stilbenes and 1-(4-methoxyphenyl)-2-(3-4-5-trimethoxyphenyl)ethene

A series of stilbenes has been prepared and tested for cytotoxicity in the five human cancer cell lines A-549 non-small cell lung, MCF-7 breast, HT-29 colon, SKMEL-5 melanoma, and MLM melanoma. The cis stilbenes 6a-f proved to be cytotoxic in all five cell lines, with potencies comparable to that of combretastatin A-4. These cytotoxic compounds were all potent inhibitors of tubulin polymerization. The corresponding trans stilbenes 7b-f were inactive as tubulin polymerization inhibitors and were significantly less cytotoxic in the five cancer cell lines. In the dihydro series, 8b, 8c, and 8f were inactive as tubulin polymerization inhibitors, while 8a, 8d, and 8e were less active than the corresponding cis compounds 6a, 6d, and 6e. The lack of tubulin polymerization inhibitory activity and cytotoxicity displayed by the phenanthrene 23b, which was synthesized as a conformationally rigid analogue of the lead compound 1, indicates that the activity of the stilbenes is not due to a totally planar conformation. Similarly, inactivity of the conformationally restricted analogue 26 suggests that the biologically active conformation of 1a resembles that of the cis alkene 1. Additional inactive compounds prepared include the benzylisoquinoline series 28-32 as well as the protoberberines 38 and 39. Shortening the two-carbon bridge of 1a to a one-carbon bridge in the diphenylmethane 20 resulted in a decrease in cytotoxicity and tubulin polymerization inhibitory activity. Although the corresponding benzophenone 18 was as active as 1a as a tubulin polymerization inhibitor, it was less cytotoxic than 1a, and the benzhydrol 19 was essentially inactive. With the exception of the amide 15c, which displayed low antitubulin activity, all of the phenylcinnamic acid derivatives 14a-c and 15a-f were inactive in the tubulin polymerization inhibition assay. The acid 14b and the ester 15a were cytotoxic in several of the cancer cell cultures in spite of their inactivity as tubulin polymerization inhibitors.

Topics: Antineoplastic Agents; Breast Neoplasms; Cell Division; Colonic Neoplasms; Humans; Lung Neoplasms; Melanoma; Stilbenes; Structure-Activity Relationship; Tubulin; Tubulin Modulators; Tumor Cells, Cultured

An array of cis-, trans-, and dihydrostilbenes and some N-arylbenzylamines were synthesized and evaluated for their cytotoxicity in the five cancer cell cultures A-549 lung carcinoma, MCF-7 breast carcinoma, HT-29 colon adenocarcinoma, SKMEL-5 melanoma, and MLM melanoma. Several cis-stilbenes, structurally similar to combretastatins, were highly cytotoxic in all five cell lines and these were also found to be active as inhibitors of tubulin polymerization. The most active compounds also inhibited the binding of colchicine to tubulin. The most potent of the new compounds, both as a tubulin polymerization inhibitor and as a cytotoxic agent, was (Z)-1-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)ethene (5a). This substance was almost as potent as combretastatin A-4 (1a), the most active of the combretastatins, as a tubulin polymerization inhibitor. Compound 5a was found to be approximately 140 times more cytotoxic against HT-29 colon adenocarcinoma cells and about 10 times more cytotoxic against MCF-7 breast carcinoma cells than combretastatin A-4. However, 5a was found to be about 20 times less cytotoxic against A-549 lung carcinoma cells, 30 times less cytotoxic against SKMEL-5 melanoma cells, and 7 times less cytotoxic against MLM melanoma cells than combretastatin A-4. The relative potencies 5a greater than 8a greater than 6a for the cis, dihydro, and trans compounds, respectively, as inhibitors of tubulin polymerization are in agreement with the relative potencies previously observed for combretastatin A-4 (1a), dihydrocombretastatin A-4 (1c), and trans-combretastatin A-4 (1b). The relative potencies 5a greater than 8a greater than 6a were also reflected in the results of the cytotoxicity assays. Structure-activity relationships of this group of compounds are also discussed.

Topics: Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Breast Neoplasms; Chemical Phenomena; Chemistry; Colchicine; Colonic Neoplasms; Humans; Lung Neoplasms; Melanoma; Molecular Structure; Polymers; Stilbenes; Structure-Activity Relationship; Tubulin; Tubulin Modulators; Tumor Cells, Cultured