Natural products syntheses based on the biotransformation using biocatalyst.
(2011)
Journal - Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan (Japan )
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 afforded 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 ß-position of hydroxyl group and secondary alcohols were subjected to the lipase-assisted acylation in the presence of acyl donor to afford 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 ß-glucosidase gave alkyl ß-glucosides in high yield. Pentaacetate of allyl ß-glucoside was subjected to Mizoroki-Heck type reaction with phenylboronic acid derivatives to give phenylpropenoid ß-D-glucopyranosid congeners.
Total synthesis of (+)-macrosphelides A, C, E, F, and G based on enzymatic function.
(2003)
Journal - Chirality (United States )
Abstract :
The total synthesis of (+)-macrosphelide A (1) (18.5% overall yield in 11 steps), (+)-macrosphelide C (2) (25% overall yield in 9 steps), (+)-macrosphelide E (3) (23.9% overall yield in 11 steps), (+)-macrosphelide F (4) (20% overall yield in 9 steps), and (+)-macrosphelide G (5) (22% overall yield in 9 steps) was achieved from a chemoenzymatic reaction product (4R,5S)-4-benzyloxy-5-hydroxy-2(E)-hexenoate 10.Copyright 2003 Wiley-Liss, Inc.
| ISSN : | 0899-0042 |
|---|
| Mesh Heading : | Anti-Bacterial Agents Heterocyclic Compounds Lactones Molecular Structure Stereoisomerism chemical synthesis chemistry |
|---|
| Mesh Heading Relevant : | chemical synthesis chemistry chemical synthesis chemistry |
|---|
Enzymatic synthesis of (-)- and (+)-acetoxyhexamides and (-)- and (+)-hydroxyhexamides.
(1999)
Journal - Chemical & pharmaceutical bulletin (JAPAN )
Abstract :
The enantioselective hydrolysis of (+/-)-4-(1-acetoxyethyl)-N-(cyclohexylcarbamoyl)-benzenesulfona mides 3 with lipase Amano P from Pseudomonas sp. in a water-saturated solvent gave (R)-4-(1-hydroxyethyl)-N-(cyclohexylcarbamoyl)benzenesulfonamide 2 (39%, > 99% ee) and unchanged (S)-3 (50%, 62% ee). On the other hand, enantioselective esterification of (+/-)-2 with lipase Amano P in the presence of vinyl acetate provided (R)-3 (41%, > 99% ee) and unchanged (S)-2 (46%, 78% ee).
| ISSN : | 0009-2363 |
|---|
| Mesh Heading : | Acetohexamide Acetylation Benzamides Hydrolysis Lipase Pseudomonas Solvents Stereoisomerism Vinyl Compounds chemical synthesis chemistry chemistry |
|---|
| Mesh Heading Relevant : | analogs & derivatives chemical synthesis chemistry enzymology |
|---|
Simple approach to optically active drimane sesquiterpenes based on enzymatic resolution.
(1997)
Journal - Chemical & pharmaceutical bulletin (JAPAN )
Abstract :
When the beta-acyloxy esters (+/-)-10 and (+/-)-11 were exposed to the lipase OF-360 from Candida rugosa or immobilized lipase OF-360 in a water-saturated organic solvent, the hydrolyzed product (8aS)-6 was obtained in high chemical (40%) and optical (> 99% ee) yields. The absolute structure of (8aS)-6 was confirmed by the fact that (8aS)-6 was converted into an authentic sample gamma-keto nitrile (8aS)-17. Treatment of the diol (+/-)-12 with isopropenyl acetate in the presence of the lipase Godo E-4 from Pseudomonas sp. provided the unchanged (8aR)-12 (89% ee) in 42% yield.
| ISSN : | 0009-2363 |
|---|
| Mesh Heading : | Acetylation Candida Enzymes, Immobilized Hydrolysis Lipase Sesquiterpenes Stereoisomerism enzymology chemistry isolation & purification |
|---|
| Mesh Heading Relevant : | chemical synthesis |
|---|