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Volume 39, Issue 3
Displaying 1-50 of 62 articles from this issue
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Takuzo HISANO, Kazunobu HARANO, Toshikazu MATSUOKA, Tatsuya MATSUZAKI, ...1991 Volume 39 Issue 3 Pages 537-544
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn connection with the pericyclic reaction of pyridine N-oxides with dipolarophiles, the cycloaddition behavior of some aromatic N-oxides toward electron-deficient allenes was investigated. In the reaction of 2-phenylpyridine N-oxide with dimethyl 2, 3-pentadienedioate, the 2, 3-dihydropyridine type 1 : 1 cycloadducts, which resulted from 1, 5-sigmatropic rearrangement of the primary cycloadduct, were isolated. The reactio of 3, 5-dihalogenopyridine N-oxides with the allene gave the dehydrohalogenated cycloadducts of the 1, 5-sigmatropic rearrangement products. The reaction of 3, 5-dimethylpyridine N-oxide with the allene caused deoxygenation to give 3, 5-dimethylpyridine. which in turn reacted with two molecules of the allene to give the 1 : 2 cycloadduct (1, 4-dipolar cycloaddition product). The structure of the cycloadduct was determined by single crystal X-ray analysis.The observed reaction behaviors are discussed in terms of frontier molecular orbital considerations.View full abstractDownload PDF (1117K) -
Seiichi MATSUGO, Nobuko KAYAMORI, Tatsuo OHTA, Tetsuya KONISHI1991 Volume 39 Issue 3 Pages 545-548
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe decomposition of 4-alkoxy-1, 4-dihydro-2, 3-benzodioxin-1-ols (1, Bd) in aqueous media was examined. Increasing the water content of the medium accelerated the decomposition of 1 and increased the formation of the corresponding 2-formyl benzoic acid ester (2) as the decomposition product. Electron spin resonance (ESR) studies using dimethylpyrroline N-oxide (DMPO) as a spin trapping reagent had revealed that bydroxyl radicals are formed during the decomposition of 1 (Matsugo et al., FEBS Lett., 184, 25 (1985)). Thus, water-mediated decomposition of 1 was suggested to occur, affording the ester 2 and hydroxyl radical. Direct involvement of water was confirmed by an 18O isotopic tracer experiment which revealed that 18O was incorporated exclusively into the formyl position of the ester 2. It is plausible that a hydrated hydroperoxide (5) is formed by the addition of water at the formyl position of the ring-opened structure of 1 at the initial stage fo the decomposition of 1. Preliminary studies on the antibacterial activities of 1 showed moderate cell-killing activity, especially to Pseudomonas strains, and the activity was found to be related to the decomposition of 1.View full abstractDownload PDF (693K) -
Weijie ZHAO, Yasuhiro TEZUKA, Tohru KIKUCHI, Jun CHEN, Yongtian GUO1991 Volume 39 Issue 3 Pages 549-554
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAlkaloidal constituents of the roots and rhizoma of Veratrum nigrum L. var. ussuriense (Liliaceae), which are used as a source of the Chinese crude drug "Li-lu, " were examined and a new alkaloid named verussurinine and six known alkaloids have been isolated. The structure of verussurinine was determined to be 16-O-(2-methylbutyroyl)germine (1) by means of spectroscopic methods, and six other alkaloids were identified as germidine (2), germerine (3), 15-O-(2-methylbutyroyl)germine (4), verazine (5), jervine (6), and neogermbudine (7), Complete assignments of the proton and carbon-13 nuclear magnetic resonance (1H- and 13C-NMR) signals of these alkaloids are also presented.View full abstractDownload PDF (749K) -
Hideki TAKAZAWA, Setsuo KASHINO1991 Volume 39 Issue 3 Pages 555-557
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new sesquiterpene, incarnal, was isolated from culture fluid of Gloeostereum incarnatum (Japanese name : Nikawaurokotake). Incarnal inhibited the growth of gram-positive bacteria at 6.25-12.5 μg/ml. The structure of incarnal has been determined to be (1-hydroxy-2, 10, 10-trimethyl)-3-methylene-tricyclo[6.3.0.0.2, 6]undec-5, 7-diene-4, 9-dione by X-ray diffraction and spectroscopic methods.View full abstractDownload PDF (496K) -
Machiko ONO, Reiko TODORIKI, Shinzo TAMURA1991 Volume 39 Issue 3 Pages 558-565
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAlcoholysis of N1-Arenesulfonyl-N1, N2-diarylacetamidines (1-30) was studied kinetically. The rate of the reaction between the substrates and ethoxide ion depended on the electron-withdrawing resonance effect of the substituents on both the N1-aryl and N2-aryl groups to a similar extent. The rate of the neutral alcoholysis depended on the resonance effect of the N1-aryl substituent to a larger extent than in the former reaction, and depended hardly at all on the electron-releasing resonance effect of the N2-aryl substituent, showing that the reaction does not proceed by the solvolysis mechanism.A reaction mechanism is proposed in which the rate-determining attack of the nucleophile is accompanied by the concerted departure of the N-arylarenesulfonamide group.View full abstractDownload PDF (1062K) -
Yoshitaka IKEDA, Masanori SUGIURA, Chikara FUKAYA, Kazumasa YOKOYAMA, ...1991 Volume 39 Issue 3 Pages 566-571
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSDuring the course of our screening of bioactive natural products, three new saponins named periandradulcins A (1), B (2) and C (3) were isolated as phosphodiesterase (PDE, EC 3.1.4.17) inhibitors from 80% MeOH extract of the roots of Periandra dulcis MART. (Leguminosae) by a combination of column chromatography and reversed- and normal-phase high-performance liquid chromatography (HPLC). On the basis of -1H, 13C- and two-dimensional nuclear magnetic resonance (NMR) spectral data and chemical evidence, their chemical structures were characterized as 3-O-β-[α-L-rhamnopyranosyl(1→2)-β-D-xylopyranosyl(1→2)-β-D-glucuronopyranosyl]-30-hydroxyl-25-formylolean-18-ene-22β-O-syringate, 3-O-β-[α-L-rhamnopyranosyl(1→2)-β-D-xylopyranosyl(1→2)-β-D-glucuronopyranosyl]-22β-hydroxyl-25-formylolean-12-ene and 3-O-β-[α-L-rhamnopyranosyl(1→2)-β-D-glucopyranosyl(1→2)-β-D-glucuronopyranosyl]-22β-hydroxyl-25-formylolean-18-ene, respectively.The concentrations of periandradulcins A, B and C required to give 50% inhibition (IC50 values) of PDE from bovine heart, were 0.033, 7.6 and 7.7 μM, respectively. Compound 1 was the most potent among the known PDE inhibitors; it inhibited PDE-I (IC50 : 0.0022 μM) twenty and forty times more effectively than PDE-II and -III, respectively.View full abstractDownload PDF (880K) -
Hisashi ISHI, Takao SUGIURA, Kimiko KOGUSURI, Toshiko WATANABE, Yasuok ...1991 Volume 39 Issue 3 Pages 572-578
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn order to clarify the mechanism of Fischer indolization of 2-methoxyphenylhydrazones, Fischer indolization of ethyl pyruvate 2-(2-methoxyphenyl)phenylhydrazone (2) was carried out with hydrochloric acid in ethanol and zinc chloride in acetic acid. The reactions proceeded smoothly to give N-arylindoles (11-14) and some chlorinated diphenylamine derivatives (8-10) as by-products. Consideration of the indole products revealed that the Fischer indolization proceeded mainly at the unsubstitued phenyl nucleus rather than at the 2-methoxyphenyl nucleus. This result is inconsistent with the previous result that Fischer indolization of diarylhydrazones proceeded at the electron-richer nucleus. The structures of the diphenylamines were determined by chemical means and the mechanism of their formation is discussed.View full abstractDownload PDF (1108K) -
Mitsuaki WATANABE, Kenji KAWANISHI, Sunao FURUKAWA1991 Volume 39 Issue 3 Pages 579-583
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS2-Methyl-5-(tert-butyldimethylsilyloxy)phenyl N, N, N', N'-tetramethylphosphorodiamidate was lithiated with sec-BuLi in the presence of N, N, N', N'-tetramethylethylenediamine at -105°C to generate the corresponding benzylic anion. This benzylic anion was reacted with various methyl benzoates to provide deoxybenzoin derivatives which, without purification, were treated with formic acid to give 2-aryl-6-hydroxybenzo[b]furans. The utility of this strategy has been demonstrated by its application to the short synthesis of phytoalexins, such as vignafuran, 6-demethylvignafuran, and moracin M.View full abstractDownload PDF (859K) -
Koichi KAWASAKI, Toshiki TSUJI, Katsuhiko HIRASE, Masanori MIYANO, Yos ...1991 Volume 39 Issue 3 Pages 584-589
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSN-Terminal tripeptide analogs of fibrin α-chain were synthesized and their inhibitory effect on fibrinogen/thrombin clotting was examined. A new water-soluble active ester, 3-pyridinium ester, was used for the synthesis. Among the synthetic peptides, H-Gly-Pro-Arg-hexamethyleneimine exhibited the highest inhibitory effect on fibrinogen-thrombin clotting.View full abstractDownload PDF (1147K) -
Kunio HIGASHI, Kiyoshi NAKAYAMA, Kouichi UOTO, Emiko SHIOYA, Tsuneo KU ...1991 Volume 39 Issue 3 Pages 590-592
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA novel glycoside anomerization occurred when trimethylsilyl bromide (TMSBr) and zinc bromide were utilized in combination as a catalyst. Treatment of β-glycosides with TMSBr and zinc bromide in the presence of alcohols afforded anomerized products in good yields.View full abstractDownload PDF (477K) -
Yauhiro TEZUKA, Hiroyuki HIRANO, Tohru KIKUCHI, Guo-Jun XU1991 Volume 39 Issue 3 Pages 593-598
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSConstituents of Ephemerantha lonchophylla (HOOK. f.) P. F. HUNT et SUMMERH, which is used as a source plant of the Chinese crude drug "Shi-Hu", were examined and four new phenolic compounds, 3-O-methylgigantol (2), ephemeranthoquinone (3), ephemeranthol-A (5), and ephemeranthol-B (7), and a new diterpene glucoside named ephemeranthoside (9) were isolated along with four known compounds, denbinobin (1), 4, 7-dihydroxy-2, 3-dimethoxyphenanthrene (4), erianthridin (6), and gigantol (8). The structures of the new compounds were determined on the basis of spectroscopic data.View full abstractDownload PDF (795K) -
Tsuneatsu NAGAO, Ryuichiro TANAKA, Yukiko IWASE, Hiroshi HANAZONO, Hik ...1991 Volume 39 Issue 3 Pages 599-606
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom the herb of Luffa acutangula ROXB. (Cucurbitaceae), seven oleanane-type triterpene saponins, acutosides A-G, were isolated and their structures were determined.Acutoside A is oleanolic acid 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside. Acutosides B, D, E, F and G have a common prosapogenin structure, acutoside A, and only differ in the structures of the ester-linked sugar moieties. Acutoside B is a 28-O-[O-β-D-xylopyranosyl-(1→4)-O-α-L-rhamopyranosyl-(1→2)-α-L-arabinopyranosyl] ester, D is a 28-O-[O-β-D-xylopyranosyl-(1→3)-O-β-D-xylopyranosyl-(1→4)-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl] ester, E is a 28-O-[O-α-L-arabinopyranosyl-(1→3)-O-β-D-xylopyranosyl-(1→4)-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl] ester, F is a 28-O-[O-β-D-xylopyranosyl-(1→3)-[O-β-D-xylopyranosyl-(1→4)]-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl] ester, and G is a 28-O-[O-β-D-xylopyranosyl-(1→3)-[O-α-L-arabinopyranosyl-(1→3)-O-β-D-xylopyranosyl-(1→4)]-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl] ester. Acutoside C is a machaelinic acid (=21β-hydroxyoleanolic acid) saponin having the same sugar moiety as that of acutoside B.View full abstractDownload PDF (1240K) -
Yuko TSUDA, Yoshio OKADA, Miho TANAKA, Nobuharu SHIGEMATSU, Yasuhiro H ...1991 Volume 39 Issue 3 Pages 607-611
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe structure of WS1279, isolated from Streptomyces sp. as an immunoactive lipopeptide, has been deduced on the basis of chemical and physical evidence as S-[2, 3-bis(palmitoyloxy)propyl]-Nα-palmitoyl-Cys-Asn-Ser-Gly-Gly-Ser-OH. This was confirmed by synthesis.View full abstractDownload PDF (977K) -
Takashi HARAYAMA, Reiko YANADA, Taishin AKIYAMA, Mihiko TANAKA, Yuki F ...1991 Volume 39 Issue 3 Pages 612-615
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSBromohydrins (2, 3, 4, and 5), oxidatively damaged products of thymine bases, were repaired on exposure to sunlight, heat, and/or some reagents to regenerate the thymine bases. A radical mechanism is proposed for the repair reaction with sunlight and beat. A hypothesis concerning the biological significance of thymidine in deoxyribonucleic acid is presented.View full abstractDownload PDF (639K) -
Kunio HIROI, Jun ABE1991 Volume 39 Issue 3 Pages 616-621
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe palladium-catalyzed asymmetric allylations of chiral enamines, derived from (S)-2-(diphenylphosphinomethyl)pyrrolidine, produced optically active α-allyl carbonyl compounds in high optical yields. The phosphino group in the chiral enamines presumably serves as a chiral ligand in these palladium-catalyzed reactions. In the transition states of π-allylpalladium complexes coordinated with the intramolecular phosphine group, the anionic counterparts or allylating reagents are considered to play an important role in controlling of the grade of the enantioselectivity.View full abstractDownload PDF (930K) -
Yusuke AMINO, Hisao IWAGAMI1991 Volume 39 Issue 3 Pages 622-625
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSReductive elimination of vicinal acetylated halohydrins with Na2S2O4 as the reducing agent and viologen as the reduction mediator in a two-phase water-organic system is described. 2', 3'-Unsaturated nucleosides such as 1-(5-O-acetyl-2, 3-dideoxy-β-D-glycero-pent-2-enofuranosyl)adenine, -hypoxanthine and uracil were obtained from 2'(3')-acetoxy-3'(2')-halogeno derivatives in good yields by meanes of this procedure.View full abstractDownload PDF (637K) -
Masafumi YAMAGISHI, Yoshihisa YAMADA, Ken-ichi OZAKI, Junichi TANI, Ma ...1991 Volume 39 Issue 3 Pages 626-629
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSReaction of 1-ethoxycarbonylisatin (1b) with urea gave 5-(2-ethoxycarbonylaminophenyl)-5-hydroxyhydantoin (4b) in a good yield. Treatment of 4b with several amines directly gave the corresponding spiro[imidazolidine-4, 4'(1'H)-quinazoline]-2, 2', 5(3'H)-trione derivatives (7a-d) in moderate yields. 3-Unsubstituted and 3-methylspiroquinazolin-2-one derivatives 7a, b were also synthesized from 5-ethoxy and 5-ethylthiohydantoins 5a, d, which in turn were easily obtained by the reaction of either ethanol or ethylmercaptan with 4b in the presence of a catalytic amount of sulfuric acid.View full abstractDownload PDF (734K) -
Seung-Ho LEE, Takashi TANAKA, Gen-ichiro NONAKA, Itsuo NISHIOKA1991 Volume 39 Issue 3 Pages 630-638
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA chemical investigation of tannins in three Euphorbia species (E. helioscopia, E. jolkini and E. supina) has led to the isolation and characterization of four new hydrolyzable tannins, named supinanin (15), euphorscopin (16), euphorhelin (17) and jolkianin (18), together with fourteen known compounds (1-14). On the basis of chemical and spectroscopic evidence, the structures of supinanin and euphorscopin were established as 1, 3, 6-tri-O-galloyl-2, 4-(S)-dehydrohexahydroxydiphenoyl-β-D-glucose (15) and 1, 3-(S)-dehydrohexahydroxydiphenoyl-2-O-galloyl-4, 6-(S)-hexahydroxydiphenoyl-β-D-glucose (16), respectively. Euphorhelin and jolkianin were characterized as dimeric hydrolyzable tannins (17 and 18, respectively), in which two glucopyranose units are linked via valoneoyl and dehydrodigalloyl groups, respectively, and each molecule possesses a dehydrohexahydroxydiphenoyl group.View full abstractDownload PDF (1196K) -
Ya-Ming XU, Takashi SAKAI, Takashi TANAKA, Gen-ichiro NONAKA, Itsuo NI ...1991 Volume 39 Issue 3 Pages 639-646
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTo avoid tautomerism in the hydrolyzable tannins which lack an acyl group at the glucose C-1 position, a new method for the protection fo the C-1 atom has been developed. That is reaction of the tannins with p-anisidine in the presence of acetic acid, followed by sodium cyanoborohydride reduction, afforded, without notable hydrolysis of ester bonds, the aminoalditol derivatives (1a-7a) in 50-80% yields. The proton and carbon-13 nuclear magnetic resonance (1H-and 13C-NMR) spectra of these derivatives exhibited much simpler signal patterns typical of an open-chain form of glucose, and almost all the singals could be assigned.Application of this method to the structure elucidation of the new tannins, flosin A (22) and reginins A (23) and B (24), isolated from the leaves of Lagerstroemia flos-reginae RETZ. (Lythraceae), established their structures including the orientation of the 4, 6-positioned valoneoyl group. In addition, the structure of a new hydrolyzable tannin, lagerstroemin (21), which was concomitantly isolated from the above species, was elucidated.View full abstractDownload PDF (1154K) -
Ya-Ming XU, Takashi TANAKA, Gen-ichiro NONAKA, Itsuo NISHIOKA1991 Volume 39 Issue 3 Pages 647-650
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFurther chemical work on tannins in the leaves of Lagerstroemia flos-reginae RETZ. (Lythraceae) has resulted in the isolation of new monomeric (flosin B) and dimeric ellagitannins (reginins C and D), together with pterocarinin A (1) and 5-desgalloylpterocarinin A (2). On the basis of chemical and spectroscopic evidence, the structure of flosin B was determined to be a C-glycosidic ellagitannin (3) possessing a valoneic acid dilactonyl group, while reginins C and D were characterized as dimeric ellagitannins (6 and 10, respectively), in which a pedunculagin moiety is connected to pterocarinin A and casuarinin [the C-1 epimer of stachyurin (5)] moieties, respectively, through a carbon-to-oxygen bond.View full abstractDownload PDF (611K) -
Norihiko SEKO, Kohichiro YOSHINO, Koichi YOKOTA, Goro TSUKAMOTO1991 Volume 39 Issue 3 Pages 651-657
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSDiphenylimidazole and diphenylthiazole derivatives were synthesized and tested as inhibitors of platelet aggregation in in vitro experiments with the rabbit. Diphenylthiazole derivatives (10) were more potent than diphenylimidazole derivatives (4) in inhibiting arachidonic acid-induced platelet aggregation of rabbit platelet-rich plasma. Two diphenylimidazole and eight diphenylthiazole derivatives were evaluated for ex vivo arachidonic acid and collagen-induced platelet aggregation inhibitory activity using guinea pigs. In these compounds, 4, 5-bis(4-methoxyphenyl)-2-(1, 5-dimethyl-2-pyrrolyl)thiazole (10n) showed strong activity in vitro and ex vivo. The ex vivo activity of 10n was 200 times stronger than that of aspirin. The mechanism of the activity of 10n was the inhibition of cyclo-oxygenase.View full abstractDownload PDF (1026K) -
Mitsuru IMUTA, Shoichiro UYEO, Tadashi YOSHIDA1991 Volume 39 Issue 3 Pages 658-662
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe synthesis of 1α- and/or 1β-methylcarbapenems, 2-unsubstituted and 2-(5-methyl-1, 3, 4-thiadiazol-2-yl)thiomethyl derivatives having a 1-(hydroxy)methylethylidene or cyclic carbonate side chain at the C-6 position, is described. The in vitro antibacterial activities of these compounds and their corresponding 1-unsubstituted carbapenems are compared.View full abstractDownload PDF (854K) -
Mitsuru IMUTA, Hikaru ITANI, Hisao ONA, Yoshinori HAMADA, Shoichiro UY ...1991 Volume 39 Issue 3 Pages 663-671
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe synthesis and antibacterial activity of the 1-methylcarbapenems, 2-heteroaromatic-thiomethyl and 2-carbamoyloxymethyl derivatives having a 6-[(R)-1-hydroxyethyl] side chain, are described. The introduction of a methyl substituent at the C-1 position was accomplished by a newly developed procedure using crotyl halides and zinc dust. The 2-hydroxymethyl carbapenems as key intermediates allowed an easy entry into the preparation of title carbapenems.View full abstractDownload PDF (1558K) -
Mitsuru IMUTA, Hikaru ITANI, Hisao ONA, Toshiro KONOIKE, Shoichiro UYE ...1991 Volume 39 Issue 3 Pages 672-678
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe synthesis and antibacterial activity of a series of 1β-methylcarbapenems having quaternary heteroaromatic-thiomethyl groups at the C-2 position are described. Both 2-hydroxymethyl and 2-chloromethyl carbapenems (1 and 7) respectively served as the common key intermediates for the preparation of these compounds. Of these, the 4-pyridiniothiomethyl derivatives exhibited the best antibacterial properties and turned out to possess high in vivo efficacy as well.View full abstractDownload PDF (1197K) -
Ikuo UEDA, Katsuyuki ISHII, Heihachiro ARAI, Shin-ichi IKEDA, Yuji HIT ...1991 Volume 39 Issue 3 Pages 679-684
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA novel indomethacin ester prodrug, 2-[N-[3-{3-(piperidinomethyl)phenoxy}propyl]carbamoylmethylthio]ethyl 1-(p-chlorobenzoyl)-5-methoxy-2-methylindole-3-acetate (1) was prepared from a new histamine H2-receptor antagonist, [N-[3-{3-(piperidinomethyl)phenoxy}propyl]-2-(2-hydroxyethylthio)acetamide (2) and indomethacin (3). The compound 1 was shown to be essentially similar to 3 in its antiinflammatory action and to almost completely inhibit carrageenin-induced hing-paw edema in the rat at a very high dose of 230 mg/kg (280 μmol/kg), which is comparable to that of 100 mg/kg (280 μmol/kg) of 3, without producing gastric lesions. On a molar basis, the acute gastric lesioning properties of 1 were near one-hundred times less than those of 3, resulting in over a twenty-fold improvement in the ratio of antiedema activity to ulcerogenicity. The effect of the co-administration of histamine H2-receptor antagonists on antiedema activity and ulcerogenicity caused by 3 is also discussed.View full abstractDownload PDF (903K) -
Kaoru FUJI, Hai-Jian XU, Hiroshi TATSUMI, Hidekazu IMAHORI, Nozomu ITO ...1991 Volume 39 Issue 3 Pages 685-689
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo active sites responsible for antitumor activity, an oxirane ring and an α-methylene-cyclopentanone moiety, have been extracted from studies on the structure-activity relationship of the cytotoxic diterpenoids isolated from Rabdosia shikokiana. Series of the simplified cyclopentanone derivatives containing both of the two active sites in the molecule have been synthesized and evaluated for cytotoxicity against P 388 cells. The compounds possessing both of two active sites displayed cytotoxicity at a concentration of 1 μg/ml, while those possessing a single active site showed no activity.View full abstractDownload PDF (852K) -
Yoshihiro KANO, Qine ZONG, Ken-ichi KOMATSU1991 Volume 39 Issue 3 Pages 690-692
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe orally administered Goshuyu-to ( ?? ?? ?? ?? ) or Evodia fruit ( ?? ?? ?? ) extract and Ginger ( ?? ?? ) extract to untreated rats, and found a slight but not significant rise in their body temperature. In rats treated with chlorpromazine, the administration of Goshuyu-to prevented decrease in the body temperature. After administration of each extract of component crude drugs (Evodia fruit, Ginger, Ginseng : ?? ??, Jujube : ?? ?? ), such an effect was recognized only by Evodia fruit, and other component crude drugs exhibited no body temperature retaining effect in this experiment system. We further studied the effect of Evodia fruit alkaloid hydroxyevodiamine, evodiamine, rutaecarpine and evocarpine used individually and confirmed that the body temperature retaining effect occurred mainly with evodiamine.View full abstractDownload PDF (606K) -
Hiroshi MORITA, Masahiko NAKAYAMA, Hiroshi KOJIMA, Koichi TAKEYA, Hide ...1991 Volume 39 Issue 3 Pages 693-697
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSCasearins G-R, new cytotoxic clerodane diterpenes have been isolated from the leaves of Casearia sylvestris SW. (Flacourtiaceae). Their structures have been elucidated by spectroscopic methods and chemical conversions, and their structure-activity relationships have been discussed.View full abstractDownload PDF (781K) -
Yutaka SASHIDA, Kazuhiro KAWASHIMA, Yoshihiro MIMAKI1991 Volume 39 Issue 3 Pages 698-703
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom the bulbs of Allium giganteum, three new steroidal saponins, (25R)-3-O-acetyl-5α-spirostan-2α, 3β, 5α, 6β-tetraol 2-O-β-D-glucopyranoside (2), (25R)-5α-spirostan-2α, 3β, 5α, 6β-tetraol 2-O-β-D-glucopyranoside (3) and (25R)-3-O-benzoyl-5α-spirostan-2α, 3β, 5α, 6β-tetraol 2-O-β-D-glucopyranoside (4), have been isolated. The new saponins are unique in structure having the sugar moiety at the C-2 hydroxyl position on the steroidal skeleton.View full abstractDownload PDF (803K) -
Qing-Ming CHE, Teruaki AKAO, Masao HATTORI, Kyoichi KOBASHI, Tsuneo NA ...1991 Volume 39 Issue 3 Pages 704-708
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSBy anaerobic incubation with a bacterial mixture from human feces, aloesin (aloeresin B; 1) was converted to 2-acetonyl-7-hydroxy-5-methylchromone (aloesone; 3) and dl-7-hydroxy-2-(2'-hydroxypropyl)-5-methylchromone (aloesol; 4a+4b) through a cleavage of the C-glucosyl bond, followed by reduction of the acetonyl side chain. An analogous compound, aloeresin A (2), was converted to p-coumaric acid and aloesin (1), the latter being subsequently transformed to aloesone (3) and dl-aloesol (4a+4b). On the other hand, 7-O-methylated derivatives (7, 5a and 5b) of aloesin and of 8-C-glucosylaloesol were not cleaved to the corresponding aglycones, suggesting the importance of a free hydroxy group adjacent to the C-glucosyl group in the molecule for the bacterial cleavage of aloesin derivatives. This is the first report on the cleavage of the C-glycosyl bond of chromone C-glucosides by intestinal bacteria.View full abstractDownload PDF (794K) -
Yutaka SASHIDA, Kazunori OGAWA, Makoto KITADA, Hiroyuki KARIKOME, Yosh ...1991 Volume 39 Issue 3 Pages 709-711
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new glucosides of (Z)-6, 7, 3', 4'-tetrahydroxyaurone, (Z)-7-O-β-D-glucopyranosyl-6, 7, 3', 4'-tetrahydroxyaurone, (Z)-6-O-(6-O-p-coumaroyl-β-D-glucopyranosyl)-6, 7, 3', 4'-tetrahydroxyaurone, (Z)-6-O-(6-O-acetyl-β-D-glucopyranosyl)-6, 7, 3', 4'-tetrahydroxyaurone, together with (Z)-6-O-β-D-glucopyranosyl-6, 7, 3', 4'-tetrahydroxyaurone, and two new phenylpropanoid glucosides, 4-O-(6-O-p-coumaroyl-β-D-glucopyranosyl)-p-coumaric acid and 4-O-(2-O-acetyl-6-O-p-coumaroyl-β-D-glucopyranosyl)-p-coumaric acid, have been isolated from the fresh leaves of Bidens pilosa. These structures have been elucidated on the basis of spectral data and chemical correlation.View full abstractDownload PDF (644K) -
Kaoru KINOSHITA, Junko TANAKA, Keiko KURODA, Kiyotaka KOYAMA, Shinsaku ...1991 Volume 39 Issue 3 Pages 712-715
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom Leonuri Fructus, a cyclic peptide composed of twelve amino acid residues was isolated. The sequence of the residues was established by mass spectroscopy and by the use of a protein sequencer for the partial hydrolysates obtained by α-chymotrypsin.View full abstractDownload PDF (586K) -
Shunsuke TOYOKAWA, Tadahiro TAKEDA, Yukio OGIHARA1991 Volume 39 Issue 3 Pages 716-719
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new abortifacient protein, named karasurin, was isolated from fresh root tubers of Trichosanthes kirilowii MAXIMOWICZ var. japonicum KITAMURA (Cucurbitaceae, Japanese name : kikarasuuri) by the procedure involving acetone fractionation and ion-exchange chromatography on Toyopearlpak SP 650S. Homogeneity of Karasurin was demonstrated by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, and high performance liquid chromatography (HPLC). Karasurin was a highly basic protein of pI 10.1 and the molecular weight was estimated as 28000 by SDS-polyacrylamide gel electrophoresis. Karasurin showed a strong abortion effect in pregnant mice.View full abstractDownload PDF (548K) -
Atsunori KAIBARA, Misako HIROSE, Terumichi NAKAGAWA1991 Volume 39 Issue 3 Pages 720-723
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe contribution of hydrophobic interaction to the protein binding of acidic drugs has been evaluated in terms of a new hydrophobic index (r-value), defined as the slope of the log-log plots of capacity factor vs. reciprocal of methanol concentration in an aqueous binary mobile phase, measured by the reversed-phase high-performance liquid chromatography. The logarithms of the binding constants (log K1) of the selected acidic drugs and the related aromatic carboxylic acids indicated linear relationship with their r-values, suggesting that the effect of hydrophobicity on protein binding can be explained similarly to that on the retention onto the reversed-phase stationary ligand.View full abstractDownload PDF (601K) -
Mitsuru IRIKURA, Akira TAKADATE, Shujiro GOYA, Masaki OTAGIRI1991 Volume 39 Issue 3 Pages 724-728
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS7-Alkylaminocoumarin-4-acetic acids I-IX having alkylamino groups different in alkylchain length were synthesized as fluorescence probes for characterization of drug-binding sites on human serum albumin (HSA). The fluorescences of I-IX were quenched or enhanced in the presence of HSA with shifts of the emission maxima to shorter wavelength. The binding constants and the number of binding sites were determined by the spectral changes of the probes I-IX bound to HSA through analysis of Scatchard's and Job's plots. The primary binding sites of the tested probes were found to be site 2 (diazepam site) on HSA from the results of competitive displacement studies. The polarity of site 2 was estimated from the relationship between the emission maximum of the probe of IV and Z-values, and was found to be comparable to that of acetonitrile. Simple attempts to estimate the site 2 region from the molecular size of the probe of VIII obtained using the Corey-Pauling-Koltun molecular model suggest that the hydrophobic cleft at site 2 is about 21-25 Å in depth. The distance between the lone tryptophan residue in HSA and probes bound to site 2 was estimated to be 15-17 Å using Forster's equation on the basis of fluorescence energy transfer. The present data suggest that I-IX are useful as fluorescence probes for the characterization of site 2 on HSA.View full abstractDownload PDF (756K) -
Dong-Hyun KIM, Kyoichi KOBASHI1991 Volume 39 Issue 3 Pages 729-731
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSInduction and inhibition of a novel sulfotransferase produced by Eubacterium sp. A-44 isolated from human feces have been studied. Production of the enzyme was induced by phenylsulfate esters, sulfate donor substrates, but not by phenols, sulfate acceptor substrates, or inorganic sulfate.p-Nitrophenylsulfate (PNS), a good donor substrate, stimulated enzyme production more than 10-fold. Sulfotransferase production was strongly inhibited by phenylphosphate esters. Enzyme activity was competitively inhibited by phenylphosphate esters, but not by inorganic phosphate. High yields of sulfotransferase from sonicated cells were obtained when the bacteria were grown in a media containing 0.6% (w/v) or less of glycine.View full abstractDownload PDF (539K) -
Takako YOKOZAWA, Hae Young CHUNG, Tae Woong LEE, Hikokichi OURA, Gen-i ...1991 Volume 39 Issue 3 Pages 732-736
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe renal responses of magnesium lithospermate B were investigated in the presence or absence of pretreatment with the converting enzyme (kininase II) inhibitor, captopril, in rats with adenine-induced renal failure. Magnesium lithospermate B (10 mg/kg body weight) cased a marked increase in the levels of the renal functional parameters (glomerular filtration rate, renal plasma flow and renal blood flow), accompanied by significant increases in urinary excretions of prostaglandin E2 (PGE2), kallikrein, sodium and creatinine. The administration of magnesium lithospermate B in combination with captopril (2 mg/kg body weight, 2 times) caused a further increase in renal functional parameters, urinary sodium and creatinine excretions. However, the kallikrein activity was similar to the control level. There were no significant changes between urinary PGE2 following magnesium lithospermate B alone, or in combination with captopril. In addition, angiotensin converting enzyme activity did not change following the administration of magnesium lithospermate B alone, but was significantly decreased in rats given captopril, both alone and in combination with magnesium lithospermate B. The captopril administration group (captopril alone or in combination with magnesium lithospermate B) showed a significant decrease in blood pressure. From these results, it seems that the combination of magnesium lithospermate B and captopril induces a further increase in renal function by improving the renal circulatory state.View full abstractDownload PDF (826K) -
Koichi SAKURAI, Taketo OGISO1991 Volume 39 Issue 3 Pages 737-742
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSDeoxyribose (DOR) degradation, an indicator of hydroxyl radical (OH·) generation, was observed in the reaction system of glutathione (GSH)-alloxan in the presence of Fe3+-ethylenediaminetetraacetic acid (EDTA). GSH had a biphasic action on the DOR degradation, i.e. GSH at low concentrations caused marked activation and at high concentrations had an inhibitory effect. GSH at high concentrations had an ability to scavenge OH· in the hypoxanthin-xanthine oxidase in the presence of Fe3+-EDTA and to inhibit the oxygen consumption and the generation of the alloxan radical (AH·) and superoxide anion radical in the GSH-alloxan system. At GSH : alloxan ratio of 10 : 1 led to an immediate formation of dialuric acid. The autoxidation of dialuric acid was suppressed by GSH in a concentration-dependent fashion. These results indicate that autoxidation of dialuric acid is strongly suppressed by excess GSH in the alloxan-dialuric acid redox cycle, resulting in the decrease of AH·generation and oxygen consumption.On the other hand, the reduction of Fe3+-EDTA to Fe2+-EDTA by dialuric acid and AH· was scarcely inhibited by any concentrations of GSH. These results indicate that adding an excess of GSH suppresses the generation of OH· in the GSH-alloxan system through the inhibition of the redox cycling reaction between alloxan and dialuric acid independently on the reduction of Fe3+-EDTA to Fe2+-EDTA.View full abstractDownload PDF (871K) -
Haruyoshi MATSUYAMA, Ryo TAGUCHI, Hiroh IKEZAWA1991 Volume 39 Issue 3 Pages 743-746
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSPhospholipase D from Streptomyces sp. AA586, PLDP, was modified with methoxypolyethylene glycol succinimidylsuccinate (ss-PEG), an active derivative of polyethylene glycol. By titration with trinitrobenzene sulfonate (TNBS), approximately 70% of the free amino groups in the enzyme protein were shown to be modified by treatment with ss-PEG. By this modification, the molecular weight of the enzyme was increased, judging from the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel filtration with Toyopearl HW-55F and TNBS titration. Due to the loss of cationic charges, the enzyme protein became eluted faster in high performance liquid chromatography with CM-Toyopearl. By modification with ss-PEG, the enzyme became fairly thermostable, while pH-stability and optimal pH were not influenced. The value of Km for phosphatidylcholine of the hydrolytic reaction increased 2-fold, whereas that of the transphosphatidyl reaction was not significantly altered.View full abstractDownload PDF (797K) -
Reiko TESHIMA, Hideharu IKEBUCHI, Tadao TERAO, Mamoru NAKANISHI1991 Volume 39 Issue 3 Pages 747-751
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe examined the effect of staurosporine on cytosolic calcium response in rat basophilic leukemia (RBL-2H3) cells using fura-2 as a fluorescent indicator of calcium ion.Staurosporine at a dose of 30 nM inhibited antigen-stimulated Ca2+-influx into the cells from the extracellular environment. In contrast, the drug at this concentration inhibited neither the mobilization of Ca2+ from intracellular stores nor inositol 1, 4, 5-trisphosphate (IP3) formation. At a high concentration (300 nM), however, staurosporine completely inhibited the cytosolic calcium responses as well as IP3 formation. These results indicate that staurosporine, if used at an appropriate concentration, can be used to discriminate Ca2+-influx from extracellular environment from mobilization of the ion from intracellular stores.These results also suggest that protein kinases, possibly protein kinase C, are involved in the calcium influx of RBL-2H3 cells from the extracellular environment.Serotonin release was strongly inhibited by the drug at 30 nM staurosporine. Since the inhibition of serotonin release and suppression of cytosolic calcium increase in response to the antigen were in parallel, we concluded that the inhibition of serotonin release from RBL-2H3 cells caused by the drug was elicited by the suppression of Ca2+ influx into the cells.View full abstractDownload PDF (853K) -
Takashi ABIKO, Hiroshi SEKINO1991 Volume 39 Issue 3 Pages 752-756
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA fragment analog, [D-Arg30]prothymosin α fragment 1-30, containing D-arginine in place of arginine residue at position 30 was synthesized by the liquid phase procedure and studied for immunological effect on the impaired blastogenic response of T-lymphocytes isolated from uremic patients after treatment of human serum. Deacetyl-thymosin α1, a synthetic octaeicosapeptide corresponding to deacetyl-prothymosin α fragment 1-28, has restoration ability for the impaired blastogenic response of T-lymphocytes of uremic patients but is susceptible to proteolytic digestion. On the other hand, the fragment analog, [D-Arg30]prothymosin α fragment 1-30 retained activity and was shown to exhibit a high degree of stability when incubated in human serum. These results indicate that N-terminal acetylation and the introduction of D-residue into the C-terminal residue of prothymosin α fragment 1-30 increase resistance to proteolytic degradation by exopeptidases.View full abstractDownload PDF (932K) -
Qing-Ming CHE, Teruaki AKAO, Masao HATTORI, Yoshisuke TSUDA, Tsuneo NA ...1991 Volume 39 Issue 3 Pages 757-760
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSEubacterium sp. strain BAR, isolated from human feces, transformed barbaloin to aloe-emodin anthrone in a basal medium lacking carbohydrate. Barbaloin remarkable stimulated the growth of strain BAR in the basal medium, the stimulative extent of the growth depending on the amount of barbaloin added. The addition of D-glucose, D-galactose, maltose, cellobiose, sucrose or D-amygdalin to the basal medium containing barbaloin caused a decrease of the growth stimulated by barbaloin to the growth level with each sugar, resulting in a complete inhibition of the barbaloin transformation. On the other hand, the addition of D-fructose, which itself stimulated the growth of strain BAR, further increased the growth in the presence of barbaloin and little inhibited barbaloin transformation. Nojirimycin bisulfite, a specific inhibitor of glucosidases, potently inhibited the growth with barbaloin, but did not affect the growth with glucose or cellobiose. Also, nojirimycin bisufite completely inhibited the transformation of barbaloin to aloe-emodin anthrone.These results indicate taht a unique enzyme capable of cleaving the C-glycosyl bond is induced in strain BAR by barbaloin and, consequently, strain BAR grows by utilizing as a nutrient the carbohydrate liberated from barbaloin. It is further suggested that the barbaloin-cleaving enzyme is inhibited by nojirimycin bisulfite and that the induction of the enzyme is repressed with D-glucose and D-galactose.View full abstractDownload PDF (581K) -
Yusuke TANIGAWARA, Yan-Ling HE, Katsuhiko OKUMURA, Ryohei HORI1991 Volume 39 Issue 3 Pages 761-764
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe pulmonary and hepatic clearances of the synthesized angiotensin converting enzyme (ACE) substrate, hippuryl-L-histidyl-L-leucine (HHL) were evaluated by applying the multiple sites of input method and the recirculation pharmacokinetic model. Rats received a constant rate infusion via the carotid artery, jugular vein or portal vein in the absence or presence of the ACE inhibitor, captopril. Blood samples were collected from the femoral artery. The organ extraction ratio was calculated from the steady-state plasma concentrations and the mean organ transit time was computed as the difference in the mean residence times for various administration routes. Pronounced elimination in the lung and liver was observed in the absence of captopril. Pulmonary metabolism was completely depressed in the presence of captopril while the hepatic elimination was little affected. This suggests that the pulmonary elimination was entirely ascribed to ACE while there exists an alternative elimination process in the liver. The mean cardiopulmonary transit time was very short, indicating the pulmonary elimination of HHL may take place on the surface of the vascular endothelium. The evaluation of the pulmonary elimination of HHL described in this paper indicates a simple in vivo method for assessing the pharmacological effect of ACE inhibitors. The present pharmacokinetic approach will be useful for the quantification of drug disposition in individual organs in vivo.View full abstractDownload PDF (685K) -
Naoki NAGAKURA, Shinji SOUMA, Tadayori SHIMIZU, Katsuji UNO, Yasutake ...1991 Volume 39 Issue 3 Pages 765-768
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe cross-reactivity of imipenem (IPM) in a delayed-type hypersensitivity (DTH) reaction was investigated by intradermal skin reaction, macrophage migration inhibition tests (MIT) and lymphocyte stimulation tests (LST) in guinea pigs. The animals were immunized with IPM, ampicillin (ABPC) or cephalexin (CEX) using Freund's complete adjuvant. Three sensitized-drugs exhibited the same immunogenicity in the skin reaction. The cross-reactivities in skin reaction among IPM, sulbactam, aztreonam, ABPC and 6-aminopenicillanic acid as penam, and CEX, ceftizoxime, 7-aminocephalosporanic acid as cephem were examined. IPM did not show cross-reactions with any of the tested drugs in three sensitized groups, indicating that the drugs possessed no cross-reactivity with tested beta-lactams in DTH.In MIT, 4 or 5 of 6 animals reacted to be sensitized drugs in each group. The cross-reactivity of IPM- and ABPC-sensitized groups in MIT was similar to that of a skin reaction, however, the CEX-sensitized animals showed broad cross-reactions. Using a kind of test drug, one or two animals in the ABPC-sensitized group showed migration enhancement, but IPM- or CEX-sensitized animals did not exhibit migration enhancement. In LST, most of the animals tested exhibited lymphocyte prolifration by sensitized drugs but a cross-reaction was scarcely observed. The above results suggest that among beta-lactams, IPM has a very low cross-reactivity. LST is considered to be more a useful assay than MIT for in vitro identification of causative drugs in animal models.View full abstractDownload PDF (664K) -
Yorinobu YONEZAWA, Kenji SHIRAKURA, Akinobu OTSUKA, Hisakazu SUNADA1991 Volume 39 Issue 3 Pages 769-772
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAn equation for dissolution from the whole surface of a nondisintegrating single component tablet under the sink condition was derived. Also, equations for several dissolution manners of the tablet under the sink condition were derived in the postulation of the dominant dissolution rate constant which determines the dissolution manner. The applicability or validity of these equations were examined by the dissolution measurements with nondisintegrating single component tablets. About one-tenth the amount of the amount needed to saturate the solution was used to prepare a tablet, and dissolution measurements were carried out with the tablet whose flat or side surface was masked with an adhesive tape in accordance with the conditions for derivation of equations.Among the derived equations, dissolution from the whole surface of a tablet was expressed by a form similar to the cube root law equation for particles. Hence, a single component tablet compressed by the use of a suitable amount was thought to behave like a single crysta. Also, equations derived for several dissolution manners were thought to be applicable for the dissolution of a nonspherical particle and crystal concerning the crystal's habit and its dissolution property, and the extended applicability was examined by converting the crystal into a simplified or idealized form, i.e., rectangle or plate.View full abstractDownload PDF (597K) -
Eiji HAYAKAWA, Masashi NAKAKURA, Yasuki KATO, Yuichi OKUBO, Toshihito ...1991 Volume 39 Issue 3 Pages 773-776
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWhen doxorubicin was encapsulated into liposomes by freeze-thawing, the percentage of encapsulated doxorubicin (EN%) was found to vary according to the type of buffer solution used. The reason for this was investigated in the present report. Drug-free liposomes prepared by hydration were mixed with doxorubicin dissolved in a certain type of buffer solution that shows a pH decrease on freezing, and this mixture was subjected to freeze-thawing. Doxorubicin was encapsulated by the liposomes due to the difference in pH between freezing and thawing. EN% depended on the pH of the buffer solution before freezing and increased significantly at over pH 7. About 60% of doxorubicin was encapsulated into liposomes after the 1st freeze-thawing cycle, and EN% was increased gradually with the number of freeze-thawing cycles. The addition of sugar to the experimental system was seen to affect doxorubicin encapsulation and the particle size of liposomes.View full abstractDownload PDF (686K) -
Kouhei TOYOOKA, Yoshiyuki TAKEUCHI, Hiroyuki OHTO, Masayuki SHIBUYA, S ...1991 Volume 39 Issue 3 Pages 777-779
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSOptically active 3-substituted 2, 3-dihydro-1, 3, 4-thiadiazoles (2-5) were synthesized by the reaction of aldehyde methylthio(thiocarbonyl)hydrazones (1) and chiral 5-substituted 1, 3-dioxolane-2, 4-diones. The absolute configurations of compounds 2-5 were deduced from their circular dichroism spectra.View full abstractDownload PDF (556K) -
Hiroaki TAKAYANAGI, Rieko IRIMAJIRI, Haruo OGURA, T. Brian H. MCMURRY1991 Volume 39 Issue 3 Pages 780-783
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe conformations of 1α, 2β-dichloro-1, 2-dihydro-6β-santonin (5), 1, 2, 4, 5-tetrachloro-6β-santonin (6), 1α, 2β-dibromo-1, 2-dihydro-6βsantonin (8), and 1, 2-dihydro-6β-santonin (9) were elucidated by proton nuclear magnetic resonance spectrometry and X-ray crystallographic analysis. Among these derivatives (5, 6, 8, and 9), only 1α, 2β-dichloroenone (5) shows a difference in the conformation of the cyclohexenone ring between solution (half-chair form) and crystal (half-boat form) states.View full abstractDownload PDF (637K) -
Shinzo KAGABU, Keisuke SAWAHARA, Masaki MAEHARA, Sachiko ICHIHASHI, Ka ...1991 Volume 39 Issue 3 Pages 784-785
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSPreparation of arylthiocyanates by simply mixing aromatic sulfinates with cyanotrimethylsilane (TMSCN) was achieved in good to moderate yields. The thiocyanates were also obtained directly from sulfonyl chloride using TMSCN, sodium sulfite, and potassium carbonate.View full abstractDownload PDF (504K) -
Kinfe K. REDDA, Kode N. RAO, Ann S. HEIMAN, Folakemi Y. ONAYEMI, Janin ...1991 Volume 39 Issue 3 Pages 786-791
Published: March 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNucleophilic attack of tert-butyl/phenylpyridines 3 on 1-chloro-2, 4-dinitrobenzen 4 results in the formation of tert-butyl/phenyl substituted 2, 4-dinitrophenylpyridinium chlorides 5. Benzoyl hydrazide and pyridyl acid hydrazides 6 were reacted with the pyridinium chlorides 5 furnishing the 2, 4-dinitroanilino derivatives 7, which were subsequently hydrolyzed with water : p-dioxane to yield N-[pyridyl(phenyl)carbonylimino]-tert-butyl/phenylpyridinium ylides 8. The title compounds 9, N-[pyridyl(phenyl)carbonylamino]-tert-butyl/phenyl-1, 2, 3, 6-tetrahydropyridines, were obtained by sodium borohydride reduction of the pyridinium ylides 8. The anti-inflammatory activities of compounds 9a-p were determined using the carrageenan-soaked sponge model of inflammation in Sprague Dawley rats. All compounds tested showed moderate to good anti-inflammatory effects compared to indomethacin. Compounds 9b, 9c and 9p were the most active analogs of the group in this model.View full abstractDownload PDF (883K)