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Volume 44, Issue 7
Displaying 1-26 of 26 articles from this issue
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Hitoshi ISHIDA, Hidekazu MIYAMOTO, Takako KAJINO, Hidetoshi NAKAYASU, ...1996 Volume 44 Issue 7 Pages 1289-1292
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNew sodium bile alcohol sulfates were obtained from the bile of megamouth shark by chromatography on silica gel and Sephadex LH-20, together with two sodium scymnol sulfates, (24R, 25S)- and (24R, 25R)-(+)-3α, 7α, 12α, 26-pentahydroxy-5β-cholestan-27-yl sodium sulfate (2 and 3). On hydrolysis in pyridine-dioxane, the new salts afforded a new bile alcohol (1), whose structure was determined to be (24R)-5β-cholestane-3α, 12α, 24, 26, 27-pentol, besed on chemical and spectral data. On the basis of the physicochemical data, the new salts were established as (24R, 25S)- and (24R, 25R)-(+)-3α, 12α, 24, 26-tetrahydroxy-5β-cholestan-27-yl sodium sulfate.View full abstractDownload PDF (586K) -
Yoshiaki AMAKURA, Takashi YOSHIDA1996 Volume 44 Issue 7 Pages 1293-1297
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new dimeric dehydroelalgitannin, euphorbin I (3), was isolated together with twenty-eight known polyphenols including dimeric ellagitannins, euphorbins A (1) and B (2), from the fresh leaves of Euphorbia watanabei. The structure of 3 which has a macaranoyl group as a linking unit between the monomers was established based on spectroscopic methods and chemical correlation with 1. The structure of euphorbin B (2c), previously assigned as a dimer having the valoneoyl group as the linking unit, was revised to 2 having a tergalloyl group.View full abstractDownload PDF (821K) -
Toshiaki SAITHOH, Taichi OYAMA, Yoshie HORIGUCHI, Jun TODA, Takehiro S ...1996 Volume 44 Issue 7 Pages 1298-1304
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThermal reaction of aroylketenes 2 with cyclic enol ethers such as 2, 3-dihydrofuran (A), 2, 3-dihydropyran (B), 1-trimethylsilyloxycyclopentene (C), 1-trimethylsilyloxycyclohexene (D), 3-trimethylsilyloxyindene (E), and 4-trimethylsilyloxy-1, 2-dihydronaphalene (F) was carried out to investigate the reactivity of 2 with these olefins. The main reaction was Michael-type addition to give the 1, 3-diketones 3 and 9, and the 1, 3, 5-triketones 13, 15, 18, and 20, depending on the olefins used. The addition of the olefins was facilitated by introduction of a nitro or chloro group into the aryl part of 2 and was profoundly retarded by steric hindrance of the olefinsView full abstractDownload PDF (1132K) -
Masayuki YOSHIKAWA, Toshiyuki MURAKAMI, Hisashi MATSUDA, Takahiro UENO ...1996 Volume 44 Issue 7 Pages 1305-1313
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFollowing the characterization of E-senegasaponins a and b and Z-senegasaponins a and b, new bioactive saponins named E-senegasapinin c and Z-senegasapinin c were isolated from Senegae Radix, the root of Polygala senega L. var. latifolia TORREY et GRAY., together with Z-senegins II, III, and IV. The chemical structures of E and Z-senegasaponins c and Z-senegins II, III, and IV were elucidated on the basis of chemical and physicochemical evidence, and the geometrical isomerc structures of the 4''-methoxycinnamoyl and 3'', 4''-dimethoxycinnamoyl groups in these saponins were found to show tautomer-like behavior under irradiation with fluorescent lamps.E and Z-Senegasaponins c and E and Z-senegins II, III, and IV were found to exhibit hypoglycemic activity in the oral D-glucose tolerance test. (E) and (Z)-Senegins II also showed an inhibitory effect on alcohol absorption in rats.View full abstractDownload PDF (1215K) -
Katsuhiko ISEKI, Daisuke ASADA, Mie TAKAHASHI, Takabumi NAGAI, Yoshiro ...1996 Volume 44 Issue 7 Pages 1314-1317
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTriethylborane-mediated reactions of lithium enolates derived from chiral N-acyloxazolidinones with ethyl difluoroiodoacetate allows easy access to α-(ethoxycarbonyl)difluoromethylated carboximides with good diastereomeric excess (86->98%de). The stereochemistry of the (ethyoxycarbonyl)difluoromethylated carboximides indicates that the (ethoxycarbonyl)difluoromethyl radical generated from ethyl difluoroiodoacetate and triethylborane reacts preferentially on the si face of the lithium enolates.View full abstractDownload PDF (738K) -
Synthesis of Pygmaeocine E, a Linear Abietane Diterpene from Pygmaeopremna herbacea (ROXB.) MOLDENKETakashi MATSUMOTO, Yoshio TAKEDA, Kimiko SOH, Hisashi GOTOH, Sachihiko ...1996 Volume 44 Issue 7 Pages 1318-1325
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSMethyl 12-methoxy-7-oxo-8, 11, 13-abietatrien-18-oate (10), prepared from (+)-dehydroabietic acid (9), was rearranged into methyl 7-isopropyl-6-methoxy-1, 10-dimethyl-1, 2, 3, 4-tetrahydroanthracene-1-carboxylate (13) via a series of reaction : dehydrogenation with selenium(IV) oxide, sodium borohydrie reduction, and dehydration with boron trifluoride etherate. Reduction of 13 with lithium aluminum hydride afforded an alcohol (14), which was further reaffanged into 2-isopropyl-3-methoxy-5, 9-dimethyl-7, 8-dihydro-6H-cyclohepta[b]naphthalene (16) by treatment with methanesulfonyl chloride in pyridine. The alcohol 14 was then converted into 7-isopropyl-5, 6-dimethoxy-1, 1, 10-trimethyl-1, 2, 3, 4-tetrahydroanthracene (22) by means of the following reaction : pyridinium chlorochromate oxidation, Huang-Minlon reduction, demethylation, oxidation with Fremy's salt, catalytic hydrogenation, and methylation. Compound 22 was also prepared from methyl 11, 12-dimethoxy-7-oxo-8, 11, 13-abietatrien-18-oate (23) via methyl 7-isopropyl-5, 6-dimethoxy-1, 10-dimethyl-1, 2, 3, 4-tetrahydroanthracene-1-carboxylate (26). Treatment of 22 with DDQ produced an enone (29), which was converted into a diosphenol derivative (31) via a series of reaction : catalytic hydrogenation, and oxidations with Jones reagent and then with oxygen in the presence of potassium tert-butoxide. Demethylation of 31 with ethanethiol and anhydrous aluminum chloride afforded pygmaeocine E (1) and 3, 6-dihydroxy-7-isopropyl-1, 1, 10-trimethyl-1, 2-dihydroanthracen-2-one (32).View full abstractDownload PDF (1253K) -
Yoichi FUJIWARA, Junichi YOKOTANI, Kenichi AKAJI, Yoshiaki KISO1996 Volume 44 Issue 7 Pages 1326-1331
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSHuman C-type natriuretic peptide 22 (hCNP22), the third member of the natriuretic peptide family, was efficiently synthesized by Fmoc-based peptide chain construction on a 2-chlorotrityl (Clt) resin, followed by deprotection using tetrafluoroboric acid (HBF4). The use of Clt resin was effective in suppressing racemization at the C-terminal cysteine residue caused by the base treatment for Fmoc-cleavage. The disulfide bond of hCNP22 was constructed using the silyl chloride-sulfoxide method to avoid oxidation at the Met residue. Using amino acid- and dipeptide-resin derivatives, the effects of bases, protecting groups and resin supports on the racemization at the C-terminal Cys residue were examined in detail.View full abstractDownload PDF (921K) -
Hiroharu MATSUOKA, Nobuaki KATO, Keiichiro TSUJI, Noriaki MARUYAMA, Hi ...1996 Volume 44 Issue 7 Pages 1332-1337
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSVarious novel methotrexate (MTX) derivatives bearing an indoline moiety were synthesized and tested for biological activities using human peripheral blood mononuclear cell (hPBMC) and human synovial cells (hSC) derived from patients with rheumatoid arthritis (RA). Compounds having potent activity in vitro were further evaluated using an adjuvant arthritis model in vivo. N-[1-(2, 4-Diamino-6-pteridinylmethyl)indoline-5-carbonyl]-L-glutamic acid 2f showed more potent activities than MTX in vitro and in vivo, and N-[1-(2, 4-diamino-6-pteridinylmethyl)-indoline-5-carbonyl]-L-2-aminoadipic acid 2d exhibited fairly good activities in vitro and considerable activity in vivo. Compound 2d was, as expected, not sensitive to folyl-polyglutamate synthetase (FPGS) and did not undergo polyglutamation, a process which may be responsible for a side-effect during MTX therapy.View full abstractDownload PDF (965K) -
Chisako YAMAGAMI, Noriko KATASHIBA1996 Volume 44 Issue 7 Pages 1338-1343
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSCapacity factors, k', for m- and p-substituted phenyl N-methyl (2) and phenyl N, N-dimethyl (3) carbamates were measured on an octadecyl silica column using methanol-buffer (pH 7.4) mixtures as the mobile phase. The relationship between log P (P : 1-octanol-water partition coefficient) and log k' was studied as a function of the mobile phase composition. An eluent containing 50% MeOH gave good but separate log k'-log P linearities for (2) and (3). As the methanol concentration in the mobile phase was decreased, the correlation became more complicated due to the intervention of hydrogen-bond effects. In a water-rich eluent, the log k' values for the combined data set of (2) and (3) were found to be expressed by a correlation equation of the type, log k'=a log P+ρσ°+hAHBA+hAMHBAM+const., where σ° represents the Hammett type electronic substituent constant. HBA and HBAM are indicator variables for hydrogen-accepting substituents and compounds (2) (amphiprotics), respectively. As expected, the log kW approach failed to give reliable log P values due to the strongly hydrogen-accepting property of the fixed substituents.View full abstractDownload PDF (839K) -
Toru OKAYAMA, Ryo MURAMATSU, Sumie SEKI, Eriko NUKUI, Masaki HAGIWARA, ...1996 Volume 44 Issue 7 Pages 1344-1350
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe designed a unique anticoagulant decapeptide, which possesses two O-sulfated tyrosine residues, based on the structure of hirudin's C-terminal functional domain. We first prepared a series of octa-, nona- and decapeptides with no sulfation, Suc-Phe-Glu-Pro-Ile-Pro-Glu-Tyr-Tyr-X-OH [X=bond, Leu or Leu-Gln], by a solution phase method and measured their thrombin times (TT) using human thrombin and rabbit plasma. The shortest octapeptide (3a) showed full antithrombin activity compareble to that of the lead compound hirudin (54-65), and the longest decapeptide (3c) prolonged TT most potently with an IC50 value of 5.8 μM. We consequently converted 3c to a disulfated decapeptide (NF-22) with SO3·pyridine complex and compared its antithrombin activity with that of known hirudin-related peptides : hirugen, MDL28050 and hirulog-1. NF-22 showed potent antithrombin activity with an IC50 value of 0.3 μM, being more potent than hirugen and MDL28050 (IC50 values of 4.0 μM and 1.1 μM, respectively). NF-22 was as potent as hirulog-1. NF-22 showed no change in activity in aqueous solution for 10 d at 60°C, and remained about 90% unchanged in rat plasma on incubation for 24 h at 37°C, whereas the corresponding unsulfated peptide (3c) was completely digested under the same condition. NF-22 appears to be one of the most potent and stable peptide anticoagulants among the hirudin analogs.View full abstractDownload PDF (1113K) -
Sachihiko NUMAJIRI, Kenji SUGIBAYASHI, Yasunori MORIMOTO1996 Volume 44 Issue 7 Pages 1351-1356
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSEffect of species and concentrations of pharmaceutical additives on the iontophoretic transport of benzoate anion through excised hairless rat skin was investigated using a 2-chamber iontophoretic diffusion cell quipped with platinum electrodes at 0 mA for 4 h (control) followed by a constant direct current of 0.5 mA for another 4 h. One cell facing the stratum corneum was filled with sodium benzoate solution, and the other cell facing the dermis with lithium chloride (LiCl), potassium chloride (KCl) or tetraethylammonium bromide (TEA-Br) solution. Iontophoretic delivery rate of benzoate anion that permeated through skin increased with an increase in the sodium benzoate concentration while maintaining a constant KCl concentration. In contrast, a flux of benzoate anion decreased with an increase in KCl concentration and a constant concentration of sodium benzoate. When KCl was replaced by LiCl or TEA-Br, the flux of benzoate anion was almost the same. These phenomena were evaluated by a concept of transport numbers : theoretical values of benzoate anion flux were very close to the observed data. Potential difference between the skin during the permeation study was also measured between two salt bridges which were connected via calomel electrodes to a potentiometer. It gradually decreased to a certain level in each case, but increased again in some cases. This gradual decrease and increase in the potential difference, in spite of a constant current, were theoretically explaind by a gradual increase of ion concentration in the skin membrane and depletion of the cation in the receiver cell, respectively. Analysis of ionic mobility and concentration of penetrants gave a great deal of information on iontophoretic drug permeation through skin.View full abstractDownload PDF (800K) -
Satoru WATANO, Masafumi UCHIGAMI, Kei MIYANAMI, Teruhito YASUTOMO1996 Volume 44 Issue 7 Pages 1357-1360
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSModeling of agitation fluidized bed granulation was conducted using a proposed random coalescence model, in which adhesion of two colliding particls was judged by the coherent strength of a liquid bridge formed between the particles and the separation force caused mainly by agitator rotation. Properties of coherent strangth and water absorbing characteristics of the starting materials, which were very important to determine granule growth, were also teken into consideration. Granule growth in various powder samples with different properties were simulated and the effects of moisture content and agitator rotational speed on this growth were numerically investigeted. The simulated results were in good agreement with the actual granulation data, and granule growth in various powder samples and operating conditions could be simulated with high accuracy. The mechanism of agitation fluidized bed granulation was also elucidated by the proposed model.View full abstractDownload PDF (640K) -
Hiroshi YUASA, Yuki TAKASHIMA, Yoshio KANAYA1996 Volume 44 Issue 7 Pages 1361-1366
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe prepared an intragastric floating preparation using porous calcium silicate (Florite[○!R] RE, FLR) as a floating carrier, which has floating ability due to the air included in the pores when they are covered with a polymer, it also has a sustained drug release property. Floating granules were prepared by dropping a 5 or 10% (w/v) ethanol solution of hydroxypropylcellulose (HPC) and ethylcellulose (EC) in 4 different concentration ratios while the FLR was being agitated in a beaker. After the mixture was dried in vacuo and sieved, we regarded the granules obtained as primary coated granules (PCG). After drying, the ethanol solution of the polymer was dropped and dried in vacuo again, and sieving was carried out to obtain secondary coated granules (SCG). The floating property and surface and inner structures of PCG and SCG were studies. Further, we prepared PCG and SCG including diclofenac sodium (DS) (DS-PCG, DS-SCG) as a model drug, and the drug release profile from these granules was observed.The floating property of SCG was better than that of PCG. A longer floating time was observed with a higher polymer concentration and a lower HPC composition ratio. It was observed by a scanning electron microscope (SEM) and the pore size distribution that more pores of FLR in SCG were covered with polymer than those in PCG. DS-SCG showed a smaller release rate than DS-PCG. These results suggest that FLR is a useful floating carrier for the development of floating and sustained release preparations.View full abstractDownload PDF (930K) -
Preparation and Characterization of Sealed Heated Mixture of Ethenzamide and Porous Calcium SilicateTakehisa HANAWA, Rieko IKOMA, Atsushi WATANABE, Masato HIDAKA, Masayas ...1996 Volume 44 Issue 7 Pages 1367-1371
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA sealed heated mixture of ethenzamide (EZ) and porous calcium silicate (Florite[○!R]RE : FR) was prepared by heating the physical mixture in a sealed container. No diffraction peaks due to EZ crystals were observed in the powder X-ray diffraction pattern of the sealed heated mixture (FR : EZ=9 : 1) nor was an endothermic peak observed on the differential scanning calorimetric measurement of the sealed heated mixture (FR : EZ=9 : 1), indicating the amorphization of the EZ crystals caused by heating in a sealed container. The sealed heated mixture with FR showed a greater dissolution rate than EZ crystals or the sealed heated mixture with nonporous calcium silicate (CS). The sealed heating method using porous FR thus provides a promising way of amorphizing EZ crystals without using any solvents and of improving the dissolution rate of EZ.View full abstractDownload PDF (903K) -
Hiraku IKEDA, Shigeo YAMAMURA, Kozo TAKAYAMA, Tsuneji NAGAI1996 Volume 44 Issue 7 Pages 1372-1375
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA novel method to prepare a chitosan film using a newly developed apparatus in which the cast plate was loaded an electric charge was previously reported. In this study, the film prepared with or without the electric charge was characterized by X-ray diffractometry, differential scanning calorimetry (DSC), a microwave molecular orientation analyzer and an optical birefringence analyzer.X-Ray diffraction patterns indicated that the film prepared with an electric charge (VF) had higher crystallinity than the film prepared without an electric charge (NVF). These findings suggested that well-crystallized chitosan fibers were formed during the preparation of VF. Furthermore, chitosan fivers in VF had more preferred orientation.The DSC findings also indicated that the crystallinity of VF was higher than that of NVF. An electric charge during preparation of chitosan film might help making a particular fiber arrangement of chitosan macromolecules. The mechanical properties of VF and NVF reported previously were discussed from physicochemical characteristics of the films.View full abstractDownload PDF (577K) -
Toshihiko YOSHIDA, Youichi YAMAMOTO, Hitomi ORITA, Masato KAKIUCHI, Yo ...1996 Volume 44 Issue 7 Pages 1376-1386
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe previously demonstrated that 5-amino-7-(3-amino-1-pyrrolidinyl)-1-cyclopropyl-1, 4-dihydro-8-methyl-4-oxoquinoline-3-carboxylic acid (7) has strong in vitro antibacterial activity even against quinolone-resistant bacteria.We examined optimization of the 3-aminopyrrolidine moiety of 7 by introduction of C-alkyl (Me, Et, Pr, di-Me, cyclopropyl) and N-alkyl groups (Me, di-Me). C-Alkylation at the 4-position of the 3-aminopyrrolidine moiety enhanced in vitro and in vivo antibacterial activity. (S)-5-Amino-7-(7-amino-5-azaspiro[2.4]hept-5-yl)-1-cyclopropyl-6-fluoro-1, 4-dihydro-8-methyl-4-oxoquinoline-3-carboxylic acid (15h) and (3S, 4S)-5-amino-7-(3-amino-4-methyl-1-pyrrolidinyl)-1-cyclopropyl-6-fluoro-1, 4-dihydro-8-methyl-4-oxoquinoline-3-carboxylic acid (15b) showed strong antibacterial activity (in vitro antibacterial activity including quinolone-resistant bacteria is 4 times more potent than that of ciprofloxacin (CPFX) (1); in vivo antibacterial activity is 1.5 to 20 times more potent than that of CPFX (1)) and reduced quinolone toxicity (free from both phototoxicity at a dosage of 30 mg/kg in guinea pigs (i.v.) and convulsion when coadministered with 4-biphenylacetic acid at a dosage of 20 μg in rats (i.c.v.)). Their selectivity between DNA topoisomerase II (derived from eukaryotic cells) and DNA gyrase (derived from bacterial cells) was about 3000-fold.View full abstractDownload PDF (1429K) -
Toshimasa ISHIDA, Yasuko IN, Eiji KAWAMOTO, Takashi AMANO, Jyutoku KAN ...1996 Volume 44 Issue 7 Pages 1387-1390
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe chemical structure of imidazolopyrroloquinoline (IPQ), a main reaction product of pyrroloquinolinequinone and L-tryptophan in vitro, has been determined by X-ray crystal analysis. The IPQ molecules exist in keto form, having three neutral carboxyl groups, and they form continuous and prominent stacking structures in a crystal which are stabilized by van der Waals, dipole-dipole and electrostatic interactions. There are three crystallographically independent dimethyl sulfoxide solvents in a crystal, and they stabilize the stacking layers of IPQ molecules by intermolecular hydrogen bonds between neighboring oxygen atoms.View full abstractDownload PDF (559K) -
Shinji NAGUMO, Takayuki ARAI, Hiroyuki AKITA1996 Volume 44 Issue 7 Pages 1391-1394
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSChiral inductions of meso triacetate (4) and meso diol (15) were carried out on the basis of enzymatic reaction using lipase to give chiral synthons having three consecutive chiral centers with high enantiomeric excess.View full abstractDownload PDF (653K) -
Ken-ichi KOYAMA, Kenichi HITOMI, Isamu TERASHIMA, Kohfuku KOHDA1996 Volume 44 Issue 7 Pages 1395-1399
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe mechanism of formation of N2-benzylguanine in the reaction of 2-amino-6-chloropurine with a large excess (12-13 molar eq) of sodium benzyl oxide in benzyl alcohol at 130°C was studied, N2, O6-Dibenzylguanine, a reaction intermediate, was isolated and a possible mechanism for its formation is discussed. Furthermore, using this sodium benzyl oxide system, benzylation at the amino group of nucleic acid bases was facilitated.View full abstractDownload PDF (762K) -
Dennis Patrick PIET, Romano Vincenzo Antonio ORRU, Louis Henri Dieudon ...1996 Volume 44 Issue 7 Pages 1400-1403
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe total synthesis of the title compound (±)-1 is described. The key step in the synthesis of this cis-fused trinor-guaiane is the base-induced and -directed rearrangement of the tosylate ester 4. Because of differences in the spectral data of synthetic (±)-1 and natural dictamnol, a trinor-guaiane isolated from Dictamnus dasycarpus TURCZ., a revised structure for the natural product is proposed. Nuclear Overhauser effect (NOE) difference experiments and a detailed investigation of the air-induced cyclization reaction of pregeijerene, isolated from Amyris diatrypa SPRENGEL, support the structure revision of natural dictamnol.View full abstractDownload PDF (622K) -
Hideaki SHIRAHASHI, Takashi MORIMOTO, Akito NAGATSU, Nobutoshi MURAKAM ...1996 Volume 44 Issue 7 Pages 1404-1406
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS1-O-Acyl-3-O-(6'-O-acyl-β-D-galactopyranosyl-sn-glycerol, which was isolated from a nitrogen-fixing freshwater cyanobacterium, Anabaena flos-aquae f. flos-aquae, was synthesized by utilizing lipase-catalyzed acylation.The antitumor-promoting activities of these galactolipids were evaluated using a short-term in vitro assay of Epstein-Barr virus activation in Raji cells induced by 12-O-tetradecanoyl-phorbol 13-acetate (TPA). The glyceroglycolipids which have a palmitoleoyl residue at the 1-O-position exhibited more potent activities than the others in this assay.View full abstractDownload PDF (550K) -
Tokumi MARUYAMA, Mitsutoshi FUKUHARA1996 Volume 44 Issue 7 Pages 1407-1411
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSReaction of trans-2, 3-bis[(tert-butyldimethylsilyl)oxymethyl]-1-cyclobutanone (4a) with phenylmagnesium bromide or lithiated aromatic compounds gave two adducts, the (1R*, 2R*, 3R*) isomers (5a-c) and the (1R*, 2S*, 3S*) isomers (6a-c). The major products (5a, c) were treated with tetrabutylammonium fluoride to give the (1R*, 2R*, 3R*)-1-aryl-2, 3-bis(hydroxymethyl)-1-cyclobutanols (1a, c). The 3-(oxazol-2-yl)-phenyl adduct 5b was converted to the benzamide congener 1b in 6 steps. On catalytic reduction of 1a with Raney Ni the stereochemistry at C-1' was mostly retained, but in the case of 10% Pd-C catalyst, steric inversion occurred. Compounds 1a-c displayed no cytotoxicity towards human nasopharyngeal carcinoma KB cell line.View full abstractDownload PDF (805K) -
Masato SATOH, Yoshinori OKAMOTO, Hiroyuki KOSHIO, Mitsuaki OHTA, Akito ...1996 Volume 44 Issue 7 Pages 1412-1414
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of (3-substituted phenyl)urea analogues of the potent gastrin/cholecystokinin (CCK)-B receptor antagonist YM022 has been prepared. Structure-activity relationship studies of this series suggested that a number of analogues retained good in vitro potency for gastrin/CCK-B receptor. In particular, the (3-amino substituted phenyl)urea derivatives (10-12) were more potent inhibitors of pentagastrin-induced gastric acid secretion in rats than YM022 on intraduodenal (i.d.) administration.View full abstractDownload PDF (546K) -
Sunee CHANSAKAOW, Nijsiri RUANGRUNGSI, Tsutomu ISHIKAWA1996 Volume 44 Issue 7 Pages 1415-1417
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAntiviral activity-guided isolation studies on the leaves of Atalantia monophylla (ROXB.) CORR. (Rutaceae) led to the identification of pyropheophorbide a (1), a simple chlorin derivative, from the chloroform extract (fr. B) as a possible antiviral active principle against herpes simplex virus type 2 (HSV-2). Pyropheophorbide a methyl ester (2) was also isolated from the hexane extract (fr. A).View full abstractDownload PDF (492K) -
Yoshiyasu FUKUYAMA, Mai NAKAHARA, Hiroyuki MINAMI, Mitsuaki KODAMA1996 Volume 44 Issue 7 Pages 1418-1420
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNew benzofuran-type lignans, vibsanol (1) and 9'-O-methylvibsanol (2), along with dihydrodehydrodiconiferyl alcohol (3), have been isolated from the wood of Viburnum awabuki (Caprifoliaceae). Their structures have been elucidated mainly on the basis of spectroscopic data. The antioxidant property of new compounds has been evaluated.View full abstractDownload PDF (547K) -
Ajit K. CHAKRAVARTY, Binayak DAS, Kazuo MASUDA, Hiroyuki AGETA1996 Volume 44 Issue 7 Pages 1421-1423
Published: July 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSGlycoric acid (1) belonging to a new 10-normegastigmane skeleton was isolated from the hepatoprotective n-butanol soluble fraction of the methanol extract of Glycosmis arborea and characterized as (7E, 3R*, 5S*, 6R*)-3, 6-dihydroxy-10-normegastigm-7-en-9-oic acid on the basis of 2D NMR and other spectral analyses.View full abstractDownload PDF (396K)
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