Isolation and characterization of a new nucleoside antibiotic, amipurimycin.

A new antibiotic amipurimycin, active against Pyricularia oryzae in vitro and in vivo, was isolated from the culture filtrate of Streptomyces novoguineensis nov. sp. The antibiotic was purified by a combination of ion-exchange and adsorption chromatography based on its amphoteric water-soluble characteristics. Its molecular formula was estimated to be C20H27approximately31N7O8-H2O. Characteristic maxima in the UV spectrum and signals in the PMR and CMR spectra were similar to those of 2-aminopurine 9-(beta-D)-riboside. These findings indicated that amipurimycin is a new nucleoside antibiotic and the first example of a natural product containing 2-aminopurine.