Mutated variants of squalene-hopene cyclase: enzymatic syntheses of triterpenes bearing oxygen-bridged monocycles and a new 6,6,6,6,6-fusded pentacyclic scaffold, named neogammacerane, from 2,3-oxidosqualene
作者:Yoriyuki Fukuda、Takashi Watanabe、Tsutomu Hoshino
DOI:10.1039/c8ob02009d
日期:——
reaction have been extensively reported, but investigations of the cyclization reactions of (3R,S)-oxidosqualene by SHC have rarely been reported. The cyclization reactions of oxidosqualene with W169X, G600F/F601G and F601G/P602F were examined. The variants of the W169L generated new triterpene skeletons possessing a 7-oxabicyclo[2.2.1]heptane moiety (oxygen-bridged monocycle) with (1S,2S,4R)- and (1R,2S
角鲨烯-戊环化酶(SHC)催化无环角鲨烯分子转化为6,6,6,6,5-稠合的五环戊烯和hop醇。SHC还能够将(3 S)-2,3-氧化角鲨烯转化为3β-羟基戊烯和3β-羟基紫杉醇,并可以从(3 R)-2,3-氧化角鲨烯生成3α-羟基戊烯和3α-羟基紫杉醇。关于角鲨烯环化反应的活性位点残基的功能分析已被广泛报道,但对(3 R,S很少报道过SHC产生的)-氧化角鲨烯。检查了氧化鲨烯与W169X,G600F / F601G和F601G / P602F的环化反应。W169L的变体生成了具有7-氧杂双环[2.2.1]庚烷部分(氧桥联的单环)的新三萜骨架,其中(1 S,2 S,4 R)-和(1 R,2 S,4 S) -立体化学,由(3 R)-和(3 S)-氧化角鲨烯。F601G / P602F双突变体还提供了一种新的三萜,名为neogammacer-21(22)-en-3β-ol,它由一个6,6,6,6