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De A, Saha N, Manna T, Singh V, Husain SM. Highly Efficient One-Pot Multienzyme Cascades for the Stereoselective Synthesis of Natural Naphthalenones. ACS Catal 2022. [DOI: 10.1021/acscatal.2c02772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Arijit De
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, Sanjay Gandhi Postgraduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow226014, India
| | - Nirmal Saha
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, Sanjay Gandhi Postgraduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow226014, India
| | - Tanaya Manna
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, Sanjay Gandhi Postgraduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow226014, India
| | - Vidya Singh
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, Sanjay Gandhi Postgraduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow226014, India
| | - Syed Masood Husain
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, Sanjay Gandhi Postgraduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow226014, India
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Contrasting Dihydronaphthoquinone Patterns in Closely Related Drosera (Sundew) Species Enable Taxonomic Distinction and Identification. PLANTS 2021; 10:plants10081601. [PMID: 34451645 PMCID: PMC8400376 DOI: 10.3390/plants10081601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 07/30/2021] [Accepted: 08/02/2021] [Indexed: 11/26/2022]
Abstract
Dihydronaphthoquinones are described as constituents of sundews (Drosera), Venus flytraps (Dionaea), and dewy pines (Drosophyllum) for the first time. As in the corresponding naphthoquinones, these reduced derivatives may occur in two regio-isomeric series distinguished by the relative position of a methyl group (at position 2 or 7 in the naphthalene skeleton), depending on the taxon. Species producing plumbagin (2-methyljuglone, 1) do commonly contain the corresponding dihydroplumbagin (5), while species containing ramentaceone (7-methyljuglone, 2) also contain dihydroramentaceone (7-methyl-β-dihydrojuglone, 6). So far, only few species containing plumbagin (1) and dihydroplumbagin (5) additionally form dihydroramentaceone (6) but not ramentaceone (2). Thus, subtle but constant differences in the chemism of closely related and morphologically similar species reliably define and distinguish taxa within D. sect. Arachnopus, which is taken to exemplify their chemotaxonomic utility. The joint presence of quinones and hydroquinones allows observations and predictions on the chemical structures and the reactions of these intriguing natural products.
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Juribašić M, Bregović N, Stilinović V, Tomišić V, Cindrić M, Šket P, Plavec J, Rubčić M, Užarević K. Supramolecular Stabilization of Metastable Tautomers in Solution and the Solid State. Chemistry 2014; 20:17333-45. [DOI: 10.1002/chem.201403543] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Indexed: 11/11/2022]
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Nicolaou KC, Hale CR, Nilewski C, Ioannidou HA, ElMarrouni A, Nilewski LG, Beabout K, Wang TT, Shamoo Y. Total synthesis of viridicatumtoxin B and analogues thereof: strategy evolution, structural revision, and biological evaluation. J Am Chem Soc 2014; 136:12137-60. [PMID: 25317739 PMCID: PMC4210137 DOI: 10.1021/ja506472u] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Indexed: 11/29/2022]
Abstract
The details of the total synthesis of viridicatumtoxin B (1) are described. Initial synthetic strategies toward this intriguing tetracycline antibiotic resulted in the development of key alkylation and Lewis acid-mediated spirocyclization reactions to form the hindered EF spirojunction, as well as Michael-Dieckmann reactions to set the A and C rings. The use of an aromatic A-ring substrate, however, was found to be unsuitable for the introduction of the requisite hydroxyl groups at carbons 4a and 12a. Applying these previous tactics, we developed stepwise approaches to oxidize carbons 12a and 4a based on enol- and enolate-based oxidations, respectively, the latter of which was accomplished after systematic investigations that revealed critical reactivity patterns. The herein described synthetic strategy resulted in the total synthesis of viridicatumtoxin B (1), which, in turn, formed the basis for the revision of its originally assigned structure. The developed chemistry facilitated the synthesis of a series of viridicatumtoxin analogues, which were evaluated against Gram-positive and Gram-negative bacterial strains, including drug-resistant pathogens, revealing the first structure-activity relationships within this structural type.
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Affiliation(s)
- K. C. Nicolaou
- Department of Chemistry, Department of Biochemistry
and Cell Biology, and Department of
Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Christopher R.
H. Hale
- Department of Chemistry, Department of Biochemistry
and Cell Biology, and Department of
Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Christian Nilewski
- Department of Chemistry, Department of Biochemistry
and Cell Biology, and Department of
Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Heraklidia A. Ioannidou
- Department of Chemistry, Department of Biochemistry
and Cell Biology, and Department of
Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Abdelatif ElMarrouni
- Department of Chemistry, Department of Biochemistry
and Cell Biology, and Department of
Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Lizanne G. Nilewski
- Department of Chemistry, Department of Biochemistry
and Cell Biology, and Department of
Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Kathryn Beabout
- Department of Chemistry, Department of Biochemistry
and Cell Biology, and Department of
Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Tim T. Wang
- Department of Chemistry, Department of Biochemistry
and Cell Biology, and Department of
Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Yousif Shamoo
- Department of Chemistry, Department of Biochemistry
and Cell Biology, and Department of
Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, Texas 77005, United States
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Rubčić M, Užarević K, Halasz I, Bregović N, Mališ M, Dilović I, Kokan Z, Stein RS, Dinnebier RE, Tomišić V. Desmotropy, polymorphism, and solid-state proton transfer: four solid forms of an aromatic o-hydroxy Schiff base. Chemistry 2012; 18:5620-31. [PMID: 22447516 DOI: 10.1002/chem.201103508] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Indexed: 11/06/2022]
Abstract
The Schiff base derived from salicylaldehyde and 2-amino-3-hydroxypyridine affords a diversity of solid forms, two polymorphic pairs of the enol-imino (D1 a and D1 b) and keto-amino (D2 a and D2 b) desmotropes. The isolated phases, identified by IR spectroscopy, X-ray crystallography, and (13)C cross-polarization/magnetic angle spinning (CP/MAS) NMR spectroscopy, display essentially planar molecular conformations characterized by strong intramolecular hydrogen bonds of the O-H⋅⋅⋅N (D1) or N-H⋅⋅⋅O (D2) type. A change in the position of the proton within this O⋅⋅⋅H⋅⋅⋅N system is accompanied by substantially different molecular conformations and, subsequently, by divergent supramolecular architectures. The appearance and interconversion conditions for each of the four phases have been established on the basis of a number of solution and solvent-free experiments, and evaluated against the results of computational studies. Solid phases readily convert into the most stable form (D1 a) upon exposure to methanol vapor, heating, or by mechanical treatment, and these transformations are accompanied by a change in the color of the sample. The course of thermally induced transformations has been monitored in detail by means of temperature-resolved powder X-ray diffraction and infrared spectroscopy. Upon dissolution, all forms equilibrate immediately, as confirmed by NMR and UV/Vis spectroscopy in several solvents, with the equilibrium shifted far towards the enol tautomer. This study reveals the significance of peripheral groups in the stabilization of metastable tautomers in the solid state.
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Affiliation(s)
- Mirta Rubčić
- Department of Chemistry, Faculty of Science, University of Zagreb, Croatia.
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