Abstract
A new glycopeptide antibiotic, OA-7653, was isolated and purified from the culture broth of an actinomycete, designated as Streptomyces hygroscopicus subsp. hiwasaensis subsp. nov. OA-7653 appears to be most analogous to vancomycin in that it is a water-soluble compound with an ultraviolet absorption maximum at around 280 nm, containing only glucose as a neutral carbohydrate component and active against Gram-positive bacteria. The antibiotic exhibited moderate antimicrobial activities against Gram-positive bacteria including Mycobacterium and showed very low toxicity. It inhibited specifically the synthesis of cell wall peptidoglycan in bacteria.