7 results on '"Marvin M. Vega"'
Search Results
2. Ion Mobility Mass Spectrometry as an Efficient Tool for Identification of Streptorubin B in Streptomyces coelicolor M145
- Author
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Erin E. Carlson, Andrew R. Johnson, Regan J. Thomson, Marvin M. Vega, and Andrew P. Marshall
- Subjects
Streptorubin B ,Ion-mobility spectrometry ,Stereochemistry ,Pharmaceutical Science ,Streptomyces coelicolor ,01 natural sciences ,Article ,Analytical Chemistry ,chemistry.chemical_compound ,Ion Mobility Spectrometry ,Drug Discovery ,Pharmacology ,Biological Products ,Natural product ,Molecular Structure ,biology ,010405 organic chemistry ,Prodigiosin ,Organic Chemistry ,Prodiginine ,biology.organism_classification ,Metacycloprodigiosin ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Complementary and alternative medicine ,chemistry ,Molecular Medicine - Abstract
Ion mobility spectrometry was utilized to corroborate the identity of streptorubin B (2) as the natural product produced by Streptomyces coelicolor. Natural product 2 was initially assigned as butylcycloheptylprodigiosin (3), and only relatively recently was this assignment clarified. We present additional evidence of this assignment by comparing collisional cross sections (Ω) of synthetic standards of 2, 3, and metacycloprodigiosin (4) to the cyclic prodiginine produced by S. coelicolor. Calculated theoretical Ω values demonstrate that cyclic prodiginines could be identified without standards. This work highlights ion mobility as an efficient tool for the dereplication of natural products.
- Published
- 2020
3. Synthesis and surface spectroscopy of α-pinene isotopologues and their corresponding secondary organic material
- Author
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Li Fu, Ariana Gray Bé, Marvin M. Vega, Regan J. Thomson, C. J. Ebben, Zheming Wang, Aashish Tuladhar, Zizwe A. Chase, Hilary M. Chase, Franz M. Geiger, Mary Alice Upshur, Yue Zhang, and Scot T. Martin
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010405 organic chemistry ,General Chemistry ,Methylene bridge ,010402 general chemistry ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,Aerosol ,Cyclobutane ,Chemistry ,chemistry.chemical_compound ,Deuterium ,chemistry ,13. Climate action ,Particle ,Isotopologue ,Methylene ,Spectroscopy - Abstract
The synthesis and surface-specific spectroscopic analysis of α-pinene isotopologues and their corresponding secondary organic material is reported., Atmospheric aerosol–cloud interactions remain among the least understood processes within the climate system, leaving large uncertainties in the prediction of future climates. In particular, the nature of the surfaces of aerosol particles formed from biogenic terpenes, such as α-pinene, is poorly understood despite the importance of surface phenomena in their formation, growth, radiative properties, and ultimate fate. Herein we report the coupling of a site-specific deuterium labeling strategy with vibrational sum frequency generation (SFG) spectroscopy to probe the surface C–H oscillators in α-pinene-derived secondary organic aerosol material (SOM) generated in an atmospheric flow tube reactor. Three α-pinene isotopologues with methylene bridge, bridgehead methine, allylic, and vinyl deuteration were synthesized and their vapor phase SFG spectra were compared to that of unlabeled α-pinene. Subsequent analysis of the SFG spectra of their corresponding SOM revealed that deuteration of the bridge methylene C–H oscillators present on the cyclobutane ring in α-pinene leads to a considerable signal intensity decrease (ca. 30–40%), meriting speculation that the cyclobutane moiety remains largely intact within the surface bound species present in the SOM formed upon α-pinene oxidation. These insights provide further clues as to the complexity of aerosol particle surfaces, and establish a framework for future investigations of the heterogeneous interactions between precursor terpenes and particle surfaces that lead to aerosol particle growth under dynamically changing conditions in the atmosphere.
- Published
- 2019
4. Genome Mining and Metabolomics Uncover a Rare d-Capreomycidine Containing Natural Product and Its Biosynthetic Gene Cluster
- Author
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William W. Metcalf, Matthew T. Robey, Marvin M. Vega, Li Chen, James H. Tryon, Neil L. Kelleher, Jennifer C. Rote, Regan J. Thomson, Wan Cheng Phua, and Kou San Ju
- Subjects
0301 basic medicine ,Peptide ,Computational biology ,Arginine ,01 natural sciences ,Biochemistry ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Metabolomics ,Biosynthesis ,Bacterial Proteins ,Gene cluster ,Pyridoxal phosphate ,Peptide Synthases ,chemistry.chemical_classification ,Natural product ,010405 organic chemistry ,General Medicine ,Genomics ,Streptomyces ,0104 chemical sciences ,Biosynthetic Pathways ,030104 developmental biology ,Enzyme ,chemistry ,Multigene Family ,Molecular Medicine ,Heterologous expression - Abstract
We report the metabolomics-driven genome mining of a new cyclic-guanidino incorporating non-ribosomal peptide synthetase (NRPS) gene cluster and full structure elucidation of its associated hexapeptide product, faulknamycin. Structural studies unveiled that this natural product contained the previously unknown (R,S)-stereoisomer of capreomycidine, d-capreomycidine. Furthermore, heterologous expression of the identified gene cluster successfully reproduces faulknamycin production without an observed homologue of VioD, the pyridoxal phosphate (PLP)-dependent enzyme found in all previous l-capreomycidine biosynthesis. An alternative NRPS-dependent pathway for d-capreomycidine biosynthesis is proposed.
- Published
- 2020
5. Structure-Activity Relationship-based Optimization of Small Temporin-SHf Analogs with Potent Antibacterial Activity
- Author
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Emily Darby, Daniel J. O'Leary, Katy A. Muzikar, Ali Ladram, Marvin M Vega, Thierry Foulon, Christophe Piesse, Ari D Filip, Sonia André, Shannon K Washington, Nathaniel S Ash, Biosynthèse des Signaux Peptidiques [IBPS] (IBPS-BIOSIPE), Institut de Biologie Paris Seine (IBPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Ingénierie des protéines, PCR, Interaction Moléculaires [IBPS] (IBPS-IPIM), University Pierre and Marie Curie (UPMC), Pomona College, and French Ministere de l'Enseignement Superieur et de la Recherche
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Stereochemistry ,[SDV]Life Sciences [q-bio] ,Antimicrobial peptides ,Peptide ,Microbial Sensitivity Tests ,Biochemistry ,Cell Line ,Structure-Activity Relationship ,Escherichia coli ,Humans ,Structure–activity relationship ,Amino Acid Sequence ,Peptide sequence ,chemistry.chemical_classification ,Molecular Structure ,Chemistry ,Circular Dichroism ,Genetic Variation ,Proteins ,General Medicine ,Antimicrobial ,Temporin ,Anti-Bacterial Agents ,Multiple drug resistance ,Molecular Medicine ,Antibacterial activity ,Antimicrobial Cationic Peptides - Abstract
International audience; Short antimicrobial peptides represent attractive compounds for the development of new antibiotic agents. Previously, we identified an ultrashort hydrophobic and phenylalanine-rich peptide, called temporin-SHf, representing the smallest natural amphibian antimicrobial peptide known to date. Here, we report on the first structure activity relationship study of this peptide. A series of temporin-SHf derivatives containing insertion of a basic arginine residue as well as residues containing neutral hydrophilic (serine and alpha-hydroxymethylserine) and hydrophobic (alpha-methyl phenylalanine and p-(t)butyl phenylalanine) groups were designed to improve the antimicrobial activity, and their alpha-helical structure was investigated by circular dichroism and nuclear magnetic resonance spectroscopy. Three compounds were found to display higher antimicrobial activity with the ability to disrupt (permeabilization/depolarization) the bacterial membrane while retaining the nontoxic character of the parent peptide toward rat erythrocytes and human cells (THP-1 derived macrophages and HEK-293). Antimicrobial assays were carried out to explore the influence of serum and physiological salt concentration on peptide activity. Analogs containing D-amino acid residues were also tested. Our study revealed that [p-(BuF2)-Bu-t, R-5]SHf is an attractive ultrashort candidate that is highly potent (bactericidal) against Gram-positive bacteria (including multidrug resistant S. aureus) and against a wider range of clinically interesting Gram-negative bacteria than temporin-SHf, and also active at physiological salt concentrations and in 30% serum.
- Published
- 2015
6. Enantioselective synthesis of metacycloprodigiosin via the 'Wasserman pyrrole'
- Author
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Regan J. Thomson, Leah C. Konkol, Diana M. Crain, and Marvin M. Vega
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Stereochemistry ,Organic Chemistry ,Enantioselective synthesis ,Total synthesis ,Key features ,Metathesis ,Biochemistry ,Metacycloprodigiosin ,Article ,chemistry.chemical_compound ,Ring-closing metathesis ,chemistry ,Drug Discovery ,Oxidative coupling of methane ,Pyrrole - Abstract
A concise, nine-step enantioselective total synthesis of metacycloprodigiosin is reported. The synthesis provides increased step-efficiency over the previous racemic and enantioselective syntheses of this compound. Key features of the work include investigations into a convergent oxidative coupling reaction and subsequent ring-closing metathesis to deliver an advanced pyrrole intermediate we name the ‘Wasserman pyrrole’ that can be converted to metacycloprodigiosin in one step.
- Published
- 2014
7. Strategies and Tactics for Site Specific Deuterium Incorporation at Each Available Carbon Atom of α-Pinene.
- Author
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Luo J, Upshur MA, Vega M, Doering NA, Varelas J, Ren Z, Geiger FM, Sarpong R, and Thomson RJ
- Abstract
The development of several unique strategies and tactics for the synthesis of α-pinene isotopologues that has culminated in access to all eight possible isomers with deuterium incorporated selectively at each available carbon atom is described. Access to this library of isotopologues provides new tools to more fully investigate the atmospheric autoxidation of α-pinene, a complex process that plays a major role in the formation of secondary organic aerosol in the Earth's atmosphere.
- Published
- 2024
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