Detail of "3149-68-6"

Reference

Solvent isotope effects on a-glucosidase

Some chemicals with cas registry numbers like 3149-68-6 and 2492-87-7 are also used. Solvent isotope effects on a-glucosidase. O'Donnell, Anne H.; Yao, Xiaojie; Byers, Larry D. (Department of Chemistry, Tulane University, New Orleans, LA 70118, USA). Biochimica et Biophysica Acta, Proteins and Proteomics, 1703(1), 63-67 (English) 2004 Elsevier B.V. CODEN: BBAPBW. ISSN: 1570-9639. DOCUMENT TYPE: Journal CA Section: 7 (Enzymes) The solvent kinetic isotope effects (SKIE) on the yeast a-glucosidase-catalyzed hydrolysis of p-nitrophenyl and methyl-D-glucopyranoside were measured at 25°C. With p-nitrophenyl-D-glucopyranoside (pNPG), the dependence of k cat/K m on pH (pD) revealed an unusually large (for glycohydrolases) solvent isotope effect on the pL-independent second-order rate const., DOD(kcat/Km), of 1.9 (±0.3). The two pK as characterizing the pH profile were increased in D2O. The shift in pKa2 of 0.6 units is typical of acids of comparable acidity (pKa = 6.5), but the increase in pKa1 (= 5.7) of 0.1 unit in going from H2O to D2O is unusually small. The initial velocities show substrate inhibition (Kis/Km ~ 200) with a small solvent isotope effect on the inhibition const. [DOD Kis = 1.1 (±0.2)]. The solvent equil. isotope effects on the Kis for the competitive inhibitors D-glucose and a-Me D-glucoside are somewhat higher [DOD Ki = 1.5 (±0.1)]. Me glucoside is much less reactive than pNPG, with kcat 230 times lower and kcat/Km 5 ′ 104 times lower. The solvent isotope effect on kcat for this substrate [=1.11 (±0. 02)] is lower than that for pNPG [=1.67 (±0.07)], consistent with more extensive proton transfer in the transition state for the deglucosylation step than for the glucosylation step. .

The effect of physicochemical properties on the in vitro diffusion of drug through synthetic membranes and pigskin

The effect of physicochemical properties on the in vitro diffusion of drug through synthetic membranes and pigskin. II. Salicylic acid. Walkow, Janet C.; McGinity, James W. (Coll. Pharm., Univ. Texas, Austin, TX 78712, USA). Int. J.Some commonly used reagents like 3149-68-6 and 27613-77-0 are used in this experiment. Pharm., 35(1-2), 103-9 (English) 1987. CODEN: IJPHDE. ISSN: 0378-5173. DOCUMENT TYPE: Journal CA Section: 63 (Pharmaceuticals) Section cross-reference(s): 1 The effect of membrane type and receptor phase compn. on the in vitro diffusion of salicylic acid [69-72-7] was studied. Salicylic acid solns. (5% wt./wt.) contg. either lanolin or Me glucoside [52673-60-6] derivs. were diffused across cellulose [9004-34-6], di-Me polysiloxane and pigskin into a receptor phase of aq. glycol, water or a buffered soln. The permeabilities and diffusion profiles were unique for each membrane type that was examd. and the salicylic acid solns. demonstrated the same rank order of membrane penetration (with one exception): pigskin > cellulose > di-Me polysiloxane. Diffusion of salicylic acid into buffer solns. (pH 2.2-7.4) yielded patterns that were prediced by the pH partition hypothesis. The salicylic acid diffusion was decreased as the receptor phase pH was lowered. .