ON THE STEREOSELECTIVE SYNTHESIS OF (+)-PINORESINOL IN FORSYTHIA-SUSPENSA FROM ITS ACHIRAL PRECURSOR, CONIFERYL ALCOHOL
ON THE STEREOSELECTIVE SYNTHESIS OF (+)-PINORESINOL IN FORSYTHIA-SUSPENSA FROM ITS ACHIRAL PRECURSOR, CONIFERYL ALCOHOL
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DOI：
10.1016/s0031-9422(00)97544-7
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发表时间：
1992-11-01
期刊：
影响因子：
3.8
通讯作者：
LEWIS, NG
中科院分区：
文献类型：
--
作者：
DAVIN, LB;BEDGAR, DL;LEWIS, NG
从连翘茎的残留物，在去除可溶性酶，提供了第一个立体选择性偶联酶木脂素生物合成的证据。在不存在外源提供的辅因子的情况下，该制备催化由[8-C-14]松柏醇优选形成（约65%）（+）-[8，8 '-C-14]松柏醇;加入H2 O2对对映体组成几乎没有影响。然而，当提供NAD和苹果酸时，偶联反应的立体选择性显著增强，并且获得由约80%的（+）-对映体组成的松醇。显然，不溶性残留物含有催化松柏醇形成（+）-松柏醇的特异性偶联酶。相比之下，当[8-C-14]芥子醇作为底物时，仅形成外消旋的沉香树脂醇：这种非立体选择性的过氧化物酶催化的偶联反应大概是当松柏醇用作底物时在该系统中遇到的低水平的（-）-蒎烷醇的原因。
The residue from Forsythia suspensa stems, upon removal of soluble enzymes, has provided the first evidence for a stereoselective coupling enzyme in lignan biosynthesis. This preparation catalyses the preferred formation (ca 65%) of (+)-[8,8'-C-14]pinoresinol from [8-C-14]coniferyl alcohol in the absence of exogenously provided cofactors; addition of H2O2 had little effect on enantiomeric composition. However, when NAD and malate were supplied, the stereoselectivity of the coupling reaction was significantly enhanced and pinoresinol consisting of ca 80% of the (+)-antipode was obtained. Clearly, the insoluble residue contains a specific coupling enzyme which catalyses (+)-pinoresinol formation from coniferyl alcohol. By contrast, when [8-C-14]sinapyl alcohol was employed as substrate, only racemic syringaresinols were formed: this non-stereoselective peroxidase-catalysed coupling reaction presumably accounts for the low levels of (-)-pinoresinol encountered in this system when coniferyl alcohol is used as a substrate.