Vibrational spectra and normal coordinate analysis of lithium pyruvate monohydrate and its isotopic compounds

IR and Raman spectra of lithium pyruvate monohydrate and its O- and C-deuterated and 13C- and 18O-substituted compounds have been recorded in the solid state, and the observed bands have been assigned by using the isotope effects and the normal coordinate calculations based on the gem-diol structure (lithium 2,2-dihydroxypropionate). The refined force constants have well reproduced the observed frequencies and the 13C- and 18O-shifts. These results support the structures of these compounds discussed by many authors. The potential energy distributions show that many vibrational modes are very complicated except for the well-known group vibrations. The additive property of the isotopic frequency shifts has also been discussed

Effect of cyclodextrins on the thermal epimerization of tea catechins

金沢大学理工研究域物質化学系The epimerization reaction of tea catechins was investigated at pH 5.5 and 120°C in the absence/presence of cyclodextrins (CDs). In the absence of CDs, a considerable quantity (∼20%) of products originating from reactions other than the epimerization ("other products") was formed during the epimerization of gallated catechins. In the case of (-)-EGCg, addition of β-CD to the reaction solution reduced the quantity of these other products to just a few percent, but other CDs with different cavity sizes had little effect. Generally, the addition of β-CD increased the ratio of non-epi type catechins, that is, [non-epi type catechin] / ([epi type catechin]+[non-epi type catechin]). Molecular orbital (MO) calculations using the PM3 method suggested that non-epi type catechins are more thermodynamically stable than their epi-type counterparts, moving the equilibrium position in favor of non-epi type catechins in the epimerization process

(R)-1-phenylethylammonium N-tetradecanoyl-L-phenylalaninate monohydrate

金沢大学理工研究域物質化学系The title compound, C8H12N+·C 23H36,NO3-·H2O, has one molecule of N-tetradecanoyl-L-phenylalanine and one molecule of (R)-l-phenylethylamine as a diastereoisomeric salt, and a water molecule in the asymmetric unit. In the crystal structure, the packing of the molecules is stabilized by N - H⋯O and O-H⋯O hydrogen bonds involving the amide, ammonium and carboxylate groups, and the solvent water molecule. © 2006 International Union of Crystallography Printed in Great Britain - all rights reserved

Crystal structure of phenolphthalein

金沢大学大学院自然科学研究科先端機能物質金沢大学工学

Crystal structure of (1R,2R)-trans-1,2-cyclohexanedicarhoxylic acid-(R)- 1-phenylethylamine salt

金沢大学大学院自然科学研究科先端機能物質金沢大学工学