Antibiotic g-418 and verdamycin i - produced by fermentation of micromonospora rhodorangea or m grisea

摘要

Antibiotic G-418 is of formula (I): (where R1, R2 and R3 are OH and is a single bond), and verdamycin I is of formula (I) (where R1 is NH2 R2 and R3 is H, and is a double bond). The acid addn salts and oxazolidine Schiff-base derivs of G-418 and verdamycin (I) are also claimed. The fermentation of M. rhodorangea or M. grisea also produces the known antibiotics sisomycin and gentamycin A.