62182-21-2Relevant academic research and scientific papers
Enantioselective Synthesis of Dilignol Model Compounds and Their Stereodiscrimination Study with a Dye-Decolorizing Peroxidase
Huang, Gaochao,Shrestha, Ruben,Jia, Kaimin,Geisbrecht, Brian V.,Li, Ping
, p. 1820 - 1823 (2017/04/11)
A four-step enantioselective approach was developed to synthesize anti (1R,2S)-1a and (1S,2R)-1b containing a β-O-4 linkage in good yields. A significant difference was observed for the apparent binding affinities of four stereospecific lignin model compounds with TcDyP by surface plasmon resonance, which was not translated into a significant difference in enzyme activities. The discrepancy may be attributed to the conformational change involving a loop widely present in DyPs upon H2O2 binding.
Convenient synthesis of chiral lignin model compounds via optical resolution: Four stereoisomers of guaiacylglycerol-β-guaiacyl ether and both enantiomers of 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy) -propan-1-one (erone)
Hishiyama, Shojiro,Otsuka, Yuichiro,Nakamura, Masaya,Ohara, Seiji,Kajita, Shinya,Masai, Eiji,Katayama, Yoshihiro
, p. 842 - 845 (2012/03/11)
Guaiacylglycerol-β-guaiacyl ether (GGE) is one of the most important phenolic compound for studying the chemistry and biochemistry of lignin. GGE contains two asymmetric carbons at the alpha and beta positions of its side chain; therefore, theoretically it can exist as four different stereoisomers. It has been proposed that a Gram-negative bacterium, Sphingobium sp. SYK-6 (formerly referred as Sphingomonas paucimobilis SYK-6), degrades GGE enantiospecifically via cleavage of the ether bond. The cleavage was thought to proceed in two steps, each catalyzed by a different enantiospecific enzyme. In the first step, the alcohol residue at the alpha position of the side chain in GGE was thought to be oxidized enantiospecifically by four distinct Cα-dehydrogenases (LigD, LigN, LigL and LigO), to produce two enantiomers of 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)-propan-1-one (erone). To study this enantiospecific degradation step by the four dehydrogenases, we synthesized all four stereoisomers of GGE and both enantiomers of erone and separated them into enantiopure samples. The stereoisomers and our synthetic methods to prepare them are useful both for microbial and chemical investigations of lignin degradation.
Oxidation of Lignin Model Compounds Using Single-Electron-Transfer Catalysts
DiCosimo, Robert,Szabo, Hsiao-Chiung
, p. 1673 - 1679 (2007/10/02)
The single-electron-transfer oxidation of model compounds representative of the arylglycerol β-aryl ether and 1,2-diarylpropane linkages of lignin has been examined by using Co(II), Mn(II), or Co(II)/Mn(II) as catalysts.Catalytic oxidation of 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol (DMMP) in 80percent acetic acid with 500 psi of 4percent oxygen in nitrogen and at 170 deg C resulted predominantly in products of Cα-Cβ bond cleavage when using Co(II)/Mn(II) as catalyst.Cα-Cβ bond cleavage of DMMP results from an initial single-electron oxidation toproduce an intermediate aromatic radical cation; in the absence of oxygen and catalyst, acid-catalyzed β-aryl ether cleavage was the predominant reaction pathway.Dihydroanisoin (DHA) and 1,2-bis(4-methoxyphenyl)propane-1,3-diol (BMPD) were oxidized by stoichiometric quantities of Co(III) to give solely products of Cα-Cβ bond cleavage but produced only acid-catalyzed dehydration products under reaction conditions necessary for catalytic oxidation.The application of this oxidation reaction as a replacement for chlorine bleaching of paper pulp is discussed.
