RESUMO
The amount of water bound to disodium cromoglycate (DSCG) in frozen aqueous solutions was determined from the amplitude of the n.m.r. free induction decay. The hydration number was found to be 15 molecules H2O/molecule DSCG of which 6 H2O molecules were less strongly bound than the rest. Proton T1 and T2 relaxation times in non-frozen solutions implied a values of 10(-8) s for the correlation time of the bound water at 291 K. This is consistent with the mobility of DSCG molecules in a smectic mesophase.
Assuntos
Cromolina Sódica , Água/análise , Fenômenos Químicos , Química , Congelamento , Espectroscopia de Ressonância Magnética , Soluções/análiseRESUMO
A colloidal dispersion of chloranil in water or an aqueous solution of an amino acid shows an ESR signal characteristic of the semiquinone radical anion. The signal is broadened in the presence of bovine plasma albumin, and the available evidence supports the idea that the freedom of the free radical is restricted by a weak association with a specific site in the protein.
Assuntos
Cloranila , Quinonas , Soroalbumina Bovina , Aminoácidos , Animais , Bovinos , Fenômenos Químicos , Química , Cloranila/análogos & derivados , Coloides , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres , Soluções , ÁguaRESUMO
Charge carrier generation and transport in the mitochondrial lipoprotein system has been investigated by electrical conductivity, low frequency dielectric relaxation, and thermoelectric power. A parallel study was conducted on morphological/structural changes by DTA and NMR. The results obtained confirm the need to consider concurrently free charge carrier processes and polarization phenomena. All techniques show a "transition" at the same temperature. The steady state conductivity is correlated with main chain segmental reorientations of the phospholipid moiety below the transition and with an interfacial polarization process above it. The Seebeck coefficient provides a useful new aid to characterizing the charge carriers, confirming that they are electronic. The terminal cytochrome oxidase component was investigated separately but it largely reflected ionic impurities characteristic of the isolation process, so that the results were of no intrinsic value.
