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Volume 43, Issue 6
Displaying 1-34 of 34 articles from this issue
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Mohammed RAFIQUZZAMAN, Keiko KOMAGOE, Keietsu TAMAGAKE1995 Volume 43 Issue 6 Pages 905-909
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe breakdown of methyllinoleate hydroperoxide (LOOH) and peroxidation of methyllinoleate (LH) catalyzed by hemin and hematin were studied in 98% methanol. Spectrophotometry was used to follow the breakdown of LOOH. The peroxidation process of LH was monitored by the oxygen consumption. The pKa for the conversion of hemin to hematin was determined as 7.3 in 98% methanol. The catalytic rates for both processes were found to reach a maximum at pH 8 where about 80% of hemin was in the hematin form. This could be accounted for by the acceleration of the breakdown of LOOH due to binding of hydroxide or methoxide ion to the hemin iron. The reduction in the catalytic activity at a higher pH, where 100% of hemin was in the hematin form, however, suggested that H+ was also necessary. We propose a new scheme which shows the role of H+ and OH- (or CH3O-) together with ferryl iron in the catalytic process.The breakdown of hemin itself was also observed and its catalytic cycle number was estimated as 9. The gradual decomposition of hemin suggests involvement of a Fenton-type mechanism as a minor catalytic process.View full abstractDownload PDF (877K) -
Shun-ichi WADA, Akira IIDA, Naoshige AKIMOTO, Michiko KANAI, Nobuo TOY ...1995 Volume 43 Issue 6 Pages 910-915
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTrichorovins (TV)-I-XIV are new antibiotic peptides obtained from conidia of the fungus Trichoderma viride. The peptide mixture of TVs was repeatedly fractionated by preparative HPLC until individual TVs showed a single peak on their analytical HPLC chromatograms. Nevertheless, FAB-MS or NMR indicated that each of TVs-I-XIV was composed of at least two components. We attempted to elucidate their structures within the fractions by electrospray ionization (ESI)-MS, FAB-MS, FAB-MS/MS and NMR. TVs generally have molecular weights of approximately 1100-1200 Da, and are characterized by an acetylated N-terminus, the presence of an aminoalcohol, e.g. leucinol, isoleucinol or valinol, at the C-terminus, and eleven residues including three α-aminoisobutyric acids in the molecule. Thus, it was determined that TVs belong to the class of peptaibols.View full abstractDownload PDF (812K) -
Yutaka YAMAMOTO, Hidekazu OUCHI, Takuo TANAKA1995 Volume 43 Issue 6 Pages 916-919
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSDi-tert-butyl dicarbonate was found to be effective for direct introduction of a tert-butoxycarbonyl group at the α-position of the pyridine nucleus via the trialkylstannyl group; reaction of α-trialkylstannyl derivatives of pyridine, quinoline, and isoquinoline with di-tert-butyl dicarbonate gave the corresponding α-tert-butoxycarbonyl derivatives in good yields, althrough small amounts of a variety of by-products were formed except in the case of pyridine.View full abstractDownload PDF (628K) -
Tomoyuki FUJITA, Kumiko OHIRA, Kazutaka MIYATAKE, Yoshihisa NAKANO, Mi ...1995 Volume 43 Issue 6 Pages 920-926
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSMonoterpene glucosides, perillosides A and C, obtained from the leaves of Perilla frutescens, were found to be inhibitors of aldose reductase (EC 1.1.1.21) which is considered to be a key enzyme in diabetic complications such as cataract. The apparent type of inhibition of rat lens aldose reductase by perillosides A and C was competitive with respect to glyceraldehyde and their Ki values were 1.4×10-4 and 2.3×10-4M, respectively. The type of inhibition by their tetraacetates was non-competitive with respect to the same substrate, although their inhibitory effects were increased by about one order of magnitude compared with those of the perillosides and the Ki values were 2.5×10-5 and 7.1×10-5M, respectively. We also prepared related monoterpene glucosides and their tetraacetates and determined their inhibitory activities towards aldose reductase in order to elucidate the relationship between structure and inhibitory activity.View full abstractDownload PDF (954K) -
Shunji SAKURABA, Toshimi OKADA, Toshiaki MORIMOTO, Kazuo ACHIWA1995 Volume 43 Issue 6 Pages 927-934
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of (β-N-sulfonylaminoalkyl)phosphine ligands has been developed and employed for asymmetric palladium-catalyzed hydrosilylation and Heck-type hydroarylation, affording up to 72% ee and 90% yield.View full abstractDownload PDF (1211K) -
Shirou MAEDA, Hiroshi MASUDA, Takashi TOKOROYAMA1995 Volume 43 Issue 6 Pages 935-940
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe oxidative coupling reactions of 2-hydroxycinnamates were investigated as a continuation of our previous studies on 4-hydroxy derivatives. The reaction of 2-hydroxycinnamate 1 and 2-hydroxy-4-methoxycinnamate 3 with silver oxide afforded polymerized lignin-like products, while that of 2-hydroxy-bis(methoxymethoxy)cinnamates 5 and 6, after acetylation, gave the enol acetates, 8 and 14, of oxotetrahydrobenzoxanthene derivatives, respectively. These two products were also obtained by the oxidation of 5 and 6 with potassium hexacyanoferrate(III). In the reactions of 5 and 6 with iron(III) chloride, the major products were the partially demethoxymethoxylated compounds 9 and 15, respectively. Thus, the course of the reactions in the oxidation of 2-hydroxycinnamates is quite different from that in the case of 4-hydroxy derivatives. The product 8 and the corresponding oxotetrahydrobenzoxanthene derivative were found to show moderate inhibitory effects upon lipid peroxidation.View full abstractDownload PDF (1029K) -
Maria L. LOPEZ-RODRIGUEZ, M.Jose MORCILLO, Bellinda BENHAMU, Esther FE ...1995 Volume 43 Issue 6 Pages 941-946
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSeveral 2-substituted 5, 6, 11, 11a-tetrahydro-1H-imidazo[1', 5' : 1, 6]pyrido (1) and 5, 6, 11, 11b-tetrahydro-1H-imidazo[1', 5' : 1, 2]pyrido[3, 4-b]indole-1, 3(2H)-diones (2) were synthesized and studied by 2D-NMR spectroscopy and difference nuclear Overhauser effect experiments. All the compounds were evaluated for in vitro α1 adrenoceptor affinity by radioligand receptor binding assays. The most active derivative in displacement of [3H]prazosin from rat cortical membranes was 1b (Ki=219 nM). At 1 μM concentration, compounds 1 and 2 had no effect on the benzodiazepine or 5-HT1A receptor. The biological activity profile of 1b makes it a possible lead compound for the design of new selective α1 adrenoceptor ligands.View full abstractDownload PDF (1163K) -
Mitsuru OHKUBO, Atsushi KUNO, Hiroyoshi SAKAI, Hisashi TAKASUGI1995 Volume 43 Issue 6 Pages 947-954
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNovel 4-arylazole (i.e. thiazole, oxazole, and imidazole) derivatives, possessing an amino moiety at the C-5 position of the azole ring, were prepared and tested for anti-anoxic (AA) activity in mice. Among them, 5-(4-methylpiperazin-1-yl)methyl-4-(3-nitrophenyl)-2-phenylthiazole (3b, FR75094) possessed significant AA activity (10 mg/kg, i.p. and 100 mg/kg, p.o., respectively), and was also effective on anti-lipid peroxidation (ALP) assay and inhibited arachidonate-induced cerebral edema in rats. Structure-activity relationships in regard to AA activity of this series of compounds are discussed.View full abstractDownload PDF (1042K) -
Tokumi MARUYAMA, Kunihiko UTSUMI, Hiroshi TOMIOKA, Masumi KASAMOTO, Yo ...1995 Volume 43 Issue 6 Pages 955-959
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA procedure for the synthesis of 2'-deoxy-2'-fluoropuromycin (1b) was developed. Ring opening of the lyxo-epoxide (4) or nucleophilic displacement of the 3'-O-mesylate (5) by an azide ion afforded two azido nucleosides, 6a and 7a. The major product (7a) was reacted with diethylaminosulfur trifluoride (DAST) to give the 2'-fluoronucleoside (8), which was converted to the 3'-aminonucleoside (9) by hydrogenation. Compound 9 was condensed with an amino acid by the conventional method subsequently deprotected by acid to give 1b. Compounds 1b, 6b and 7b exhibited no selective antiviral activity against several DNA and RNA viruses. Compound 1b had weak antibacterial activity (minimum inhibitory concentration approximately 25-50 μg/ml) and was cytotoxic to several tumor cell lines (L1210, Molt 4, CEM) at a concentration of about 5 μM. This antitumor cell activity may be attributed to inhibition of protein biosynthesis.View full abstractDownload PDF (783K) -
Ryuichi KIYAMA, Kunio HAYASHI, Mariko HARA, Masafumi FUJIMOTO, Tomoji ...1995 Volume 43 Issue 6 Pages 960-965
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA novel series of 6-alkyl-7-oxo-4, 7-dihydropyrazolo[1, 5-a]pyrimidine-3-carboxylic acid derivatives was prepared as angiotensin II (AII) receptor antagonists. When evaluated in an in vitro binding assay using COS cells transfected with a cDNA encoding a human AT1 angiotensin II receptor, the compounds in this series showed Ki values in the range of 0.4-4.0 nM. In anesthetized spontaneously hypertensive rats (SHRs), administration of the 6-propyl derivative 4d (1 mg/kg, i.v.) reduced the mean blood pressure (MBP) by a maximum of more than 30 mmHg from the normal value.View full abstractDownload PDF (846K) -
Dongming ZHANG, Toshio MIYASE, Masanori KUROYANAGI, Kaoru UMEHARA, Aki ...1995 Volume 43 Issue 6 Pages 966-970
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNine new oleanane-type saponins polygalasaponins XI-XIX were isolated from the aerial part of Polygala japonica. The structures of these compounds were established on basis of spectroscopic and chemical evidence.View full abstractDownload PDF (749K) -
Yoshihiro MIMAKI, Osamu NAKAMURA, Yutaka SASHIDA, Kazuo KOIKE, Tamotsu ...1995 Volume 43 Issue 6 Pages 971-976
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSPhytochemical examination of the fresh tubers of Brodiaea californica resulted in the isolation of four new steroidal saponins. Their structures were determined, by extensive spectral analysis including two-dimensional (2D) NMR spectroscopy and acid-catalyzed hydrolysis, to be (25S)-spirost-5-ene-1β, 3β-diol [(25S)-ruscogenin] 1-O-{O-β-D-glucopyranosyl-(1→3)-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside} (1), (25S)-ruscogenin 1-O-{O-β-D-glucopyranosyl-(1→3)-O-α-L-rhamnopyranosyl-(1→2)-O-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranoside} (2), the C-20 and C-22 isomer of 2 (3) and the 6'-O-acetyl derivative of 2 (4), respectively. The conformations of the tetrasaccharide moiety of 2 and 4 were inspected through molecular mechanics and molecular dynamics calculation studies, showing that the acetyl group attached to C-6 of the inner glucose was near the C-21 methyl of the aglycon in the calculated preferred conformation of 4, which must cause the downfield shift of 21-Me by 0.07 ppm in comparing the 1H-NMR of 4 with that of 2. The inhibitory activity of the isolated saponins on 12-O-tetradecanoylphorbor-13-acetate (TPA)-stimulated 32P-incorporation into phospholipids of HeLa cells was evaluated to identify new antitumor-promoter compounds.View full abstractDownload PDF (954K) -
Tsutomu WARASHINA, Tadataka NORO1995 Volume 43 Issue 6 Pages 977-982
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNovel steroidal glycosides 2-4, 6-11, 13-19 and 20 were isolated from the roots of Cynanchum caudatum M. (Asclepiadaceae). The structures of these steroidal glycosides were determined on the basis of spectral and chemical evidence. All of these glycosides contain 2, 6-dideoxyhexopyranoses as component sugars, and their structures were elucidated as esterified pregnane-type.View full abstractDownload PDF (869K) -
Miquel PONS, Monica LIZONDO, Montserrat GALLARDO, Joan FREIXAS, Joan E ...1995 Volume 43 Issue 6 Pages 983-987
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA method for the mass production of liposomes was developed : lipids and nonionic surfactant were dispersed in ethanol at 50°C, when ethanol evaporated, glycerin was added resulting in a homogeneous mixture. Parallelly, enrofloxacin in a mixture of buffer solution and glycerin (1 : 1, v : v) was heated to 50°C. The drug solution was then added to the lipid mixture and homogenized at 3000 rppm for 2-3 min by a homogenizer. This method provided a suspension of multilamellar vesicles (high speed dispersed vesicles, HSDV) with an average diameter that ranged from 280 to 350 nm, their size distribution being bimodal. Such liposomes were characterized in comparison with other traditional liposomes, namely extrusion, reverse phase evaporation, ethanol injection and dehydration-rehydration vesicles. The entrapment efficiency of HSDV (20%) was never less that by others and they showed a high physical stability, since after 23 months both the size and the polydispersity retained the same values they had at the time of the preparation. Encapsulation efficiency also remained almost constant evidencing that the leakage from liposomes was apparently insignificant. Chemical stability of lipid and of the encapsulated drug showed that if liposomes are kept at 4°C and protected from natural light, they do not undergo any degradation.View full abstractDownload PDF (834K) -
Haruo SEKIZAKI, Kazumi DANJO, Hiroshi EGUCHI, Yorinobu YONEZAWA, Hisak ...1995 Volume 43 Issue 6 Pages 988-993
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe found that ibuprofen (IPF) became amorphous when the crystalline powder was merely mixed with polyvinylpyrrolidone (PVP), using a test tube mixer, and allowed to stand at appropriate temperatures. The crystallinity of the mixture was evaluated from the X-ray diffraction spectra by Ruland's method. The degree of decrease in crystallinity (A), defined as the ratio of the decrease in crystallinity to the value calculated by assuming additivity of crystallinity, increased gradually with time for the IPF-PVP system. We found that the higher the storage temperature, the higher the weight ratio of PVP in the mixture and the lower the molecular weight of PVP, the greater was the degree of decrease in crystallinity. The effect of PVP particle size was observed in 1 : 1 and 1 : 3 IPF/PVP mixtures.The interaction of IPF with PVP in the solid state was investigated by IR and 13C-NMR analyses, and the molecular geometry of 1-ethyl-2-pyrrolidone (EtP, a model compound for PVP) was calculated by the molecular orbital method (PM3). Our findings suggested that EtP undergoes O-protonation, forming a hydrogen bond at the carbonyl oxygen, in preference to N-protonation.View full abstractDownload PDF (678K) -
Suwannee P. PANOMSUK, Tomomi HATANAKA, Tetsuya AIBA, Kazunori KATAYAMA ...1995 Volume 43 Issue 6 Pages 994-999
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe release profile of indomethacin (IM) from a direct compressible matrix containing three hydrophilic cellulose derivatives, methylcellulose (MC25 and MC50), hydroxypropylcellulose (HPC140), and hydroxypropylmethylcellulose (HPMC50) was studied. The drug release profile was affected by matrix size, polymer type, drug : polymer ratio and water soluble additive (lactose). An IM zero-order release matrix can be obtained by mixture and direct compression with MC50, HPMC50 and HPC140. The release rate from the MC50 and HPC140 matrix can be modified by replacing MC50 or HPC140 with MC25, and a zero-order release could be obtained even when the amount of replacement with MC25 is up to 35 and 45%, respectively. Lactose up to 10% slightly affected the release profile. IM released from this kind of matrix by a zero-order rate seems to be controlled by the swelling and relaxation of the polymer.View full abstractDownload PDF (826K) -
Tetsu MORIMURA, Tomoko OHNO, Hayashi MATSUKURA, Yoshifumi NOBUHARA1995 Volume 43 Issue 6 Pages 1000-1004
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe photodegradation kinetics of orbifloxacin (1-cyclopropyl-5, 6, 8-trifluoro-1, 4-dihydro-7-(cis-3, 5-dimethyl-1-piperazinyl)-4-oxoquinoline-3-carboxylic acid) was investigated in aqueous solution at various pH values (1.2-12.5) and at an ionic strength of 0.5. The photodegradation experiments were performed using a fluoroscent or a chemical lamp as a light source and the cummulative number of photons during exposure was determined by a ferroxalate actinometer. It was found that the photodegradation of orbifloxacin followed apparent first-order kinetics under both types of artificial light. The photodegradation rates of orbifloxacin in a neutral medium were higher than those in acidic and alkaline media. Orbifloxacin was most unstable in solution at pH 7.4, and its degradation half-life was 0.9 h. Also, the log k-pH profile indicated that the photodegradation rate of orbifloxacin was related to the dissociation of the carboxylic and dimethylpiperazinyl groups and the main photo-labile species was the zwitterionic form. In addition, the photodegradation kinetics of the decarboxylated derivative of orbifloxacin in aqueous solution was investigated to determine the effect of the functional groups on the photodegradation of orbifloxacin.View full abstractDownload PDF (651K) -
Hideki ISHIWATA, Aline VERTUT-DOI, Takeo HIROSE, Koichiro MIYAJIMA1995 Volume 43 Issue 6 Pages 1005-1011
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSPoly(ethylene glycol)-coated liposomes were prepared with poly(oxyethylene) cholesteryl ethers (mPEG-Chol). PEG unit numbers tested were 50, 100 and 200, of which the average molecular weights (m) of PEG were 2200, 4400 and 8800, respectively. Properties of both PEG-coated liposomes and PEG-Chol molecules were investigated. These liposomes exhibited a long circulation time in the blood after i.v. injection in rats, estimated by both the lipid membrane marker, L-α-dipalmitoylphosphatidylcholine [2-palmitoyl-9, 10-3H] (3H-DPPC), and an internal aqueous marker, 3H-inulin. Accumulation in the liver and spleen at 8 h-post-injection was significantly reduced compared with conventional liposomes. The percentage of PEG-Chol incorporation in liposomal membranes was also investigated. Liposomes composed of egg yolk phosphatidylcholine (EPC)/PEG-Chol at various molar ratios were separated from free PEG-Chol molecules, which are not incorporated in liposomal membranes by chromatography over Sepharose CL-4B columns. PEG-Chol incorporation reached approx. 14 and 18 mol% of the total lipids with 25% PEG-Chol unit numbers of 200 and 50, respectively. The occupied area per molecule of PEG-Chol was larger than that of Chol, and the fluorescence anisotropy (γ) of the initial 25 mol% 8800PEG-Chol liposomes was smaller than that observed for 12.5 mol% Chol liposomes. PEG-coated liposomes containing calcein were incubated at 37°C in heat-inactivated fetal bovine serum (FBS). In the presence of FBS, calcein leakage was increased with PEG-Chol percentage incorporation and an increase in FBS concentration. The amount released from PEG-coated liposomes represented 60% at maximum and was larger than that of the control liposomes. PEG-Chol molecules are interesting compounds since they can be easily synthesized in a large amount on an industrial scale. The basic physical-chemistry characteristics investigated in this article are critical to assess the pharmacological application of PEG-Chol liposomes as drug delivery systems.View full abstractDownload PDF (1149K) -
Kaori IKEDA, Izumi SAITOH, Takayoshi OGUMA, Yasushi TAKAGISHI1995 Volume 43 Issue 6 Pages 1012-1016
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe hydrophobic interaction between long-chain alkyl groups of hydrophobically-modified hydroxypropyl methylcellulose (HM-HPMC) and indomethacin (IM) was studied using a fluorescence probe method in which pyrene molecules are allowed to associate with long-chain alkyl groups. In an HM-HPMS solutin, the hydrophobicity of the pyrene environment markedly increased as the concentration of HM-HPMS was increased, indicating an increase of hydrophobic interaction between the long-chain alkyl groups. When IM was added to this solution, the hydrophobicity of the pyrene environment decreased as the IM concentration increased. Thus, it was suggested that the hydrophobic interaction between long-chain alkyl groups and IM caused a weakening of the hydrophobic interaction between HM-HPMC molecules themselves.When isopropanol (IPA) was added to an HM-HPMC solution, IPA weakened the hydrophobic interaction through long-chain alkyl groups. Thus, IPA caused an expansion of the intermolecular hydrophobic regions. For this reason, the amount of IM entrapped in these regions increased when the IPA concentration was increased. However, when the IPA concentration was further increased, the hydrophobic interaction finally disappeared. Thus, as IM molecules could no longer be trapped in the hydrophobic regions, the activity of HM-HPMC suppressing the growth of IM crystals disappeared.View full abstractDownload PDF (801K) -
Tetsuaki TANAKA, Osamu OKUDA, Kazuo MURAKAMI, Hitoshi YOSHINO, Hidenor ...1995 Volume 43 Issue 6 Pages 1017-1023
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA novel and stereoselective spiroannelation reaction was developed. Treatment of the suitably functionalized cyclohexene derivative (3) with trimethylsilyl trifluoromethanesulfonate (TMSOTf) afforded the spiro[5.5]undecanes 4A and 5S exclusively. Changing the solvent from CH2Cl2 to CH3CN or THF increased the stereoselectivity; predominant formation of 4A in CH3CN and 5S in THF was observed. The spirocyclic compounds 4A and 5S were transformed into the tricyclo[6.3.1.01, 6]dodecane derivatives (19A and 27S) corresponding to the B/C/D rings of aphidicolanes (1) and stemodanes (2).View full abstractDownload PDF (1091K) -
Kazue OHKURA, Koh-ichi SEKI1995 Volume 43 Issue 6 Pages 1024-1027
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSPhotolyses of 5-substituted 1, 3-dimethyluracils (1a-e : a, R=F; b, R=Cl; c, R=H; d, R=CH3; e, R=p-xylyl) in p-xylene in the presence of trifluoroacetic acid (TFA) afforded 5, 6-dihydro-1, 3-dimethyl-6-p-methylbenzyluracils (3a-d), 5, 6-dihydro-1, 3-dimethyl-5-p-methylbenzyluracils (4a-e), and 5, 6-dihydro-1, 3-dimethyluracils (5a-e) in varying ratios. It is suggested that the 6-isomers (3) are derived from the O(4)-protonated electron adducts of 1, while 4 and 5 are the products from the C(6)-protonated electron adducts. The ratio of (4+5) vs. 3 depends on the ionization potentials of the O(4)-protonated intermediates. The formation of 4+5 increases with increasing concentration of TFA.View full abstractDownload PDF (652K) -
Yutaka YAMAMOTO, Hidekazu OUCHI, Takuo TANAKA1995 Volume 43 Issue 6 Pages 1028-1030
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAlkoxycarbonylation and acylation at the α-position of pyridine, quinoline, and isoquinoline via the respective trimethylstannyl derivatives were satisfactorily performed by employing ethyl chloroglyoxylate and acylformyl chloride under mild conditions.View full abstractDownload PDF (570K) -
Shigeto NEGI, Motosuke YAMANAKA, Yuki KOMATSU, Akihiko TSURUOKA, Atsus ...1995 Volume 43 Issue 6 Pages 1031-1034
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSE1101, a new oral caphalosporin, has a (N, N-dimethylcarbamoyloxy)methyl group at the C-3 position of the cephem nucleus. The previous methods for manufacturing 3-(N, N-disubstituted carbamoyloxy)methyl cephems generate various amounts of intractable Δ2 isomers as by-products. In this report, we describe a new, practical synthetic method for cephems of this type without generating Δ2 isomers, via 7-acylamino-3-(4-nitrophenoxy-carbonyloxy)methyl-Δ3-cephem-4-carboxylic acid (5) as a key intermediate.View full abstractDownload PDF (636K) -
Qing HUANG, Yasuhiro TEZUKA, Yasumaru HATANAKA, Tohru KIKUCHI, Arasuke ...1995 Volume 43 Issue 6 Pages 1035-1038
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new sesquiterpene alcohol, named tricho-acorenol (1), was isolated from the culture broth of Trichoderma koningii OUDEMANS along with methyl benzoate (2), cyclonerodiol (3), cyclo-(L-Pro-L-Leu) (4), 4-hydroxyphenethyl alcohol (5), uracil (7), and a ceramide (6). The ceramide (6) was identified as (2S, 3S, 4R)-2-[(2R)-2-hydroxytetracosanoylamino]-1, 3, 4-octadecanetriol by the use of ion-spray ionization MS (ISI-MS) and comparison of the optical rotation and the 1H-NMR data with those of (2S, 3S, 4R)-2-[(2R)-2-hydroxytetracosanoylamino]-1, 3, 4-hexadecanetriol. The structure of tricho-acorenol was elucidated to be (1S, 4S, 5S, 7R)-1-isopropyl-4, 8-dimethyl-spiro-[4.5]dec-8-en-7-ol on the basis of chemical and spectroscopic evidence.View full abstractDownload PDF (570K) -
Tsutomu ISHIKAWA, Ken-Ichiro KOTAKE, Hisashi ISHII1995 Volume 43 Issue 6 Pages 1039-1041
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSToddacoumaquinone (1), a coumarin-naphthoquinone dimer, was synthesized through Diels-Alder reaction between 8-(1-acetoxy-3-methyl-1, 3-butadienyl)-5, 7-dimethoxycoumarin (15) and 2-methoxy-1, 4-benzoquinone (5). The activities of 1 against several viruses were examined. A weak activity (EC50=10 μg/ml) was observed against HSV-1 and HSV-2, but no activity was seen against HIV-1.View full abstractDownload PDF (474K) -
Kohji TERASHIMA, Teru TANIMURA, Hiroshi SHIMAMURA, Akito KAWASE, Keiji ...1995 Volume 43 Issue 6 Pages 1042-1044
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWith the aim of applying mast cell-stabilizing agents as antiulcer agents, N-(1H-tetrazol-5-yl)-2-anilino-5-pyrimidinecarboxamides were synthesized, and initially evaluated pharmacologically for activity in the rat passive cutaneous anaphylaxis test by oral administration. The most active compound 6 was proved to inhibit potently the release of histamine from passively sensitized rat peritoneal mast cells in vitro. When compared with other mast cell-stabilizing agents and an antiulcer agent, compound 6 was found to show excellent gastric mucosal protection and gastric antisecretion activities. Furthermore, compound 6 revealed good activity against acidified aspirin ulcer in rats and water-immersion stress ulcer in rats.View full abstractDownload PDF (559K) -
Nigel R. BAKER, Nick G. BYRNE, Apollo P. ECONOMIDES, Tariq JAVED1995 Volume 43 Issue 6 Pages 1045-1048
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of 1-(2, 3-epoxypropoxy)-2(4)-fluorobenzenes and their corresponding 1-(2-hydroxy-3-morpholino propoxy and piperazino)fluorobenzene derivatives (8a-f) were synthesised via a short synthetic route in good chemical yields and were evaluated for intropic and chronotropic activity in isolated guinea-pig atria preparation. The compounds act as potential phosphodiesterase (PDE) inhibitors with desirable biological activity and have considerable promise in heart therapy.View full abstractDownload PDF (684K) -
Noriko MATSUDA, Masao KIKUCHI1995 Volume 43 Issue 6 Pages 1049-1051
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new polyhydric alcohol glycosides (1-3) were isolated from the leaves of Lonicera gracilipes var. glandulosa MAXIM. (Caprifoliaceae). Their structures were determined to be erythritol-1-O-(6-O-trans-caffeoyl)-β-D-glucopyranoside (1), 1, 2, 3, 4-tetrahydroxy-2-methylbutane-4-O-(6-O-trans-caffeoyl)-β-D-glucopyranoside (2) and arabitol-5-O-(6-O-trans-caffeoyl)-β-D-glucopyranoside (3) on the basis of chemical and spectral data.View full abstractDownload PDF (515K) -
Tetsu MORIMURA, Tomoko OHNO, Hayashi MATSUKURA, Yoshifumi NOBUHARA1995 Volume 43 Issue 6 Pages 1052-1054
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe degradation kinetics of orbifloxacin [1-cyclopropyl-5, 6, 8-trifluoro-1, 4-dihydro-7-(cis-3, 5-dimethyl-1-piperazinyl)-4-oxoquinoline-3-carboxylic acid] was investigated as a function of pH (1.5-10.5), temperature (100-120°C) and buffer concentration (0.05-0.2M) by means of high-performance liquid chromatography.The degradation of orbifloxacin in aqueous solution followed apparent first-order kinetics under all experimental conditions. No appreciable effect of buffer on the degradation of orbifloxacin was observed for any of the buffer species used in this study. The log k-pH profiles indicated specific-acid and specific-base catalyses and there were inflection points near pH 6 and 9 corresponding to the pKa1 and pKa2 values. From the Arrhenius plots, the activation energies for k'H, k'H2O, kH2O, k''H2O and k''OHwere found to be 31.9, 36.9, 23.5, 26.5 and 19.0 kcal/mol, respectively. Arrhenius data obtained from this study showed that the degradation of orbifloxacin at room temperature negligible at all pH values studied conditions (pH 1.5-10.5).View full abstractDownload PDF (523K) -
Shoko YOKOYAMA, Yoshihiro FUJINO, Miho KONDO, Tadao FUJIE1995 Volume 43 Issue 6 Pages 1055-1056
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe self-association of cyclohexylamine (CHA) in water at 25°C was investigated by measuring the fluoroscence spectrum and intensity of ammonium 8-anilino-1-naphthalenesulfonate as a fluorescent probe. The surface tension of an aqueous solution of CHA was also measured with a Du Nouy tensiometer at 25°C. CHA formed self-association in water, and the association was micellar. The critical micelle concentration of CHA in water at 25°C was estimated as 0.5-0.6 M by the fluorescence method, and this value coincided with that of 0.54M obtained by the surface tension method.View full abstractDownload PDF (422K) -
Naohito OHNO, Takayoshi TERUI, Norihisa CHIBA, Kazuya KURACHI, Yoshiyu ...1995 Volume 43 Issue 6 Pages 1057-1060
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSmall molecular weight (MW) glucan derivatives could be a useful tool for studying the mechanisms of β-glucan mediated biological activity, especially as antagonists for a β-glucan receptor. This paper descrived the stability of various (1→6) branched (1→3)-β-D-glucans to formolysis in the preparation of small MW derivatives. The glucans used were curdlan (linear), pachyman (few branches), GRN (one branch in every third main chain unit; 2/6), SPG (2/6), SSG (3/6), and OL-2 (4/6). Curdlan and pachyman were easily degraded to oligosaccharides by degradation for 20 min at 100°C by 90% formic acid. However, branched glucans, especially the highly branched glucans, SSG and OL-2, were significantly resistant to degradation, and the majority remained high MW. SSG required a longer period and/or a higher temperature (121°C treatment) to produce small MW derivatives. Branched glucans were also resistant to zymolyase (an endo-(1→3)-β-D-glucan hydrolase) digestion. These facts suggest that the (1→6)-β-D-branched residues contribute to the glucans' resistance to formic acid degradation and zymolyase digestion.View full abstractDownload PDF (692K) -
Naoki NODA, Kyoko TSUJI, Toshio KAWASAKI, Kazumoto MIYAHARA, Hiroshi H ...1995 Volume 43 Issue 6 Pages 1061-1063
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA novel resin glycoside, merremin (1), has been isolated from the root of Merremia hungaiensis (Convolvulaceae). The structure has been determined to be an ester-type dimer of tuguajalapin X (2) on the basis of chemical and spectral data.View full abstractDownload PDF (440K) -
Hideaki MURATAKE, Naoshige MATSUMURA, Mitsutaka NATSUME1995 Volume 43 Issue 6 Pages 1064-1066
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA total synthesis of natural (+)-duocarmycin SA (1) was achieved as shown in Chart 1, starting from L-malic acid (5) by using a Lewis acid-mediated indole formation reaction of a pyrrole precursor 14 to form the key compound 15.View full abstractDownload PDF (435K) -
Yukio OHSHIBA, Takehiko YOSHIMITSU, Kunio OGASAWARA1995 Volume 43 Issue 6 Pages 1067-1069
Published: June 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA practical route to all possible stereoisomers of the muscarine alkaloids in optically pure forms has been developed starting from a readily accessible chiral starting material.View full abstractDownload PDF (444K)
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