Effect of preinduction of metallothionein on tissue distribution of silver and hepatic lipid peroxidation.

Silver ion causes a number of toxic effects, it decreases the activities of lactate dehydrogenase and glutathione peroxidase, and the peroxidation of membrane lipids. Silver ions complex strongly to sulfhydryl groups and the effects of preinduction of metallothionein, a sulfur-rich protein, on silver administration in rats were examined. The preinduction of metallothionein decreased the mortality of mice following silver administration.

Structural studies on the bacterial lyase-resistant tetrasaccharides derived from the antithrombin III-binding site of porcine intestinal heparin.

Three discrete tetrasaccharide structures which are resistant to Flavobacterium heparinase and heparitinases I and II were isolated from porcine intestinal heparin after exhaustive digestion with a mixture of all the above enzymes, and the tri-, tetra-, and penta-sulfated structures were determined by negative ion mode fast atom bombardment mass spectrometry and 500-MHz 1H NMR analysis as delta 4,5GlcA beta 1-4GlcNAc (6-sulfate)alpha 1-4GlcA beta 1-4GlcN(N,3-disulfate), delta 4,5 GlcA beta 1-4GlcNAc(6-sulfate)alpha 1-4GlcA beta 1-4GlcN (N,3,6-trisulfate), and delta 4,5GlcA beta 1-4GlcN (N,6-disulfate)alpha 1-4GlcA beta 1-4GlcN(N,3,6-trisulfate). The three components share the 3-O-sulfated reducing GlcN and the 6-O-sulfated internal GlcN, indicating that they are structural variants derived from the nonreducing portion of the minimal pentasaccharide sequence required for binding to antithrombin III. Isolation of the pentasulfated component has never been reported.

Hydrophobicity parameter of diazines. III: Relationship of partition coefficients of monosubstituted diazines and pyridines in different partitioning systems.

The logarithm of the 1-octanol-water partition coefficient value (log Poct) was compared with those from CHCl3-water (log PCL) and di-n-butyl ether-water (log PE) for (di)azines substituted singly by nonhydrogen-bonding and hydrogen-accepting substituents (2-substituted pyrazines, 2-substituted pyrimidines, 5-substituted pyrimidines, and 2-substituted pyridines). The difference between log Poct and log PCL for diazines was primarily governed by the number of hydrogen-bonding sites in the substituent. For 2-substituted pyridines, the difference in the hydrogen-bonding association of the ring N-atom with octanol from that with CHCl3 was also significant.

Antifeedant and Insecticidal Activity of Quassinoids against Diamondback Moth (Plutella xylostella).

The antifeedant and insecticidal activities of sixteen quassinoids against 3rd instar larvae of the diamondback moth (Plutella xylostella) were compared with those of known insect antifeedant chlordimeform (1), and the structure-activity relationship was discussed. The insecticidal activity of quassin (2) was higher than that of 1, although its antifeedant activity was nearly the same as that of the reference compound.

Peripherally administered serotonin induces hyperglucagonemia in mice.

Peripherally administered serotonin (5-HT) induced a marked increase in the plasma glucagon level in mice. The hyperglucagonemic effects of 5-HT were completely antagonized by methysergide, ketanserin and ritanserin which have a high affinity for 5-HT2 receptors. However, the 5-HT3 receptor antagonist ICS 205-930 and MDL 72222 were without effect.

Hygroscopic stability and dissolution properties of spray-dried solid dispersions of furosemide with Eudragit.

Spray-dried solid dispersions of furosemide-Eudragit RS100 and RL100 (ethyl methacrylate chlorotrimethylammoniumethyl methacrylate copolymer) were studied to determine their stability at 45 degrees C and 0, 44, and 75% relative humidity and their dissolution characteristics. The crystallization rates of the solid dispersions were measured by X-ray powder diffractometry and calculated on the basis of the Jander equation to estimate physicochemical stability in the presence of water vapor. The stability of the solid dispersion depended on the kind of acrylic resins and the drug content.

Jasamplexosides A, B and C: Novel Dimeric and Trimeric Secoiridoid Glucosides from Jasminum amplexicaule.

Three new secoiridoid glucosides, jasamplexosides A, B and C, were isolated from the crude drug "Niu du teng", the leaves and stems of JASMINUM AMPLEXICAULE, together with the known secoiridoid glucosides, 10-hydroxyligstroside and jasminoside. Their structural elucidation by spectroscopic studies is described.

The effects of the serotonin1A receptor agonist buspirone on the blood glucose and pancreatic hormones in rats.

The effects of the serotonin1A (5-HT1A) receptor agonist buspirone on the plasma glucose and pancreatic hormones insulin and glucagon were investigated in rats. Buspirone elicited significant hyperglycemia and hyperglucagonemia, although it did not affect the insulin levels. Adrenodemedullation inhibited both the increase in blood glucose and glucagon levels.

One- and two-dimensional 1H-NMR characterization of two series of sulfated disaccharides prepared from chondroitin sulfate and heparan sulfate/heparin by bacterial eliminase digestion.

The 1H-NMR spectra of eight unsaturated disaccharides obtained by bacterial eliminase digestion of chondroitin sulfate and of heparan sulfate/heparin were recorded in order to construct an NMR data base of sulfated oligosaccharides and to investigate the effects of sulfation on the proton chemical shifts. These shifts were assigned by two-dimensional HOHAHA (homonuclear Hartmann-Hahn) and COSY (correlation spectroscopy) methods. The results indicated the following.

High-performance liquid chromatographic separation and spectral identification of the photoreaction products of methyl 5,8-epoxyretinoate.

Photoreaction of methyl 5,8-epoxyretinoate was investigated. Irradiation of methyl 5,8-epoxyretinoate in acetonitrile with a light from a high-pressure mercury lamp or a daylight fluorescent lamp afforded three new products, which were purified by high-performance liquid chromatography. They were characterized on the basis of spectroscopic data as 11-(Z), 13-(Z), and 11,13-di(Z) isomers, respectively.

Specific base recognition of oligodeoxynucleotides by capillary affinity gel electrophoresis using polyacrylamide-poly(9-vinyladenine) conjugated gel.

Poly(9-vinyladenine) was synthesized and utilized as an affinity macroligand entrapped within the gel matrix. Base-specific separation of oligodeoxynucleotides was achieved with high resolution and high speed by electrophoresis, using capillaries filled with conjugated polyacrylamide-poly(9-vinyladenine) gel. Oligothymidylic acids were selectively separated from the mixture of oligothymidylic and oligodeoxyadenylic acids by utilizing a specific hydrogen bonding between poly(9-vinyladenine) and oligothymidylic acids.

Amorphism and physicochemical stability of spray-dried frusemide.

The physicochemical properties of amorphous forms of frusemide, prepared by spray-drying at 50 or 150 degrees C, and their hygroscopic stability at temperatures of 25 and 40 degrees C, and at 0 and 75% relative humidity were investigated. The glass transition temperature of the amorphous form A was 44.2 degrees C as measured by differential scanning calorimetry, while that of the amorphous form B was 54.

Hyperglucagonemia induced in mice by tryptamine: involvement of the peripheral 5-HT2 receptors.

The effects of an indoleamine, tryptamine, on plasma glucagon levels were investigated in mice. Tryptamine induced dose-related increases in plasma glucagon levels. The hyperglucagonemia effects of tryptamine were completely antagonized by methysergide and ketanserin which have a high affinity to 5-HT2 receptors.

Mitogenic activities in the protein fractions of crude drugs.

Eighteen different crude drugs were extracted with hot water and saline, and protein fractions were prepared from the extracts by ammonium sulfate precipitation. Mitogenic activities of the protein fractions were examined both on human peripheral blood lymphocytes and on mouse spleen cells. Potent mitogenic activities for both human and/or mouse lymphocytes were found in the protein fractions of four crude drugs, namely, Bupleuri radix, Pinelliae tuber, Sophorae radix, and Zedoariae rhizoma.

Identification of the reaction products of the purified hyaluronidase from stonefish (Synanceja horrida) venom.

Recently we purified to homogeneity hyaluronidase from stonefish (Synanceja horrida) venom, for the first time from a marine source [Poh, Yuen, Chung & Khoo (1992) Comp. Biochem. Physiol.

Enzyme immunoassay for serum dexamethasone using 4-(carboxymethylthio)dexamethasone as a new hapten.

A sensitive and simple enzyme immunoassay for direct quantitation of serum dexamethasone was established. An antiserum with high specificity was produced by the immunization of rabbits with a newly synthesized 4-(carboxymethylthio)dexamethasone-bovine serum albumin conjugate. Alkaline phosphatase was used as a labeling enzyme.

Transformations of (+-)-salsolinol into optically active O- and/or N-methylated derivatives by several Papaveraceae plants and their tissue-cultured cells.

(+-)-Salsolinol [3], a substance possibly inducing parkinsonism, was biotransformed into optically active O- and/or N-methylated salsolinols 5, 6, and 7 by several Papaveraceae plants and tissue-culture cells derived from these plants. The bioconversion of racemic salsolinol into optically active tetrahydroisoquinolines has never been shown to occur, either in animals or in plants.

Optical resolution of (+/-)-all-trans-3-hydroxyretinal by use of high-performance liquid chromatography.

Racemic all-trans-3-hydroxyretinal (3-OH-RAL) (1) was converted by a reaction with (-)-camphanic acid chloride (CpCl) into a diastereomixture of camphanates (2a) and (2b) which was separated by preparative high-performance liquid chromatography (HPLC) to give two esters (2a) and (2b) in pure state, respectively. Saponification of (2a) and (2b) independently afforded optically active (3S)- and (3R)-3-OH-RALs (3a) and (3b), respectively, whose absolute structures were determined by circular dichroism (CD) spectra. Racemic 3-OH-RAL was separated to two peaks by HPLC using chiral column (ChiraSpher, Merck).

Rotating-disk dissolution kinetics of nitrofurantoin anhydrate and monohydrate at various temperatures.

The dissolution behavior of nitrofurantoin anhydrate and monohydrate in JP XI, second fluid (pH 6.8) was investigated at various temperatures using a dispersed-amount method and a rotating-disk method. The initial dissolution process of the monohydrate obtained by the rotating-disk method followed the Noyes-Whitney-Nernst equation, but that of the anhydrate did not.

Synergistic antiproliferative effect of interferons and azidothymidine on HL60 cells.

Proliferation of human leukemia cells, HL60, was synergistically inhibited by a combination of human interferons and azidothymidine in vitro. Combination of interferon-gamma (3000 U/ml) and azidothymidine (30 microM) inhibited cell growth by 76%, whereas interferon-gamma alone suppressed growth by 23% and azidothymidine alone by 33%. Interferon-alpha-2a and interferon-beta also exerted synergistic effects with azidothymidine, but the potentiation was weaker than that by the combination of interferon-gamma and aziodthymidine.

Metabolism of orally administered ergosterol and 7-dehydrocholesterol in rats and lack of evidence for their vitamin D biological activity.

Metabolism of orally administered ergosterol (Erg) and 7-dehydrocholesterol (7-DHC) in rats and their vitamin D biological activity were investigated. Most of orally administered Erg and 7-DHC were excreted in feces and the remaining sterols were absorbed through intestine. The absorbed sterols were not transported in skin as the intact forms but metabolized into brassicasterol and cholesterol, respectively, within 25 h.