1H-nmr analysis of herbimycins and dihydro-herbimycins.

Herbimycin A [1] and herbimycin C [3] and their dihydro-derivatives 5 and 6, respectively, have been obtained from the cell broth of Streptomyces hygroscopicus, and the assignment of their 1H-nmr has been completed. Strong cytotoxic activity of antibiotics 1, 3, 5, and 6 against the P-388 and KB lymphocytic leukemia test systems has been demonstrated.