Abstract
Structure-activity relationship among the diastereomers of an antifungal aminosugar antibiotic, prumycin [1] was studied. Among its seven possible diastereomers concerning the 2, 4-diamino sugar moiety, D-arabino-[2], D-ribo-[6], L-[7], and D-lyxo-prumycin [8] were newly prepared via the corresponding benzyl 4-azido-2-benzyloxycarbonylamino-2, 4-dideoxypentopyranosides followed by selective reduction of 4-azido group with Raney nickel, conde sation of N-benzyloxycarbonyl-D-alanine with dicyclohexylcarbodiimide and hydrogenolytic removal of the protecting groups. Antimicrobial activity of these diastereomers together with previously reported L-[3] and D-x yio-[4], and L-ribo-prumycin [5] was tested to prove that only [7] showed a moderate activity. Considering the ring structure and conformation determined by 1H and 13C-NMR data, the importance of spacial rearrangement of 4- (D-alanylamino)and 2-amino groups for development of activity was indicated.
