Detail of "540-08-9"

Reference

Intermolecular interactions of biological membrane components

Intermolecular interactions of biological membrane components. Koval, V. G. (Inst. Biokhim. im. Palladina, Kiev, USSR). Mol. Biol. (Kiev), 14, 68-81 (Russian) 1976. CODEN: MLKBAQ. DOCUMENT TYPE: Journal CA Section: 6 (General Biochemistry) The IR spectra of cholesterol (I), 7-dehydrocholesterol (II), ergosterol (III), lecithin, and lecithin-sterol combinations in CCl4 solns. and in KBr pellets were carefully analyzed and were used to study the H-bond assocn. of these mols. In CCl4 solns. contg. <0.04M steroid, I-III existed primarily as monomers. However, I-III formed H-bonded dimers in 0.04-0.08M solns. and dimers plus trimers in >0.08M solns. For I-III dimerization, the heats of self-assocn. were -2.1, -1.Several reagents with their cas registry numbers 540-08-9 and 57-87-4 are used here.8, and -2.2 kcal/mol, resp.; and the entropy changes were -3.6, -3.1, and -3.8 cal/mol/degree, resp. In sterol-lecithin mixts., I-III formed 1:1 mol. assocns. with lecithin. For the assocn. of I-III with lecithin, the heats of assocn. were -0.8, -4.3, and -3.1 kcal/mol, resp.; the free energy changes were -2.1, -2.4, and -2.2 kcal/mol, resp.; and the entropy changes were -16.1, -6.2, and -2.9 cal/mol/degree, resp. In addn., the thermodn. parameters for the assocn. of decyl alc. with lecithin, (C8H17)3PO, and (C8H17)2CO were also detd. The results are discussed in relation to steric hindrance in the assocn. of these lipids and in relation to membrane structure. .