Naphthomycins L–N, Ansamycin Antibiotics from Streptomyces sp. CS

Abstract

Previous analyses of the naphthomycin biosynthetic gene cluster and a comparison with known naphthomycin-type products from Streptomyces sp. CS have suggested that new products can be found from this strain. In this study, screening by LC-MS of Streptomyces sp. CS products formed under different culture conditions revealed several unknown peaks in the product spectra of extracts derived from oatmeal medium cultures. Three new naphthomycins, naphthomycins L (1), M (2), and N (3), and the known naphthomycins A (4), E (5), and D (6) were obtained. The structures were elucidated using spectroscopic data from 1D and 2D NMR and HRESIMS experiments.

Methanethiol as a catabolite of methionine provides methylthio- group for chemical formation of 19-S-methylgeldanamycin and 17,19-dimethylthioherbimycin A

“…Thiol-containing compounds such as ethanethiol, glutathione (GSH), N-acetyl-L-cysteine, and so on, can also react chemically with benzoquinone or naphthoquinone ansamycins, producing many semisynthetic or natural thioansamycins. 12,20,21 Recently, Yang et al 22 reported two thionaphthomycins (naphthomycins M and N). Naphthomycin M contains a thioglycolic acid group connected to C-30 of the naphthomycin skeleton via sulfur, and naphthomycin N is a dimer-like molecule, with a 2-aminoethanethiol group as bridge to connect two naphthomycin monomers.…”

“…But the (bio)synthetic mechanism(s) of naphthomycins M and N remains unclear. 22 Ō mura 23 and Shibata 24 reported chemical modification of herbimycin A, and obtained more than a dozen herbimycin A derivatives with various modifications at C-17 or C-19 of the benzoquinone moiety of herbimycin A. Among them, derivatives with a methylpiperazino group or bromine substituent at C-19 showed high antitumor activity.…”

Small Molecule Accurate Recognition Technology (SMART) to Enhance Natural Products Research

“…Hence, in order to make the training stable and comparison fair, we created two different datasets: SMART5 and SMART10, containing all spectra of compound families ( e.g . veraguamides 64 , ebractenoids 57 , naphthomycins 65 , viequeamides, etc.) with at least 5 and 10 HSQC spectra, respectively, per family.…”

Chemical constituents ofMeconopsis horridulaand their simultaneous quantification by high‐performance liquid chromatography coupled with tandem mass spectrometry

“…With reference to to reports , compounds 5 and 14 were tentatively identified as magnoflorine and amurine. Compound 29 exhibited [M+H] + ion at m/z 284, [M+H–137] + ion at m/z 147 and [M+H–137–CO] + ion at m/z 119, and therefore was assigned as N ‐ p ‐hydroxyl‐ trans ‐coumaroyltyramine .…”