The Synthesis of trans‐Flavan‐3‐ol Gallates by Regioselective Oxidative Etherification and Their Cytotoxicity Mediated by 67 LR |
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| Authors: | Nana Shiraishi Dr Motofumi Kumazoe Dr Shinichiro Fuse Prof?Dr Hirofumi Tachibana Dr Hiroshi Tanaka |
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| Institution: | 1. Department of Chemical Science and Engineering, Tokyo Institute of Technology, Tokyo, Japan;2. Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan;3. Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan |
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| Abstract: | We report on a chiral pool approach for the synthesis of trans‐flavan‐3‐ol gallates from epichlorohydrin. The trans‐flavan‐3‐ol gallates were prepared by the cycloetherification of the phenol at the C2 benzylic position of 2‐acylozyl‐1,3‐diarylpropane during regioselective C?H oxidation. The 1,3‐diarylpropanes were prepared starting from epichlorohydrin by epoxide opening with A and B ring precursors, followed by acylation of the resultant alcohol with galloyl chloride. The availability of both the enantiomers of epichlorohydrin allowed the preparation of the corresponding enantiomer using the same procedure. The cytotoxicity of the compounds against U266 cells was tested, in which 5‐deoxy‐7,3′‐O‐dimethyl gallocatechin gallate exhibited cytotoxicity that was more than ten times stronger than natural (?)‐EGCG. In addition, the absolute configuration of the derivatives did not critically affect the biological activity. |
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| Keywords: | 67 LR biological activity chirality natural products oxidative etherification |
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