Effect of pH variation on the relative astringency (RA) was investigated to improve reproducibility of RA values and to measure variations of tannin activity by difference in tannin structure. The calibration curves of J.P. tannic acid obtained at various pH showed the best sensitivity, linearity, and reproducibility, at pH 6.0. The calibration curves of geraniin also showed best properties and the best analogy to J.P. tannic acid, at pH 6.0. Marked difference of calibration curves between J.P. tannic acid and geraniin was observed when pH of the test solution was significantly different from 6.0. The RA values measured at various pH by the calibration curve of J.P. tannic acid at pH 6.0 showed that the hydrolysis of geraniin, and also of Geranium thunbergii extracts in boiling water induce slow decrease of the activity at pH 6.0, and marked temporary increase of RA at lower pH. This property could be characteristic of geraniin since RA of J.P. tannic acid measured at various pH showed only slow decrease after hydrolysis. The RA values obtained at pH 6.0 (RApH6) were measured for seasonal variation of tannin content in G. thunbergii, for tannin contents of Geranium species and of other tannin-containing plants, to give results somewhat different from those obtained without pH regulation. The RA values based on the calibration curve of geraniin (RAG), which should give better reproducibility of the data because of homogeneity of geraniin, were also obtained for the above samples.
A new colorimetric determination of tannin, measuring absorbances of the solutions after precipitating Methylene Blue with the sample, was investigated to develop an analytic method of higher sensitivity and reproducibility. Comparison of the calibration curves of tannic acid in Japanese Pharmacopoeia (J.P.), geraniin, chebulinic acid, and chebulagic acid at various pHs showed that the best result in sensitivity, linearity, and reproducibility common to these four tannins is obtained at pH 7.0. The determined value (RMB) of geraniin by this method at pH 7.0, based on the calibration curve of tannic acid J.P. (RMBpH7) was 1, but appreciable differences between these two tannins were observed at other pH range. The RMB values of samples at pH ranges other than 7.0 were based on the calibration curve of tannic acid J.P. at pH 7.0. Marked similarity between RMBpH7 and RApH6 was observed for variation of the activity induced by hydrolysis of geraniin, and extracts of Geranium thunbergii. The RMBpH7 values for seasonal variation of tannin content in G. thunbergii, for tannin content of Geranium species, and of several species of plants were obtained before and after treating the extracts with methanol. The RMB values of these specimens, based on the calibration curve of geraniin (RMBG), and RMB of geraniin and hydrolyzed geraniin based on the calibration curve of tannic acid J.P. at the same pH, were also obtained. The amount of the samples required for RMBpH7 determinations was ca. 1/50 of those for RApH6 determinations.
Conformations of the ketyl radicals generated by metal reduction of 2-methyl-1, 1'-dinaphthyl ketone (I) and 1, 1'-dinaphthyl ketone (II) were evaluated on the basis of informations from electron spin resonance and visible absorption spectra, and molecular orbitals (MO) calculations. By comparing the experimental spin density and transition energies with the corresponding theoretical quantities obtained by McLachlan's method and by unrestricted PPP-SCF-MO method, the rotational angles about the C-C bond connecting the aromatic group were found to be about (0°, 60°) to (49°, 0°) for I and (34°, 34°) for II.
The mechanism of the microbiological assay was interpreted as the diffusional mass transfer of the drug starting from the drug phase, travelling through the receptor phase, reacting with bacteria, death and growth of bacteria in the receptor phase, and the show-up of clear zone. Simulation technique using an electronic computer can be applied to the calculation of the drug concentration and the concentration (number) of bacteria in the receptor phase. If the same diffusional medium is used in the drug and the receptor phase, the drug concentration at the drug-receptor interface may be maintained constant (C0/2) in the linear diffusion system. This phenomenon can be applicable to the determination of the minimum growth inhibitory concentration (MIC). In a two-dimensional diffusion system, the drug concentration at the drug-receptor interface is not constant theoretically, then the system is not applicable to the determination of MIC. In general, the two-dimensional diffusion system gives a shorter clear zone length than in the linear diffusion system. This phenomenon may be attributed to the lower drug concentration at the interface than in the linear diffusion system.
Experimental verification of the theory in the"band culture method"was carried out by using various drugs and various bacteria, and it was clarified that the method is more sensitive than the two-dimensional diffusion system (cup method). The relation between the length of clear zone and the drug concentration, and the relation between the minimum growth inhibitory concentration (MIC) and the initial bacteria concentration closely resemble the simulation results presented in a preceding report. The drug release from the gelatinous (gel-type) ointment base is faster than that from petrolatum. This result can be applied to the assessment of an ointment base.
The reaction of trimethylenediamine and propyleneglycol (PGL) was examined in the alumina-packed bed reactor. Main product was 2-methylhomopiperazine. Since this reaction mechanism is unknown, statistical method was used to find optimum conditions for the yield of 2-methylhomopiperazine. The first part of the investigation consisted of simplex type design. Four variables were chosen ; molar ratio of reactants (A), amount of water added (B), percentage of promoter added (C), and reaction temperature (D). Experiments in the direction of the steepest ascent based on the second-order response function showed that the optimum conditions were as follows : (A) 0.5 ml/1.0 ml (trimethylenediamine/PGL), (B) 1.087 ml/1.0 ml (H2O/PGL), (C) 4.873% (K2O), (D) 291.6°. Maximum yield under these conditions was 25.43%.
A high performance liquid chromatographic method was developed for the determination of berberine in Coptidis rhizoma and Oriental pharmaceutical preparations. Retention time of berberine (flow rate : 1.0 ml/min) was approximately 4 min 40 sec on a μ-Bondapak C18 column (4×300 mm) with an eluent of acetonitrile : phosphate buffer (pH 5.2)=60 : 40. Naphthalene was used as an internal standard, whose retention time was approximately 9 min 36 sec. Berberine was extracted from the samples with methanol and injected into the column. Coefficient of variation for berberine content in Coptidis rhizoma was found to be less than 0.45%. It was concluded from the comparison of this method with three other methods (thin-layer chromatography, thin-layer chromatography densitometry, and gas chromatography) that this method was significantly better than other methods with respect to simplicity, analytical time, and accuracy.
The hydroxyl and acylamino groups on four sets of cis- and trans-isomers of five-, six-, and seven-membered 2-acylamino-1-benzocycloalkanols (I-IV) have been assigned preferred conformations of axial (a)-equatorial (e) for the cis-isomers and e-e for the trans ones on the basis of their nuclear magnetic resonance (NMR) spectra in (CD3)2SO. In each set of isomers of five- (I) and six-membered systems (II and III), hydroxyl-carbinol proton coupling constants (JHCOH) of the cis-isomers (a-OH proton) are found to be smaller than their trans counterparts (e-OH proton), and the chemical shifts of hydroxyl proton (δOH) of the former are found at higher field than the latter. However, the reverse relationship between the configurations of the substituents and both of JHCOH and δOH was observed in the seven-membered ring system. The difference between the five- and six-membered and the seven-membered ring systems may be related to the effect of Ar-C1-C2 angle (θ). NMR and infrared spectra in CDCl3 indicated the presence of intramolecular -OH.... O=C-NH hydrogen bonds in the trans-five-(Ib) and six-membered (IIb and IIIb) and the cis-seven-membered (IVa) ring derivatives.
The reaction of isoquinolinium N-ylides with ketenethioacetals in the presence of triethylamine or potassium carbonate as a base in ethanol or dimethylformamide gave isoquinolinium N-allylides, pyrrolo [2, 1-a] isoquinolines, and pyrrolo [1, 2-b] isoquinolines. The reaction of isoquinolinium N-imines with ketenethioacetals afforded the stabilized isoquinolinium N-imine and pyrazolo [5, 1-a] isoquinoline derivatives.
Schiff bases of 4- and 5-nitrosalicylaldehydes (4 and 5), with amino acids and their esters were prepared, and their absorption spectra in acidic, neutral, and alkaline methanol were measured. The Schiff bases are present as anionic, I, enolimine, II, and ketoenamine, III, species according to the environment. Addition of Al(III), Cu (II), Zn (II), or Ni (II) ion to the Schiff base solution resulted in the formation of metal chelates, M, spectral properties of which are described. A transient absorption at 494 nm was observed on addition of Al (III) ion to the Schiff base of 4 and alanine methyl ester in neutral methanol and was ascribed to the formation of the Al (III) chelate of the quinoid, B, in which α-carbon of the amino acid moiety in the Schiff base is deprotonated. The loss of α-H was confirmed by nuclear magnetic resonance study. A similar species was not formed with Schiff bases derived from salicylaldehyde or 5, or those of 4 with amino acids or ester of 2-methylalanine, or with the bivalent transition metal ions.
4-Amino-1-(o-, m-, or p-nitrophenyl)-1H-pyrazolo [3, 4-d] pyrimidine (Io, Im, or Ip), and 41 kinds of their derivatives were synthesized and the compounds were screened for antitumor activity against Ehrlich carcinoma. Antitumor activity was found in 4-elaidamido-1-(o-nitrophenyl)-1H-pyrazolo [3, 4-d] pyrimidine (VIIIo) and 4-oleamido-1-(p-nitrophenyl) compound (IXp).
Reaction with aroyl chloride and potassium cyanide was carried out with isoquinoline 2-oxide (Ix) with a substituent in 1-position or substituents in 1- and 4-positions. Ten kinds of Ix were used, including 1-phenyl-(Ia), 1-benzyl-(Ib), 1-methyl-(Ic), 1-ethyl-(Id), and 1-butyl-isoquinoline 2-oxide (Ie), isoquinolinecarbonitrile 2-oxide (If), 1, 4-diphenyl-(Ig) and 1-ethyl-2-phenyl-isoquinoline 2-oxide (Ih), 4-phenyl-1-isoquinolinecarbonitrile 2-oxide (Ii), and 1, 1'-diphenyl-4, 4'-biisoquinoline 2, 2'-dioxide (Ij), and results were as follows : 1) From 1-substituted isoquinoline 2-oxides, isoquinoline derivatives (II) with introduction of the aroyloxyl group into 4-position, accompanied with liberation of oxygen from the N→O group, were obtained. In some cases, 1, 4-dihydro-1-isoquinolinecarbonitrile derivatives (III) with introduction of CN group into 1-position and aroyloxy group into 4-position, accompanied with deoxygenation of N-O group, were formed. III is considered to be an intermediate in the formation of II. 2) III was formed from 1, 4-disubstituted isoquinoline 2-oxides. 3) A difference from the same reaction of quinoline derivatives was found in the absence of a derivative with introduction of the aroyloxy group into α-carbon when there is an alkyl group in 1-position and no formation of a derivative with introduction of the aroyloxy group into benzene portion of the isoquinoline ring when there is a phenyl group in 1-position.
Reaction of isoquinoline 2-oxide (V), and its 1-phenyl (V1), 1-cyano (V2), 1-cyano-4-phenyl (V3), 4-bromo (V4), and 4-cyano (V5) derivatives with sulfonic acid chloride (RSO2Cl) and potassium cyanide, in acetone-water, was carried out. Reaction of V with methane-, ethane-, benzene-, or p-toluene-sulfonyl chloride and potassium cyanide resulted in the introduction of a sulfonyl group into 1 or 3 position, with liberation of oxygen from the N→O group, producing 1-alkylsulfonyl- or 1-arylsulfonyl-isoquinoline (VIx) and 3-alkylsulfonyl- or 3-arylsulfonyl-isoquinoline (VIIx), with 4-alkanesulfonyloxy- or 4-arenesulfonyloxy-isoquinoline (VIIIx) and isocarbostyril (X). Reaction of Vx with methanesulfonyl chloride and potassium cyanide gave 1-methylsulfonyl compounds (VI4, VI5) or 3-methylsulfonyl compound (VII1), while the same reaction of V4 gave 4-(methanesulfonyloxy)-1-(methylsulfonyl) isoquinoline (XI), with concurrent formation of 1-(2-oxopropyl)-4-isoquinolinecarbonitrile (XII) from V5. Reaction process for the introduction of the sulfonyl group was considered to progress in the same way as in the case of quinoline.
The acid-catalyzed rearrangement of 1, 3-oxazepin-4-one was carried out successfully to give 2-benzazepin-3-ones, and these products were transformed to galanthamine analogues expecting their analgesic activity.
Examination was made on the effect of acid polysaccharides on the intestinal absorption of quinidine in rats, and also on the intermolecular interaction between quinidine and polysaccharides. The absorption in situ of quinidine was inhibited markedly by dextran sulfate (Na salt). Sodium carboxymethylcellulose and sodium alginate showed a weaker inhibitory effect. The inhibitory effect of dextran sulfate on the absorption was well reflected on the blood level patterns of quinidine administered into the small intestine by the loop method ; the time of the maximum blood level was delayed in the presence of dextran sulfate, and after that time, the blood level of quinidine became higher than that in the absence of the polysaccharide. The degree of binding of quinidine and polysaccharides was quantified by the use of ultrafiltration and fluorescence analysis. A parallel relationship was established between the order of inhibitory effect of polysaccharides on the intestinal absorption of quinidine and the order of binding ratios of the quinidine-polysaccharide systems. Based on the results of analysis of the mode of binding, it was presumed that, in the physiological pH region, dissociation of the quinuclidine ring of quinidine played an important role in the ionic binding of quinidine and dextran sulfate.
The chemical assignments were given to the absolute configurations of di-O-methylhydroxythujaplication methyl ether (I) (2S, 3S), pluviatolide (VI) (2R, 3R), and 2-(3", 4"-dimethoxybenzyl)-3-(3', 4'-methylenedioxybenzyl) butyrolactone (VII) (2R, 3R) by their conversion to known compounds, whose absolute configurations have already been established. The present results agreed with the assignments proposed previously on the basis of optical rotatory dispersion and circular dichroism of these compounds.
From Calystegia japonica CHOISY, kaempferol 3-rhamnoside, 3-glucoside, 3-galactoside, and 3-rutinoside (IV), β-sitosterol, palmitic acid, linoleic acid, and stearic acid were isolated and identified with authentic samples.
From the herbs of Farfugium hiberniflorum (MAKINO) KITAM. (Ligularia hiberniflora MAKINO ; Japanese name : Kan-tsuwabuki) (Compositae) five constituents were isolated and characterized ; bakkenolide A (I), β-sitosterol, palmitic acid, linoleic acid, and linolenic acid.