1. Genome-guided discovery of two undescribed 6,6-spiroketal polyketides and stereochemical correction of bafilomycins P and Q from the marine-derived Streptomyces sp. SCSIO 66814.
- Author
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Ding, Wenping, Li, Yanqun, Li, Xingyu, Shi, Songbiao, Yin, Jiajia, Tian, Xinpeng, Xiao, Min, Zhang, Si, and Yin, Hao
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POLYKETIDES , *STREPTOMYCES , *NON-small-cell lung carcinoma , *COLON cancer , *GENOMICS - Abstract
Bafilomycins are macrocyclic polyketides with intriguing structures and therapeutic value. Genomic analysis of Streptomyces sp. SCSIO 66814 revealed a type I polyketide synthase biosynthetic gene cluster (BGC), namely blm , which encoded bafilomycins and featured rich post-modification genes. The One strain many compounds (OSMAC) strategy led to the discovery of six compounds related to the blm BGC from the strain, including two previously undescribed 6,6-spiroketal polyketides, streptospirodienoic acids D (1) and E (2), and four known bafilomycins, bafilomycins P (3), Q (4), D (5), and G (6). The structures of 1 and 2 were determined by extensive spectroscopic analysis, quantum calculation, and biosynthetic analysis. Additionally, the absolute configurations of the 6/5/5 tricyclic ring moiety containing six consecutive chiral carbons in the putative structures of 3 and 4 were corrected through NOE analysis, DP4+ calculation, and single-crystal X-ray diffraction data. Bioinformatic analysis uncovered a plausible biosynthetic pathway for compounds 1 – 6 , indicating that both streptospirodienoic acids and bafilomycins were derived from the same blm BGC. Additionally, sequence analysis revealed that the KR domains of module 2 from blm BGC was B1-type, further supporting the configurations of 1 – 4. Notably, compounds 3 and 4 displayed significant cytotoxic activities against A-549 human non-small cell lung cancer cells and HCT-116 human colon cancer cells. [Display omitted] • Genome-guided method facilitated discovery of two previously undescribed 6,6-spiroketal polyketides. • The stereo-configurations of bafilomycins P and Q were corrected. • Streptospirodienoic acids sharing the same blm BGC with bafilomycins was first discovered. • Bafilomycins P and Q displayed significant cytotoxic activities. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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