Natural Products Syntheses Based on the Biotransformation Using Biocatalyst

Abstract

This review summarizes the chemoenzymatic synthesis of the biologically active natural products based on a combination of chemical diastereoselectivity and enzymatic enantioselectivity using biocatalyst. Asymmetric reduction of 2-methyl-3-keto ester with yeast gave the optically active syn-2-methyl-3-hydroxy ester, which was converted to natural product such as (-)-oudemansin B. Asymmetric hydrolysis of 3-acetoxy-2-methy esters possessing syn-or anti-structure aŠorded the optically active 3-hydroxy-2-methyl esters and 3-acetoxy-2-methy esters corresponding to the starting material. One of these optically active 3-hydroxy-2-methyl esters was converted to aglycone of macrolide, venturicidins A and B possessing 10 chiral centers. Both primary alcohols possessing a chiral center at b-position of hydroxyl group and secondary alcohols were subjected to the lipase-assisted acylation in the presence of acyl donor to aŠord the optically active esters and the optically active alcohols corresponding to the starting material. These optically active compounds were converted to the biologically active natural products such as bisabolane type sesquiterpenes, decaline type diterpenes or triterpenes, nikkomycin B, (＋)-asperlin, (-)-chuangxinmycin, (-)-indolmycin, cystothiazoles melithiazols, myxothiazols and piericidins possessing antifungal and cytotoxicic activities, inhibition of NADH oxidation, etc. Reaction of primary alcohol and glucose using immobilized b-glucosidase gave alkyl b-glucosides in high yield. Pentaacetate of allyl b-glucoside was subjected to Mizoroki-Heck type reaction with phenylboronic acid derivatives to give phenylpropenoid b-D-glucopyranosid congeners.

Biotransformation of 4-Chromanol, 4-Flavanol, Xanthydrol, and their Analogs by Tissue Cultured Cells

“…Many types of biocatalysts have been examined, such as fungi, microorganisms, and insects [1][2][3][4][5][6][7][8][9][10][11]. Furthermore, the Hamada group at the Okayama University of Science has investigated organic synthesis methods using tissue culture cells of higher plants as biocatalysts for reactions such as the glycosylation of terpenes [12][13][14][15][16].…”