abstract |
There is provided new antitumor antibiotic substances designated herein as BBM-1675C and BBM-1675D, said substances being produced by selective chemical hydrolysis of the bioactive components BBM-1675A1 (esperamicin A1) or BBM-1675A2 (esperamicin A2) produced from Actinomadura verrucosospora. BBM 1675C and BBM 1675D have molecular weights of approx 855 and 695 respectively. |