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Enzymatic Cascade Reactions for the Synthesis of Chiral Amino Alcohols from L-lysine
Published on: February 16, 2018
Stereochemical course in water addition during LUP1-catalyzed triterpene cyclization
Tetsuo Kushiro1, Masaki Hoshino, Takehiko Tsutsumi
1Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan.
Abstract:
Arabidopsis thaliana LUP1 (At1g78970) catalyzes the cyclization of oxidosqualene into lupeol and 3beta,20-dihydroxylupane (lupanediol). The stereochemical course of water addition to the lupanyl cation was studied. The X-ray crystal structure of lupanylepoxide 3,5-dinitrobenzoate established the configuration of epoxide as 20S. LiAlD4 reduction of the epoxide enabled the chemical shift assignment of prochiral methyl groups at C20 of lupanediol. Correlation of these methyl groups with biosynthetic lupanediol from [1,2-(13)C(2)] acetate established the stereochemical course of water addition. [reaction: see text].
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