26790-87-4Relevant academic research and scientific papers
A single residue change leads to a hydroxylated product from the class II diterpene cyclization catalyzed by abietadiene synthase
Criswell, Jared,Potter, Kevin,Shephard, Freya,Beale, Michael H.,Peters, Reuben J.
, p. 5828 - 5831 (2013/02/23)
Class II diterpene cyclases catalyze bicyclization of geranylgeranyl diphosphate. While this reaction typically is terminated via methyl deprotonation to yield copalyl diphosphate, in rare cases hydroxylated bicycles are produced instead. Abietadiene synthase is a bifunctional diterpene cyclase that usually produces a copalyl diphosphate intermediate. Here it is shown that substitution of aspartate for a conserved histidine in the class II active site of abietadiene synthase leads to selective production of 8α-hydroxy-CPP instead, demonstrating striking plasticity.
Bifunctional cis-abienol synthase from Abies balsamea discovered by transcriptome sequencing and its implications for diterpenoid fragrance production
Zerbe, Philipp,Chiang, Angela,Yuen, Macaire,Hamberger, Bjoern,Hamberger, Britta,Draper, Jason A.,Britton, Robert,Bohlmann, Joerg
experimental part, p. 12121 - 12131 (2012/07/14)
The labdanoid diterpene alcohol cis-abienol is a major component of the aromatic oleoresin of balsam fir (Abies balsamea) and serves as a valuable bioproduct material for the fragrance industry. Using high-throughput 454 transcriptome sequencing and metabolite profiling of balsam fir bark tissue, we identified candidate diterpene synthase sequences for full-length cDNA cloning and functional characterization. We discovered a bifunctional class I/II cis-abienol synthase (AbCAS), along with the paralogous levopimaradiene/ abietadiene synthase and isopimaradiene synthase, all of which are members of the gymnosperm- specific TPS-d subfamily. The AbCAS-catalyzed formation of cis-abienol proceeds via cyclization and hydroxylation at carbon C-8 of a postulated carbocation intermediate in the class II active site, followed by cleavage of the diphosphate group and termination of the reaction sequence without further cyclization in the class I active site. This reaction mechanism is distinct from that of synthases of the isopimaradiene- or levopimaradiene/ abietadiene synthase type, which employ deprotonation reactions in the class II active site and secondary cyclizations in the class I active site, leading to tricyclic diterpenes. Comparative homology modeling suggested the active site residues Asp-348, Leu-617, Phe-696, and Gly-723 as potentially important for the specificity of AbCAS. As a class I/II bifunctional enzyme, AbCAS is a promising target for metabolic engineering of cis-abienol production.
Oxidative degradation of the sclareol side chain: hemisyntheses of ambergris derivatives using in the key steps palladium complexes or ruthenium tetroxide generated in situ
Zahra, Jean-Pierre,Chauvet, Frederic,Coste-Maniere, Ivan,Martres, Paul,Perfetti, Patricia,Waegell, Bernard
, p. 1001 - 1024 (2007/10/03)
We report the hemisyntheses of various ambergris-type derivatives: ambraoxide 4, Ambrox 8, 13-methylambraoxide 13, ambraketal 14, norambraketal 15, non-norambraketal 16 and dioxepane 53.Sclareol 12 is used as starting material because it is currently available from Salvia sclarea.The key steps involve an oxidative degradation of the sclareol 12 side chain, using either palladium complexes or ruthenium tetroxide generated in situ. - Keywords: sclareol; Ambrox; ambraoxide; 13-methylambraoxide; ambraketal; norambraketal; nor-norambraketal; farnesylic aldehyde; palladium complex; ruthenium tetroxide generated in situ; oxidative degradation
