QSAR of antineoplastics IV: Hansch analysis of N-(7-indolyl)benzenesulfonamides against KB human nasopharynx carcinoma, colon 38 murine adenocarcinoma and P388 murine leukemia cell lines.

Abstract

Hansch analysis of recently reported antitumor activities of novel N-(7-indolyl)benzenesulfonamide derivatives against KB human nasopharynx carcinoma, colon 38 murine adenocarcinoma and P388 murine leukemia cell lines reveals that the pattern of receptor interactions in human KB cells differs from that in murine (colon 38 and P388 leukemia) cells. The latter two activities are autocorrelated and show similar receptor specificity. It seems that two binding sites, one interacting with the indole fragment and another with phenyl fragment of the indolylbenzenesulfonamide compounds, are present on the murine cell receptors (colon 38 and P388 leukemia) while only the latter binding site is active on the human KB cell receptors. For the activity against KB cells, a para-methyl or paramethoxy substituent on the phenyl ring of benzenesulfonamide moiety greatly enhances the activity. For the other two activities, a 3-chloro or 3-cyano substituent on indole nucleus enhances activities, while presence of bulkier meta or para substituent on the phenyl ring decreases activities. Presence of an ortho substituent on the phenyl ring appears to be detrimental for all the three activities. Equations generated by both QSAR and QAAR studies are quite robust as evidenced from cross-validation by 'leave-one-out' technique.