The N-glycosyl bonds of deoxyuridine, thymidine, and 5-bromodeoxyuridine undergo slow hydrolysis in aqueous solution, pH 3-7. The reaction rates are independent of the pH in this range, and of the nature and concentration of the buffer. The reactions have positive entropies of activation. A linear correlation exists between the logarithms of the rate constants for the three nucleosides and the ionization constants for the 1-protons of the corresponding bases. It is pro-
Abstract. Stereochemical considerations and total valence electron calculations suggest congruities among the ostensibly dissimilar hallucinogenic compounds, D-lysergic acid diethylamide (LSD), indolealkylamines, and methoxylated amphetamines. In LSD the aromatic benzene ring A and the N-6 nitrogen are essential for hallucinogenic activity; these sites may react with the receptor. The conformations of amphetamines and indolealkylamines at the receptor are such that the aromatic benzene ring lies like ring A of LSD and the alkylamino nitrogen lies like the N-6 of LSD. Ring A may interact with the receptor by forming a ir-molecular complex, as suggested by the correlation between hallucinogenic activity and energy of the highest occupied molecular orbital (EH) of congeneric series. The N-6 nitrogen of LSD and the sterically congruent nitrogen of the other hallucinogenic compounds may react with the receptor by forming a donor acceptor complex of the n-7r* or n-&* type. Other portions of the hallucinogenic molecules confer a favorable EH: these include the methoxy and hydroxyl groups of the amphetamines (and mescaline), and the indolealkylamines; and the pyrrole ring of LSD and the indolealkylamines.D-Lysergic acid diethylamide (LSD), certain N,N-dimethyltryptamines (e.g., psilocin), and mescaline (and methoxylated amphetamines) have the same kind of central nervous system activity. They produce hallucinations in appropriate doses and show cross-tolerance, suggesting a common mechanism for their actions.1 2 These compounds, despite their structural dissimilarities, may have common electronic and stereochemical characteristics that permit them to act oil the same biological receptor.Stereochemical correlations among these compounds have been proposed.3'4 Their electronic structures have been calculated by the simple Huckel molecular orbital methods6 that considers only the ir-electrons, a special shortcoming when applied to LSD, which has two rings lacking ir-electrons. The results suggested that hallucinogenic activity was associated with a high energy of the highest molecular orbital. Recently, total valence electron calculations on twelve hallucinogenic methoxy amphetamines, which are qualitatively indistinct from mescaline,8 showed that their potency in man correlates with the energy of the highest occupied molecular orbital.9Comparable calculations on LSD and some hallucinogenic indolealkylamines 62
The rates of hydroboration of a number of representative olefins and substituted styrenes with monochloroborane in tetrahydrofuran at a variety of temperatures have been measured. The rate and product distribution data for the addition to substituted styrenes correlate best with
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.