Showing papers on "Brucine published in 1993"

Solid molar volumes of interest to supercritical extraction at 298 K: atropine, berberine hydrochloride hydrate, brucine dihydrate, capsaicin, ergotamine tartrate dihydrate, naphthalene, penicillin V, piperine, quinine, strychnine, theobromine, theophylline, and yohimbine hydrochloride

Abstract: Solid molar volumes of interest to supercritical extraction were measured for a number of alkaloids, spices and other substances at 298 K with a gas buoyancy technique. The values obtained were 240.2 cm 3 /mol, atropine; 288.1 cm 3 /mol, berberine hydrochloride hydrate; 320.2 cm 3 /mol, brucine dihydrate; 289.8 cm 3 /mol, capsaicin; 893.0 cm 3 /mol, ergotamine tartrate dihydrate; 109.9 cm 3 /mol, naphthalene; 243.2 cm 3 /mol, penicillin V; 226.4 cm 3 /mol, piperine; 253.0 cm 3 /mol, quinine; 242.0 cm 3 /mol, strychnine; 120.5 cm 3 /mol, theobromine; 123.7 cm 3 /mol, theophylline; and 296.8 cm 3 /mol, yohimbine hydrochloride

X-Ray Structural Investigation of the Chiral Recognition of Brucine in Salt Formation with an N-Protected Amino Acid, N-Phthaloyl-threo-β-hydroxy-D- and L-leucine

Abstract: In order to determine how brucine recognizes the chirality of an N-protected amino acid in complex formation, three kinds of brucine complex crystals of N-phthaloyl-threo-β-hydroxyleucines, i.e., two (yellow and transparent) crystals for the L-isomer and one (transparent) crystal for the D-isomer, were prepared, and their structures were determined by X-ray crystallography. In addition to the interaction mode specific for each complex crystal, the carboxyl and β-hydroxyl groups of the amino acids were commonly linked with the methoxyindole and piperidine ring moieties of brucine through hydrogen bonds and electrostatic and van der Waals interactions. In addition to the direct interactions between the molecules, the molecular arrangement of brucine in the crystal structure played an important role in the D/L-recognition of the amino acids. The molecular packing of the brucine molecules translated by a crystallographic 2-fold screw symmetry operation provided a shape for the cavity that was most suitable fo...

Metabolism of Strychnine N-Oxide and Brucine N-Oxide by Human Intestinal Bacteria

Abstract: Anaerobic incubation of strychnine N-oxide with human intestinal bacteria resulted in its transformation to strychnine and 16-hydroxystrychnine. Similarly, brucine N-oxide was transformed to brucine and 16-hydroxybrucine.

[Studies on the chemical constituents of alkaloids in seeds of Strychnos nux-vomica L.]

Abstract: Thirteen alkaloids were isolated from the seeds of Strychnos nux-vomica. They were identified as strychnine, beta-colubrine, pseudostrychnine, strychnine N-oxide, brucime, brucine N-oxide, novacine, icajine, vomicine, isostrychnine, isobrucine, isobrucine N-oxide and isostrychnine N-oxide by chemical and spectroscopic analysis.

Effect of processing on the extraction of alkaloids from Strychnos

Abstract: Results of experiments showed that the contents of strychnine and brucine were about the same in decoction of Strychnos nux-vomica and S. pierriana, but the contents of vomicine, strychnine N-oxide and brucine N-oxide were greater in the former than in the latter. The contents of strychnine and brucine were greater under scalding with hot sand than deep-frying with sesame oil.

The optical resolution of bicyclo[2.2.1]Hept-5-Ene-2-cyanohydrins using brucine : a crystallographic and molecular-mechanics study

Abstract: The structures of the brucine complexes with (+)-(1R,2S,4R)-bicyclo[2.2.1]hept-5-ene-2-cyanohydrin and (+)-(1R,2R,4R)-7-oxabicyclo[2.2.1]hept-5-ene-2-cyanohydrin {(6) 2,3-dimethoxystrychnidine-2-hydroxybicyc-lo[2.2.1]hept-5-ene-2-carbonitr ile (1/1) and (7) 2,3-dime-thoxystrychnidine-2-hydroxy-7-oxabicyclo[2.2. I]hept-5-ene-2-carbonitrile (1/1)} have been determined. The primary interaction in the complexes is a hydrogen bond between the OH group of the cyanohydrin and the most basic N atom of brucine. Molecular-mechanics calculations on the 7-oxa derivative indicate that the enantiomeric cyanohydrin will fit into the same cavity in the brucine matrix at the cost of ca 71 kJ mol-1

X‐Ray Structural Investigation of the Chiral Recognition of Brucine in Salt Formation with an N‐Protected Amino Acid, N‐Phthaloyl‐threo‐β ‐hydroxy‐D‐ and L‐leucine.

Abstract: In order to determine how brucine recognizes the chirality of an N-protected amino acid in complex formation, three kinds of brucine complex crystals of N-phthaloyl-threo-β-hydroxyleucines, i.e., two (yellow and transparent) crystals for the L-isomer and one (transparent) crystal for the D-isomer, were prepared, and their structures were determined by X-ray crystallography. In addition to the interaction mode specific for each complex crystal, the carboxyl and β-hydroxyl groups of the amino acids were commonly linked with the methoxyindole and piperidine ring moieties of brucine through hydrogen bonds and electrostatic and van der Waals interactions. In addition to the direct interactions between the molecules, the molecular arrangement of brucine in the crystal structure played an important role in the D/L-recognition of the amino acids. The molecular packing of the brucine molecules translated by a crystallographic 2-fold screw symmetry operation provided a shape for the cavity that was most suitable fo...