5343-92-0Relevant articles and documents
Baeyer-villiger oxidation of acyl carrier protein-tethered thioester to acyl carrier protein-linked thiocarbonate catalyzed by a monooxygenase domain in FR901464 biosynthesis
Tang, Man-Cheng,He, Hai-Yan,Zhang, Feng,Tang, Gong-Li
, p. 444 - 447 (2013)
Baeyer-Villiger monooxygenases (BVMOs), generally catalyzing the transformation of carbonylic compounds into the corresponding esters or lactones known as Baeyer-Villiger oxidation in organic chemistry, are widely distributed among microorganisms and have stimulated great interest as biocatalysts for organic synthesis. The physiological roles of this type of MOs are usually classified as degradation of organic compounds involved in primary metabolism. Recently, increasing numbers of BVMOs have been found to be involved in the biosynthesis of secondary metabolites, especially for postmodification; however, to date, none of them has been reported functionally as a tailoring domain within polyketide synthase (PKS) acting on carrier protein-tethered substrates. FR901464, an antitumor natural product that targets spliceosome and inhibits both splicing and nuclear retention of pre-mRNA, was elucidated to be biosynthesized by a hybrid acyltransferase-less PKS/nonribosomal peptide synthetase (NRPS) system. Within the hybrid system, an unprecedented domain that was proposed to mediate the chain release process was located in the termination module. In this paper, we report the in vitro biochemical characterization of this domain to be a BVMO tailoring domain that catalyzes the BV oxidation of an acyl carrier protein (ACP)-tethered thioester to an ACP-linked thiocarbonate, which represents the first example of BVMOs operating in cis within the PKS and NRPS biosynthetic paradigm.
Hydrogenolysis of Furfuryl Alcohol to 1,2-Pentanediol Over Supported Ruthenium Catalysts
Yamaguchi, Aritomo,Murakami, Yuka,Imura, Tomohiro,Wakita, Kazuaki
, p. 731 - 736 (2021/06/12)
Hydrogenolysis of the furan rings of furfural and furfuryl alcohol, which can be obtained from biomass, has attracted attention as a method for obtaining valuable chemicals such as 1,2-pentanediol. In this study, we examined the hydrogenolysis of furfuryl alcohol to 1,2-pentanediol over Pd/C, Pt/C, Rh/C, and various supported Ru catalysts in several solvents. In particular, we investigated the effects of combinations of solvents and supports on the reaction outcome. Of all the tested combinations, Ru/MgO in water gave the best selectivity for 1,2-pentanediol: with this catalyst, 42 % selectivity for 1,2-pentanediol was achieved upon hydrogenolysis of furfuryl alcohol for 1 h at 463 K. In contrast, reaction in water in the presence of Ru/Al2O3 afforded cyclopentanone and cyclopentanol by means of hydrogenation and rearrangement reactions.
Highly selective 1-pentene epoxidation over Ti-MWW with modified microenvironment of Ti active sites
Jiang, Jingang,Tian, Wenwen,Wang, Bowen,Wu, Peng,Xu, Hao,Yin, Jianyong,Yin, Jinpeng
, p. 6050 - 6064 (2020/09/23)
A titanosilicate/H2O2catalytic system was applied to process the liquid-phase selective epoxidation of 1-pentene to 1,2-epoxypentane (EP). The effects of titanosilicate topology (MWW, MFI, MSE, MEL, MOR, and *BEA), solvent, H2O/H2O2ratio, catalyst amount, reaction temperature, pressure, and time on the EP production were investigated systematically. The Ti-MWW/H2O2/acetonitrile system exhibited the highest 1-pentene conversion of 72.9% together with high EP selectivity of 99.9% and H2O2utilization efficiency of 91.5%. Moreover, it was proved that the Ti active sites located inside the intralayer 10-membered ring sinusoidal channels catalyzed the epoxidation process primarily owing to their supplying more steric fitness for 1-pentene molecules. A piperidine (PI)-assisted structural rearrangement of Ti-MWW was performed to further enhance the catalytic activity, almost doubling the turnover number value. The evolution of the microenvironment of Ti active sites in this structural rearrangement process was carefully investigated, revealing the coordination of N atoms in PI molecules to the Ti atoms. More importantly, we identified that the hexa-coordinated Ti sites with the PI molecules as ligand could significantly accelerate H2O2activation, the effect of which far exceeded the inhibition effect caused by the electronegativity increase of Ti active sites.