Mitomycins are a group of unique
chemical structures in which three different carcinostatic
functions – aziridine, carbamate, and
quinone – are arranged around a pyrroindole nucleus . The first mitomycins
were discovered in 1956by Hata in a culture
filtrate of Streptomyces caespitosus. These compounds,
designated mitomycins A and B, show
highly potent antibacterial activity and moderate
antitumor activity, but they are quite toxic in
mice. In 1958, mitomycin C, an extremely valuable
antitumor drug, was isolated from Streptomyces
caespitosus , . In 1960, another
mitomycin, porfiromycin, was isolated
from Streptomyces ardus.
