The anesthetic potency of n-alcohols. A model spectroscopic study in inverted micelles

Abstract

. 64, 633 (1986). A relation has been found between the anesthetic potency of n-alcohols (rz = 1,3,6,7,9, 11, 14, and 16) and their association constants with polar groups in inverted micelles. From this point of view, cholesterol and 7-dehydrocholesterol behave like short-chain n-alcohols while cholestanol behaves like a long-chain n-alcohol. PIERRE M~NASSA, T H~R~S E LUSSIER et CAMILLE SANDORFY. Can. J. Chem. 64, 633 (1986). On a pu dkmontrer qu'il existe une relation entre le pouvoir anesthksique des n-alcools et leur constante d'association avec des groupements polaires dans des micelles Inverses, qui a Ct C determinCe pour rz = 1 , 3, 6,7,9, 11, 14 et 16. De ce point de vue, le cholestCrol et le dehydro-7 cholestCrol se comportent comme des 11-alcools a chaine courte alors que le cholestanol s'apparente aux 11-alcools 2 chaine longue.Alcohols are known to have anesthetic potency (1). Pringle et al. (2) have shown that this potency increases with the length of the hydrocarbon chain in n-alcohols. There is, however, a "cutoff" at CI3. While the latter still possesses a weak anesthetic potency, C14 has no anesthetic potency at all (3).In an attempt to find a correlation between this behavior and the physico-chemical properties of alcohols, Wilson et al. (4) compared the hydrogen bond (H-bond) forming tendencies in the series of alcohols from C, to CI8 by infrared spectroscopic means. They found that in neutral solvents, the free/H-bonded ratio for self-association is independent of the chain length. The same applies to ester carbonylln-alcohol association. Subsequently, MCnassa and Sandorfy (5) undertook similar studies in a membrane mimetic environment. Their system consisted of sodium di(2-ethylhexyl) sulfosuccinate (AOT) with traces of water in carbon tetrachloride to which an alcohol was added. The detergent AOT containing traces of water forms inverted micelles in carbon tetrachloride (6). The infrared spectra were recorded on a Nicolet model 5DXB Fourier-transform ir spectrometer with a resolution of 2cm-I. The method for computing association constants hos been given previously (5, 7). The association constants of n-alcohols with AOT exhibit a pronounced dependence on chain length. The alcohol/AOT association constant decreases with increasing chain length as shown in Fig. 1. The spectra give evidence that association occurs between the alcohols and the SO3-group of AOT. The carbonyl bands were not observably affected with the dilute solutions that were used in those studies. However, with higher water content and alcohol concentrations, alcohol/carbonyl (AOT) association could also be detected.More importantly, the H-bond association constants stopped decreasing at C l o (5) and remained constant at about 5 L mol-l.Thus there appears to be a parallelism between the effect of the chain length on the H-bond equilibria of alcohols in these systems and their anesthetic potency. While AOT can only be a remote model for actual cell membranes, an analogy exists: the alcohol (anesthetic) must cross a hydropho...

Binding of Nitrodiphenylamines to Reverse Micelles of AOT inn-Hexane and Carbon Tetrachloride: Solvent and Substituent Effects

“…It is known that AOT forms reversed micelles in refer to the maximum absorption wavelength of the free and bound compound, respectively. these solvents (46,47). The water content that these micelles accept is near 11.…”

Solubilization in AOT−Water Reverse Micelles. Effect of the External Solvent

“…The incorporation of solutes to reverse micellar aggregates is a matter of current interest . The partition of different solutes between the micellar aggregates and the external solvent has been determined for a variety of solutes employing different experimental techniques. − Most of these studies have been performed in sodium 1,4-bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micellar systems, although some data have been also obtained employing other surfactants. In principle, it can be expected that the distribution of a solute, measured at a given temperature and pressure, will be determined by the type of surfactant employed, the [internal solvent]/[surfactant] mole ratio ( W ), the properties of the internal polar solvent, and the characteristics of the external solvent.…”

“…In most of the previously reported studies, the partitioning of a variety of solutes as a function of W has been determined in AOT−water−hydrocarbon systems. There are considerably fewer studies in which different surfactants 1,13-15,21 and/or different internal polar solvents were considered. ,− , With regard to the effect of the external solvent upon the distribution of solutes, the studies are even more scarce, ,− and to the best of our knowledge, there are not systematic studies comprising solvents of different characteristics. In the present work, we attempt to fill this gap by measuring the partitioning of a solute (1-pyrenemethanol) between AOT−water reverse micelles and the external solvent employing solvents of different characteristics.…”

The modeling of chemical phenomena using topological indices

“…Although the carbon number index has been in existence [111, anesthetic potency [12], and carcinogenic behavior [13] among others. A plot of nC against boiling point for normal alkane species is shown in Figure 3.…”