A series of new amino phoephonic acid derivatives of vinblastine (1, VLB) has been synthesized and teated in vitro and in vivo for antitumor activity. The compounds were obtained from 0'-deacetyl-VLB azide (5). All of the new products studied were capable of inhibiting tubulin polymerization in vitro. The most potent antitumor compounds bore an alkyl substituent on the phosphonate. In these compounds, the antitumor activity strongly ...
