Antibacterial Gilvocarcin-Type Aryl- C -Glycosides from a Soil-Derived Streptomyces Species.

Seven new gilvocarcin-type aryl- C -glycosides ( 1 - 7 ) and six known analogues ( 8 - 13 ) were isolated from the soil-derived Streptomyces sp. OUCMDZ-945. Their structures including absolute configurations were determined based on detailed spectroscopic analysis, chemical methods, ECD curves, and quantum chemical calculations. Compound 1 , which we named digilvocarcin A, is the first reported bis-gilvocarcin derivative possessing a novel cyclobutane moiety. This dimeric skeleton was confirmed to be formed from gilvocarcin V ( 8 ) through a light-induced [2 + 2] cycloaddition. Compounds 1 , 2 , 5 - 8 , and 11 showed antibacterial activity against Staphylococcus aureus ATCC 6538 and methicillin-resistant Staphylococcus aureus subsp. aureus ATCC 43300 (MIC values: 0.25-64 μg/mL).