Chemo-enzymatic approach towards the capsaicin glucoside

ORGN 161

Israt Sultana, israt31@yahoo.com, Miwa Shimamoto, Rika Obata, Shigeru Nishiyama, and Takeshi Sugai, sugai@chem.keio.ac.jp. Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Yokohama, 223-8522, Japan
Capsaicins have biological activities such as adrenal catecholamine secretion, which enhances energy metabolism, and are expected for “diet effect”. Their strongly pungent taste, which has very well been known as a spice for a long time, is an obstacle for intake in a large quantity. To overcome this problem, dihydronorcapsaicin beta-D-glucopyranoside has been developed as non-pungent, water-soluble derivative, which eventually becomes biologically active after degradation in our body. A seven-step and scalable synthesis of dihydronorcapsaicin beta-D-glucopyranoside, was accomplished from vanillin, a commercially available starting material. The key-steps were 1) a simple chemical glycosylation of phenol bearing electron-withdrawing group under basic conditions; 2) the lipase-catalyzed amide bond formation between primary amine and fatty acid methyl ester without any activation of functional group, often being encountered in peptide synthesis. Our synthetic approaches directed toward the synthesis of beta-D-glucopyranoside will be presented.