To evaluate the spermicidal effect of several nonionic surfactants against human spermatozoa, the physicochemical lysis of liposomal membranes by the surfactants has been investigated. Surfactants employed in this work were menfegol (TS-88), nonoxynol-9 (INP-90), octoxynol-9 (NOP-90), hexadecyltrimethylammonium bromide (CTAB), and sodium dodecylsulfate (SDS). Lysis of liposomes by these spermicidal surfactants was quantitatively followed by monitoring the induced release of carboxyfluorescein (CF) encapsulated in the interior of liposomes. When the liposomes reconstituted with boar spermatozoal lipids and about 31% (by wt.) cholesterol were employed, the sequence in efficiency of the surfactant-induced CF release from the liposomes was significantly correlated with that of efficiency of the surfactants in immobilizing human sperm (p<0.05). On the other hand, when egg lecithin liposomes or the liposomes reconstituted with boar spermatozoal lipids and cholesterol less than 21% (by wt.) were utilized, the sequence in efficiency of CF release from these liposomes coincided with that in the inhibiting effect of the surfactants on the fertilizing ability of sea urchin sperm. These effects were closely correlated with the membrane fluidity as controlled by the cholesterol content or lipid composition. Among menfegol analogues from TS-40 through TS-200, the efficiency in induced CF release from the liposomes showed a maximum at around ten ethylene oxide units length of the hydrophilic moiety in the surfactant. This was also the case for spermicidal effect of the TS-series surfactants. The data obtained are discussed at the molecular level from the viewpoint of the structural characteristics of the surfactants.

View full abstract

When the concentration of aminopyrine, [AMP], was greater than that of peroxyphenylacetic acid, [PPAA], the reaction of PPAA with AMP in the absence of catalase at pH 4.5 showed the electron spin resonance (ESR) spectrum of the aminopyrine cation radical (1), whereas that at pH 6.8 did not. On the other hand, when [AMP]&gne;[PPAA], a new ESR spectrum (g=2.0053, A₁=16.9 (1N), A₂=14.5G (6H) which was entirely different from that of 1 was obtained at both pH 4.5 and 6.8. Spin-trapping experiments suggested that the new spectrum was derived from the phenylacetyl radical-adduct of AMP (2). In the presence of catalase, when [AMP]>[PPAA], the reaction of PPAA with AMP showed the ESR spectrum of 1 even at pH 6.8. The amount of benzyl alcohol formed was decreased in the presence of catalase in comparison with that in the absence of catalase. These results suggest that homolytic oxygen-oxygen bond cleavage and oxy radicals generated play no major role in the PPAA-supported oxidation of AMP by catalase.

View full abstract

The effect of temperature on the solubilization of ethyl p-hydroxybenzoate (ethylparaben) in hexaoxyethylene lauryl ether (C₁₂E₆) micelles was examined by the gel filtration method using Sephadex G-200. The values of standard Gibbs energy (ΔG^〓), enthalpy (ΔH^〓) and entropy (ΔS^〓) changes for the micellar solubilization of ethylparaben were calculated, together with the interaction energy parameter (ω). The negative values of ΔH^〓 and ω showed that there is an interaction between the phenolic OH group in ethylparaben and the polyoxyethylene groups in the C₁₂E₆ micellar phase. The positive values of ΔS^〓 suggest that the alkane moiety of ethylparaben is incorporated into the hydrocarbon core of C₁₂E₆ micelles. These results showed that both enthalpy and entropy effects control the micellar solubilization of ethylparaben.

View full abstract

The reaction of 1 with pyridinium N-ylides (2a, R=H ; 2b, R=3-CH₃ ; 2c, R=2-CH₃ ; and 2d, R=2-NH₂) gave the corresponding stable pyridinium N-allylide compounds (3a and 3b), 2-(2-indanyl) indolizine (4), and 3-(2-indanylidenyl) methylimidazo [1, 2-a] pyridine (5) in good yields. A fused thiabenzene oxide, 2-methyl-4-methylthio-5-oxo-5H-indeno [1, 2-c] thiapyran 2-oxide (8), was synthesized by the reaction of 1 with trimethylsulfoxonium iodide under similar conditions. An azathiabenzene oxide, 2-methyl-4-methylthio-5-oxo-5H-indeno [2, 1-d] [1, 2] thiazine 2-oxide (11), was also synthesized from 2-(1-dimethylsulfoximino-1-methylthio) methyleneindan-1, 3-dione (10), which was prepared from 1 and sulfoximine.

View full abstract

S-Adenosylhomocysteine analogues, 1-(5, 6-dideoxy-6-nitro-β-D-ribo-hexofuranosyl) uracil (7a), 9-(5, 6-dideoxy-6-nitro-β-D-ribo-hexofuranosyl) adenine (7b), 4-(5'-deoxyuridin-5'-yl)-4-nitrobutyronitrile (15) and 4-(5'-deoxyadenosin-5'-yl)-4-nitrobutyramide (20) were synthesized as potential inhibitors of S-adenosylmethionine (SAM)-dependent methyltransferases and S-adenosylhomocysteine hydrolases. The chemistry developed for the preparation of these compounds should be useful in the total synthesis of the nucleoside antibiotics sinefungin and A9145C, which are potent inhibitors of certain SAM-dependent methyltransferases.

View full abstract

Five stereoisomeric analogues, 2-6, of FK-156 (1), an immunostimulating microbial metabolite, have been synthesized and screened for immunostimulating activity. The results indicate that the D-configuration of glutamic acid and L-configuration of diaminopimelic acid at the site combining with other amino acids are essential, while the configurations of lactic acid and alanine are of little importance for the biological activity of the FK-156 series.

View full abstract

Five partial structures, 3-7, of FK-156 (1), an immunostimulating acyl peptide, have been prepared. The compounds were evaluated for biological activities, and it was found that N²-(γ-D-glutamyl)-2 (L), 2' (D)-diaminopimelic acid (3) represents the minimal active structure unit essential for the immunostimulating property of FK-156 (1). Its caprylyl derivative 8 and stearoyl derivative 9 were found to be capable of increasing resistance to bacterial infection as efficiently as 1. Moreover, compound 9 showed a potent tumor-suppressive activity lacking in 1.

View full abstract

1-Substituted 2 (1H)-pyrimidinones (I) underwent ring transformation with malononitrile and ethyl acetoacetate in the presence of sodium ethoxide to give 2-amino-3-pyridinecarbonitriles (II-VII) and N-(substituted) amino-3-pyridinecarboxylic acids (XIV and XV), respectively. Further, I reacted with ethyl cyanoacetate, dialkyl malonate, or ethyl benzoylacetate to give pyridine derivatives (VIII-XIII) bearing various functional groups at the C-3 position. The reaction of 1-substituted 2 (1H)-pyrimidinethiones and 4, 6-dimethyl-1-phenyl-2-phenylimino-1, 2-dihydropyrimidine with active methylene compounds is also discussed.

View full abstract

New iridoids, including isoallamandicin, allamcin, allamancin, 3-O-methyl derivatives of allamcin and allamancin, allamcidin allamcidin glucoside, 13-O-acetylplumieride, plumiepoxide, and protoplumericin B, were isolated in addition to ten known iridoids from the stem and leaves of Allamanda neriifolia Hook. Their structures were determined on the basis of spectral and chemical evidence. Gardenoside and 10-dehydrogardenoside, two ordinal-type iridoids, were also obtained.

View full abstract

Alkylation of the title compound (2) with alkyl halides in the presence of Et₃N proceeded exclusively on the sulfur atom to give the S-alkyl-1, 3-oxazine derivatives. Acylation with acylchlorides took place regioselectively on the nitrogen atom, giving the N-acyl derivatives. 1, 3-Oxazine 2 was found to undergo cleavage of the ring into acetylketene and thiocyanic acid. Hence, treatment of 2 with alkyl halides in the presence of K₂CO₃gave alkyl thiocyanates ; treatment with active methylene compounds afforded γ-pyrone derivatives. N-Acyl derivatives of 2 also underwent thermal cleavage of the ring, leading to the corresponding acyl isothiocyanates.

View full abstract

The heptadecapeptide corresponding to the entire amino acid sequence of melaninconcentrating hormone (MCH), isolated from chum salmon pituitaries, was synthesized by successive condensation of four peptide fragments and the N-terminal amino acid, i. e., Boc-(14-17)-OBzl, Boc-(9-13)-OH, Boc-(5-8)-NHNH₂, Boc-(2-4)-NHNH₂ and Boc-Asp (OBzl)-OH, followed by deprotection with 1 M trifluoromethanesulfonic acid-thioanisole in trifluoroacetic acid (TFA) and disulfide formation through the S-sulfonate. When melanin-concentrating activity was measured on a tilapia scale, the minimum effective concentration of the synthetic peptide was equivalent to that of natural salmon MCH (1nM).

View full abstract

In order to establish a versatile method for the preparation of antiumor benzo [c] phenanthridine alkaloids, the reaction steps from the 2-aryl-1-formamido-1, 2, 3, 4-tetrahydronaphthalenes (2) to the fully aromatized benzo [c] phenanthridine derivatives (5) via the 4b, 10b, 11, 12-tetrahydrobenzo [c] phenanthridines (4) in the Robinson preparative sequence were examined in detail. Bischler-Napieralski reaction of the formamide (2) having an alkoxy group at the para position to the cyclizing point of the 2-phenyl ring substituent gave a mixture of the trans-and cistetrahydrobenzo [c] phenanthridines (4) with or without formation of the 2-aryl-3, 4-dihydronaphthalene derivative (6). There is a limitation in that the presence of the alkoxy group at the para position is required for success in cyclizing the formamide derivative (2). Otherwise, the 2-aryl-3, 4-dihydronaphthalene derivative (6) is the sole product. For the dehydrogenation of the resulting trans-and cis-tetrahydrobenzo [c] phenanthridines (trans-and cis-4) into the fully aromatized product (5), catalytic dehydrogenation with 30% palladium-charcoal in p-cymene and 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ) oxidation in the presence of or in the absence of 5% sodium hydroxide aqueous solution were investigated. The catalytic dehydrogenation provided either the desired fully aromatized product (5) or the dihydrobenzo [c] phenanthridine (8). The species of the product depends upon the species of the starting material (4). The DDQ-oxidation gave a variety of results. The mode of product formation seems to be regulated by various factors, including the reaction conditions, the species of substituents of the starting material (4), and the stereochemistry of the starting material (4). The mechanisms of formation of various products are discussed.

View full abstract

A versatile method of synthesis of the quaternary benzo [c] phenanthridine alkaloid (1), having a tertiary benzo [c] phenanthridine skeleton, from the norbase (3) is described. Treatment of the norbase (3) with sodium borohydride in formic or in acetic acid gave the N-methyl-(5) or the N-ethyl-(7) dihydrobase, respectively, in good yield. The N-methyldihydrobase (5) could also be prepared by treatment of the norbase (3) with sodium borohydride and dimethyl sulfate in hexamethylphosphoric triamide. The dihydrobases (5 and 7) were readily convertible to the corresponding quaternary benzo [c] phenanthridine alkaloids by oxidation with Jones reagent or with 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ) in good yields. In addition, we found that the air-oxidation of the carbanions derived from the ψ-cyanides (11) of the quaternary bases (1) gave the corresponding oxybases (10) in excellent yields.

View full abstract

The molecular formula of carzinophilin has been decided as C₃₁H₃₃N₃O₁₂. A structure for carzinophilin is proposed on the basis of the nuclear magnetic resonance data obtained.

View full abstract

Several oxygenated sterols, e.g. ergosterol peroxide, 7-oxocholesterol and 7β-hydroxycholesterol, were identified from the fungus-infected carcass of silkworm, Bombyx cum Botryte. However, they were nontoxic to the silkworm Bombyx mori reared on a diet containing these oxygenated sterols (0.01%) together with sitosterol or cholesterol (0.1%).

View full abstract

Two new phenylpropanoid glycosides, named cistanoside A (III) and cistanoside B (IV), were isolated from the whole plant of Cistanche salsa (C. A. MEY.) G. BECK (Orobanchaceae), together with acteoside (I) and echinacoside (II). The structures of III and IV were determined to be 2-(4-hydroxy-3-methoxyphenyl) ethyl O-α-L-rhamnopyranosyl-(1→3)-O-[β-D-glucopyranosyl-(1→6)]-(4-O-caffeoyl)-β-D-glucopyranoside and 2-(4-hydroxy-3-methoxyphenyl) ethyl O-α-L-rhamnopyranosyl-(1→3)-O-[β-D-glucopyranosyl-(1→6)]-(4-O-feruloyl)-β-D-glucopyranoside, respectively, on the basis of chemical and spectral data.

View full abstract

A new base, 3-O-acetylhamayne (11), was isolated from Crinum latifolium L. (Amaryllidaceae) along with crinamine (3), powelline (4), crinine (5), 1-O-acetyllycorine (6), hamayne (8), undulatine (13), and cherylline (14). The bases 3, 4, 5, and 14, as well as diacetyllycorine (7), crinamidine (16), O-acetylcrinine (17), deacetylbowdensine (18), and bowdensine (19), were also isolated from Crinum bulbispermum MILNE-REDHEAD et SCHWEICKERDT (Amaryllidaceae).

View full abstract

From the bulbs of an Amaryllidaceous plant, Crinum zeylanicum L., a Sri Lankan folk medicine (Sinhalese name, Goda-manel), five alkaloids I-V were isolated and identified as lycorine (I), 3-acetylhamayne (III), 6-hydroxycrinamine (IV), hamayne (V), and a new alkaloid, 6-methoxycrinamine (II).

View full abstract

Syntheses of 1-methyl-2-azathiabenzene 1-oxide and its 5-methyl derivative are described. The physical (¹H-nuclear magnetic resonance (NMR) and¹³C-NMR spectra) and chemical properties (deuteration, bromination, and nitration) suggest that 1-methyl-2-azathiabenzene 1-oxides are best considered as cyclic sulfur ylides.

View full abstract

Three new guaianolide glucosides, ixerins D, E and F, and a new melampolide glucoside, ixerin G, have been isolated from the polar fraction of lxeris tamagawaensis KITAM. Their structures were elucidated on the basis of spectral data and several chemical transformations.

View full abstract

A new sesquiterpene glycoside, ainsliaside A (II) was isolated from Ainsliaea acerifolia SCH. BIP., together with glucozaluzanin C (I). Another new sesquiterpene glycoside, ainsliaside B (III) was isolated from A. dissecta FRANCH. et SAV. The structures of II and III were determined on the basis of chemical and spectral data.

View full abstract

Photolysis of 6, 11-dihydro-11-oxodibenz [b, e] oxepin-3-acetic acid (1, oxepinac) in 1N NaOH solution by sunlight gave 3-methyldibenz [b, e] oxepin-11 (6H)-one (2), 2-methylanthraquinone (3), 4-carboxy-3-(2-methylphenoxy) phenylacetic acid (4) and 4-(2-carboxybenzyl)-3-hydroxyphenylacetic acid (5). Their structures were established by direct comparison with synthetic samples (2, 4, 5) and a commercial sample (3).

View full abstract

New syntheses of 2-(alkylamino) benzoxazoles (III) and 3-alkyl-2-(alkylimino) benzoxazolines (IV) were developed. Various compounds III were obtained by the reactions of 2-(methylthio) benzoxazole with amines. In the alkylation of 2-(monoalkylamino) benzoxazoles, the use of a base as a catalyst was found to be important for the selective preparation of 2-(N, N-dialkylamino) benzoxazoles ; in the absence of base, IV was obtained, On the other hand, alkylation of N, N'-dialkyl-N-(2-hydroxyphenyl) thioureas resulted in the development of another method for the preparation of IV.

View full abstract

The electrostatic potentials of five drugs targetting dopamine receptors were calculated on the molecular surface, or the solvent-accessible surface, using Cartesian coordinates and Mulliken net atomic charges obtained by the use of semi-empirical molecular orbital method, modified neglect of diatomic overlap. All of these electrostatic potential images, which were represented by color-coded graphics, showed the interesting feature that a positive potential region exists on one side of the molecular surface. This may reflect the specific orientation of the drug molecules for binding to dopamine receptors, which presumably show electrostatic and topographic complementarity.

View full abstract

3-Benzoylglycidic acid derivatives were prepared and tested for hypolipidemic properties in normal rats. A structure-activity relationship study showed that trans-3-(phenoxybenzoyl)-glycidic acids have hypolipidemic activity. Among these compounds, trans-3-[4-(4-chlorophenoxy) benzoyl] glycidic acid (38) and trans-3-[4-(4-bromophenoxy) benzoyl] glycidic acid (39) possessed very potent activities.

View full abstract

Aurantio-obtusin and obtusin were identified as inhibitors of adenosine 3', 5'-cyclic monophosphate (cAMP) phosphodiesterase in seeds of Cassia obtusifolia L. and Cassia tora L. The structure-activity relationships of 22 anthraquinones and 17 analogous compounds were studied. Anthraquinones of the emodin and obtusin types were generally more inhibitory towards cAMP phosphodiesterase than other types of anthraquinones, anthrones and lactones.

View full abstract

We made a pneumatically-driven injection device and a computer analyzing system for chemiluminescence studies. This total instrument provided superior reproducibilities ; e.g. withinrun variabilities (n=4 to 6) of entire light emission were about 1 to 4%. The entire emission is calculated from both an integration of the signal and an approximation to a first-order reaction. It observed that rapid, intense light (t_1/2=0.35) was produced by luminol reaction catalyzed by concentrated hemin (10^-5M). Applications of the equipment, the analyzing method and hemin as a catalyst are discussed to analytical and clinical chemistry.

View full abstract

The preparation and antigenic properties of 3β-hydroxy-5-cholen-24-oyl-glycine-bovine serum albumin (BSA) conjugate in which the hapten is linked to the carrier protein through an (O-carboxymethyl) oxime bridge at the C-19 position on the steroid portion are described. Antibody raised against the antigen in rabbits possessed high titer and specificity to 3β-hydroxy-5-cholen-24-oyl-glycine, exhibiting no significant cross-reactions with various bile acids.

View full abstract

Substitution of the 4-sulfonate in sodium 1, 2-naphthoquinone-4-sulfonate (I) with many kinds of aliphatic amines (II) yields colored 4-substituted 1, 2-naphthoquinones (Q) : 4-morpholino-Q (IIIa), 4-piperidino-Q (IIIb), 4-pyrrolidino-Q (IIIc), 4-(1, 2, 4-triazol-1-yl)-Q (IIId), 4-(2-pyrrolyl)-Q (IIIe), 4-dimethylamino-Q (IIIf), 4-diethylamino-Q (IIIg), 4-isopropylamino-Q (IIIh), and 4-(4-amino-2-methyl-5-pyrimidylmethylamino)-Q (IIIi). The eliminated sulfite adds rapidly to the 4-position in I to form a colorless by-product, disodium 2-hydroxy-1-oxo-1, 4-dihydro-4, 4-naphthalenedisulfonate (IV). The rates of reactions were measured by polarography. The formations of IIIa and IV are successive second-order reactions. The pH profile of the rate constant, with a rounded peak at pH 10, suggests nucleophilic substitution of the free base (II) at the 4-carbon in the o-quinone form (I). The hydrolysis of IIIa to 2-hydroxy-1, 4-naphthoquinone (V) is an acid-base-catalyzed pseudo-first-order reaction. The best conditions for photometric determination of morpholine (IIa) were found to be reaction of IIa with excess I at pH 8 and 25°C for 30 min.

View full abstract

The yellow chromogen produced in the assay of glutathione or glycocholic acid by their reactions with acetic anhydride and pyridine was found to be a conjugated compound containing pyridylidene and 2-oxazoline rings. The structure was confirmed by hydrolysis of the chromogen to 4-aminomethylpyridine. The same chromogen was formed with benzoylpeptides having C-terminal glycine.

View full abstract

The autolysis of semi-alkaline proteinase (SAP) purified from Aspergillus melleus was studied from the viewpoint of enzyme stability. We also prepared inactive phenylmethylsulfonyl semialkaline proteinase (PMS-SAP) in order to avoid the influence of autolysis and used it to study the denaturation profile or structural change in urea solution. Experiments with native SAP and PMS-SAP were performed in parallel under the same conditions. It was found that the rate of inactivation of this enzyme, as determined from the decrease in enzyme activity, followed firstorder kinetics and that there was a good relationship between the degree of inactivation and the amount of autolyzed products during urea treatment. The rate of urea denaturation of PMS-SAP was followed by high-performance liquid chromatography (HPLC) and circular dichroism (CD) spectral measurement ; the denatured enzyme could be completely separated from the intact PMS-SAP by HPLC. The results suggested that the inactivation of the enzyme was a result of the denaturation, which was accompanied by conformational change. Thus, it seems likely that the cause of the inactivation of SAP is denaturation rather than autolysis, because during autolysis, SAP was proteolyzed through the denatured form produced in the process of inactivation.

View full abstract

The amino acid residues responsible for the enzyme activity of semi-alkaline proteinase from Aspergillus melleus were identified by means of chemical modification studies. The modification of the enzyme with N-bromosuccinimide (NBS) resulted in the loss of the enzyme activity and a subtle alteration of conformation. NBS-modified enzyme still retained the antigenic structure, but became labile to heat and pH as the extent of modification of tryptophan increased. The relation between the extent of tryptophan oxidation and the enzyme stability suggested that 1 of the 3 tryptophan residues is important for the maintenance of structural integrity of the enzyme. The dye-sensitized photooxidation of the enzyme led to the loss of the enzyme activity with first-order kinetics. The rate of inactivation of this enzyme was pH-dependent and the rate constant-pH profile gave a sigmoidal curve with an inflection point at pH 6.5. Amino acid analysis of photooxidized enzyme indicated that the inactivation of this enzyme was directly proportional to the loss of histidine residue. Thus, these results suggested that at least 1 histidine residue is involved in the active site of the enzyme.

View full abstract

The subcellular distribution of aldehyde reductase activity has been studied in chicken liver. Most of the activity with D-erythrose as a substrate appeared in cytosol, but 11% of the total activity appeared to be present in mitochondria. Two reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent aldehyde reductases from chicken liver mitochondria have been partially purified and characterized. One enzyme (mitochondrial aldehyde reductase I) has a molecular weight of 29000 and has an isoelectric point of 7.0, whereas a second enzyme (mitochondrial aldehyde reductase II) has a molecular weight of 31000 and has an isoelectric point of 7.7. Substrate specificity studies showed that mitochondrial aldehyde reductase 1 and II are capable of reducing various aldehydes such as D-glyceraldehyde, D-erythrose, D-erythrose 4-phosphate and aromatic aldehydes. Unlike mitochondrial aldehyde reductase II, mitochondrial aldehyde reductase 1 very efficiently reduces D-glucuronic acid and succinic semialdehyde, and has higher K_m values for aldehydes. Mitochondrial aldehyde reductase I activity is much more susceptible to inhibition by sodium valproate than mitochondrial aldehyde reductase II activity. With respect to substrate specificity and inhibitor sensitivity, mitochondrial aldehyde reductase I and II could be classified as high-K_m aldehyde reductase and low-K_m aldehyde reductase, respectively.

View full abstract

Potentiation of the nerve growth factor (NGF)-mediated nerve fiber production in organ cultures of chicken embryonic dorsal root ganglia (DRG) and lumbar sympathetic ganglia (SymG) by saponins isolated from Panax ginseng C. A. MAYER and Panax japonicum C. A. MAYER and related compounds was studied in order to elucidate the structure-activity relationship. Panax saponins and related compounds so far tested did not promote nerve fiber production, but some 20 (S)-protopanaxadiol glycoside having glucose units in their two sugar moieties potentiated the effect of NGF. Removal of glucose or introduction of a hydroxy group into the side chain of ginsenoside Rd reduced the activity. Little difference was observed in the potentiation of the NGF effect by the saponins in organ cultures of DRG and SymG.

View full abstract

Six and eight peaks of activity toward 1-chloro-2, 4-dinitrobenzene (CDNB) were observed in carboxymethyl (CM)-cellulose chromatograms of hepatic glutathione S-transferases in female and male rats, respectively. These peaks were named transferases I, II, IIIa, III, IIIb, IV, V and VI in the order of elution with KCl (transferases IIIa and IIIb could not be detected in the case of female rats). Transferase I could be further resolved into at least two enzymes by CM-Sepharose CL-6B chromatography. Transferase II was confirmed to consist of YaYa subunits (ligandin) by CM-cellulose chromatography ; Habig et al. did not detect this transferase because of their use of 1, 2-dichloro-4-nitrobenzene (DCNB) as a substrate for assaying these species of transferases. Phenobarbital treatment caused 43 and 93% increases in the total activity toward CDNB in female and male rat livers, respectively. Transferases I and II were strongly induced in both sexes of rats by this treatment. Transferases IV was slightly increased in both sexes. Transferases III and V were induced in male rats, but not in female rats. The subunit species and substrate specificities of the present transferases were compared with those of reported transferases.

View full abstract

The effects of ricin, a proteinous toxin from castor bean seeds, on glucose absorption by rat small intestine have been examined by the everted sac method. Glucose absorption was affected by ricin poisoning at 1 h after oral administration, and the inhibition reached the maximum at 5h, whereas very slight impairment of glucose absorption was observed at 5h after intraperitoneal injection of ricin. The dose required for 50% impairment of glucose absorption was 10mg ricin/kg body weight of rat when determined at 5 h after oral administration. This inhibition of glucose absorption was found only when ricin or ricin B-chain had been in contact with the mucosal membrane of the small intestine of the normal rats. The inhibition was prevented by the presence of a galactose-containing sugar, lactose. The effect of ricin on glucose absorption under physiological conditions was analyzed in situ, and the increase in blood glucose level was inhibited in ricin-intoxicated rats. These results suggest that ricin, especially its B-chain, interacts primarily with the intestinal mucosa and inhibits sugar absorption of the rat small intestine. It was also inferred that ricin B-chain is cytotoxic to the epithelial absorptive cells of the small intestine, but that impairment of sugar absorption by the small intestine alone is not the direct cause of death of animals following oral administration of ricin.

View full abstract

The reactivity of several (+)-cyanidanol-3 (cianidanol) derivatives with sodium sulfite in aqueous solution was investigated at pH 7.5 and 60°C. 5, 7-O-Dimethylcianidanol was degraded by sodium sulfite to yield a water-soluble degradation product, which was assumed to be 5, 7-O-dimethylepicatechin carrying the sodium sulfonate function in place of the aliphatic hydroxy group at the C-3 position. The degradation by sodium sulfite was inhibited by the addition of boric acid and by lowering the pH of the solution to 3.0. On the other hand, 3', 4'-O-dimethylcianidanol and 5, 7, 3', 4'-O-tetramethylcianidanol were very stable in aqueous solution containing sodium sulfite. The mechanism of the attack of sulfite ion and/or bisulfite ion at the C-3 position of the dissociated form of cianidanol or 5, 7-O-dimethylcianidanol is discussed.

View full abstract

The interaction of hydralazine (HP) and a major metabolite, pyruvate hydrazone (HPH), with rat plasma protein or human serum albumin (HSA) was studied both in vivo (by the ultrafiltration method) and in vitro (at 20 and 30°C, by the equilibrium dialysis method). The binding of HP and HPH to plasma proteins was fairly high (96.0 and 81.7%. respectively) after i.v. administration to rats. HPH, which had an association constant higher than HP, was found to interact with a single class of site on HSA, while HP was bound to at least two heterogeneous binding sites. The interaction between HP and rat plasma protein or HSA was temperaturedependent at the secondary binding site, suggesting that a nonionic mechanism is involved in the binding, and the interaction at the primary site was ionic strength-dependent. In contrast, the interaction of HPH with HSA showed less temperature-dependence. The thermodynamic analyses of the HP binding process at the secondary site showed a negative value for ΔG°, a large contribution of ΔH° to ΔG° and a positive ΔS°, while at the primary site a large contribution to ΔG° by ΔS° was seen. Thus, these findings suggest that the main binding energies at the primary and secondary sites are derived from electrostatic and nonionic sources, respectively. For HPH binding, however, the predominantly bound species was ionic. HP did not induce competitive displacement of fluorescent probes except for a slight displacement of dansylamide in the presence of a high concentration of HP. This suggests that HP is bound weakly to sites other than sites I and II, two specific sites for acidic drugs, on HSA. The present results lead us to postulate that HP interacts with the receptor sites mainly by hydrophobic and hydrogen bonding forces and partly by electrostatic forces.

View full abstract

Correlations between the in vivo and in vitro dissolution rates of (α-bromoisovaleryl) urea polymorphs were investigated. The calculated dissolution rate constants obtained in the in vitro dissolution experiments were 0.135 and 0.133 (cm/min) for form I and form II, respectively. On the other hand, the crystals were administered intraduodenally into rats and the time course data of the plasma concentration were analyzed by the least-squares method on the basis of the Hixson-Crowell dissolution model for the intestinal dissolution process. The in vivo dissolution rate constants were obtained as 0.0629 and 0.0758 (cm/min) for form I and form II, respectively. These in vivo and in vitro dissolution rate constants are based on the Noyes-Nernst dissolution theory and should be comparable in nature. Nevertheless, the in vivo rate constants were about a half of those in vitro. This result suggests that the stirring efficiency in the intestine is about a half of that of the in vitro dissolution experiment in this study.

View full abstract

The effects of aminoglycosides, 3', 4'-dideoxykanamycin B (DKB), gentamicin, and amikacin, on rat kidney cortical lysosomes were investigated. The binding of ³H-DKB to the lysosomal fraction was significantly larger than that to any other subcellular fraction examined. In the presence of 10^-2M aminoglycosides, about 70% of the N-acetyl-β-D-glucosaminidase was released. However, the release of this enzyme fell below the control level at 10^-5M DKB. In the case of acid phosphatase, the release increased gradually with aminoglycosides concentration. The higher the concentration of aminoglycosides became, the greater was the fluidity of the lysosomal membrane. These results suggest that aminoglycoside binds to the lysosomal membrane and increases the membrane fluidity, leading to the release of N-acetyl-β-D-glucosaminidase and acid phosphatase from the lysosomes.

View full abstract

The metabolites of isopropylantipyrine (IPA) were identified in urine of rats by gas chromatography-mass spectrometry (GC-MS) combined with stable isotope tracer techniques. After the oral administration of an equimolar mixture of IPA and IPA-1-C₆D₅, the urinary metabolites were extracted with chloroform before or after hydrolysis with β-glucuronidase. The extracts were subjected to GC-MS after trimethylsilylation. Characteristic doublet peaks in the mass spectra indicated the presence of 13 metabolites in the urine. The metabolized positions were determined on the basis of the retained numbers of deuterium atoms after the administration of various deuterated IPAs, i.e., IPA-2-CD₃, IPA-3-CD₃ and IPA-4-CH (CD₃)₂. The identified metabolites were oxidation products of the phenyl, 2-methyl, 3-methyl and isopropyl groups and of the C-4 position of the pyrazolone ring. In humanurine, one major metabolite, hydroxyphenyl-IPA, and four minor metabolites were detected after administration of IPA.

View full abstract

The mechanisms of the enhancing effect of nonsteroidal anti-inflammatory drugs (NSAID) on rectal permeability were investigated. It was found that the interaction of NSAID with membrane components (proteins and lipids) plays an important role in the permeation process of marker drugs. Both the permeation of the drugs and the accumulation of NSAID were specifically decreased by pretreatment of the rectal membrane with HgCl₂ or papain. In liposomes prepared from rectal lipids, the permeability of the lipid layer was markedly increased by the presence of NSAID. Furthermore, NSAID induced a solvent drag effect in the permeation of marker drugs through the rectal membrane. It is suggested that the interactions of NSAID with the membrane components, as well as the solvent drag effect, are at least partly responsible for the enhanced permeability.

View full abstract

A simple, specific and sensitive ion-pair high-performance liquid chromatographic analysis was developed for aminopyrine, sulpyrine and their metabolites (4-methylaminoantipyrine, 4-aminoantipyrine, 4-acetylaminoantipyrine and 4-formylaminoantipyrine) in rabbit plasma. Following deproteinization with acetonitrile and separation on an octadecylsilane-bonded silica column (250×4mm, JASCO Fine SIL C-18), the eluted components were detected with a multiwavelength ultraviolet monitor at 260nm. The mobile phase consisted of 22% (v/v) acetonitrile and 78% (v/v) of an aqueous solution containing 10mM KH₂PO₄ and 1.24mM tetra-n-butylammonium bromide, adjusted to pH 4.5 with 0.1M phosphoric acid solution. Hexobarbital was employed as an internal standard. Based on 0.1ml of plasma, the detection limits were 0.35μM for 4-acetylaminoantipyrine, 0.35μM for 4-formylaminoantipyrine, 0.7μM for sulpyrine, 1μM for 4-aminoantipyrine, and 2μM for 4-methylaminoantipyrine at the signal-to-noise ratio of 5 : 1.

View full abstract

The effect of coadministered fluid volume on the gastrointestinal absorption of quinine was investigated in mice, rabbits and humans. In mice, an increase in fluid volume from 5 to 40ml/kg resulted in a significant increase in the maximum plasma quinine concentration (C_max) ; the time required to reach C_max (T_max) was reduced. However, fluid volume had little effect on the area under the plasma concentration-curve (AUC_0→180). The gastric emptying of quinine in the initial stage after administration increased in proportion to the fluid volume. These results indicate that in mice, an increase in fluid volume enhances the rate of gastrointestinal absorption of quinine by producing an early increase of the gastric emptying. In rabbits, quinine was introduced via a tube into the washed and emptied stomach ; an increase in fluid volume had little effect on C_max, T_max and AUC of quinine. Furthermore, the fluid volume did not affect the gastric emptying rate. In humans, C_max, T_max and AUC of quinine after oral administration were not affected even when the fluid volume was increased from 20 to 500ml. These results show that in mice, the effect of fluid intake on gastric emptying is different from that in rabbits and humans.

View full abstract

Metals-catalyzed hydrolysis of clioquinol (C) conjugates, namely C-glucuronide (CG) and C-sulfate (CS), was examined to investigate the effects of pH and ligands on the activities. The initial rates of hydrolysis (V_o) of CG and CS were measured as a function of pH in systems containing various metals. The profiles of V_o of CG varied from metal to metal, but the order of V_o in the acidic pH region was Cu (II) > Fe (III) > Ni (II) > Zn (II) > Mn (II), Mg (II), Ca (II). Acid hydrolysis of CG in the absence of metals was negligible down to pH 1. The profiles of V_o of CS were similar to that of acid hydrolysis in the absence of metals, except for the Cu (II) system, which gave a higher V_o. Under the condition [substrate] : [Cu (II)] : [ligand]=1 : 10 : 10, the hydrolysis in the presence of various ligands was a pseudo-first order reaction (rate constant=k'). All ligands which coordinate to Cu (II) reduced the value of k'. Such metals-catalyzed hydrolysis may be one of the mechanism of hydrolysis of C conjugates to produce C-metal chelates in vivo.

View full abstract

Metal-catalyzed hydrolyses of clioquinol-glucuronide (CG) and clioquinol-sulfate (CS) in the rabbit body were studied following intravenous injection of Cu (II)- or Fe (III)-gluconic acid complex system 6h after the oral administration of clioquinol (C). Molar fractions of C, CG and CS remained nearly constant through 24 h after administration of C at doses of 90-300mg/kg weight in rabbits which were not injected with Cu (II) or Fe (III). Therefore, molar fractions of C, CG and CS after the injection of Cu (II) or Fe (III) were monitored to clarify the metabolic changes of C. In rabbits injected with 2.5mg of Cu (II)/kg weight, C rapidly increased and CG and CS decreased after the injection of Cu (II). In rabbits injected with 20 mg of Fe (III)/kg weight, C and CS slowly increased and CG decreased until 18h after the injection of Fe (III). The patterns of the changes in molar fractions of C, CG and CS are consistent with the catalytic features of Cu (II) and Fe (III) seen in previous studies, and therefore, the changes in molar fractions of C, CG and CS observed in this study were considered to have been brought about as a result of metalcatalyzed hydrolyses of CG and CS or metal-catalyzed hydrolysis of CG in the rabbit body.

View full abstract

With the aim of obtaining compounds with strong antitumor activity and weak toxicity, we have synthesized a series of alkylethers, fatty acid esters, benzoates and other derivatives of RA-V, an antitumor cyclic hexapeptide discovered in Rubiae Radix, and examined their antitumor activities against P-388 lymphocytic leukemia. It was found that the introduction of C₁ and C₆ chains (hydrophobic coefficient log P=about 3.2 and 5.8, respectively) on the phenol moiety of RA-V gave the most desirable compounds in terms of antitumor activity and toxicity. The caproic ester of RA-V, the n-hexylether of RA-V and RA-VII (C₁) also exhibited strong antitumor activity against other experimental tumors (L-1210 lymphocytic leukemia, B-16 melanoma and MM2 mammary carcinoma).

View full abstract

When rat erythrocyte membranes or phosphatidylcholine (PC) liposomes were incubated in a xanthine oxidase system, lipid peroxidation was stimulated by the addition of catalase. Addition of a large amount of xanthine oxidase caused no significant increase in the lipid peroxidation of PC liposomes unless catalase was present in the reaction system. Enhanced peroxidations of both membranes and liposomes observed in the presence of catalase were strongly inhibited by superoxide dismutase (SOD), suggesting that O^-₂ is an essential species in these reactions. Several iron-chelators strongly inhibited the lipid peroxidations, suggesting an involvement of iron in the peroxidation reaction. Unless catalase was present, the rate of liposome peroxidation was stimulated only slightly by addition of Fe³⁺, but in the presence of catalase, the addition of Fe³⁺ markedly accelerated the peroxidation reaction, which was inhibited by SOD or desferrioxamine. Furthermore, the addition of Fe³⁺ to the xanthine oxidase system in the presence of catalase caused a significant decrease in the rate of cytochrome c reduction, suggesting that Fe³⁺ may be reduced to Fe²⁺ by O^-₂. The peroxidations enhanced by catalase may be induced by supply of sufficient O^-₂ and Fe²⁺ for lipid peroxidation. Histidine and 1, 4-diazabicyclo-(2, 2, 2)-octane, quenchers of ¹O₂, inhibited the peroxidation of membranes and liposomes. Mannitol and benzoate, scavengers of OH^·, showed no significant effect on the peroxidation of membranes or liposomes. These results indicate possible participation of ¹O₂ species in the O^-₂-dependent lipid peroxidation induced by the xanthine oxidase system in the presence of catalase.

View full abstract

The present study was undertaken to investigate the activities of aminopeptidases which were reported to degrade physiologically active peptides including angiotensins, vasopressin, oxytocin and so on, in various nephron segments isolated from the rat kidney. These peptidases include leucine aminopeptidase-, aminopeptidase A-, angiotensinase A- and cystine aminopeptidase-like enzymes. The activities of these peptidases were found to be higher in the proximal tubule than in other segments. In the proximal tubule, these peptidases showed their highest activities in the pars recta. The activities of aminopeptidase A- and angiotensinase A-like enzyme (s) were also high in the glomerulus. In contrast, the activities of these peptidases were hardly detectable in distally located nephron segments. From this distribution of the peptidases, we speculate that the above physiologically active peptides are metabolized in the proximal tubule, particularly in the pars recta, and that angiotensins are metabolized in the glomerulus in addition to the proximal tubule.

View full abstract

The effect of protective groups on the allylic bromination and the subsequent dehydrobromination of cholesterol and 1α-hydroxycholesterol derivatives was investigated. 1α-Hydroxy-7-dehydrocholesterol derivatives were selectively obtained in high yield by using alkoxycarbonyl groups as protective groups.

View full abstract