Synthesis of Sulfur Containing Colchicine Derivatives and their Biological Evaluation as Cytotoxic Agents

Semi-synthetic C-10 alkyl thio analogues of the cytotoxic natural alkaloid colchicine have been found to exhibit cytotoxicity towards tumour cell lines at levels comparable to that of the natural product. An efficient synthesis of 10-alkyl thiocolchicines in mild conditions is proposed and the products are studied by H-1 and C-13 NMR, FT-IR, MS-EI methods and elementary analysis. The crystal structure of 10-ethylthiocolchicine is characterised using X-ray diffraction methods. Cytotoxic activity against selected cancer cell lines for all obtained 10-alkylthio analogues of colchicine is also reported.