort in academia and industry has focused on the modulation (both inhibition and stabilization) of protein–protein interactions (PPIs) in order to develop novel therapeutic approaches and target-selective agents in drug discovery. Discussion: The diversity and complexity of highly dynamic systems such as PPIs present many challenges for the identification of drug-like molecules with the ability to modulate the PPI with the necessary selectivity and potency. In this review, a number of these strategies will be presented along with a critical overview of the challenges and potential solutions relating to the exploitation of PPIs as molecular targets. Conclusions: Both traditional drug discovery approaches and some more recently developed innovative strategies have already provided valuable tools for the discovery of PPI modulators, and a number of successful examples have highlighted the potential of targeting PPIs for therapeutic intervention, especially in the oncology area.
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424
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Luo JM, Dai CF, Lin SY, Huang PQ. Asymmetric syntheses and Wnt signal inhibitory activity of melleumin A and four analogues of melleumins A and B. Chem Asian J 2009; 4:328-35. [PMID: 19072738 DOI: 10.1002/asia.200800355] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Guided by nature: A flexible and epimerization-free approach for the asymmetric syntheses of melleumin A and four analogues of melleumins A and B was developed, which allowed confirming the stereochemistry at C-4 of melleumin A, and revealed that the unnatural 4-epi-melleumin B possesses a modest inhibitory activity on Wnt signaling. The first total synthesis of melleumin A and four analogues of melleumins A and B is described. The N-acyl L-Thr-Gly/beta-hydroxy-gamma-amino acid coupling/macrolactamization strategy allowed the efficient assembly of the three segments being free of epimerization. While the Jouin-Castro method with minor modification allows a rapid entrance to the key syn-beta-hydroxy-gamma-amino acid segment, required for the synthesis of melleumin A, an extension of our malimide-based methodology using a changed N-protecting group affords a flexible access to several anti-beta-hydroxy-gamma-amino acids, and hence analogues of melleumins A and B. Among them, unnatural 4-epi-melleumin B (2 a) exhibits a modest inhibitory activity on Wnt signaling. The total synthesis of melleumin A allowed confirmation of its full structure.
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Affiliation(s)
- Jie-Min Luo
- Department of Chemistry and Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
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425
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Williams GJ, Gantt RW, Thorson JS. The impact of enzyme engineering upon natural product glycodiversification. Curr Opin Chem Biol 2009; 12:556-64. [PMID: 18678278 DOI: 10.1016/j.cbpa.2008.07.013] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Accepted: 07/07/2008] [Indexed: 12/20/2022]
Abstract
Glycodiversification of natural products is an effective strategy for small molecule drug development. Recently, improved methods for chemo-enzymatic synthesis of glycosyl donors has spurred the characterization of natural product glycosyltransferases (GTs), revealing that the substrate specificity of many naturally occurring GTs as too stringent for use in glycodiversification. Protein engineering of natural product GTs has emerged as an attractive approach to overcome this limitation. This review highlights recent progress in the engineering/evolution of enzymes relevant to natural product glycodiversification with a particular focus upon GTs.
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Affiliation(s)
- Gavin J Williams
- Laboratory for Biosynthetic Chemistry, Pharmaceutical Sciences Division, School of Pharmacy, National Cooperative Drug Discovery Program, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705, USA
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426
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Natural products and drug discovery. Can thousands of years of ancient medical knowledge lead us to new and powerful drug combinations in the fight against cancer and dementia? EMBO Rep 2009; 10:194-200. [PMID: 19229284 DOI: 10.1038/embor.2009.12] [Citation(s) in RCA: 362] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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427
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Jarussophon S, Acoca S, Gao JM, Deprez C, Kiyota T, Draghici C, Purisima E, Konishi Y. Automated molecular formula determination by tandem mass spectrometry (MS/MS). Analyst 2009; 134:690-700. [PMID: 19305917 DOI: 10.1039/b818398h] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Automated software was developed to analyze the molecular formula of organic molecules and peptides based on high-resolution MS/MS spectroscopic data. The software was validated with 96 compounds including a few small peptides in the mass range of 138-1569 Da containing the elements carbon, hydrogen, nitrogen and oxygen. A Micromass Waters Q-TOF Ultima Global mass spectrometer was used to measure the molecular masses of precursor and fragment ions. Our software assigned correct molecular formulas for 91 compounds, incorrect molecular formulas for 3 compounds, and no molecular formula for 2 compounds. The obtained 95% success rate indicates high reliability of the software. The mass accuracy of the precursor ion and the fragment ions, which is critical for the success of the analysis, was high, i.e. the accuracy and the precision of 850 data were 0.0012 Da and 0.0016 Da, respectively. For the precursor and fragment ions below 500 Da, 60% and 90% of the data showed accuracy within < or = 0.001 Da and < or = 0.002 Da, respectively. The precursor and fragment ions above 500 Da showed slightly lower accuracy, i.e. 40% and 70% of them showed accuracy within < or = 0.001 Da and < or = 0.002 Da, respectively. The molecular formulas of the precursor and the fragments were further used to analyze possible mass spectrometric fragmentation pathways, which would be a powerful tool in structural analysis and identification of small molecules. The method is valuable in the rapid screening and identification of small molecules such as the dereplication of natural products, characterization of drug metabolites, and identification of small peptide fragments in proteomics. The analysis was also extended to compounds that contain a chlorine or bromine atom.
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Affiliation(s)
- Suwatchai Jarussophon
- Biotechnology Research Institute, National Research Council Canada, 6100 Royalmount Avenue, Montréal, Québec, Canada H4P 2R2
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428
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Enna SJ, Williams M. Challenges in the search for drugs to treat central nervous system disorders. J Pharmacol Exp Ther 2009; 329:404-11. [PMID: 19182069 DOI: 10.1124/jpet.108.143420] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The history of drug discovery spans approximately 200,000 years. For much of this time, the identification of therapeutic agents was empirical, with the shift to a more hypothesis-driven approach occurring in the late 19th century. Since then, the objective has changed from identifying an active drug and its mechanism of action to determining therapeutic potential only after identifying drug-like compounds that interact with a target site. Although the emphasis on target identification, or "targephilia," has yielded novel drugs, overall it appears to have slowed the drug discovery process, especially for compounds used in treating central nervous system (CNS) disorders. This is because the "targephilic" approach requires a good understanding of target physiology and its integration with the target organ, with a hierarchical integration from in vitro cellular and functional tissue studies to animal models that reasonably predict human responses. Because the majority of CNS drugs were discovered empirically, drug discovery in this area appears less amenable to target-based approaches than it seems for other types of therapeutics. Improving the success rate in CNS drug discovery requires a more pharmacometric-based approach, with a renewed emphasis on defining basic CNS function in intact animals and a more systematic in vivo screening of novel structures. Efforts must also be directed toward defining the sites of action of existing CNS drugs to aid in the design of second-generation agents with improved efficacy and safety.
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Affiliation(s)
- S J Enna
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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429
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Shin DS, Kim HN, Shin KD, Yoon YJ, Kim SJ, Han DC, Kwon BM. Cryptotanshinone inhibits constitutive signal transducer and activator of transcription 3 function through blocking the dimerization in DU145 prostate cancer cells. Cancer Res 2009; 69:193-202. [PMID: 19118003 DOI: 10.1158/0008-5472.can-08-2575] [Citation(s) in RCA: 253] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Because signal transducer and activator of transcription 3 (STAT3) is constitutively activated in most human solid tumors and is involved in the proliferation, angiogenesis, immune evasion, and antiapoptosis of cancer cells, researchers have focused on STAT3 as a target for cancer therapy. We screened for natural compounds that inhibit the activity of STAT3 using a dual-luciferase assay. Cryptotanshinone was identified as a potent STAT3 inhibitor. Cryptotanshinone rapidly inhibited STAT3 Tyr705 phosphorylation in DU145 prostate cancer cells and the growth of the cells through 96 hours of the treatment. Inhibition of STAT3 Tyr705 phosphorylation in DU145 cells decreased the expression of STAT3 downstream target proteins such as cyclin D1, survivin, and Bcl-xL. To investigate the cryptotanshinone inhibitory mechanism in DU145 cells, we analyzed proteins upstream of STAT3. Although phosphorylation of Janus-activated kinase (JAK) 2 was inhibited by 7 micromol/L cryptotanshinone at 24 hours, inhibition of STAT3 Tyr705 phosphorylation occurred within 30 minutes and the activity of the other proteins was not affected. These results suggest that inhibition of STAT3 phosphorylation is caused by a JAK2-independent mechanism, with suppression of JAK2 phosphorylation as a secondary effect of cryptotanshinone treatment. Continuing experiments revealed the possibility that cryptotanshinone might directly bind to STAT3 molecules. Cryptotanshinone was colocalized with STAT3 molecules in the cytoplasm and inhibited the formation of STAT3 dimers. Computational modeling showed that cryptotanshinone could bind to the SH2 domain of STAT3. These results suggest that cryptotanshinone is a potent anticancer agent targeting the activation STAT3 protein. It is the first report that cryptotanshinone has antitumor activity through the inhibition of STAT3.
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Affiliation(s)
- Dae-Seop Shin
- Laboratory of Chemical Biology and Chemical Genomics, Korea Research Institute of Bioscience and Biotechnology, 52 Uendong Yoosunggu, Daejeon, Korea
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430
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Williams M, Martin Garraffo H, F. Spande T. Epibatidine: From Frog Alkaloid to Analgesic Clinical Candidates. A Testimonial to “True Grit”! HETEROCYCLES 2009. [DOI: 10.3987/rev-08-sr(d)5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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431
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Ishibashi M, Arai MA. Search for Bioactive Natural Products Targeting Cancer-Related Signaling Pathways. J SYN ORG CHEM JPN 2009. [DOI: 10.5059/yukigoseikyokaishi.67.1094] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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432
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Voss ME, Ralph JM, Xie D, Manning DD, Chen X, Frank AJ, Leyhane AJ, Liu L, Stevens JM, Budde C, Surman MD, Friedrich T, Peace D, Scott IL, Wolf M, Johnson R. Synthesis and SAR of vinca alkaloid analogues. Bioorg Med Chem Lett 2008; 19:1245-9. [PMID: 19147348 DOI: 10.1016/j.bmcl.2008.12.077] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 12/16/2008] [Accepted: 12/17/2008] [Indexed: 10/21/2022]
Abstract
Versatile intermediates 12'-iodovinblastine, 12'-iodovincristine and 11'-iodovinorelbine were utilized as substrates for transition metal based chemistry which led to the preparation of novel analogues of the vinca alkaloids. The synthesis of key iodo intermediates, their transformation into final products, and the SAR based upon HeLa and MCF-7 cell toxicity assays is presented. Selected analogues 27 and 36 show promising anticancer activity in the P388 murine leukemia model.
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Affiliation(s)
- Matthew E Voss
- Albany Molecular Research, Inc., 26 Corporate Circle, PO Box 15098, Albany, NY 12212-5098, USA.
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433
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Hunter WN. Structure-based ligand design and the promise held for antiprotozoan drug discovery. J Biol Chem 2008; 284:11749-53. [PMID: 19103598 PMCID: PMC2673241 DOI: 10.1074/jbc.r800072200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The development of the pharmaceutical industry, driven by progress in
chemistry, biology, and technology, ranks as one of the most successful of
human endeavors. However, serious health problems persist, among which are
diseases caused by protozoan parasites, largely ignored in modern times.
Advances in genomic sciences, molecular and structural biology, and
computational and medicinal chemistry now set the scene for a renewed assault
on such infections. A structure-centric approach to support discovery of
antiparasitic compounds promises much. Current strategies and benefits of a
structure-based approach to support early stage drug discovery will be
described.
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Affiliation(s)
- William N Hunter
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, United Kingdom.
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434
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Williams PG. Panning for chemical gold: marine bacteria as a source of new therapeutics. Trends Biotechnol 2008; 27:45-52. [PMID: 19022511 DOI: 10.1016/j.tibtech.2008.10.005] [Citation(s) in RCA: 150] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Revised: 10/01/2008] [Accepted: 10/13/2008] [Indexed: 11/30/2022]
Abstract
Marine bacteria are emerging as an exciting resource for the discovery of new classes of therapeutics. The promising anticancer clinical candidates salinosporamide A and bryostatin only hint at the incredible wealth of drug leads hidden just beneath the ocean surface. For example, if properly developed, marine bacteria could provide the drugs needed to sustain us for the next 100 years in our battle against drug-resistant infectious diseases. This review will focus on several recently discovered compounds, primarily from cyanobacteria and actinobacteria, that illustrate the tremendous potential of marine bacteria as a source of new therapeutics within the areas of oncology and infectious diseases.
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Affiliation(s)
- Philip G Williams
- Department of Chemistry, University of Hawai'i at Manoa, 2545 McCarthy Mall, Honolulu, HI 96822, USA.
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435
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436
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Bolognesi ML, Calonghi N, Mangano C, Masotti L, Melchiorre C. Parallel Synthesis and Cytotoxicity Evaluation of a Polyamine−Quinone Conjugates Library. J Med Chem 2008; 51:5463-7. [DOI: 10.1021/jm800637b] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Maria Laura Bolognesi
- Department of Pharmaceutical Sciences, Alma Mater Studiorum, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy, Department of Biochemistry “G. Moruzzi”, Alma Mater Studiorum, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Natalia Calonghi
- Department of Pharmaceutical Sciences, Alma Mater Studiorum, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy, Department of Biochemistry “G. Moruzzi”, Alma Mater Studiorum, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Chiara Mangano
- Department of Pharmaceutical Sciences, Alma Mater Studiorum, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy, Department of Biochemistry “G. Moruzzi”, Alma Mater Studiorum, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Lanfranco Masotti
- Department of Pharmaceutical Sciences, Alma Mater Studiorum, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy, Department of Biochemistry “G. Moruzzi”, Alma Mater Studiorum, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Carlo Melchiorre
- Department of Pharmaceutical Sciences, Alma Mater Studiorum, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy, Department of Biochemistry “G. Moruzzi”, Alma Mater Studiorum, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
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437
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Bugni TS, Harper MK, McCulloch MW, Reppart J, Ireland CM. Fractionated marine invertebrate extract libraries for drug discovery. Molecules 2008; 13:1372-83. [PMID: 18596663 PMCID: PMC2505051 DOI: 10.3390/molecules13061372] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 06/18/2008] [Accepted: 06/18/2008] [Indexed: 11/16/2022] Open
Abstract
The high-throughput screening and drug discovery paradigm has necessitated a change in preparation of natural product samples for screening programs. In an attempt to improve the quality of marine natural products samples for screening, several fractionation strategies were investigated. The final method used HP20SS as a solid support to effectively desalt extracts and fractionate the organic components. Additionally, methods to integrate an automated LCMS fractionation approach to shorten discovery time lines have been implemented.
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Affiliation(s)
| | | | | | | | - Chris M. Ireland
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1 (801) 581-8305; Fax: +1 (801) 585-6208
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