Dess–Martin periodinane oxidative rearrangement for preparation of α-keto thioesters
作者:Randy Sanichar、Ciaran Carroll、Ryan Kimmis、Bela Reiz、John C. Vederas
DOI:10.1039/c7ob02959d
日期:——
Dess–Martin Periodinane (DMP) mediated oxidative rearrangement reaction was uncovered. The reaction proceeds via oxidation of a β-hydroxy thioester to a β-keto thioester, followed by an α-hydroxylation and then further oxidation to form a vicinal thioester tricarbonyl. This product then rearranges, extruding CO2, to form an α-keto product. The mechanism of the rearrangement was elucidated using 13C labelling
identify a set of µM inhibitors, with the most potent representative (1) demonstrating activity against six FabG-orthologues. A co-crystal structure with FabG from A. baumannii (PDB:6T65) confirms inhibitorbinding at an allostericsite located in the subunit interface, as previously demonstrated for other sub-µM inhibitors of FabG from P. aeruginosa. We show that inhibitorbinding distorts the oligomerization
Insights into the programmed ketoreduction of partially reducing polyketide synthases: stereo- and substrate-specificity of the ketoreductase domain
作者:Ishin Soehano、Lifeng Yang、Feiqing Ding、Huihua Sun、Zhen Jie Low、Xuewei Liu、Zhao-Xun Liang
DOI:10.1039/c4ob01777c
日期:——
hallmarks of iterative polyketidesynthases (PKSs) is the programming mechanism which is essential for the generation of structurally diverse polyketide products. In partially reducing iterative PKSs (PR-PKSs), the programming mechanism is mainly dictated by the ketoreductase (KR) domain. The KR domain contributes to the programming of PR-PKSs through selective reduction of polyketide intermediates. How
The acylalkylpyrone synthase CsyB from Aspergillus oryzae catalyzes the one-pot formation of the 3-acyl-4-hydroxy-6-alkyl-alpha-pyrone scaffold from acetoacetyl-CoA, fatty acyl-CoA, and malonyl-CoA. This is the first type III polyketidesynthase that performs not only the polyketide chain elongation but also the condensation of two beta-ketoacyl units. The crystal structures of wild-type CsyB and its
results provide overview of the biosynthesis pathway. Furthermore, in vitro characterization of the terminal polyketide synthase module with the thioesterase domain using β-ketoacyl substrates was performed. That revealed a pathway where the α-pyridone ringformation is dependent on hydrolysis of the product β, δ-diketo carboxylic acid by the C-terminal thioesterase followed by amidation and cyclization