Showing papers on "Brucine published in 1979"
TL;DR: Cutaneous hyper‐irritability was produced in the trigeminal sensory distribution of chronically prepared rats by injecting various central stimulants into the dorsal subarachnoid space overlying caudal medulla by picrotoxin and penicillin G‐K and d,l‐homocysteic acid.
Abstract: Cutaneous hyper-irritability was produced in the trigeminal sensory distribution of chronically prepared rats by injecting various central stimulants into the dorsal subarachnoid space overlying caudal medulla. Effective substances were classified into three groups according to the behavioral patterns induced. These were (1) picrotoxin and penicillin G-K, (2) strychnine and brucine, and (3) d,l -homocysteic acid. Of these substances, picrotoxin was the most effective. The hyper-irritability elicited by picrotoxin or penicillin G-K was associated with a relatively localized trigger zone in the face, while that elicited by strychnine or brucine spread beyond the trigeminal region to the first cervical dermatome. d,l -homocysteic acid evoked only spontaneous scratching and vocalization. Picrotoxin-induced hyper-irritability involved facilitation of impulse transmission from cutaneous afferent terminals to second-order neurons in the trigeminal nucleus caudalis.
23 citations
TL;DR: The tertiary bases from a sample of Strychnos nux-vomica contain, as well as the expected strychnine and brucine, an unusually high proportion of 4-hydroxy compounds as mentioned in this paper.
20 citations
TL;DR: In this article, the stereoisomers of monocrotalic acid have been synthesized and their stereochemistry was assigned respectively as S- and R-configuration by correlation to the known (R)-(−)-2-phenylpropanoic acid.
Abstract: All stereoisomers (3a, b–6a, b) of monocrotalic acid have been synthesized. Methylation of (±)-cis-2,3,4-trimethyl-2-pentenedioic acid with diazomethane followed by cis-hydroxylation with potassium permanganate afforded two epimeric γ-lactone esters in a ratio of ca. 1:5. These esters were then hydrolyzed with dilute hydrochloric acid to the corresponding acids, (±)-3 and racemic monocrotalic acid (4). Optical resolution of (±)-3 with brucine afforded 3a (2R,3R,4S) and 3b (2S,3S,4R). The racemic monocrotalic acid was also resolved by means of brucine to give natural monocrotalic acid (4a: 2R,3R,4R) and its enantiomer (4b: 2S,3S,4S). Subsequently, (±)-trans-2,3,4-trimethyl-2-pentenedioic acid was resolved with cinchonidine to give 8a and 8b, whose stereochemistry was assigned respectively as S- and R-configuration by correlation to the known (R)-(−)-2-phenylpropanoic acid. Methylation of 8a followed by cis-hydroxylation and hydrolyses afforded γ-lactone acids, 5a (2R,3S,4S) and 6b (2S,3R,4S). Similarly, th...
11 citations
TL;DR: The natural abundance 13C-NMR spectra of brucine and strychnine were obtained using the pulse Fourier transform technique and thechemical shifts of various carbon resonances were assigned on the basis of substituent effects on benzene shifts, intesities of signals, multiplicites generated in single-frequency off-resonance-decoupled spectra, and comparisons with the chemical shifts of structurally related compounds.
9 citations
TL;DR: In this article, the mechanism of kinetic resolution of an oxaziridine by brucine is re-examined and it is shown that oxazidines do not transfer oxygen to the tertiary amine, Brucine.
3 citations