Double Bond Geometric Isomers of Pentaketide Ansamycins from Streptomyces sp. S008

Abstract

Six new pentaketide ansamycins, namely, shengliangmycins A−F (1−6, respectively), were obtained from the fermentation products of Streptomyces sp. S008OEslmR2 that was derived by constitutive expression of LAL regulator gene slmR2. The structures of 1−6 were determined through comprehensive spectroscopic analysis and single-crystal X-ray diffraction. Compound 1 has a cis-C6�C7 bond, which is different from that of compounds 2−5. Compounds 3−6 feature a morpholinone structural moiety, whereas 5 is characterized by a pyrazoline ring, which is rare in natural products.Letter pubs.acs.org/OrgLett

Goondansamycins A–H: Benzenoid Ansamycins from an Australian Volcanic Crater Soil-Derived Actinomadura sp. S4S-00069B08

“…A review of the literature revealed that 7 was identical with shengliangmycin C, reported in 2023 from a genetically modified Chinese soil-derived Streptomyces. Importantly, this earlier study had confirmed the structure and absolute configuration of 7 by an X-ray analysis, as the 4-epimer of 1 .…”

“…Shengliangmycin C (7). Colorless powder; [α] D 24 – 242 ( c 0.01, MeOH); 1D and 2D NMR (DMSO- d 6 ) see Table S9 and Figures S53–S59, identical with literature; HRESIMS m / z 368.1465 [M + Na] + (calcd. for C 19 H 23 NNaO 5 , 368.1468).…”

Hot off the Press

“…Activation of a cryptic gene cluster from Streptomyces species S008O has led to the discovery of six new pentaketide ansamycins. 27 Constitutive expression of the LAL regulator gene slmR2 led to polyketides such as shengliangmycin E 36 , which has an unusual pyrazoline ring.…”

Discovery and Heterologous Production of Tetrapetalones Provide Insights into the Formation of the Tetracyclic System

“…According to the polyketide chain length, known ansamycins are classified into several subgroups, and pentaketide ansamycins are the smallest. Eight different types of pentaketide ansamycins have been reported, including Q-1047, tetrapetalones, , cebulactams, juanlimycins, microansamycins, aminoansamycins, catellatolactams, and shengliangmycins . Tetrapetalones represent a unique group of pentaketide ansamycins, which were first isolated from the culture broth of Streptomyces sp.…”