Isolation and structural elucidation of new saframycins Y3, Yd-1, Yd-2, Ad-1, Y2b and Y2b-d.

A new series of saframycins Y3, Yd-1, Yd-2, Ad-1, Y2b and Y2b-d was produced by directed biosynthesis employing resting cells of saframycin producer, Streptomyces lavendulae No. 314. Their structures were determined by comparison with the spectral data of UV, IR, and 1H and 13C NMR of saframycin A, whose structure has already been established. Saframycin Y3 is 25-deoxy-25-aminosaframycin A, while saframycin Yd-1 is 26-homosaframycin Y3, and saframycin Y2b is a dimer of saframycin Y3. Saframycin Ad-1 is 26-homosaframycin A. Saframycin Yd-2 is 26-demethylsaframycin Y3, and saframycin Y2b-d is a dimer of saframycin Yd-1.