ASSIGNMENT OF THE ABSOLUTE-CONFIGURATION OF NATURAL LENTIGINOSINE BY SYNTHESIS AND ENZYMATIC ASSAYS OF OPTICALLY PURE (+)-ENANTIOMERS AND (-)-ENANTIOMERS

被引:218
作者
BRANDI, A [1 ]
CICCHI, S [1 ]
CORDERO, FM [1 ]
FRIGNOLI, R [1 ]
GOTI, A [1 ]
PICASSO, S [1 ]
VOGEL, P [1 ]
机构
[1] UNIV LAUSANNE,INST CHIM ORGAN,BCH,CH-1015 LAUSANNE,SWITZERLAND
关键词
D O I
10.1021/jo00126a033
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
The structure and absolute configuration of natural lentiginosine isolated from plant sources was determined to be (1S,2S,8aS)-1,2-dihydroxyindolizidine ((+)-4) on the basis of the synthesis of both enantiomers (+)-4 and (-)-4 and their inhibition of amyloglucosidases. Alkaloid (+)-4 was derived from (L)-(+)-tartaric acid via a highly stereo- and regioselective 1,3-dipolar cycloaddition of (3S,4S)-3 ,4-bis[(tert-butyldiphenylsilyl)oxy]-1-pyrroline N-oxide to methylenecyclopropane, followed by thermal rearrangement of the adduct into (1S,2S,8aS)-1,2-[(tert-butyldiphenylsily)oxy]octahydroindolizin-7-one. The enantiomer (-)-4 was derived in the same way from (D)-(-)-tartaric acid. Both (+)-4 and (-)-4 displayed inhibition specificity for amyloglucosidases, being inactive toward 17 other glycosidases. With amyloglucosidase from Aspergillus niger, synthetic (+)-4 displayed inhibition (K-i = 2 mu M) 5 times stronger than that reported for natural lentiginosine, 35 times that measured for (-)-4, and twice that of castanospermine. Alkaloid (+)-4 is thus the most potent and specific competitive inhibitor of amyloglucosidases among azasugars and their analogues.
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页码:6806 / 6812
页数:7
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