Synthesis of (S)- and (R)-3-Hydroxy-4-butanolide and (2S,4S)-, (2R,4S)-, (2S,4R)-, and (2R,4R)-2-Hydroxy-4-hydroxymethyl-4-butanolide and Their Satiety and Hunger Modulating Activities
Synthesis of (S)- and (R)-3-Hydroxy-4-butanolide and (2S,4S)-, (2R,4S)-, (2S,4R)-, and (2R,4R)-2-Hydroxy-4-hydroxymethyl-4-butanolide and Their Satiety and Hunger Modulating Activities
Selective hydrogenolysis of biomass-derived xylitol to ethylene glycol and propylene glycol on Ni/C and basic oxide-promoted Ni/C catalysts
作者:Jiying Sun、Haichao Liu
DOI:10.1016/j.cattod.2013.12.040
日期:2014.10
formation of the two glycols with negligible lactic acid. For instance, on Ni-CaO/C (at a CaO/Ni molar ratio of 0.66), the combined selectivity to ethylene glycol and propyleneglycol, together with glycerol, reached 69.5% at nearly 100% xylitol conversion at 473 K, 4.0 MPa H2. These features of the basic oxide-promoted Ni catalysts show their promising advantages over the noble Rucatalysts, upon optimization
Paul; Tchelitcheff, Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences, 1954, vol. 239, p. 1504
作者:Paul、Tchelitcheff
DOI:——
日期:——
Synthesis of (<i>S</i>)- and (<i>R</i>)-3-Hydroxy-4-butanolide and (2<i>S</i>,4<i>S</i>)-, (2<i>R</i>,4<i>S</i>)-, (2<i>S</i>,4<i>R</i>)-, and (2<i>R</i>,4<i>R</i>)-2-Hydroxy-4-hydroxymethyl-4-butanolide and Their Satiety and Hunger Modulating Activities
Two endogenous γ-lactones, 3-hydroxy-4-butanolide (1) and 2-hydroxy-4-hydroxymethyl-4-butanolide (2) have been identified as substances that enhance, respectively, satiety and hunger by their effects on the feeding behavior and the central neurons of rats. To determine the stereochemistry of the physiologically active isomers, all the stereoisomers of these two lactones were synthesized and their effects on the feeding behavior and humoral factors were assessed by infusion into the rat third cerebroventricle. Among four isomers, (2S,4S)-2-hydroxy-4-hydroxymethyl-4-butanolide (2a) was most effective in elicitating the feeding and caused potent hypoglycemia with hyperinsulinemia. (S)-3-Hydroxy-4-butanolide (1a) suppressed the food intake more potently than the antipode and caused humoral responses reciprocal to those of 2a. From these facts, it was concluded that 1a and 2a are physiologically active forms for conveying intrinsic signals of satiety and hunger to neurons in the hypothalamus.