New piericidin glucosides, glucopiericidins A and B.

The new piericidin group antibiotics, glucopiericidins A and B were isolated from the culture broth of Streptomyces pactum S48727 (FERM P-8117) as co-metabolite of piericidin A1. The structures of glucopiericidins A and B were determined as piericidin A1, 10-O-beta-D-glucoside and piericidin A1, 3'-O-D-glucoside on the basis of their spectral and chemical properties, respectively. Glucopiericidins were more potent in inhibiting antibody formation than piericidin A1 in vitro. In addition, these substances showed better antimicrobial activities than piericidin A1. Acute toxicities of these substances in mice were lower than that of piericidin A1. This indicates that D-glucose in glucopiericidin molecules is important in modulating their physiological activities.