Recently much attention has been focused in the research of curcumin, a secondary metabolite isolated from Curcuma longa L. and from other species of Curcuma. Current investigation of curcumin is fastly increasing due to its biological activities (anti-inflammatory, [1] antioxidant, anti-HIV, [2] including cytotoxic effects on several cancer line cells [3, 4] and upon cystic fibrosis [5]).
A benzothiazol derivative of curcumin was obtained by systematic structural modification of curcumin (Scheme). We have described previously the synthesis of new heterocyclic derivatives of curcumin including the compound 4 [6].
The benzothiazol 4 was prepared by the reaction of 3 and 2-aminobenzenethiol. During the ring formation a part of the molecule of curcumin suffered fragmentation. The structure of 4 was assessed by spectroscopic methods (IR, 1D and 2D NMR, mass spectrometry), also the crystal structure was analyzed by X-ray crystallography.
In our preliminary biological studies, compound 4 has shown important cytotoxic effect toward a nasopharyngeal carcinoma cell line KB (ED50 =3.38µg/mL) as well as modification of the percentage of cells on cell cycle phases of the monocytic human cell line TPH1.
Acknowledgements: CONACYT of México (37821-N and 40959-Q); DGAPA of UNAM (IN232202).
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