Synthesis and antitumor activities of phosmidosine A and its N-acetylated derivative

A new antitumor active phosmidosine A, which was isolated from Streptomyces sp., was successfully synthesized by a series of reactions involving construction of the N-acyl phosphoramidate linkage which was achieved by the reaction of the 5′-O-phosphoramidite derivative with a prolinamide derivative in the presence of 5-(3,5-dinitrophenyl)-1H-tetrazole. The growth inhibitory effect of phosmidosine A and its N-acetyl analog on the various human cell lines was examined. These results showed that both compounds have a significant growth inhibitory activity and that the 6-amino group is not required for the growth inhibitory activity of phosmidosine A.