Tepuazines A–E: Phenazine Glycosides from a Venezuelan Quartz-Rich (Tepui) Cave Soil-Derived Streptomyces virginiae CMB-CA091

• Published in: Journal of natural products (Washington, D.C.) D.C.), 2024-04, Vol.87 (4), p.1084-1091
• Main Authors: Kankanamge, Sarani, Khalil, Zeinab G., Capon, Robert J.
• Format: Article
• Language: English
• Subjects: biosynthesis; Caves; class; glycosides; Glycosides - chemistry; Glycosides - isolation & purification; Molecular Structure; Phenazines - chemistry; Quartz - chemistry; secondary metabolites; soil; Soil Microbiology; spectral analysis; Streptomyces - chemistry; Streptomyces virginiae; Venezuela
• ISSN: 0163-3864; 1520-6025; 1520-6025
• DOI: 10.1021/acs.jnatprod.4c00042

Investigation of the secondary metabolites of Streptomyces virginiae CMB-CA091 isolated from the quartz-rich (tepui) soil of a cave in Venezuela yielded two new dimeric phenazine glycosides, tepuazines A and B (1 and 2); three new monomeric phenazine glycosides, tepuazines C–E (3–5); and a series of known analogues, baraphenazine G (6), phenazinolin D (7), izumiphenazine C (8), 4-methylaminobenzoyl-l-rhamnopyranoside (9), and 2-acetamidophenol (10). Structures were assigned to 1–10 on the basis of detailed spectroscopic analysis and biosynthetic considerations, with 1 and 2 featuring a rare 2-oxabicyclo[3.3.1]nonane-like ring C/D bridge shared with only a handful of known Streptomyces natural products. We propose a plausible convergent biosynthetic relationship linking all known members of this structure class that provides a rationale for the observed ring C/D configuration.