1356090-81-7Relevant articles and documents
Total Synthesis and Antimycobacterial Activity of Ohmyungsamycin A, Deoxyecumicin, and Ecumicin
Hawkins, Paige M. E.,Tran, Wendy,Nagalingam, Gayathri,Cheung, Chen-Yi,Giltrap, Andrew M.,Cook, Gregory M.,Britton, Warwick J.,Payne, Richard J.
supporting information, p. 15200 - 15205 (2020/10/23)
The ohmyungsamycin and ecumicin natural product families are structurally related cyclic depsipeptides that display potent antimycobacterial activity. Herein the total syntheses of ohmyungsamycin A, deoxyecumicin, and ecumicin are reported, together with the direct biological comparison of members of these natural product families against Mycobacterium tuberculosis (Mtb), the etiological agent of tuberculosis (TB). The synthesis of each of the natural products employed a solid-phase strategy to assemble the linear peptide precursor, involving a key on-resin esterification and an optional on-resin dimethylation step, before a final solution-phase macrolactamization between the non-proteinogenic N-methyl-4-methoxy-l-tryptophan amino acid and a bulky N-methyl-l-valine residue. The synthetic natural products possessed potent antimycobacterial activity against Mtb with MIC90’s ranging from 110–360 nm and retained activity against Mtb in Mtb-infected macrophages. Deoxyecumicin also exhibited rapid bactericidal killing against Mtb, sterilizing cultures after 21 days.
An efficient preparation of N-Methyl-α-amino acids from N-Nosyl-α-amino acid phenacyl esters
Leggio, Antonella,Belsito, Emilia Lucia,De Marco, Rosaria,Liguori, Angelo,Perri, Francesca,Viscomi, Maria Caterina
experimental part, p. 1386 - 1392 (2010/06/11)
Chemical Equation Presented In this paper we describe a simple and efficient solution-phase synthesis of N-methyl-TV-nosyl-α-amino acids and N-Fmoc-N-methyl-α-amino acids. This represents a very important application in peptide synthesis to obtain N-methylated peptides in both solution and solid phase. The developed methodology involves the use of N-nosyl-α-amino acids with the carboxyl function protected as a phenacyl ester and the methylating reagent diazomethane. An important aspect of this synthetic strategy is the possibility to selectively deprotect the carboxyl function or alternatively both amino and carboxyl moieties by using the same reagent with a different molar excess and under mild conditions. Furthermore, the adopted procedure keeps unchanged the acid-sensitive side chain protecting groups used in Fmoc-based synthetic strategies.
Total structure and inhibition of tumor cell proliferation of laxaphycins
Bonnard, Isabelle,Rolland, Marc,Salmon, Jean-Marie,Debiton, Eric,Barthomeuf, Chantal,Banaigs, Bernard
, p. 1266 - 1279 (2007/10/03)
From a mixed assemblage of Lyngbya majuscula rich marine cyanobacteria, we isolated a series of cell growth inhibitory cyclic peptides, The structures of the two major components, laxaphycins A (1) and B (2), and of two minor peptides, laxaphycins B2 (3) and B3 (4), were determined by spectroscopic methods and degradative analysis. Absolute configurations of natural and nonproteinogenic amino acids were determined by a combination of hydrolysis, synthesis of noncommercial residues, chemical derivatization, and HPLC analysis. The organism producing the laxaphycins was identified as the cyanobacterium Anabaena torulosa. The antiproliferative activity of laxaphycins was investigated on a panel of solid and lymphoblastic cancer cells. Our results demonstrate that in contrast to laxaphycin A, laxaphycin B inhibits the proliferation of sensitive and resistant human cancer cell lines and that this activity is strongly increased in the presence of laxaphycin A. This effect appears to be due to an unusual biological synergism.