Novel 2-(2-alkylthiobenzenesulfonyl)-3-(phenylprop-2-ynylideneamino)guanidine derivatives as potent anticancer agents - Synthesis, molecular structure, QSAR studies and metabolic stability.

A series of new 2-(2-alkylthiobenzenesulfonyl)-3-(phenylprop-2-ynylideneamino)guanidine derivatives have been synthesized and evaluated in vitro by MTT assays for their antiproliferative activity against cell lines of colon cancer HCT-116, cervical cancer HeLa and breast cancer MCF-7. The obtained results indicated that these compounds display prominent cytotoxic effect. The best anticancer properties have been observed for derivatives 44 (IC50 = 6-18 μM) and 45 (IC50 = 8-14 μM). Very good results of antiproliferative assays have been also shown for compounds 26, 36, and 46 and noticeable anticancer profile has been found for set of derivatives 34-39. Based on results of MTT assays the structure-activity relationships have been drawn. More in-depth biological research revealed that compounds 26, 33, 37, 39, 41 and 43 display cytotoxic effect only against cancer cells and do not inhibit the growth of non-malignant HaCaT cells. Furthermore, the novel series of derivatives have shown good metabolic stability, especially among the pharmacologically active compounds. To obtain a deeper insight into the molecular description of compounds activity the QSAR studies have been applied. Support vector machines (SVM) have been used to developed QSAR models for predicting the anti-proliferative activity of novel derivatives. The obtained SVM models have shown prognostic ability for HCT-116 and HeLa cell lines and as a result these models may be useful for further development of structurally similar derivatives with better biological properties.