16722-49-9Relevant academic research and scientific papers
Expanding the reaction space of aldolases using hydroxypyruvate as a nucleophilic substrate
De Berardinis, Véronique,Guérard-Hélaine, Christine,Darii, Ekaterina,Bastard, Karine,Hélaine, Virgil,Mariage, Aline,Petit, Jean-Louis,Poupard, Nicolas,Sánchez-Moreno, Israel,Stam, Mark,Gefflaut, Thierry,Salanoubat, Marcel,Lemaire, Marielle
supporting information, p. 519 - 526 (2017/08/14)
Aldolases are key biocatalysts for stereoselective C-C bond formation allowing access to polyoxygenated chiral units through direct, efficient, and sustainable synthetic processes. The aldol reaction involving unprotected hydroxypyruvate and an aldehyde offers access to valuable polyhydroxy-α-keto acids. However, this undescribed aldolisation is highly challenging, especially regarding stereoselectivity. This reaction was explored using, as biocatalysts, a collection of aldolases selected from biodiversity. Several enzymes that belong to the same pyruvate aldolase Pfam family (PF03328) were found to produce the desired hexulosonic acids from hydroxypyruvate and d-glyceraldehyde with complementary stereoselectivities. One of them was selected for the proof of concept as a biocatalytic tool to prepare five (3S,4S) aldol adducts through an eco-friendly process.
Oxidation of threose-series pentoses and hexoses by sodium N-chloro-p- toluenesulfonamide
Rangappa, Kanchugarakoppal S.,Manjunathaswamy, Huchappa,Raghavendra, Manikanahally P.,Gowda, D. Channe
, p. 253 - 262 (2007/10/03)
The kinetics and mechanism of oxidation of threose-series hexoses and pentoses by chloramine-T in alkaline medium was investigated. Kinetic studies with D-galactose, D-sorbose, D-xylose, and D-lyxose showed that the rate of the reaction was first order with respect to sugar and chloramine-T, and second order with respect to hydroxide ion. p-Toluenesulfonamide and chloride ions, the reduced products of chloramine-T, have no effect on the reaction rate. The rate increases with increase in ionic strength of the medium, and the dielectric effect is negative. Proton inventory studies in H2O-D2O mixtures suggested a single transition state. Product analysis for D-gulose, Didose, L-sorbose, D-galactose, D-talose, D-tagatose, D-xylose, and D-lyxose revealed that all lyxoseseries hexoses gave mainly mixtures of lyxonic and threonic acids with minor proportions of hexonic, xylonic and glyceric acids, whereas all xylose-series hexoses gave mixtures of lyxonic, threonic and glyceric acids with minor amounts of xylonic and hexonic acids. Xylose and lyxose gave mixtures consisting mainly of lyxonic, threonic, and glyceric acids with minor proportions of xylonic acid. From the results of kinetic studies, reaction stoichiometry, and product analysis, a possible mechanism for the oxidation of threose-series sugars with chloramine-T is suggested.
