TS 155-2, an antimicrobial agent, is a Bafilomycin analogue and an antibiotic. TS 155-2 can be isolated from a culture of Streptomyces sp. TS 155-2 inhibits V-ATPase activity. V-ATPase is correlated with an increasing number of diseases such as osteopetrosis, male infertility and renal acidosis[1].