Showing papers on "Brucine published in 2006"

Glycine antagonists structurally related to 4,5,6,7-tetrahydroisoxazolo [5,4-c]pyridin-3-ol inhibit binding of [3H]strychnine to rat brain membranes.

Abstract: [3H]Strychnine binding to rat pons + medulla membranes was used as a measure of glycine receptors or glycine receptor-coupled chloride channels in vitro. A series of compounds structurally related to 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP), which previously were shown to antagonize glycine responses in cat spinal cord, inhibited [3H]strychnine binding in micromolar concentrations. The most potent of these glycine antagonists, 5,6,7,8-tetrahydro-4H-isoxazolo[3,4-d]azepin-3-ol (iso-THAZ), was also the most potent inhibitor of [3H]strychnine binding, with a Ki of 1,400 nM. The Ki value for strychnine was 7.0 nM, whereas the Ki value for the mixed gamma-aminobutyric acid (GABA)/glycine antagonist 3 alpha-hydroxy-16-imino-5 beta-17-aza-androstan-11-one (RU 5135) was only 4.6 nM. Sodium chloride (1,000 mM) enhanced the affinity of strychnine, brucine, isostrychnine, and the nonselective GABA antagonist pitrazepin for [3H]strychnine binding sites, whereas the affinities of glycine, beta-alanine, and taurine were reduced. These sodium chloride shifts, however, were not predictive of antagonist or agonist properties, since the sodium chloride shift for the glycine antagonist iso-THAZ and of the other THIP-related antagonists were similar to those of the glycine-like agonists. The various sodium chloride shifts show that different groups of ligands bind to glycine receptor sites in different ways.

Molecular Recognition in Proton-Transfer Compounds of Brucine with Achiral Substituted Salicylic Acid Analogues

Abstract: The 1:1 proton-transfer brucinium compounds from the reaction of the alkaloid brucine with 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, and 5-sulfosalicylic acid, namely anhydrous brucinium 5-nitrosalicylate (1), brucinium 3,5-dinitrosalicylate monohydrate (2), and brucinium 5-sulfosalicylate trihydrate (3) have been prepared and their crystal structures determined by X-ray crystallography. All structures further demonstrate the selectivity of brucine for meta-substituted benzoic acids and comprise three-dimensional hydrogen-bonded framework polymers. Two of the compounds (1 and 3) have the previously described undulating brucine sheet host-substructures which incorporate interstitially hydrogen-bonded salicylate anion guest species and additionally in 3 the water molecules of solvation. The structure of 2 differs in having a three-centre brucinium–salicylate anion bidentate N+–H···O(carboxyl) hydrogen-bonding association linking the species through interstitial associations involving also the water molecules of solvation. A review of the crystallographic structural literature on strychnine and brucine is also given.

Rapid separation of strychnine and brucine on a dynamically modified poly(dimethylsiloxane) microchip followed by electrochemical detection

Abstract: A method has been developed for rapidly separating and detecting strychnine and brucine using a poly(dimethysiloxane) (PDMS) microchip and electrochemical (EC) detection. PDMS microchannels dynamically modified by Brij35 are shown to be more efficient than native ones. The two analytes are well separated within 90 s in 70 mmol/L acetate buffer (pH 5.5) containing 0.01% (v/v) Brij35. Detection limits were found to be 1.0 μmol/L for strychnine and 0.2 μmol/L for brucine at S/N=3. The method was used to determine trace strychnine and brucine in rat serum, and the results obtained correlate well with those obtained via high-performance liquid chromatography (HPLC).

Two pseudopolymorphic hydrates of brucine: brucine-water (1/4) and brucine-water (1/5.25) at 130 K.

Abstract: The structures of two pseudopolymorphic hydrates of brucine, C23H26N2O4·4H2O, (I), and C23H26N2O4·5.25H2O, (II), have been determined at 130 K. In both (I) and (II) (which has two independent brucine molecules together with 10.5 water molecules of solvation in the asymmetric unit), the brucine molecules form head-to-tail sheet substructures, which associate with the water molecules in the interstitial cavities through hydrogen-bonding associations and, together with water-water associations, give three-dimensional framework structures.

Determination of Strychnine and Brucine in Strychnos nux-vomica L. by Nonaqueous Capillary Electrophoresis

Abstract: A nonaqueous capillary electrophoresis method with photo diode-array detection was developed for the analysis of strychnine and brucine in Strychnos nux-vomica L. The separation of the two alkaloids was optimized with respect to the concentration of Tris-boric acid, the proportion of methanol and acetonitrile, and applied voltage. Baseline separation was obtained for the two analytes within 10 min using a running buffer containing 25 mM Tris-boric acid, 60% methanol and 20% acetonitrile with acetic acid adjusting pH to 4.0. In this paper, the method was used to determine the contents of strychnine and brucine in raw material and prepared Strychnos nux-vomica L.

Tissue distribution of brucine in mice

Abstract: AIM: To study the tissue distribution of brucine in mice.METHODS: After ig and iv administraction of brucine at doses of 60 and(10 mg·kg~(-1)) in mice,the plasma and tissue concentrations at different time points were determined by fluorescence spectrophotometry.RESULTS: After ig and iv administraction,The main tissue distribution of brucine in mice was similar,the brucine concentrations in the liver and kidney were the highest and those in the spleen,heart,lung,brain,stomach,fat and muscle decreased sequentially.CONCLUSION: There is an extensive distribution of brucine in mice and it has ability to permeate blood brain barrier.

2,3-Dimethoxy-10-oxostrychnidinium 3-carboxybenzoate trihydrate: the 1:1 proton-transfer compound of brucine with isophthalic acid

Abstract: The structure of the title compound C23H27N2O4+ . C8 H5O4 . 3H2O, has been determined at 130 K. The hydrogenisophthalate anions and the water molecules (one of which is disordered over two approximately equal sites) associate through extensive hydrogen-bonding interactions, including those with the common undulating brucinium cation layer substructures, forming a three-dimensional framework structure.

Preparation and Quality Evaluation of Brucine Long-Circulating Liposomes

Abstract: OBJECTIVE To determine optimized prescription and technique for preparing brucine long-circulating liposomes(BLCL) by means of optimization screening,and to evaluate its quality.METHODS BLCL were prepared by the technique of ammonium sulphate gradients with ethanol injection.The poly(ethylene glycol)(PEG) was added to modify the membrane of the liposomes.The shape of BLCL is surveyed under the microscope.The size of BLCL was investigated by laser particle analyzer.The pH,the entrapment efficiency and the result of stability experiment were examined.The in vitro release of brucine from long-circulating liposomes in PBS(pH 7.4) was determined by HPLC.RESULTS BLCL were round,regular in morphology with mean particle size of 120 nm,and its average pH of 6.655.The entrapment efficiency of BLCL was up to 93.72%.The stability was good in 4 ℃ and BLCL had better sustained-released effect than brucine phosphoric acid buffer solution. CONCLUSION This preparation of BLCL is practicable and the pharmaceutical characterization showed stable.

Strychnine-8-ammonio-2-naphthalenesulfonate-water (1/1/3.5): The first structure of a strychnine or brucine compound with a zwitterionic species

Abstract: The crystal structure of the 1:1 adduct hydrate of strychnine with 1,7-Cleve's acid (8-amino-2-naphthalenesulfonic acid), namely strychnine-8-ammonio-2-naphthalenesulfonate-water (1/1/3.5) has been determined and provides a unique example of a neutral association involving strychnine and an achiral zwitterionic acid species, previously unobserved in the structures of either strychnine or brucine addition compounds. Crystals are orthorhombic, space group P212121, with Z=4 in a cell with dimensions a=10.4484(8), b=30.850(3), c=9.4998(11) A. Hydrogen bonding involving all available proton-donor and acceptor sites on all species gives rise to a three-dimensional framework polymer structure. The crystallographic literature for strychnine and brucine and their compounds is also reviewed.

Analgesic and anti-inflammatory activities of brucine nano-liposome for local use on skin

Abstract: AIM: To compare brucine with the mixed solution of brucine and nano-liposomes to observe analgesic and anti-inflammatory effects of the brucine nano-liposome for local use on skin were studied METHODS: The effects of brucine,brucine and nano-liposomes mixed solution,brucine nano-liposome,on the edema of mouse ear induced by dimethylbenzene and the writhing induced by acetic acid were investigated RESULTS: The results showed that brucine nano-liposomes exhibited better anti-inflammatory and analgesic activities than the brucine(P001) CONCLUSION: Liposome is an effective carrier for the local use on skin of brucine

Comparison of antitumor effect between brucine and its liposome in mice transplanted with tumor in vivo

Abstract: Objective To evaluate and compare the effects of brucine and its liposome on inhibiting transplanted tumor growth and prolonging their survival time in mice with transplanted tumor cells. Me- thods ICR Mice of tumor model was made by inoculated with tumor cells (S_ 180 , EAC, and Heps). The antitumor activity of brucine and its liposome was evaluated by tumor inhibitory ratio for S_ 180 and Heps and life prolonging rate for EAC and Heps of mice with transplanted tumor. Results Brucine and its liposome had significant inhibiting effect on transplanted tumor growth in mice. Inhibitory rates of brucine on Heps were 35.05% [1.61 mg/(kg·d)], 43.70% [3.23 mg/(kg·d)], and 46.09% [6.46 mg/(kg·d)], while of its liposome on Heps was 45.41% [1.61 mg/(kg·d)] and 58.19% [3.23 mg/(kg·d)], respectively. The inhibitory rate of brucine on S_ 180 was 37.59% [1.61 mg/(kg·d)], 36.13% [3.23 mg/(kg·d)], and 38.87% [6.46 mg/(kg·d)], while of its liposome on S_ 180 was 53.00% [1.61 mg/(kg·d)] and 48.37% [3.23 mg/(kg·d)], respectively. However, both of them had no distinct effect on prolonging the life of mice with transplanted tumor (EAC and Heps). Conclusion Brucine and its liposome could inhibit the growth of transplanted solid tumor and the inhibitory effect of its liposome is much stronger than that of brucine.

Determinants of positive cooperativity between strychnine-like allosteric modulators and N-methylscopolamine at muscarinic receptors.

Abstract: It has been shown previously that the third extracellular loop (o3) and its vicinity play a critical role in allosteric modulation at muscarinic acetylcholine receptors (mAChRs) (Ellis et al., 1993; Krejci and Tucek, 2001; Buller et al., 2002). In this study interaction of four chemically related substances (strychnine, its dimethoxy derivate brucine, precursor for synthesis of strychnine Wieland-Gumlich aldehyde (WGA), and precursor for synthesis of alcuronium propargyl-WGA) with orthosteric antagonist N-methylscopolamine (NMS) was investigated on the M3 subtype of mAChRs mutated at the o3 loop.

Studies on Preparation of Brucine Microemulsion and Its Transdermal Absorption

Abstract: OBJECTIVE To prepare O/W microemulsion formulation containing brucine and investigate its in vitro transdermal delivery ability.METHODS The microemulsion was prepared and characterized using Zetapals Zeta potential/particle size analysis instrument.The permeation flux of brucine was determined in vitro using Franz diffusion cell.The content of brucine was measured by HPLC.RESULTS The average droplet size of microemulsion containing 1% brucine was(48.0±1.7)nm.The permeation rate of(47.36±2.87)μg·cm~(-2)·h~(-1) was showed in vitro.The permeation of the microemulsion was discribed by the Fick's first diffusion law.CONCLUSION The brucine-loaded microemulsion promoted the permeation of brucine and showed the sustained and prolonged delivery.The microeulsion may be promising for the transdermal delivery of brucine

Activation of N -benzoyl -2 -substituted -2 -hydroxymethyl -2 -amino acids with chiral coupling reagents prepared in situ from 2 -chloro -4,6 -dimethoxy -1,3,5 -triazine

Abstract: Chiral triazine condensing reagents were obtained in situ by treatment 2-chloro-4,6-dimethoxy-1,3,5-triazine with strychnine, brucine, sparteine, nicotine and quinine, and used for enantioselective activation of racemic N-benzoyl derivatives of 2-methylserine, 2-isobutylserine and 2-benzylserine affording enantiomerically enriched appropriate 2-phenyl-4-hydroxymethyl-4-substituted-1,3-oxazolin-5-one. Configuration and ee of products were determined by HPLC on chiral stationary phase. S configuration of enantiomer activated faster to oxazolinone was confirmed for all chiral amines except quinine. For the later amine, R enantiomer of N-benzoyl-2-methylserine was activated faster. For experiments involving strychnine as chiral auxiliary, enantiomeric enrichment was substantially lower than in the case ofproteinogenic amino acids and increased with the size of C α -substituent from 12% ee for methyl to 36% ee for isobutyl side chain.

Studies on the High Voltage Electrophoresis of Strychnos Alkaloids

Abstract: The pH of the initial solution of brucine and strychnine affected the electrophoretic migration, with maximum migration occurring near a pH of 6.0 for strychnine and between 5.0 and 6.0 for brucine. The pH of the solvent used to fill the cell also affected the migration of strychnine. The optimal pH for this solvent was near 6.0. Increasing the voltage increased the rate of migration of both alkaloids. Strychnine migrated more readily when introduced nearer to the cathode. The concentration of the initial solution affected the migration of strychnine and brucine. Migration occurred best when high concentrations were introduced, tapering off slightly until at low concentrations the migrations were greatly reduced. The migration of strychnine was affected by the salt anion present, which occurred in the following order: sulfate ≤ hydrochloride > phosphate > lactate.

Copyright 2006 Springer Strychnine-8-ammonio-2-naphthalenesulfonate-water (1/1/3.5): The first structure of a strychnine or brucine compound with a zwitterionic species

Abstract: The crystal structure of the 1:1 adduct hydrate of strychnine with 1,7- Cleve's acid (8-amino-2-naphthalenesulfonic acid), namely strychnine-8-ammonio-2- naphthalenesulfonate-water (1/1/3.5) has been determined and provides a unique example of a neutral association involving strychnine and an achiral zwitterionic acid species, previously unobserved in the structures of either strychnine or brucine addition compounds. Crystals are orthorhombic, space group P212121, with Z=4 in a cell with dimensions a=10.4484(8), b=30.850(3), c=9.4998(11) A. Hydrogen bonding involving all available proton-donor and acceptor sites on all species gives rise to a three-dimensional framework polymer structure. The crystallographic literature for strychnine and brucine and their compounds is also reviewed.