Synthetic reactions with organometallic reagents providing synthons of carbenes, allylic ions, and enolates are reviewed. Topics included are copper-carbene complexes, ring-enlargement with lithium carbenoids, double alkylation of cyclopropane carbon, chromium carbenoids, allylchromium reagents, stereoselective carbonyl addition, vinyl-chromiums, sulfur-stabilized allylic and vinylic anions, combined acid-base attack of organoaluminium reagents, controlling the fate of allylic cations, pi-allyl palladium mediated cyclization, vinyl cation synthons, Reformatsky reaction in the presence of diethyl-aluminium chloride, Al-Sn reagents, reduction of diiodomethane, carbonyl methylenation reaction, etc.
Ursodeoxycholic acid, C24H40O4, crystallizes in the orthorhombic space group P212121 with eight molecules in the unit cell. The cell dimensions are a=26.617 (7), b=13.272 (2), and c=12.320 (2) Å. The structure was solved by use of direct methods and refined to a residual of 0.079 for 1619 independent significant reflections. The conformations of the D rings and 17β side-chains of the two molecules in the asymmetric unit are different from each other. All the hydroxyl and carboxyl groups are involved in hydrogen bonding extended nearly parallel to the bc plane.
The reduction of substituted monocyclic 1, 2, 3-triazines with sodium borohydride in methanol afforded their 2, 5-dihydro derivatives. The reduction of their 2-methyl quaternary salts also gave the 2, 5-dihydro compounds. The reduction of their 1-oxides and 2-oxides yielded their deoxygenated products and 1, 4, 5, 6-tetrahydro compounds, respectively. The same reaction of 1-methyl-2-oxo-triazinium salts afforded their 1, 6-dihydro derivatives whose structures were elucidated by an X-ray crystallographic study.
The effects of the constituents of Cistanchis Herba [Cistanche salsa (C. A. MEY.) G. BECK, Orobanchaceae] on sex (licking, mounting and intromission) and learning behaviors in IV-CS strain adult male mice were studied according to the chronic hanging stress method modified by Saito et al. The following results were obtained. The phenylpropanoid glycosides fraction (20 mg/kg, p.o.) prepared from cistanchis Herba showed a marked protective effect against decreases of both sex and learning behaviors in the hanging stress loaded mice. The constituents, acteoside (10 mg/kg, p.o.), cistanoside A (10 mg/kg, p.o.) and cistanoside C (10 mg/kg, p.o.) also showed almost the same effects. Echinacoside (10 mg/kg, p.o.) showed a protective effect against decreases of sex behavior, but had little effect on learning behavior.
Arotinolol hydrochloride (AR) is a new kind of antihypertensive agent consisting of two enantiomers, (+)-AR and (-)-AR. We developed the separative determination of enantiomers of AR by high performance liquid chromatography (HPLC). Enantiomers in AR was separated and determined by ion-pair chromatography with (+)-10-camphorsulfonic acid by use of a mixture of methylene chloride and methanol (100 : 1) as mobile phase and LiChrosorb DIOL (5μm) as stationary phase. The method has been applied to the separation of enantiomers of AR metabolite. The method for the separation of enantiomers of AR was also developed by HPLC on optically active stationary phase, (R)-N-(3, 5-dinitrobenzoyl) phenylglycine aminopropyl-silica (OA-2000).
Glycyrrhizin and glycyrrhetinic acid in the human plasma after administration of FM-100 (the powder obtained from acidic fraction of methanolic extract of Glycyrrhiza) were determined by capillary gas chromatography-selected ion monitoring by using [2H5]glycyrrhetinic acid methyl ester as an internal standard. Plasma was subjected to direct hydrolysis, and the resulting mixture was adsorbed on a polyamide column. Glycyrrhetinic acid was eluted with methanol, and the eluant was further purified by a Sep-Pak Silica cartridge and a silicagel column after the addition of the internal standard. Glycyrrhetinic acid, a metabolite of glycyrrhizin, was directly extracted with AcOEt from the plasma with high recovery. Glycyrrhetinic acid extracted was converted to its methyl ester-O-trimethylsilyl ether derivative by treating with diazomethane and then with N, O-bis-(trimethylsilyl) trifluoroacetamide. Monitoring of the molecular ion indicated that the quantitation limit for glycyrrhizin was 1 ng/ml plasma. After oral administration of 400 mg of FM-100, plasma levels of glycyrrhizin and glycyrrhetinic acid were shown with a maximum at 8-14 h post dose period. For the study of bioavailability of glycyrrhizin, each subject was indispensable to fast in order to avoid the effect of natural glycyrrhizin from many food additives for more than 10 h before and after administration of FM-100, respectively. This method was useful for the study on pharmacokinetics of glycyrrhizin and glycyrrhetinic acid, because of having sufficient sensitivity and specificity for objective compounds.
A simple and rapid method for the determination of trace amounts of phosphate in water was proposed. The addition of phosphate to a mixture solution of ammonium molybdate and malachite green resulted in a blue green coloration due to the formation of molybdophosphate aggregate with malachite green in 0.45 M H2SO4. The aggregate was collected on a nitrocellulose-acetylcellulose membrane filter (0.45μm pore size), and dissolved in a small volume of methylcellosolve together with membrane filter. The absorbance at 627 nm was proportional to the concentration of phosphate with the molar absorptivity ; 2.7×105M-1cm-1. The present method made it possible to determine phosphate in amount ranging from 0.3 to 30 ppb phosphorus. The coefficient of variation was 3.66% in the determination of 18 ppb phosphorus. The analytical recoveries of phosphate in tap water and river water were 100.2% and 104.7%, respectively.
Batroxobin is a thrombin-like enzyme purified from Bothrops atrox moojeni venom. The enzyme hydrolyzed arginine esters, such as benzoyl-L-arginine ethyl ester (Bz-Arg-OEt) and tosyl-L-arginine methyl ester (Tos-Arg-OMe), but scarcely hydrolyzed tosyl-L-lysine methyl ester (Tos-Lys-OMe) and benzoyl-L-tyrosine ethyl ester (Bz-Tyr-OEt). Batroxobin also hydrolyzed arginine amides, such as benzoyl-L-arginine-4-methyl-coumaryl-7-amide (Bz-Arg-MCA) and benzoyl-L-arginine-p-nitroanilide (Bz-Arg-pNA) but the rates were slower than the arginine esters. Optimal pH for hydrolysis of Bz-Arg-MCA by batroxobin was 8. The enzyme was relatively heat-resistant at pH 3 to 7 but not at alkaline pH. Bz-Arg-MCA hydrolytic activity of batroxobin was inhibited by diisopropyl fluorophosphate (DFP), antipain, leupeptin and benzamidine. Trypsin inhibitors, such as N2-p-tosyl-L-lysine chloromethyl ketone (TLCK), soybean trypsin inhibitor, Trasylol and α1-antitrypsin, and specific thrombin inhibitors, such as antithrombin III and hirudin were ineffective. The inhibition constant (Ki) for antipain, leupeptin and benzamidine were 0.12μM, 4.7μM, 0.58 mM, respectively.
An experimental investigation on the end-point for the granulation process by which spherical and well-compacted granules are obtained in high yield was carried out. Power consumption of a needer mixer was measured during granulation. The tensile strength, shape index and bulk density of granules obtained were measured. Powder coating on wet spherical granules was also attempted. The end-point for granulation to obtain spherical and well-compacted granules in high yield was found when the power consumption for granulation reaches constant value. Spheronization of granules occurred before compaction of granules. The binder content and impeller speed necessary for the production of spherical, well-compacted granule in high yield were also studied. A method of powder coating, in which a powdered coating material dusted onto wet spherical granules at the end point of granulation utilizing the liquid film on the granules is formed by exudation of a binder solution, was devised.
Biochemical alterations of the connective tissue components and the cholesterol accumulation sites in atherosclerotic aorta, which were induced in rats fed with an atherogenic diet supplemented with 0.15% β-aminopropionitrile (BAPN) for 6 weeks, have been studied. There was a marked decrease in hydroxyproline and elastin-specific cross-linked amino acids, a marked increase in sulfate, and a marked decrease in the weight of residue after extraction from the aorta with boiling NaOH solution. These changes were also observed in animals treated with BAPN alone, suggesting that BAPN administration causes a reduction of total collagen and insoluble elastin, and an increase of glycosaminoglycan in the aorta. Of interest is an increase in aortic phosphorous content, but essentially no change in the calcium content. The cholesterol which was accumulated in the aorta of rats fed with a diet supplemented with high-cholesterol and BAPN was not present in the insoluble elastin fraction nor in the collagenase- and elastase-solubilized fractions of the aorta. The results suggest that such cholesterol accumulation does not result from a stable complex formation with arterial elastin, but presumably from deposition in the cells of the arterial wall.
As the basic study of therapeutic drug monitoring (TDM) of β-receptor blocking drugs (β-blockers) by gas chromatography, retention indices were accumulated, and selectivity and sensitivity were compared by flame ionization detector (FID), nitrogen-phosphorus detector (NPD) and electron capture detector (ECD). Retention indices of 15 kinds of β-blockers and those trifluoroacetyl derivative (TFA deriv.) were 2076-3336, 1976-2754 (TFA deriv.) on weakly polar column (OV-17), and 1826-2815, 1860-2329 (TFA deriv.) on nonpolar column (OV-101). Under the same conditions, retention indices of 19 kinds of concurrent medication were also accumulated as reference materials for TDM. Selectivity was shown by peak area ratio of β-blockers to n-paraffins. Selectivity of NPD was almost 2×104 times that of FID. Detectable limits were 10 ng by FID, 0.1-1 ng by NPD and 0.01-0.1 ng (TFA deriv.) by ECD. NPD and ECD showed good selectivity and sensitivity for gas chromatographic analysis of β-blockers.
The possibility of degradation of flunitrazepam with fresh stool was investigated. After the combination of flunitrazepam with sterilized broth (pH 7.1), 1% (pH 6.7) or 8% (pH 6.3) sterilized stool culture without further anaerobic precautions, the drug did not degrade in the incubation mixture. This indicates that the drug did not react with the components of broth and stool cultures and was stable at these pH values. On the other hand, after the combination of the drug with 1% or 8% human faecal contents in a broth, the drug disappeared rapidly in the incubation mixture in proportion to stool concentrations. The metabolite was identified to be 7-aminoflunitrazepam by high performance liquid chromatography (HPLC). The degradation patterns of flunitrazepam were followed by HPLC.
The in vivo and in vitro bindings of sulfadimethoxine (SDM) or sulfamethoxazole (SMX) to the serum were examined in rabbits. The in vivo binding of these sulfonamides to the serum was evidently lower than thier in vitro binding. The concentration in the serum of N4-acetylsulfadimethoxine or N4-acetylsulfamethoxazole, which is a major metabolite of SDM or SMX, was found to increase with a decrease in the concentration of SDM or SMX in the serum. In addition, these N4-acetylated sulfonamides reduced the in vitro binding of sulfonamides to the serum. These results indicate that N4-acetylated sulfonamides play an important role in the difference between the in vivo and in vitro bindings of sulfonamides to the serum.