X-ray analysis of sulfur-containing colchicine derivatives.

The crystal and molecular structures of deacetylthiocolchicine hydrochloride dihydrate and thiocolchicine hexahydrate were determined by X-ray diffraction. The replacement of oxygen by sulfur on the C ring methoxy group causes greater puckering of the troponoid ring. The conformation of one A ring methoxy group differs from that of colchicine derivatives that do not contain sulfur.