22149-65-1Relevant articles and documents
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
Fukuda, Yoriyuki,Watanabe, Takashi,Hoshino, Tsutomu
supporting information, p. 6987 - 7000 (2018/10/02)
Squalene-hopene cyclase (SHC) catalyzes the conversion of acyclic squalene molecule into a 6,6,6,6,5-fused pentacyclic hopene and hopanol. SHC is also able to convert (3S)-2,3-oxidosqualene into 3β-hydroxyhopene and 3β-hydroxyhopanol and can generate 3α-hydroxyhopene and 3α-hydroxyhopanol from (3R)-2,3-oxidosqualene. Functional analyses of active site residues toward the squalene cyclization 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,4S)-stereochemistry, which were produced from (3R)- and (3S)-oxidosqualenes, respectively. The F601G/P602F double mutant also furnished a novel triterpene, named neogammacer-21(22)-en-3β-ol, consisting of a 6,6,6,6,6-fused pentacyclic system, in which Me-29 at C-22 of the gammacerane skeleton migrated to C-21. We propose to name this novel scaffold neogammacerane. The formation mechanisms of the enzymatic products from 2,3-oxidosqualene are discussed.
Functional analysis of the DXDDTA motif in squalene-hopene cyclase by site-directed mutagenesis experiments: Initiation site of the polycyclization reaction and stabilization site of the carbocation intermediate of the initially cyclized A-ring
Sato, Tsutomu,Hoshino, Tsutomu
, p. 2189 - 2198 (2007/10/03)
In order to clarify the function of the DXDDTA motif in squalene-hopene cyclase and to identify the acidic amino acid residues crucial for the catalysis, site-directed mutagenesis experiments were carried out. The following results were found: (1) residue
Synthesis and enzymatic cyclization of (3S)11-fluoro-2,3-oxidosqualene
Robustell, Brian,Ikuro, Abe,Prestwich, Glenn D.
, p. 957 - 960 (2007/10/03)
A convergent asymmetric synthesis provided (3S)11-fluoro-2,3- oxidosqualene (11-FOS, 14), which was cyclized by bacterial squalene:hopane cyclase to a bridged ether. 11-FOS was neither a substrate nor an inhibitor for vertebrate oxidosqualene:lanosterol c