13088-48-7Relevant articles and documents
Biocatalytic Oxidative Cascade for the Conversion of Fatty Acids into α-Ketoacids via Internal H2O2 Recycling
Gandomkar, Somayyeh,Dennig, Alexander,Dordic, Andela,Hammerer, Lucas,Pickl, Mathias,Haas, Thomas,Hall, Mélanie,Faber, Kurt
, p. 427 - 430 (2018)
The functionalization of bio-based chemicals is essential to allow valorization of natural carbon sources. An atom-efficient biocatalytic oxidative cascade was developed for the conversion of saturated fatty acids to α-ketoacids. Employment of P450 monooxygenase in the peroxygenase mode for regioselective α-hydroxylation of fatty acids combined with enantioselective oxidation by α-hydroxyacid oxidase(s) resulted in internal recycling of the oxidant H2O2, thus minimizing degradation of ketoacid product and maximizing biocatalyst lifetime. The O2-dependent cascade relies on catalytic amounts of H2O2 and releases water as sole by-product. Octanoic acid was converted under mild conditions in aqueous buffer to 2-oxooctanoic acid in a simultaneous one-pot two-step cascade in up to >99 % conversion without accumulation of hydroxyacid intermediate. Scale-up allowed isolation of final product in 91 % yield and the cascade was applied to fatty acids of various chain lengths (C6:0 to C10:0).
Glucosinolate biosynthesis: Demonstration and characterization of the condensing enzyme of the chain elongation cycle in Eruca sativa
Falk, Kimberly L.,Vogel, Christine,Textor, Susanne,Bartram, Stefan,Hick, Alastair,Pickett, John A.,Gershenzon, Jonathan
, p. 1073 - 1084 (2004)
Glucosinolates are a group of sulfur-rich thioglucoside natural products common in the Brassicaceae and related plant families. The first phase in the formation of many glucosinolates involves the chain extension of the amino acid methionine. Additional methylene groups are inserted into the side chain of methionine by a three-step elongation cycle involving 2-oxo acid intermediates. This investigation demonstrated the first step of this chain elongation cycle in a partially-purified preparation from arugula (Eruca sativa). The 2-oxo acid derived from methionine, 4-methylthio-2-oxobutanoic acid, was shown to condense with acetyl-CoA to form 2-(2′-methylthioethyl)malate. The catalyst, designated as a 2-(ω-methylthioalkyl)malate synthase, belongs to a family of enzymes that mediate the condensation of acyl-CoAs with 2-oxo acids, including citrate synthase of the citric acid cycle, and 2-isopropylmalate synthase of leucine biosynthesis. The 2-(ω-methylthioalkyl)malate synthase studied here shares properties with other enzymes of this class, but appears chromatographically distinct and is found only in extracts of plant species producing glucosinolates from chain-elongated methionine derivatives. Although the principal glucosinolates of arugula are formed from methionine that has undergone two rounds of chain elongation to form dihomomethionine, studies with substrates and substrate analogs of different chain lengths showed that the isolated enzyme is responsible only for the condensation step of the first round of elongation.
Amino acid stannous and application thereof in polyurethane foam
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Paragraph 0018-0019; 0024-0026, (2021/11/27)
The invention relates to the field of chemical engineering, and relates to an organic tin catalyst, in particular to amino acid stannous and an application thereof in preparation of polyurethane foam. According to the method, firstly, pyruvic acid and aldehyde serve as raw materials, amino acid is synthesized through three steps, and then the amino acid reacts with stannous oxide to prepare the amino acid stannous. Compared with traditional stannous carboxylate, only carboxyl in the traditional stannous carboxylate is coordinated with a tin center, while amido and carboxyl in the amino acid stannous provided by the invention are coordinated with the tin center at the same time, so that the complex is more stable and higher in catalytic activity. In addition, the method for synthesizing the amino acid is not reported in public literatures, and the method is cheap in reagent, simpler in formula, more convenient to operate, green, safe, efficient, environmentally friendly and suitable for industrial production.
Investigation on the regioselectivities of intramolecular oxidation of unactivated C-H bonds by dioxiranes generated in Situ
Wong, Man-Kin,Chung, Nga-Wai,He, Lan,Wang, Xue-Chao,Yan, Zheng,Tang, Yeung-Chiu,Yang, Dan
, p. 6321 - 6328 (2007/10/03)
We found that dioxiranes generated in situ from ketones 1-6 and Oxone underwent intramolecular oxidation of unactivated C-H bonds at δ sites of ketones to yield tetrahydropyrans. From the trans/cis ratio of oxidation products 1a and 2a as well as the retention of the configuration at the δ site of ketone 5, we proposed that the oxidation reaction proceeds through a concerted pathway under a spiro transition state. The intramolecular oxidation of ketone 6 showed the preference for a tertiary δ C-H bond over a secondary one. This intramolecular oxidation method can be extended to the oxidation of the tertiary γ′ C-H bond of ketones 9 and 10. For ketone 11 with two δ C-H bonds and one γ′ C-H bond linked respectively by a sp3 hydrocarbon tether and a sp2 ester tether, the oxidation took place exclusively at the δ C-H bonds. Finally, by introducing proper tethers, regioselective hydroxylation of steroid ketones 12-14 have been achieved at the C-17, C-16, C-3, and C-5 positions.
