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Volume 39, Issue 7
Displaying 1-50 of 58 articles from this issue
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Takashi KATSU, Kozo SANCHIKA, Hiroko OKAZAKI, Tomoyo KONDO, Takashi KA ...1991 Volume 39 Issue 7 Pages 1651-1654
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAmphiphile-indused tetraethylammonium ion (TEA+) uptake into hucan erythrocytes was examined along with cell shape change. A TEA+-sensitive electrode was used to determine the amount of uptake. TEA+ was preferentially incorporated into erythrocytes when amphiphiles changed cell shape to an invaginated form. This was contrasted with the release of acetylcholinesterase outside cells which occurred markedly with the amphiphiles, causing the crenated form. It was suggested that the invagination of erythrocyte membrane stimulated the formation of vacuoles, in which TEA+ existing in an external medium was entrapped.View full abstractDownload PDF (1310K) -
Naoki TAKEUCHI, Satoko HANDA, Kumi KOYAMA, KOhji KAMATA, Kaori GOTO, S ...1991 Volume 39 Issue 7 Pages 1655-1658
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThough condensation at either the carbonyl oxygen or the unsaturaced carbon adjacent to nitrogen of enaminones can occur in the reaction with the active methylene of ethyl acetoacetate, the results obtained in the condensation reactions of the enaminones 1 and 2 with ethyl acetoacetate in the presence of Knoevenagel catalysts to give the α-pyranones 3 and 4 and with the dianion of ethyl acetoacetate to give the ethyl salicylates 6 and 19 show that these reactions proceed at the latter position.View full abstractDownload PDF (652K) -
Shinya HARUSAWA, Hirotaka OSAKI, Toshiko KUROKAWA, Harumi FUJII, Ryuji ...1991 Volume 39 Issue 7 Pages 1659-1667
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSMedium- and large-membered cyclic thiolcarbonates containing an (E)- or (Z)-double bond were synthesized by two methods using [3, 3]sigmatropic ring expansion of cyclic thionocarbonates. The [3, 3]sigmatropic ring expansion proceeds exclusively via the transition state bearing the chain tethered in a cis relationship when the cyclic thionocarbonates are 8-membered or smaller. Importantly, the ring size of the cyclic thionocarbonate determines the double bond geometry of the thiolcarbonate.Conversion of the cyclic thiolcarbonates into (E)- or (Z)-allylic sulfides is also described.View full abstractDownload PDF (1259K) -
Chiriro ITO, Mayumi NAKAGAWA, Tian-Shung WU, Hiroshi FURUKAWA1991 Volume 39 Issue 7 Pages 1668-1671
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSeven new carbazole alkaloids, named pyraryafolines-B (1), -C (3), and -D (5), and euchrestines-A (7), -B (9), -C (10), and -D (11) were isolated from stem bark of Murraya euchrestifolia HAYATA (Rutaceae) collected in Taiwan and their sturctures were characterized by means of spectral methods. Pyrayafoline-B (1) was also synthesized.View full abstractDownload PDF (672K) -
Jinjun LIU, Masako NAKAGAWA, Koreharu OGATA, Tohru HINO1991 Volume 39 Issue 7 Pages 1672-1676
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe effect of temperature on the Pictet-Spengler reaction of Nb-hydroxytryptamines (1) and cysteinals (2) has been examined. The optically active nitrones (3), obtained from 1 and 2, gave the corresponding Nb-hydroxy-β-carbolines (4α and 4β) exclusively at -78°C in the presence of an excess of trifluoroacetic acid. The mechanism is discussed in relation to the stereochemistry.View full abstractDownload PDF (769K) -
Takeshi KOIKE, Hiromitsu TAKAYAMA, Shin-ichiro SAKAI1991 Volume 39 Issue 7 Pages 1677-1681
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAn efficent synthesis of the C/D ring-cleaved compounds (13S and 13R) from hirsutine (7) and their transformation into three different type of products, 8 (C-mavacurine type), 18 (isopleicarpamine type), and 22 are describedView full abstractDownload PDF (867K) -
Nobuya KATAGIRI, Masahiro NOMURA, Makoto MUTO, Chikara KANEKO1991 Volume 39 Issue 7 Pages 1682-1688
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSReductive amido bond cleavage reaction, previously elaborated by our laboratory for the synthesis of carbocyclic ribothymidine from readily available 2-azabicyclo[2.2.1]hept-5-en-3-one, was successfully applied to the synthesis of carbocyclic analogues of thymidine and related compounds.View full abstractDownload PDF (1086K) -
Tsutomu HATANO, Kazufumi YAZAKI, Akira OKONOGI, Takuo OKUDA1991 Volume 39 Issue 7 Pages 1689-1693
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new hydrolyzable tannins, praecoxins A (1), B (2), C (3) and D (4), were isolated from leaves of Stachyurus praecos SIEB. et ZUCC (Stachyuraceae), and their structures were elucidated.View full abstractDownload PDF (817K) -
Masafumi YAMAGISHI, Ken-ichi OZAKI, Yoshihisa YAMADA, Tadamasa DA-TE, ...1991 Volume 39 Issue 7 Pages 1694-1698
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe reaction of 1-carbamoylisatins 2 with 2-ethyl-2-isothiourea hydrobromide in the presence of triethylamine followed by acid-catalyzed cyclization of the resulting 4-(2-ethyl-2-isothioureido)carbonyl-3, 4-dihydro-4-hydroxy-2(1H)-quinazolinones 7 provides a general and high-yielding route to 3'-substituted spiro[imidazolidine-4, 4'(1'H)-quinazoline]-2, 2'5(3'H)-triones 8.View full abstractDownload PDF (739K) -
Tsuneatsu NAGAO, Ryuichiro TANAKA, HIKARU OKABE1991 Volume 39 Issue 7 Pages 1699-1703
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSix oleanolic aicd glucuronide saponins, scaberosides B1, B2, B3, B4, B5 and B6 were isolated from the root of Aster scaber THUNB. (Compositae) as their methyl esters, and their structures were determined based on spectral and cheimical evidence. Scaberosides have a common prosapogenin structure, oleanolic acid 3-O-glucopyranosiduronic acid, and differ in the structures of the 28-O-linked sugar moieties.Scaberoside B1 is a 28-[α-L-arabinopyranosyl] ester, scaberoside B2, a 28-[β-D-xylopyranosyl] ester, scaberoside B3, a 28-[O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl] ester, and scaberoside B4, a 28-[O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl] ester, scaberoside B5, a 28-[O-β-D-xylopyranosyl-(1→4)-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl] ester, scaberoside B6, a 28-{O-β-xylopyranosyl-(1→4)-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl] ester of the prosapogenin.View full abstractDownload PDF (807K) -
Masao TSUKAYAMA, Yasuhiko KAWAMURA, Hiroto TAMAKI, Tokunaru HORIE1991 Volume 39 Issue 7 Pages 1704-1706
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSParvisoflavone B (2', 4', 5-trihydroxy-2", 2"-dimethylpyrano[5", 6"-g]isoflavone) (2) was synthesized by regioselective reduction of 7-[2, 4-bis(benzyloxy)phenyl]-2, 3-dihydro-5-methoxy-2, 2-dimethyl-4H, 6H-benzo[1, 2-b : 5, 4-b']dipyrano-4, 6-dione (7) with sodium borohydride and dehydration of the resultant alcohol, followed by dealkylation with boron trichloride. Its angular isomer, parvisoflavone A (2', 4', 5-trihydroxy-2", 2"-dimethylpyrano[6", 5"-h]isoflavone) (1) was also synthesized from 3-[2, 4-bis(benzyloxy)phenyl]-8, 9-dihydro-5-methoxy-8, 8-dimethyl-4H, 10H-benzo[1, 2, -b : 3, 4-b']-dipyran-4, 10-dione (15) in a similar manner.View full abstractDownload PDF (580K) -
Keizo OGAWA, Takabumi NAGAI, Masahiko NONOMURA, Toshiyuki TAKAGI, Mayu ...1991 Volume 39 Issue 7 Pages 1707-1712
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAs an extension of our studies on the ene reaction of trifluoromethyl ketones, the ene reaction of trifluoroacetaldehyde was examined. The aldehyde reacted with various ene compounds as a good enophile in the presence of Lewis acids, among which methylaluminum dichloride workded best, though polymerization of the aldehyde caused by the Lewis acid among which methylaluminum dichloride worked best, though polymerization of the aldehyde caused by the Lewis acid often lowered the isolation yields of the ene reaction. The ene reaction products were successfully oxidized to trifluoromethyl β, γ-unsaturated ketones with Dess Martin reagent. Reduction of the ene reaction products followed by oxidation with Jones reagent gave saturated trifluoromethyl ketones. The β, γ-unsaturated ketone rearranged on thermolysis to an α, β-unsaturated ketone. These ketones obtained were converted to otehr types of trifluoromethyl compounds. Thus, the ene reaction of trifluoroacetaldehyde provides a versatile method for synthesis of many types of trifluoromethyl compounds. During this derivatization, a trifluoromethyl group was found to behave as a much larger substituent than a decyl group.View full abstractDownload PDF (1170K) -
Etsuo OISHI, Naokata TAIDO, Akira MIYASHITA, Susumu SATO, Syouji OHTA, ...1991 Volume 39 Issue 7 Pages 1713-1718
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSReaction of the 7-(methylsulfonyl)-1H-imidazo[4, 5-d]pyridazine (3) with 1-(N, N-diethylamino)-1-propyne (2) resulted in the formationo f the benzimidazole (5) and the 3H-imidazo[4, 5-d][1, 2]diazocine (4) through the [4+2]- and [2+2]-cycloadducts. Similarly, reaction of the 7-(methylsulfonyl)-(9) and the 7-cyano-1H-pyrazolo[3, 4-d]pyridazines (10) with 2 gave the corresponding indazoles (14, 16) and the 1H-pyrazolo[3, 4-d][1, 2]diazocines (15, 17). A similar reaction was also found to proceed between 7-(methylsulfonyl)-1H-1, 2, 3-triazolo[4, 5-d]pyridazine (18) and 2, affording the corresponding benzotriazole (20) and the 3H-1, 2, 3-triazolo[4, 5-d][1, 2]diazocine (19).View full abstractDownload PDF (851K) -
Tsuneatsu KAGAO, Ryuichiro TANAKA, Haruki SHIMOKAWA, Hikaru OKABE1991 Volume 39 Issue 7 Pages 1719-1725
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new echinocystic acid 3, 28-O-bisdesmosides, scaberosides A1, A2, A3 and A4, were isolated together with aster saponin Ha, aster saponin Hb and foetidissimoside A from the polar glycoside fraction of the root of Aster scaber THUNB. (Compositae) as their methyl esters, and their structures were determined based on spectral and chemical evidence. Scaberosides have a common prosapogenin, echinocystic acid 3-O-β-D-glucopyranosiduronic acid, and differ in the structures of the ester-linked sugar moieties. Scaberoside A1 is a 28-[O-β-D-apiofuranosyl-(1→3)-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl] ester, A2, a 28-[O-β-D-xylopyranosyl-(1→4)-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl] ester, A3, a 28-{O-β-D-apiofuranosyl-(1→3)-[O-β-D-xylopyranosyl-(1→4)-]-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl]ester, A4, a -28-{O-β-D-xylopyranosyl-(1→3)-[O-β-D-xylopyranosyl-(1→3)-O-β-D-xylopyranosyl-(1→4)-]-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl} ester of the prosapogenin.View full abstractDownload PDF (956K) -
Akito NAKAMURA, Shin-ichi NAGAI, Taisei UEDA, Nobutoshi MURAKAMI, Jins ...1991 Volume 39 Issue 7 Pages 1726-1730
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSMonensylglycine (2a) was lactonized to macrocyclic monensylglycine-1, 29-lactone (3a) by Corey's mehtod. Lactonization of monensylamino acids (2b-d) to monensylamine acid-1, 29-lactones (3b-d) was carried out by utilizing the template effect of K+ ion. Monobenzyl esters of dicarboxylic monensylamino acids (5e-f) also were lactonized followed by debenzylation to yield carboxylic monensylamino acid-1, 29-lactones (3e-f). Sodium ion transport activity of monensin (1) and the lactones (3) was measured in a liquid membra he and in guinea pig erythrocyte membrane. Monensylaspartic acid-1, 29-lactone (3d), monensylphenylalanine-1, 29-lactone (3c), and monensyltyrosine-1, 29-lactone (3d), having smaller Na+ ion transport activity than 3e, showed weak antibacterial activity, while 3e was inactive in biological tests, probably due to the lower lipophilicity.View full abstractDownload PDF (753K) -
Yasunori NIHRO, Satoshi SOGAWA, Tadamitsu SUDO, Tokutaro MIKI, Hitoshi ...1991 Volume 39 Issue 7 Pages 1731-1735
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe previously found that 3-O-dodecylcarbomethylascorbic acid (3-RASA, 2, HX-0112) exhibited a potent inhibitory effect on biochemical lipid peroxidation and that 3-RASA (3) alleviated myocardial lesions induced by ischemia-reperfusion treatment in rats. In this study we examined the mode of action of 3-RASA (3) on the inhibition of lipid peroxidation. There was no reducing activity by 3-RASA (3) (i.e., no oxide was produced) against ferric ions and superoxide anion radicals. The low reducing activity of 3-RASA (3) against a radical as compared to that of α-tocopherol was obtained by using a stable radical. However, 3-RASA (3) had a potent inhibitory effect, almost equal to the of α-tocopherol, in the model of lipid peroxidation dependent on enzymatic superoxide generation. 3-RASA (3) very strongly inhibited the chain-reaction of the peroxidation induced by Fe+2-linoleic acid hydroxyperoxide. On the basis of these findings, it appears that the anti-lipid-peroxidative effects of 3-RASA are due to the inhibition of the radical chain-reaction, as a chain-breaking antioxidant.View full abstractDownload PDF (842K) -
Youichiro NAITO, Masanori SUGIURA, Yasunari YAMAURA, Chikara FUKAYA, K ...1991 Volume 39 Issue 7 Pages 1736-1745
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSVarious catechol derivatives (β-substitued 3, 4-dihydroxystyrenes, 1-substituted 3, 4-dihydroxybenzenes, and 6-substituted 2, 3-dihydroxynaphthalenes) were synthesized and their inhibition of 5-lipoxygenease was assayed. Their structure-activity relationships were examined quantitatively with substituent and structural parameters and regression analysis. The variations in the inhibitory activity were explained in bilinear hydrophobic parameter (log P) terms, and steric (molecular thickness) and electronic (proton nuclear magnetic resonance (1H-NMR) chemical shift of the proton adjacent to the catechol group) parameter terms. The hydrophobicity of the inhibitor molecule was important, and the optimum valur of log P was about 4.3-4.6, beyond which inhibition did not increase further. A lower electron density of the aromatic ring containing the catechol group and the greater thickness of the lipophilic side chains were unfavorable to the activity. The results added a physicochemical basis for the selection of candidate compounds for developmental studies.View full abstractDownload PDF (1415K) -
Tomio YAMAKAWA, Hitoshi MATSUKURA, Yutaka NOMURA, Mitsuko YOSHIOKA, Mi ...1991 Volume 39 Issue 7 Pages 1746-1752
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of N-substituted 2-[(2-imidazolylsulfinyl)methyl]anilines (3) was synthesized and evaluated for its biological activity against gastric H+/K+-ATPase prepared from rabbit stomach and gastric acid secretions in Heidenhain pouch dogs. Monoalkyl substituents on the nitrogen atom of the aniline moiety markedly inhibited the enzyme acticity to the same degree as omeprazole, a representative H+/K+-ATPase inhibitor. Most of these compounds, administered at 3 mg/kg i.v. inhibited histamine-stimulated gastric acid secretion. The inhibitory activity of these derivatives on the enzymes at pH 6.0 was more potent than that at pH 7.4, and was distinctly correlated to stability in aqueous solution at pH 5.0.View full abstractDownload PDF (983K) -
Yukuo EGUCHI, Fujinori SASAKI, Akiko SUGIMOTO, Hisashi EBISAWA, Masayu ...1991 Volume 39 Issue 7 Pages 1753-1759
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS3-(2-Chlorophenyl)-6-ethoxycarbonyl-5, 7-dimethyl-2, 4(1H, 3H)-quinazolinedione was newly prepared. 1-Hydrogen atoms of the compound were variously substituted in order to test for their hypotensive activites on relaxing effects of the blood vessels. The compounds with 2-(1-pyrroidinyl) ethyl, 2-(1-piperidinyl)ethyl, 3-(dimethylamino)propyl, and 3-(N-benzyl-N-methylamino)propyl moieties showed significant activity. The 2-(1-piperidinyl)ethyl compound possessed activity approximately 23 times more potent than papaverine, however, it was less potent than cinnarizine.View full abstractDownload PDF (951K) -
Haruhiko SATO, Takashi DAN, Etsuro ONUMA, Haruko TANAKA, Bunya AOKI, H ...1991 Volume 39 Issue 7 Pages 1760-1772
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of substituted 7, 8-dihydrofuro[2, 3-g]-1, 2-benzisoxazole-7-carboxylic acids 9 and 7, 8-dihydrofuro[2, 3-g]benzoxazole-7-carboxylic acids 12 were synthesized and evaluated for uricosuric and diuretic activities in rats. Many of the benzisoxazole derivatives 9 showed uricosuric and only weak diuretic activities, whereas the benzoxazoles 12 exhibited potent diuretic activities with little affecting urate excretion. Among these compounds, 5-chloro-7, 8-dihydro-3-phenylfuro[2, 3-g]-1, 2-benzisoxazole 7-carboxylic acid (9b, AA-193) was found to be a potent uricosuric agent without diuretic activity and was selected for further development.View full abstractDownload PDF (1568K) -
Isao KOUNO, Miwa HASHIMOTO, Sayuri ENJOJI, Masakatsu TAKAHASHI, Hirosh ...1991 Volume 39 Issue 7 Pages 1773-1778
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFurther studies on the constituents of Illicium majus have resulted in the isolation of five new neoanisatin derivatives and two known phytoquinoides together with two known neolignans. Two of the neoanisatin derivatives are 1-hydroxyl, which are the first examples isolated anisatin derivatives so far. Another one, 2-oxoneoanisatin, exhibited picrotoxin-like convulsions in mice, the same as anisatin. THe otehr two 3, 4-dehydroxy-2-oxoneoanisatin isomers could not be separated from each other, even with high performance liquid chromatography.View full abstractDownload PDF (880K) -
Takao OKUMURA, Takeshi ASANO, Tetuo ADACHI, Kazuyuki HIRANO1991 Volume 39 Issue 7 Pages 1779-1781
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe have developed a competitive enzyme immunoassay for a drug, which was a newly synthesized anti-ulcer agent, using an enzyme immunoassay. The polyclonal anti-drug antibody coupled to biotin, peroxidase labeled drug derivatives as a tracer, and a small column of Sepharose 4B covalently bound to avidin were used in the assay. This assay is simple and rapid, and the sensitivity and the measuring range can be controlled by the flow rate of the substrate solution. The correlation between serum drug concentrations (0.1-10μg/ml) measured by gas chromatography and this assay was good (r=0.991). This principle for the assay is very practical and applicable to the enzyme immunoassay for small and large molecules.View full abstractDownload PDF (460K) -
Yoshinori TANIGAMI, Shoichi KUSUMOTO, Shigeki NAGAO, Susumu KOKEGUCHI, ...1991 Volume 39 Issue 7 Pages 1782-1787
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA rice bran polysaccharide designated RON was subjected either to partial hydrolysis with formic acid or to partial degradation by ultrasonic irradiation. A significant change in the molecular size was also observed during simple chromatography of RON on a strongly acidic ion exchange resin, although the apparent molecular weight of RON had been assumed to be more than 1×106 daltons (Da). THis fact indicates that RON exists as molecular aggregates, presumably mediated by metal cations. Degradation products with average molecular weights above ca. 1×104 Da which were obtained by any of the three methods still retained the following activities of RON : in vivo antitumor activity against Meth-A fibrosarcoma in mice by oral administration, and in vitro macrophage stimulatory effects to induce tumoricidal activity and interleukin 1 production.This molecular size was proven to be the minimum requisite for these activities because smaller fragments were scarcely active. The aggregation was characteristic of RON but not essential for its antitumor activity because definite, though slightly reduced, activity was exhibited even by the smaller fragments obtained after the ion exchange resin treatment.View full abstractDownload PDF (1003K) -
Kyoji YOSHINO, Mitsuaki SANO, Masahiro FUJITA, Isao TOMITA1991 Volume 39 Issue 7 Pages 1788-1791
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn vitro peroxidation by air, or xanthine-xanthine oxidase (xanthine-XOD) was performed to estimate the production of aliphatic aldehydes from free polyunsaturated fatty acids (PUFA), triglycerides, phospholipids and rat liver microsomes and mitochondria. The aldehyde contents in peroxidized lipids were determined by liquid chromatography and fluorescence detection. In both peroxidation, pentanal, (E)-4-hydroxy-2-nonenal (4-HN), and hexanal were produced from ω-6 PUFA rich lipids and propanal was mainly produced from ω-3 PUFA rich lipids. The aldehyde production was markedly enhanced by increasing the degree of fatty acid unsaturation. The ratios of 4-HN to hexanal production in xanthine-XOD peroxidation of the ω-6 PUFA a righ lipids, and rat liver microsomes and mitochondris were much higher than those in air peroxidation. The ratios (4-HN/hexanal) obtained in microsomes and mitochondria by xanthine-XOD were similar to those in rat liver observed in vitamin E deficient stuides. The determination of these aldehydes may be useful to estimate the kinds of fatty acids peroxidized and investigate in vivo lipid peroxidation mechanism.View full abstractDownload PDF (628K) -
Mariko SHIN, Tetsuro SHINGUU, Keiji SANO, Chisae UMEZAWA1991 Volume 39 Issue 7 Pages 1792-1795
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe metabolism of L-tryptophan by Saccharomyces uvarum (carlsbergensis) was investigated by simultaneous measuring of fluxes through kynureinase, through transaminases and into protein using L-[methylene 14C]-and L-[side chain-2, 3-3H]tryptophan. In yeast cultivated in synthetic medium (S medium), the flux into protein was predominant, closely followed by the flux leading to 2-3H liberation. The proportion of L-tryptophan metabolized via the latter fluxincreased over 10-fold (75% of total tryptophan metabolized) as the concentration of L-tryptophan was raised from 5×10-5 to 5×10-4M. L-Tryptophan metabolized via the kynureninase flux was less than 5% of total tryptophan metabolized. In yeast extract-polypepton-glucose medium (YPG medium), more tryptophan was incoporated into protein than in the S medium. Contribution of the kynureninase flux remained very low. Tryptophan metabolism via each flux changed depending on the growth phase. 2-3H liberation was shown to be primarily due to tryptophol synthesis by high performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR), indole-3-acetic acid and kynurenic acid also contributing to 2-3H liberation but to a much lesser extent. 2-3H liberation increased dose-dependently at tryptophan concentration higher than 10-5M, while the kynureninase flux reached its plateau at 10-5M. Formation of tryptophol and indole-3-acetic acid via indole-3-pyruvic acid and indole-3-acetaldehyde with indole aldehyde as a by-product was confirmed using exogenous tryptophan metabolites with indole rings.View full abstractDownload PDF (725K) -
Yoshifumi WATANABE, Izumi HORII, Yasuhisa NAKAYAMA, Toshiaki OSAWA1991 Volume 39 Issue 7 Pages 1796-1801
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSLong-term exposure to natural sun-light (UVA, UVB) induced fluorescence and caused disulfide bond formation in bovine serum albumin (BSA). The addition of cysteine enhanced the bond formation to such an extent that a solution of BSA was transformed into an insoluble gel. The disulfide bonds in the gels are derived from internal-SH groups of protein. This reaction occurred even if cysteine was added after exposure to ultaraviolet (UV)-irradiation. Fluorescent substances seem to be involved in this reaction. On the other hand, low concentrations of cysteine (&ly;5mM) inhibited both fluorescence and disulfide bond formation. The addition of glutathione to BSA produced the same effect as that of cysteine. The addition of thiourea to BSA solution inhibited fluorescence, but did not inhibit disulfide bond formation. We assume that external-SH compounds such as cysteine and glutathione, which have high reactivity with hydroxyl radicals (.OH), act not only as free-radical scavengers, but also as radical mediators in the polymerization of protein through disulfide cross-links induced by UV-irradiation. Solar UVA as well as UVB irradiation are shown to have the same effect on the protein polymerization.View full abstractDownload PDF (1150K) -
Tomomi HATANAKA, Manami OGUCHI, Kenji SUGIBAYASHI, Yasunori MORIMOTO1991 Volume 39 Issue 7 Pages 1802-1805
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAdhesive mastric devices containing a model drug, isosorbide dinitrate (ISDN), were prepared with three different types of pressure sensitive adhesives (PSAs). ISDN permeation through excised hairless rat skin from the different devices was measured in vitro. For each PSA type, the steady state permeation rate of ISDN increased proportionally with an increase of ISDN concentration in the PSA and reached a maximum level at a certain concentration. Although the concentrations reaching the maximum skin permeation level varied among PSA types, the maximum rate for each PSA type was largely similar to that for ISDN aqueous suspension. The release rate of ISDN from devices was too fast to influence the skin permeation rate for all devices. In the PSA of devices showing maximum skin permeability, ISDN crystalline was observed by polarizing microscopy and differential scanning calorimetry. These results suggest that the skin permeation of ISDN from adhesive matrix devices was controlled by the thermodynamic activity of the drug in the PSAs.View full abstractDownload PDF (1332K) -
Yoshinobu FUKUMORI, Hideki ICHIKAWA, Yumiko YAMAOKA, Eiichi AKAHO, Yos ...1991 Volume 39 Issue 7 Pages 1806-1812
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA pulverized phenacetin powder with a mass median diameter of 11μm was slightly granulated and subsequently coated to produce fine microcapsules by the Wurster process. As a membrane material, a 1 : 1 : 1 mixture of ethyl cellulose (EC), cholesterol (CH) and talc was used in the granulation, and a 1 : 1 : 0.06 mixture of EC, CH and stearyltrimethylammonium chloride in the coating. The produced microcapsules had a mass median diameter of 31μm at 60% coating level and exhibited a practically useful sustained release at 40% or more coaitng.In the granulation process, the membrane material solution was sprayed at a high rate of 14.2 ml/min upon 250g of phenacetin powder. The mass median diameter was increased to 19μm at a binder level of 3% (EC plus CH). THe granules were then dried to reduce the particle size to 14μm. This microgranulation and drying were effective for steady fluidization of the fine powder and to avoid excessive agglomeration. Coating was performed at a lower spray rate of 11.3 ml/min under a stronger agitation to avoid excessive agglomeration. During the coating proces, however, an increase in the mass median diameter by 17μm and the broadening of size distribution were unavoidable. The smallest size of paticle which could be coated with no subsequent agglomeration was estimated to be 20μm. The agglomeration of the particles smaller than 20μm which occupied 78% of the raw powder accounted for the particle growth and the broadening of size distribution.View full abstractDownload PDF (1273K) -
Kiyomi ITO, Yasufumi SAWADA, Yuichi SUGIYAMA, Manabu HANANO, Tatsuji I ...1991 Volume 39 Issue 7 Pages 1813-1819
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn vivo receptor occupancy of psychotropic drugs in brain can be estimated by measuring the tissue radioactivity of the tracer, which binds specifically to the receptor unoccupied by the drugs (back titration method). In this study, the validity of this method was evaluated by computer simulation, using various values for the plasma elimination rate, rate of transport across the blood-brain barrier, rate of receptor association and dissoclation for both drug and tracer, and the sampling time. The differential equations based on a nonlinear three-compartment model including a plasma pool, precursor pool, and specific binding pool were solved numerically by the Runge-Kutta-Gill method. The receptor occupancy calculated by this method was cloes to the true value when the plasma concentration and specific binding fraction of the drug did not change greatly during circulation of the tracer. Although the error in calculated occupancy at 5 min after the tracer administration was smaller than that at 20 min, tracer may not greatly accumulate in brain tissue during the initial 5 min in some situations. Our analysis shows that it is necessary to adequately control the elimination rate of drug from plasma and to allow sufficient time for radioactivity to accumulate in the tissue. Therefore, this method requires previous knowledge of the pharmacokinetic behavior of both the drug and the tracer in plasma and tissue. The operation scheme that we suggest for the accurate measurement of the receptor occupancy in vivo can be used in human studies with positron emission tomography and may be useful for therapeutic drug monitoring.View full abstractDownload PDF (970K) -
Yasufumi SAWADA, Kiyomi ITO, Yuichi SUGIYAMA, Manabu HANANO, Tatsuji I ...1991 Volume 39 Issue 7 Pages 1820-1827
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA mathematical allosteric coupling model has been proposed to describe the process by which binding to the benzodiazepine/γ-aminobutyric acid (GABA) receptor complex initiates a biological response. The model states that the first receptors (benzodiazepine receptors) can diffuse independently in the plane of the membrane and reversibly associate with the second receptors (GABA receptors) to regulate their activity (induction of increased choloride ion flux due to the opening of the chloride ion channel). The ratio of agonist-bound to total GABA receptor density was defined to be directly proportional to the biological response in the model. The analysis makes the following assumptions : i) the binding affinity of agonists (muscimol or benzodiazepine) to the benzodiazepine receptor/GABA receptor complex is much greater than that to each receptor alone; ii) the double receptor-single agonist (benzodiazepine, muscimol or GABA) ternary complex binds to the other agonist with a high binding affinity as compared with that of each agonist to an agonist-free receptor complex; iii) benxodiazepine receptor-GABA receptor interaction is enhanced i the presence of each agonist; iv) the GABA receptor is desensitized after the binding of GABA agonist (GABA or muscimol) to the receptor. The modeling exercise shows that the benzodiazepine concentration required for half-maximal biological response is lower than that required for half-maximal receptor binding. In the case of the GABA agonist, a linear relationship between receptor occupancy and biolological response was observed. The degree of discrepancy between the two rofiles (receptor occupancy and biological response) concerning benzodiazepine concentration dependency and time dependency increased with a decrease in the dissociation constants based on the benodizepine receptor-GABA receptor interaction. This model offers a simple explanation for discrepancies between the receptor occupancy-concentration profile of benzodiazepine and the biological response-concentration curve that are often observed in vivo and/or in vitro.View full abstractDownload PDF (1126K) -
Isao KOHDA, Hitoshi NAGAI, Masakazu IWAI, Masahiro WATANABE, Kazumasa ...1991 Volume 39 Issue 7 Pages 1828-1831
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe effects of 2-(E-2-decenoylamino)ethyl 2-(cyclohexylethyl) sulfide (compd. III-1a) on various experimental ulcers were investigated. The oral administration of compd. III-1a at doses ranging from 30 to 300 mg/kg inhibited the acute gastric ulcerations induced by ethanol, HCl-aspirin and indomethacin in rats. Compound III-1a significantly inhitbited the water immersion stress-induced gastric ulcer at dosee of 3 mg/kg, p.o. The anti-ulcer activity of plaunotolas a referenced drug was equivalent on an ethanol-induced ulcer to that of compd. III-1a, but weaker on HCl·aspirin, indomethacin and stress-induced ulcers than that of compd. III-1a. On indomethacin-produced gastric antral ulcer, compd. III-1a showed the same significant inhibitory activity as spizofurone did at a dose of 100 mg/kg, p.o, Compound III-1a also inhibited hemorrhagic shock-, diethyldithiocarbamic acid (DDC)-and platelet activating factor (PAF)-induced ulcers dose-dependently. Plaunotol only showed significant inhibitory activity on PAF-induced ulcer in these three ulcer models. The consecutive administration of compd. III-1a (100 mg/kg, p.o.) twice a day significantly accelerated the healing of an acetic acid-induced ulcer and that of plaunotol (200 mg/kg, p.o.) showed the same activity. Moreover, orally administered compd. III-1a at a dose of 100 mg/kg decreased the gastric acid secretion in pylorus-ligated rats. The results in the present studysuggest that compd. III-1a has the dual action on ulcer formation.View full abstractDownload PDF (721K) -
Isao KOHDA, Hitoshi NAGAI, Masakazu IWAI, Masahiro WATANABE, Kazumasa ...1991 Volume 39 Issue 7 Pages 1832-1836
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTha anti-ulcerogenic mechanism of 2-(E-2-decenoylamino)ethyl 2-(cyclohexylethyl) sulfide (compd. III-1a) was investigated in various gastric defensive factors. Compound III-1a maintained the high molecular glycoprotein (relative content of Fr. I hexose) and accelerated hexosamine synthesis which were reduced by water immersion stress. But plaunotol did not have these actions. The lipid peroxide level in the gastric mucosa from water immersion stressed rat was lowered by the adiministration of compd. III-1a. Compound III-1a maintained prostaglandin E2 (PGE2) and PGI2 contents which were reduced in the early phases of the stress and accelerated PGs synethesis in the late phase of the stress. Furthermore, compd. III-1a maintained phospholipase A2 (PLA2) activity which was reduced by the stress. The plaunotol treated group showed the same tendency as the compd. III-1a treated group on the lipid on the lipid peroxide level, PGE2 and PGI2 contents, and PLA2 activity, but the potency of plaunotol was less than that of compd. III-1a. Compound III-1a accelerated gastric cell proliferation in pyloric glands of hydrocortisone treated rats. Tetragastrin accelerated significantly the cell proliferation in fundic glands. The sucralfate treated group showed the same tendency as the compd. III-1a treated group but the potency of sucralfate was less than that of compd. III-1a. The results in the present study suggest that compd. III-1a has a protective action on gastric mucosa.View full abstractDownload PDF (878K) -
Hiroaki NAKAGAWA, Taketoshi KESHIKAWA, Manabu MATSUMURA, Hisashi TSUKA ...1991 Volume 39 Issue 7 Pages 1837-1842
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAn aqueous coating was studied using various water-insoluble polymers. In an aqueous suspension system of micronized polymers, the dissolving temperature (DT) of polymers dispersed in a plasticizer upon steady heating, and the cloud point (CP) of the resultant polymer solutions upon steady cooling was examined. The plasticizers with low DT and CP showed good compatibility with the polymers. The casting films obtained from various polymer suspensions showed intrinsic dissolution behavior in pH 1.2 to 7.5 aqueous media depending on the type of polymer uesd. Tables coated with the aqueous suspension system showed the same dissolution profiles as those with an organic solution coating. A comparative study of the aqueous suspension and latex dispersion of ethylcellulose showed that the latex system needed less plasticizer for film formation than the aqueous suspension system. Tablet coating and granule coating were performed using the aqueous suspension system of a jet mill ground acid-alkaline soluble polymer with propylene glycol and the latex dispersion system of an enteric anionic methacrylate with polyethylene glycol 6000, respectively. The results indicate that propylene glycol can act as a temporary plasticizer which mostly evaporates during the coating process, and that water as well as the plasticizer plays an important role in the film formation of the latex particles.View full abstractDownload PDF (860K) -
Katsuhiro SAITO, Masatoshi KOZAKI, Kazuya UENISHI, Noritaka ABE, Kensu ...1991 Volume 39 Issue 7 Pages 1843-1845
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSReactiond of 2-(N, N-dimethylamino)- and 2-(N, N-diethylamino)tropones with palladium (II) acetate in benzene in the presence of sodium acetate afforded the corresponding 7-acetoxylated 2-aminotropones. A similar acetoxylation reaction proceeded with azulene to give 1-acetoxy- and 1, 3-diacetoxyazulenes. On the other hand, phenylation at the 7-position occurred in the reaciton using 2-(N-methyl)anilinotoropone. The acetoxylations are considered to proceed through radical cation complexes formed through oxidation of amino groups by palladium.View full abstractDownload PDF (539K) -
Yukuo EGUCHI, Masayuki ISHIKAWA1991 Volume 39 Issue 7 Pages 1846-1848
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSeveral 5-substituted derivatives of 7-ethoxycarbonyl-6, 8-dimethyl-1(2H)-phthalazione were prepared by means of nitration, reductive amination, and diazonium decomposition. The substituents introduced included NO2, NH2, F, Cl, CN. Among the derivatives, the fluorine compound was obtained only in poor yield because intramolecular cyclization occurred predominantly.View full abstractDownload PDF (477K) -
Masaru KIHARA, Keiji KONISHI, Lai XU, Shigeru KOBAYASHI1991 Volume 39 Issue 7 Pages 1849-1853
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new alkaloid, hippeastrine N-oxide (7), was isolated from the flowers of Lycoris radiata HERB. (Amaryllidaceae) together with the known alkaloids galanthamine N-oxide (1), lycoramine N-oxide (3), galanthamine (4), lycoramine (6), hipeastrine (8), O-methyllycorenine N-oxide (9), O-methyllycorenine (10), homolycorine N-oxide (12), homolycorine (13), O-demethyllycoramine (14), vittatine (15), tazettine (16), lycorine (17), haemanthidine (18), and O-demethylhomolycorine (19), as well as dipalmitoylphosphatidylcholine (20) and 1-palmitoyl-2-linoleoylphosphatidyl-choline (21).View full abstractDownload PDF (765K) -
Hiroyuki ISHIBASHI, Kiyomi MATSUOKA, Masazumi IKEDA1991 Volume 39 Issue 7 Pages 1854-1856
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSLewis acid-promoted reactions of arenes with α-chloro-α-(methylthio)acetophenones 6-8 gave the Friedal-Crafts reaction products 9, which were then treated with 3 molar eq of cupric chloride in aqueous acetone to afford the unsymmetrically substituted benzils 10.View full abstractDownload PDF (501K) -
Takashi MICHIDA, Michiko MIZUHARA, Hiroteru SAYO1991 Volume 39 Issue 7 Pages 1857-1859
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe reaction of N-alkyl 2-nitrobenzenesulfenanilides (1a-3a) with N-bromosuccinimide (NBS) gave the corresponding monobrominated 2-nitrobenzensulfenanilides (1b-3b) in good yields. The initial step of this reaction is the attack on NBS of the nitrogen atom of 1a-3a. The intermediate of this reaction is considered to be a cation radical of the sulfenanilides. A similar reaction of N-unsubstituted 2-nitrobenzenesulfenanilides (5a-10a) with NBS gave mono- or di-brominated 2-nitrobenzenesulfenanilides in low yields.View full abstractDownload PDF (605K) -
Motohiko TAKI, Akihiko KUNIYASU, Hitoshi NAKAYAMA, Yuichi KANAOKA1991 Volume 39 Issue 7 Pages 1860-1862
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSDiazipine and [3H]diazipine were synthesized as new 1, 4-dihydropyridine photoaffinity ligands containing a phenyldiazirine group. After simple high performance liquid chromatography separation, both compounds were purified in good overall yields. [3H]Diazipine (21.2Ci/mmol) was synthesized in two steps from commercially available [3H]ethanolamine. Diazipine competitively inhibited [3H]PN200-110 binding to the calcium channel of cardiac membranes with high affinity.View full abstractDownload PDF (520K) -
NZUNZU LAMI, Shigetoshi KADOTA, Tohru KIKUCHI1991 Volume 39 Issue 7 Pages 1863-1865
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new rotenoids designated as boeravinones D, E, and F have been isolated from the methanol extract of the roots of Boerhaavia diffusa L. and their structures were determined based on spectral and chemical evidence.View full abstractDownload PDF (520K) -
Toshio HONDA, Akihiko OKUYAMA, Tomohisa HAYAKAWA, Hirotsune KONDOH, Ma ...1991 Volume 39 Issue 7 Pages 1866-1868
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS(±)-Pestalotin (1) was synthesized by employing a stereoselective reduction of a 5-alkyltetronate derivative (3) and a two-carbon elongation reaction of the aldehyde (13) with ethyl diazoacetate in the presence of stannous chloride as key steps.View full abstractDownload PDF (613K) -
Tenji KONISHI, Kiyoshi IWAGOE, Shiu KIYOSAWA, Yasuhiro FUJIWARA1991 Volume 39 Issue 7 Pages 1869-1870
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNew dioxan-linked bi-2-(2-phenylethyl)chromone, tentatively named AH21 was isolated from a pridine extract of agalwood "Jinko" and structurally characterized using proton and carbon-13 nuclear magnetic resonance spectra.View full abstractDownload PDF (394K) -
Ryoji KASAI, Satomi HIRONO, Wen-Hua CHOU, Osamu TANAKA, Feng-Huai CHEN1991 Volume 39 Issue 7 Pages 1871-1872
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom leaves of Engelhardtia crysolepis HANCE (Juglandaceae), which have been used as a sweet tea in China, we have isolated a sweet dihydroflavonol glycoside, and the structure was elucidated on the basis of chemical and spectral evidence as 3-O-β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl-(2R, 3R)-taxifolin.View full abstractDownload PDF (433K) -
Mariko TANOGUCHI, Etsuko HOSONO, Mayuko KITAOKA, Masao ARIMOTO, Hideo ...1991 Volume 39 Issue 7 Pages 1873-1876
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo kinds of lignans were isolated from the seeds of Hernandia ovigera L. in addition to the nine lignans previously reported. One was confirmed as (-)-dimethylmatairesinol (11) and the other was identified as 5'-methoxypodorhizol (14) by comparison with the anthentic sample. An attempt at the cyclization of 14 afforded two compounds which were determined to be isohernandin (15) and an isomer of 15, 2-hydroxymethy 1-5, 6-methylenedioxy-7-methoxy-4-(3', 4', 5'-trimethoxyphenyl)-1, 2, 3, 4-tetrahydronaphthoic acid lactone (16).View full abstractDownload PDF (574K) -
Yoshiyasu FUKUYAMA, Junko OKINO, Mitsuaki KODAMA1991 Volume 39 Issue 7 Pages 1877-1879
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe structuers of belamcandols A (1) and B (2) isolated from the seeds of Belamcanda chinensis have beenassigned to 2, 4-dimethyoxy-6-((Z)-10'-pentadecenyl)phenol and 1-O-methyl-5-((Z)-10'-pentadecenyl)resorcinol, respectively, based on spectroscopic data and chemical degradation. Belamcandol A inhibits 5-ilpoxygenase activity at IC50 0.60 μM.View full abstractDownload PDF (550K) -
Lee-Jane W. LU, Fumiyo TASAKA, James A. HOKANSON, Kohfuku KOHDA1991 Volume 39 Issue 7 Pages 1880-1882
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSUsing synthesized 8-hydroxy-2'-deoxyguanosine 3'-monophosphate as a marker, the 32P-postlabeling method was adapted with minimum modifications for the analysis of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) content in deoxy-ribonucleic acid (DNA). This method allows the analysis of one 8-OH-dG per 104 DNA nucleotides with only 10 pmoles of nucleotides required. The amounts of 8-OH-dG in DNA detected by the postlabeling method correlated well with the electrochemical detection method but were consistently lower.View full abstractDownload PDF (579K) -
Kenji AKASAKI, Hiroshi TSUJI1991 Volume 39 Issue 7 Pages 1883-1885
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe studied the hydrolysis of a neuropeptide kyotorphin (L-Tyr-L-Arg) by an enkephalin-degrading aminopeptidase purified from cytosol of rat brain in vitro. The purified enzyme was homogeneous as judged by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE), gel filtration and isoelectric focusing. The aminopeptidase with an apparent molecular weight (Mr)=98000 catalyzed the hydrolysis of Leu-and Met-enkephalins with Km values of 125 and 142μM, respectively. The enzyme activity was inhibited by bestatin, amastatin and puromycin but not by pepstatin, leupeptin and phenylmethanesulfonyl fluoride (PMSF). Kyotorphin was degraded by the aminopeptidase at pH 7.0, and the Vmax and Km values were 9.2 μmol/min/mg protein and 95μM, respectively. The Km value for kyotorphin was compatible to those for Leu- and Met-enkephalins. Taken together, these results suggest a possible involvement of the enkephalin-degrading aminopeptidase in cytosolic degradation of kyotorphin in neuronal cells of rat brain.View full abstractDownload PDF (546K) -
Makiko FUJII, Katsuhiro HARADA, Keiko KAKINUMA, Mitsuo MATSUMOTO1991 Volume 39 Issue 7 Pages 1886-1888
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe dissolution of phenobarbital (PB) from solid dispersion with phosphatidylcholine (PC) was studied. PB was present in an amorphous state in solid dispersion (PB-PC) if the mole fraction of PB was under 0.75. Thus, supersaturation was observed when an excess amount of PB-PC was dispersed in pH 1.2 and 6.8 media. The degree of supersaturation was largest when the mole fraction of PB was 0.25, although it was only 1.3-fold of the PB solubility in this case. Dissolution from PB-PC was rapid and complete in both pH 1.2 and 6.8 media regardless of the mole fraction of PB, above 90% within 5 min. Bioavailability after the oral administration of PB-PC to rabbits with a dose of 15 mg/kg equivalent to PB was compared with that of PB crystals. The area under the plasma concentration curve was bigger, but not significant. The maximum concentration was significantly higher, and the time to maximum concentration was significantly faster. These results indicate that the absorption rate became high with PB-PC because the dissolution was rapid.View full abstractDownload PDF (491K) -
Akira NAGUMO, Kazuya TAKANASHI, Yasuo SUZUKI1991 Volume 39 Issue 7 Pages 1889-1891
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSBacteriohopane-32-ol (Monol), a hopanoid with one hydroxy group in the side chain, was prepared from hopanoids of Rhodopseudomonas palustris and incorporated into liposomal membrane composed of dipalmitoylphosphatidylcholine (DPPC). The effect of the inserted hopanoid on the stability of liposomes was compared with that of cholesterol (Cho) by measuring the release of 6-carboxyfluorescein (CF) entrapped in the liposomes. Monol has a stabilizing effect on liposomal membrane but its effect is different from that of Cho. Incorporation of Cho enhanced the stability of liposomes by increasing the contents. However, the incorporation of Monol at a low content of 20 mol% lowered, and that at higher contents increased, the stability. Furthermore, in the liposomes incorporated with Monol, there is no difference between the release of CF after incubation at 37°C and 45°C.View full abstractDownload PDF (487K) -
Sveinbjorn GIZURARSON, Erik BECHGAARD1991 Volume 39 Issue 7 Pages 1892-1893
Published: July 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSLoading and release characteristics of insulin-carrying albumin and starch microspheres have been studied in vitro.The sorption characteristics of 125I-labelled insulin onto albumin microspheres were studied and were found to be completed within 5h, and the loading capacity was found to be 0.14% w/w. Insulin did not show any sorption into the matrix of the starch microspheres. The release characteristics were analyzed by high performance liquid chromatography. About 80% was released within 5-10 min from albumin microspheres and starch microspheres, respectivelyView full abstractDownload PDF (471K)