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Volume 46, Issue 6
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Masayuki MURASE, Kazuhiro WATANABE, Takayuki KURIHARA, Seisho TOBINAGA1998 Volume 46 Issue 6 Pages 889-892
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe slime mould alkaloid of Arcyria obvelata Onsberg, arcyriacyanin A, was synthesized by the palladium catalyzed cross-coupling reaction with the indolylborate and 4-iodoindole derivatives, which provides an unsymmetrically substituted indole pigment.View full abstractDownload PDF (661K) -
Kozo ODA, Akira YOSHIDA1998 Volume 46 Issue 6 Pages 893-899
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe C-2 side-chain substitution reaction of a sulfoxide and a sulfone derived from a p-nitrobenzyl (1R, 5S, 6S)-6-[(1R)-1-(tert-butyldimethylsilyloxy)ethyl]-2-[2-(diethylcarbamoyl)phenylthio]-1-methylcarbapen-2-em-3-carboxylate with various mercaptans progressed smoothly in the presence of magnesium bromide. Bromomagnesium thiolate prepared from mercaptans proved to be especially effective for the substitution reaction and gave precursors of 1β-methylcarbapenem antibiotics in high yield.View full abstractDownload PDF (965K) -
Hiroshi KUWAJIMA, Takao TANAHASHI, Kenichiro INOUE, Hiroyuki INOUYE1998 Volume 46 Issue 6 Pages 900-905
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTo examine the biosynthetic pathway from secologanin to three types of secoiridoid glucosides characteristic of oleaceous plants, synthesis of two respective stereoisomers at C-8 of 8, 10-epoxysecologanin and -secoxyloganin was established and their deuterium-labeled analogues were prepared.View full abstractDownload PDF (931K) -
Jun TODA, Yoshihiro NIIMURA, Kaoru TAKEDA, Takehiro SANO, Yoshisuke TS ...1998 Volume 46 Issue 6 Pages 906-912
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new synthetic route to Erythrina alkaloids by formation of ring C utilizing a Pummerer-type intramolecular cyclization was developed. The N-(2-phenylthioethyl)-dioxopyrroline (3) was converted to 13 in five steps with satisfactory overall yield (69%) by means of [2+2] photocycloaddition followed by 1, 3-anionic rearrangement as crucial reactions. Treatment of the sulfoxide (13) with trifluoroacetic anhydride gave the cyclization product, 11-phenylthioerythrinan (15), in 87% yield. This was converted to the cycloerythrinan (22) by reductive elimination of the PhS group, thus constituting a formal total synthesis of (±)-erysotrine.View full abstractDownload PDF (1037K) -
Tetsuo IWAMA, Harutoshi MATSUMOTO, Taizo ITO, Hiroshi SHIMIZU, Tadashi ...1998 Volume 46 Issue 6 Pages 913-917
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS2'-Vinyl-2H-1, 4-benzothiazin-3(4H)-one-2-spirocyclopropanes (1) were irradiated with a tungsten lamp at room temperature in the presence of a catalytic amount of diphenyl dichalcogenide to provide 1, 2-dioxolane derivatives (3) in good yields. Diphenyl diselenide was more effective than diphenyl disulfide as a radical source. The photochemical [3+2] cycloaddition of 1b with electron-deficient alkenes proceeded smoothly under reflux in benzene to give spiro-cyclopentanes (5). Spiro-cyclopentenes (6) were formed by the photochemical [3+2] cycloaddition of 1b with alkynes.View full abstractDownload PDF (888K) -
Tatsumi SHINOHARA, Akira TAKEDA, Jun TODA, Yoko UEDA, Michiyo KOHNO, T ...1998 Volume 46 Issue 6 Pages 918-927
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA synthesis of 1, 2, 3, 4-tetrahydroisoquinolines (TIQs)(23) with one and two methoxyl groups at various positions of the benzene ring was achieved via the intramolecular cyclization of N-(aryl)methyl-2-(phenylsulfinyl)ethylamines (9) using the Pummerer reaction as a key step. The reaction was carried out by using trifluoroacetic anhydride (TFAA)(method A) of TFAA-BF3·Et2O (method B). The cyclization to 4-SPhTIQs (11) proceeded effectively when the reaction center at the benzene ring was electronically activated by a methoxyl group. In the reaction of the sulfoxide (9e) having two OMe groups at ortho- and para-positions a different cyclization reaction leading to a benzothiazepine (12) was observed, indicating that the high nucleophilicity of the benzene ring caused the unexpected reaction prior to the cyclization to 4-SPhTIQ (11e). The route starting from methoxylated benzaldehydes (5) was proved to provide an efficient and convenient method of TIQ synthesis which should be complementary to the well known Pictet-Spengler method.View full abstractDownload PDF (1547K) -
Ji-Wang CHERN, Hui-Ting CHEN, Nan-Yi LAI, Kuo-Rong WU, Yu-Chin CHERN1998 Volume 46 Issue 6 Pages 928-933
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSCondensation of anthranilamide and its derivatives with various 1, 3-cyclohexanediones 5a, b or 2, 4-pentanediones under acidic conditions produced a variety of heterocycles, leading to the synthesis of tetrahydropyrido[2, 1-b]-quinazolin-11-one derivatives. Condensation of anthranilamide with 5a or 5b in the presence of p-toluenesulfonic acid at the reflux temperature of tetrahydrofuran (THF) afforded compound 6a (40%) and compound 7a (22%) or compound 6b (47%) and compound 7b (39%), respectively. However, reflux of anthranilamide with 5a or 5b in 6% ethanolic hydrogen chloride provided compounds 6a and 6b in 77% and 73% yields, respectively. Heating 7a with 5a in 6% ethanolic hydrogen chloride furnished 6a in 82.4% yield. Reaction of anthranilamide with 5c under the same conditions resulted in the formation of 11 (57%). Treatment of compounds 6a and 6b with NaBH4 furnished 8a, b (89, 87% yields), which were subsequently subjected to the Mitsunobu reaction to produce 6, 7, 8, 9-tetrahydro-9-methyl-11H-pyrido[2, 1-b]quinazolin-11-one (9a) and 6, 7, 8, 9-tetrahydro-7, 7, 9-trimethyl-11H-pyrido[2, 1-b]quinazolin-11-one (9b) in 56 and 72% yields, respectively. However, heating 14 with 15a in CH3CN in the presence of p-toluenesulfonic acid furnished 19 in 31% yield. Under similar conditions, treatment of 21 with 15a provided 23a (42.4% yield), a key intermediate for the synthesis of rutaecarpine. Analogous reaction of 21 with 15b, 15c and 5a provided 22b-d in 63-99.3% yield, respectively.View full abstractDownload PDF (943K) -
Akikazu KAKEHI, Suketaka ITO, Satoshi NISHIZAWA1998 Volume 46 Issue 6 Pages 934-938
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThermolysis of trialkyl 4-alkylthio-12bH-1, 4-thiazepino[5, 4-a]isoquinoline-1, 2, 5-tricarboxylates in refluxing xylene did not afford the usually expected desulfurized products such as benzoquinolizine derivatives (5), but formed trialkyl 2-(1-isoquinolinyl)-4-alkylthio-2, 3-dihydrothiophene-2, 3, 5-tricarboxylates (4) in low to moderate yields. A similar treatment of the title compounds in the presence of a base such as 1, 8-diazabicyclo[5.4.0]undec-7-ene gave ring contraction and fragmentation products, trialkyl pyrrolo[2, 1-a]isoquinoline-1, 2, 3-tricarboxylates in moderate yields. 1, 5-Sigmatropic shift of 7-thianorcardiene intermediates is involved in the formation of 2-(1-quinolinyl)-2, 3-dihydrothiophene derivatives.View full abstractDownload PDF (719K) -
Hatsuo MAEDA, Sayaka MATSUMOTO, Takashi KOIDE, Hidenobu OHMORI1998 Volume 46 Issue 6 Pages 939-943
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe anodic transformation of 2, 3 : 5, 6-di-O-isopropylidene-α-D-mannofuranose (4) and 2, 3, 4, 6-tetra-O-benzyl-D-glucopyranose (5) to the corresponding alkoxy phosphonium ions induces dehydroxy substitution of the sugars at the anomeric positions. Their dehydroxy fluorination and chlorination has been achieved by constant-current electrolysis with CH2Cl2-1, 2-dimethoxyethane/Ph3P/Ph3PH·BF4 and with CH2Cl2/Ph3P/Et4N·Cl, respectively.The electrolysis in the presence of Ph3P has proved to serve O-glycosylation with 4 or 5 as a glycosyl donor, provided that an aliphatic alcohol as a glycosyl acceptor is a weaker nucleophile, such as (CF3)2CHOH, CF3CH2OH, and tert-BuOH, than the protected sugar toward Ph3P+· generated anodically from Ph3P. The present electrochemical reactions for 2, 3, 4, 6-tetra-O-acetyl-D-glucopyranose were unsuccessful, except for the dehydroxy chlorination.View full abstractDownload PDF (845K) -
Yasunori YAOITA, Keiko AMEMIYA, Hiroyuki OHNUMA, Katsuyuki FURUMURA, A ...1998 Volume 46 Issue 6 Pages 944-950
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSEight new sterols, 5α, 8α-epidioxy-(22E, 24R)-23-methylergosta-6, 22-dien-3β-ol (1), 3β, 5α, 9α-trihydroxy-(22E, 24R)-23-methylergosta-7, 22-dien-6-one (2), 3β, 5α, 9α-trihydroxy-(24S)-ergost-7-en-6-one (3), 3β, 5α, 9α, 14α-tetrahydroxy-(22E, 24R)-ergosta-7, 22-dien-6-one (4), (22E, 24R)-ergosta-7, 22-diene-3β, 5α, 6α, 9α-tetrol (5), 5α, 9α-epidioxy-3β-hydroxy-(22E, 24R)-ergosta-7, 22-dien-6-one (6), 5α, 9α-epidioxy-3β-hydroxy-(24S)-ergost-7-en-6-one (7) and 5α, 6α-epoxy-(22E, 24R)-ergosta-8, 22-diene-3β, 7β, 14α-triol (8), have been isolated from five edible mushrooms, Lentinus edodes, Flammulina velutipes, Hypsizigus marmoreus, Pleurotus ostreatus and Pholiota nameko together with fifteen known ones (9-23), of which two (16 and 17) are reported for the first time from a fungal source. The structures of these new compounds were elucidated on the basis of their spectral data.View full abstractDownload PDF (1027K) -
Yasuyuki TAKEDA, Keiichi KAWAGOE, Aki YOKOMIZO, Yoshihiro YOKOMIZO, To ...1998 Volume 46 Issue 6 Pages 951-961
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of phenoxyacetanilide derivatives was synthesized and their antagonist activities for human gastrin/cholecystokinin (CCK)-B and CCK-A receptors were evaluated. Among the compounds synthesized, 2-[3-[3-[N-[2-(N-methyl-N-phenylcarbamoylmethoxy)phenyl]-N-(N-methyl-N-phenylcarbamoylmethyl)carbamoylmethyl]-ureido]phenyl]acetic acid (20i, DA-3934) exhibited high affinity for gastrin/CCK-B receptors and high selectivity over CCK-A receptors. DA-3934 and its methyl ester derivative inhibited pentagastrin-induced gastric acid secretion in rats in a dose-dependent manner.View full abstractDownload PDF (1560K) -
Yeh-Long CHEN, Tai-Chi WANG, Nein-Chen CHANG, Ya-Ling CHANG, Che-Ming ...1998 Volume 46 Issue 6 Pages 962-965
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSCertain α-methylene-γ-butyrolactone derivatives of coumarin, naphthalene, and quinoline were synthesized and evaluated for vasorelaxing effects on isolated rat thoracic aorta. The 7-[(2, 3, 4, 5-tetrahydro-2-methyl-4-methylene-5-oxo-2-furanyl)methoxy]-2H-1-benzopyran-2-ones, which have an aliphatic methyl substituent at the lactone C2, were more active than their C2-phenyl counterparts against high-K+ (80 mM) medium, Ca2+ (1.9 mM)-induced vasoconstriction and the norepinephrine (NE, 3 μM)-induced phasic and tonic constrictions (2a vs. 2b; 2c vs. 2d; 2e vs. 2f; 2g vs. 2h). Although 3-chloro-7-[(2, 3, 4, 5-tetrahydro-2-methyl-4-methylene-5-oxo-2-furanyl)methoxy]-4-methyl-2H-1-benzopyran-2-one (2g) demonstrated the most potent inhibitory activities on the NE-induced phasic and tonic constrictions at concentrations of as low as 10 μg/ml, it possesses both affinity for NE-receptor and intrinsic activity to trigger the vasoconstriction. However, 8-[(2, 3, 4, 5-tetrahydro-2-methyl-4-methylene-5-oxo-2-furanyl)-methoxy]quinoline (10a) and other quinoline derivatives (11a, 12a) are pure irreversible non-competitive blockers of NE-receptor with no intrinsic activity. The aromatic ring played an important role in the vasorelaxing effects of α-methylene-γ-butyrolactones; naphthalene was inactive, quinolines exhibited only affinity to the α-receptor, and coumarins possessed both affinity and intrinsic activity.View full abstractDownload PDF (747K) -
Takumi YATABE, Yoshio KAWAI, Teruo OKU, Hirokazu TANAKA1998 Volume 46 Issue 6 Pages 966-972
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of novel hydroxamates has been prepared and tested for inhibitory activity towards rat polymorphonuclear leukocyte (PMN) 5-lipoxygenase (5-LO) in vitro and towards neutrophil migration in the rat air pouch model of inflammation in vivo. Many 3, 4-dihydronaphthyl compounds were potent inhibitors of 5-LO, and several compounds were potent inhibitors of neutrophil migration. The most potent 3, 4-dihydronaphthyl compound, N-[[(3, 4-dihydro-5-phenoxy)-2-naphthyl]methyl]-N-hydroxy-N'-ethylurea (FR122788, 18) had an IC50 of 25 nM in the 5-LO assay, and strongly reduced neutrophil migration in the rat air pouch model at 1 mg/kg (p.o.). FR122788 also had an ameliorating effect in a rat hepatiatis model induced by D-galactosamine, with an ED<50> values of 14.6 mg/kg (p.o.) for glutamate oxaloacetate transaminase (GOT) and 16.8 mg/kg (p.o.) for glutamate pyruvate transaminase (GPT).View full abstractDownload PDF (1007K) -
Toshio OKAZAKI, Toshihiro WATANABE, Kazumi KIKUCHI, Akira SUGA, Masayu ...1998 Volume 46 Issue 6 Pages 973-981
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA novel series of nonpeptide angiotensin II antagonists containing the acrylamide group at the 4-position of the imidazole ring was synthesized and their antagonistic activity was examined by functional assay in rabbit aorta.The acrylamide group was selected as a large lipophilic surrogate for the chloro group of EXP3174. A structure-activity relationship study of the acrylamide moiety has shown that substitution at the 4-position with the N-methyl-3, 3-dimethylacrylamide group resulted in the optimal compound, 2-butyl-4-[(3, 3-dimethylacryloyl)methyl-amino]-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-imidazole-5-carboxylic acid (1), which was superior to EXP3174 in vitro. Since 1 showed only poor activity against angiotensin II-induced pressor response in rats after oral administration, the carboxylic acid function of 1 was converted into prodrug esters (13). Among these, the 1-[(ethoxycarbonyl)oxy]ethyl ester (13a) showed the most potent and longest-lasting activity when given orally to rats. When administered orally to conscious furosemide-treated dogs, 13a showed an approximately-3-fold increased hypotensive activity in comparison with DuP 753. These data suggest that 13a may be an useful agent for the treatment of angiotensin II-dependent diseases, such as hypertension.View full abstractDownload PDF (1252K) -
Chao-mei MA, Norio NAKAMURA, Masao HATTORI1998 Volume 46 Issue 6 Pages 982-987
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new saponins, 3-O-[β-D-glucuronopyranosyl-(1→2)-β-D-glucopyranosyl]hederagenin (named abrus-saponin I) and 3-O-[β-D-glucuronopyranosyl-(1→2)-β-D-glucopyranosyl]oleanolic acid 28-β-D-glucopyranosyl ester (abrus-saponin II), and three new flavones, 6-C-β-D-glucopyranosyl-4', 5-dihydroxy-7, 8-dimethoxyflavone (precatorin I), 6-C-[β-D-apiofuranosyl-(1→2)-β-D-glucopyranosyl]-4', 5-dihydroxy-7, 8-dimethoxyflavone (precatorin II), 6-C-[β-D-apiofuranosyl-(1→2)-β-D-glucopyranosyl]-4', 5-dihydroxy-7-methoxyflavone (precatorin III), were isolated from the seeds of Abrus precatorius L. together with twelve known compounds including a naturally new saponin, 3-O-[β-D-glucuronopyranosyl-(1→2)-β-D-glucopyranosyl]oleanolic acid. Their structures were determined on the basis of chemical and spectroscopic methods. In addition, the unusual NMR spectral behavior of the flavone C-glycosides is also discussed.View full abstractDownload PDF (898K) -
Haruhisa KIZU, Naohiro SUGITA, Tsuyoshi TOMIMORI1998 Volume 46 Issue 6 Pages 988-1000
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom the leaves of Scutellaria repens, sixteen new neoclerodane-type diterpenes named scuterepenins A1, A2, B, C1, C2, D1, D2, E, F1, F2, G1 and G2, and scuterepenosides A1, A2, A3 and A4, have been isolated along with a new 9, 11-secoabietane-type diterpene named scuterepenin H. The structures of these compounds have been determined by spectroscopic and chemical methods as follows : scuterepenin A1, (4R, 11S, 13R)-7β-trans-cinnamoyloxy-4, 6α, 13, 18-tetrahydroxy-11, 16 : 15, 16-diepoxy-1-neoclerodanone; scuterepenin A2, cis-cinnamoyl form of A1; scuterepenin B, (4R, 11S, 13R)-7β-trans-cinnamoyloxy-2α, 4, 6α, 13, 18-pentahydroxy-11, 16 : 15, 16-diepoxy-1-neocler-odanone; scuterepenin C1, (4R, 11S, 13R)-6α-trans-cinnamoyloxy-7β, 13-dihydroxy-4, 18 : 11, 16 : 15, 16-triepoxy-1-neoclerodanone; scuterepenin C2, cis-cinnamoyl form of C1; scuterepenin D1, (4R, 11S*, 13R*)-6α-trans-cinnamoyl-oxy-1β, 7β-diacetoxy-11, 16 : 15, 16-diepoxy-18-neoclerodanal; scuterepenin D2, cis-cinnamoyl form of D1; scuterepenin E, (4R, 11S*, 13R*)-1β-acetoxy-7β-trans-cinnamoyloxy-6α-hydroxy-11, 16 : 15, 16-diepoxy-18-neoclerodanal; scuterepenin F1, (4R, 11S*, 13R*)-1β-O-acetyl-7β-O-trans-cinnamoyl-18β-O-methyl-6α, 18 : 11, 16 : 15, 16-triepoxyneoclerodane-1, 7, 18-triol; scuterepenin F2, cis-cinnamoyl form of F1; scuterepenin G1, (4R, 7R, 11S, 13R)-6α-O-trans-cinnamoyl-1, 16 : 4, 18 : 11, 16-triepoxyneoclerodane-6, 7, 15-triol; scuterepenin G2, cis-cinnamoyl form of G1; scuterepenoside A1, (4R, 13S*, 16S*)-1β-trans-cinnamoyloxy-6α-(β-D-glucopyranosyloxy)-16-methoxy-15, 16-epoxy-18-neoclerodanal; scuterepenoside A2, cis-cinnamoyl form of A1; scuterepenoside A3, (13S*, 16R*)-form of A1; scuterepenoside A4, (13S*, 16R*)-form of A2; scuterepenin H, (5S, 10R, 13S, 14S)-13-hydroxy-7-oxo-9, 11-seco-8-abieten-14, 11-olide.View full abstractDownload PDF (1560K) -
Akiko KUSANO, Masayuki TAKAHIRA, Makio SHIBANO, Toshio MIYASE, Genjiro ...1998 Volume 46 Issue 6 Pages 1001-1007
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new cyclolanostanol xylosides, bugbanosides A and B, were isolated from the underground parts of Cimicifuga simplex WORMSK. (Ranunculaceae). Bugbanosides A and B were formulated as 20(R), 23(R), 24(R), 25(S), 26(S and R)-16β, 23 : 23, 26 : 24, 25-triepoxy-1α, 3β, 26-trihydroxy-9, 19-cyclolanost-7-ene 3-O-β-D-xylopyrano-side and 20(R), 23(R), 24(R), 25(S), 26(S and R)-16β, 23 : 23, 26 : 24, 25-triepoxy-1α, 3β, 26-trihydroxy-9, 19-cyclo-lanostane 3-O-β-D-xylopyranoside respectively, by spectroscopic and chemical methods.View full abstractDownload PDF (959K) -
Masayuki YOSHIKAWA, Toshiyuki MURAKAMI, Hiromi SHIMADA, Satoshi YOSHIZ ...1998 Volume 46 Issue 6 Pages 1008-1014
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFollowing the characterization of the glycosidic constituents in a medical foodstuff "moroheiya", the leaves of Corchorus olitorius L., four higher fatty acids with a trienone function, corchorifatty acids A, B, C, and D, an undecanoic acid, corchorifatty acid E, and a trihydroxyfatty acid, corchorifatty acid F, were isolated from the less polar fraction of "moroheiya". The structures and optical purity of corchorifatty acids were determined on the basis of chemical and physicochemical evidence. Corchorifatty acids A, B, and C showed an inhibitory effect on lipopolysaccharide-induced NO production in cultured mouse peritoneal macrophages.View full abstractDownload PDF (1025K) -
Hideshi SUZUKI, Hisakazu SUNADA1998 Volume 46 Issue 6 Pages 1015-1020
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe dissolution characteristics of solid dispersions with nicotinamide and hydroxypropylmethylcellulose (HPMC) as combined carriers were investigated in water, using nifedipine and nitrendipine as model drugs. The solid dispersions were obtained by the fusion method; after both drug and HPMC dissolved in the fused liquid of nicotinamide at 140°C, the fused mixtures were cooled to solidify them. For nifedipine solid dispersions, the supersaturation behavior was enhanced with a decrease in the viscosity or an increase in the weight fraction of HPMC. Nifedipine was present as an amorphous state even in the solid dispersion with a 1 : 3 : 0.2 weight ratio of drug : nicotinamide : HPMC. Also, the more the weight fraction of nifedipine increased, the more the formation of amorphous drug in solid dispersions was suppressed, thereby lowering the drug supersaturation level. Moreover, the effect of humidity during storage on the dissolution profiles of nifedipine solid dispersions was examined. The humidity caused crystallization of amorphous nifedipine in solid dispersions, and decreased the drug supersaturation level. For nitrendipine solid dispersions, similarly to the nifedipine system, amorphous nitrendipine was obtained in solid dispersions, and this led to the supersaturation phenomenon. However, the inhibitory effect of HPMC on the crystallization of nitrendipine from supersaturated solution was less than that for nifedipine; this is attributable to the lower solubility of nitrendipine crystals. Therefore, the drug dissolution of this ternary dispersion system was influenced by the viscosity and weight fraction of HPMC, the solubility and weight fraction of the drug and the humidity during storage.View full abstractDownload PDF (877K) -
Tetsuya ARAKI, Hiroaki KITAOKA1998 Volume 46 Issue 6 Pages 1021-1026
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe photolysis of six fluoroquinolone agents was investigated in neutral aqueous solution by means of ESR spectroscopy. Lomefloxacin (LFLX), sparfloxacin (SPFX), ciprofloxacin (CPFX), enoxacin (ENX) and sitafloxacin (STFX) generated free radicals in the process of photochemical degradation, while levofloxacin (LVFX) did not.The free radicals and active oxygen species observed were presumed to be carbon-centered radical (·C), hydroxyl radical (·OH) and singlet oxygen (1O2). No superoxide anion radical (O·-2) was detected by the 5, 5-dimethyl-pyrrolineN-oxide (DMPO) spin trapping method in our system. 8-Fluorine-substituted fluoroquinolones (LFLX, SPFX) produced ·C, and generated a high degree of 1O2. On the other hand, the fluoroquinolones which have hydrogen, oxygen or chlorine at the 8-position (CPFX, LVFX, STFX) did not produce ·C, and generated a low degree of 1O2. ENX produced ·C, and generated a low degree of 1O2. These results suggest that the nature of the substituent at the 8-position of the fluoroquinolone ring plays an important role in the formation of free radicals and active oxygen species during photoirradiation.View full abstractDownload PDF (784K) -
Noriyuki HIRASAWA, Kazumi DANJO, Mitsumasa HARUNA, Akinobu OTSUKA1998 Volume 46 Issue 6 Pages 1027-1030
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNaproxen solid dispersions were prepared by melting and rapid cooling with liquid nitrogen using lactose as a carrier. The physical characterisitics of these solid dispersions were investigated by powder X-ray diffraction, differential scanning calorimetry and dissolution rate analyses. The degree of crystallinity of naproxen in solid dispersions decreased with decreases in the molar ratio of naproxen to lactose. Fourier-transform infrared (FT-IR) analysis demonstrated the presence of intermolecular hydrogen bonds between naproxen and lactose in solid dispersions. Dissolution studies indicated that the dissolution rate was markedly increased in solid dispersions compared with physical mixtures and pure drugs. These results indicated that lactose is useful as a carrier for production of solid dispersions.View full abstractDownload PDF (558K) -
Yuji NAKAI, Sumie YOSHIOKA, Yukio ASO, Shigeo KOJIMA1998 Volume 46 Issue 6 Pages 1031-1033
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSDehydration during freeze-drying often alters the native conformation of proteins, leading to a loss of activity.Solid-state rehydration of lyophilized protein formulations was studied to examine the recovery from structural damage caused by freeze-drying. Bilirubin oxidase was used as a model protein. The enzymatic activity of bilirubin oxidase decreased markedly when freeze-dried with polyvinylalcohol (PVA), but this loss in activity was partially recovered by subsequent solid-state rehydration of the lyophilized formulations. This recovery of activity upon solid-state rehydration was not observed in lyophilized formulations containing dextran that exhibited a similar loss of activity during freeze-drying. Thus, PVA appears to have a greater ability to act as a water substitute than dextran, resulting in less structural damage during dehydration. This in turn allows a recovery in activity upon solid-state rehydration.View full abstractDownload PDF (585K) -
Hiroyuki AKITA, Kimio UCHIDA, Cheng Yu CHEN, Keisuke KATO1998 Volume 46 Issue 6 Pages 1034-1038
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA short path synthesis of the ethyl (methyl 2, 3-O-isopropylidene-β-D-allofuranosid)uronate (5) and ethyl(methyl 2, 3-O-isopropylidene-α-L-talofuranosid)uronate (6) from methyl 2, 3-O-isopropylidene-β-D-ribopentodialdo-1, 4-furanoside (3) using (1-ethoxyvinyl)lithium and its application to the total synthesis of the pyrimidine nucleosides, thymine polyoxin C (1) and uracil polyoxin C (2), are described.View full abstractDownload PDF (862K) -
Takuji KAKIGAMI, Toshinao USUI, Takao IKAMI, Katsura TSUKAMOTO, Yoshih ...1998 Volume 46 Issue 6 Pages 1039-1043
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe enantiomers, (R)-(-)-1 and (S)-(+)-1, of (±)-4-amino-N-[2-(1-azabicyclo[3.3.0]octan-5-yl)ethyl]-5-chloro-2, 3-dihydro-2-methylbenzo[b]furan-7-carboxamide [(±)-1] were prepared from optically active benzyl 4-acetylamino-2, 3-dihydro-2-methylbenzo[b]furan-7-carboxylate[(R)-(+)-6, (S)-(-)-6], respectively. The requisite (R)-(+)-6 and (S)-(-)-6 were prepared by large-scale preparative HPLC on chiral stationary phases (CSPs). The absolute configuration of (S)-(+)-1 was determined by single crystal X-ray analysis. The serotonin 5-HT4 receptor agonistic activity of (S)-(-)-1 hemifumarate (SK-951) which was hemifumarate of (S)-(+)-1 was about twice that of the other enantiomer (R)-(+)-1 hemifumarate which was hemifumarate of (R)-(-)-1.View full abstractDownload PDF (735K) -
Akito NAGATSU, Hui Li ZHANG, Toshihiro WATANABE, Nari TANIGUCHI, Keiic ...1998 Volume 46 Issue 6 Pages 1044-1047
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS(15α, 20R)-Dihydroxypregn-4-en-3-one 6'-O-acetyl-20-β-cellobioside (1) and matairesinol 4'-O-β-D-apiofura-nosyl(1→2)-β-D-glucopyranoside (2) were isolated from safflower (Carthamus tinctorius L.) oil cake. The structures were confirmed by spectroscopic methods and X-ray crystal structure analysis. The 1H- and 13C-NMR signals of (15α, 20R)-dihydroxypregn-4-en-3-one (1a) were assigned.View full abstractDownload PDF (560K) -
Makio SHIBANO, Satoko NAKAMURA, Naomi AKAZAWA, Genjiro KUSANO1998 Volume 46 Issue 6 Pages 1048-1050
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new pyrrolidine alkaloids, broussonetines G and H, were isolated from the branches of Broussonetia kazinoki SIEB. (Moraceae). Broussonetines G and H were formulated as 2β-hydroxymethyl-3α, 4β-dihydroxy-5α-(1-hydroxy-6 : 10;10 : 13-diepoxytridecyl)-pyrrolidine (1) and 2β-hydroxymethyl-3α, 4β-dihydroxy-5α-(1-hydroxy-5 : 9;9 : 13-diepoxytridecyl)-pyrrolidine (2), respectively, by spectroscopic methods. 1 and 2 inhibited β-glucosidase, β-galactosidase and β-mannosidase.View full abstractDownload PDF (516K) -
Hiroyuki FUCHINO, Tetsuya SATOH, Jun HIDA, Mitsuhiko TERADA, Nobutoshi ...1998 Volume 46 Issue 6 Pages 1051-1053
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe constituents of Betula schmidtii REGAL were identified as follows. Fresh leaves : methyl (12R, 20S)-20-hydroxy-12-β-D-xylopyranosyloxy-3, 4-secodammara-4(28), 24-dien-3-oate (betula-schmidtoside A)*, myricetin 3-O-α-L-arabinofuranoside, myricetin 3-O-α-L-rhamnopyranoside, myricetin 3O-β-D-galactopyranoside, (-)-rhodo-dendrol 4'-O-β-D-glucopyranoside*. Outer bark : betulin, lupeol, oleanolic acid, betulone, betulonic acid.Inner bark : (+)-catechin, (3R)-3, 5'-dihydroxy-4'-methoxy-3', 4"-oxo-1, 7-diphenyl-1-heptene, (-)-lyoniresinol 3α-O-β-D-xylopyranoside, (+)-lyoniresinol 3α-O-β-D-glucopyranoside, monogynol A, ssioriside, (-)-rhododendrol 4'-O-β-D-glucopyranoside*, (-)-rhododendrol 4'-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside*. Root bark : oleanolic acid 3-caffeate, 27-hydroxyoleanolic acid 27-caffeate. The three compounds with asterisks are new.View full abstractDownload PDF (531K) -
Hiroshi WADA, Hironori TACHIBANA, Hiroyuki FUCHINO, Nobutoshi TANAKA1998 Volume 46 Issue 6 Pages 1054-1055
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new diarylheptanoid glycosides, hirsutanonol 5-O-(6-O-galloyl)-β-D-glucopyranoside and 3-deoxo-hirsutanonol 5-O-β-D-glucopyranoside, were isolated from fresh leaves of Alnus japonica together with three known diarylheptanoids [hirsutanonol, hirsutanonol 5-O-β-D-glucopyranoside and hirsutenone], five known triterpenes [β-amyrin, 3-O-acetyl-β-amyrin, 3-O-acetyltaraxerol, glutinone and lupenone] and quercitrin. One more new diarylheptanoid glycoside, 3-deoxohirsutanonol 5-O-(6-O-β-D-apiosyl)-β-D-glucopyranoside, was also isolated from bark together with 3-deoxohirsutanonol 5-O-β-D-glucopyranoside, two known diarylheptanoids [hirsutoside and hirsutanonol 5-O-β-D-glucopyranoside] and four known triterpenes [glutinol, glutinone, lupenone and taraxerone].Their structures were determined on the basis of spectroscopic and chemical evidence.View full abstractDownload PDF (448K) -
Koichi MACHIDA, Mami OGAWA, Masao KIKUCHI1998 Volume 46 Issue 6 Pages 1056-1057
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new iridoids, des-p-hydroxybenzoyl kisasagenol B, 6-O-p-hydroxybenzoyl asystasioside E, 6-O-p-hydroxybenzoyl glutinoside and 6-O-cis-p-coumaroyl catalpol, were isolated from Catalpae Fructus. Their structures were established by spectral analysis.View full abstractDownload PDF (455K) -
Abolghasem JOUYBAN-GHARAMALEKI1998 Volume 46 Issue 6 Pages 1058-1061
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSApplicability of the modified Wilson model for calculating drug solubility in water-cosolvent mixtures is presented. The accuracy and predictability of the model are compared with those of other models which calculate solute solubility as a function of the solvent composition. Mean of percent deviations from experimental values are 7.77, 8.70, 9.06, 10.72, 10.72 and 18.71, for the modified Wilson, double-log exponential, general single model, combined nearly ideal binary solvent/Redlich-Kister, excess free energy and mixture response surface methods, respectively.View full abstractDownload PDF (563K) -
Yoshio Takeuchi, Makoto Kamezaki, Kiyotoshi Kirihara, Gunter Haufe, Kl ...1998 Volume 46 Issue 6 Pages 1062-1064
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe Gabriel reaction was used as a key step in the first synthesis of protected α-fluoroglycine-containing dipeptides 10.View full abstractDownload PDF (469K) -
Masahiko TANIGUCHI, Yong-Qing XIAO, Xiao-Hong LIU, Akiko YABU, Yousuke ...1998 Volume 46 Issue 6 Pages 1065-1067
Published: June 15, 1998
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new spirobicoumarins, rivulobirins C and D (1 and 2), were isolated from the underground part of Pleurospermum rivulorum.They are characterized as two stereoisomers having a different configuration at the C-2 position resulting from the condensation of two heraclenol units, respectively, on the basis of spectral analysis.View full abstractDownload PDF (380K)
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