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Volume 48, Issue 7
Displaying 1-38 of 38 articles from this issue
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Hatsuo MAEDA, Shinya MATSU-URA, Toshihisa SENBA, Seiji YAMASAKI, Hitos ...2000 Volume 48 Issue 7 Pages 897-902
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSResorufin (1) has been found to act as an electron acceptor in glucose oxidase (GOD)-catalyzed oxidation of glucose. When a 1 : 1 : 1 mixture of solutions of 1 (5.0 μM), glucose, and GOD (4.0 mg/ml) in phosphate buffer (pH 7.4, 0.1 M) was incubated at 36°C under aerobic conditions and the reaction was followed by a measurement of changes in fluorescence intensity due to 1, only two types of fluorometric traces were observed : (1) when a glucose solution of less than 0.7 mM was subjected to the enzymatic reaction, no consumption of 1 was observed; (2) the reaction with glucose at more than 1.0 mM always consumed 1, affording a regression fluorometric curve, and yet the obtained fluorometric traces could be almost superimposed on one another with no dependence on the glucose concentration. The reasons for the observed phenomena are discussed.View full abstractDownload PDF (928K) -
Yoshitomo SUHARA, Hiroaki TAKAYAMA, Shinji NAKANE, Tomoyuki MIYASHITA, ...2000 Volume 48 Issue 7 Pages 903-907
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe synthesized 2-arachidonoylglycerol (1), an endogenous cannabinoid receptor ligand, and its metabolically stable ether-linked analogues. Compound 1 was synthesized from 1, 3-benzylideneglycerol (6) and arachidonic acid in the presence of N, N'-dicyclohexylcarbodiimide and 4-dimethylaminopyridine followed by treatment with boric acid and trimethyl borate. An ether-linked analogue of 2-arachidonoylglycerol (2) was synthesized from 6 and 5, 8, 11, 14-eicosatetraenyl iodide (9). The ether-linked analogues of 2-palmitoylglycerol (4) and 2-oleoyglycerol (5) were synthesized from 6 and hexadecyl iodide (12) and 9-octadecenyl iodide (14), respectively. We confirmed that 1 stimulates NG108-15 cells to induce rapid transient elevation of the intracellular free Ca2+ concentrations through a CB1 receptor-dependent mechanism. Noticeably, 2 exhibited appreciable agonistic activity, although its activity was significantly lower than that of 1. Compound 2 would be a useful tool in exploring the physiological significance of 1, because this compound is resistant to hydrolyzing enzymes in contrast to 1. On the other hand, the ether-linked analogues of either 4 or 5 failed to act as a CB1 receptor agonist. Compounds 4 and 5 would also be valuable as control molecules in experiments where 2 is employed.View full abstractDownload PDF (841K) -
Jun-ichi UEDA, Akira HANAKI, Keiichiro HATANO, Terumi NAKAJIMA2000 Volume 48 Issue 7 Pages 908-913
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSpectroscopic and kinetic studies on the autoxidation of ascorbic acid catalyzed by copper complexes of histidine oligopeptides, (His)iGly (i=4, 9, 19, 29), and their acetyl derivatives, Ac-(His)iGly (i=9, 19) have been carried out at pH 4.4 and 25°C under dioxygen. The reaction was monitored at 260 nm using a stopped-flow spectrophotometric technique. The reaction fitted the "Michaelis-Menten" mechanism, and ascorbate was oxidized by the "Ping-Pong" mechanism. The Cu(II) complexed with the oligopeptide (i≥9) enhanced the reaction approximately two-fold relative to the aqueous Cu(II). The catalytic activity depends on the molecular weight which is related to the number of histidyl residues and on the coordination mode of the copper-binding site. Results of circular dichroism (CD) experiments revealed the existence of two types of Cu(II). The catalytically active Cu(II), which is accommodated in the imidazole clusters composed of at least six histidyl residues, exhibits d-d transition bands at 520 and 630 nm, and is easily dissociable, enhances the autoxidation; Ac-(His)19Gly is likely to accommodate approximately three active Cu(II) ions. The Cu(II), which is complexed tightly with the terminal H2N-X-Y-His- moiety, where X and Y denote amino acids, inhibits the autoxidation, and exhibits absorption bands at 480 and 550 nm.View full abstractDownload PDF (898K) -
Tawfik H. RAKHA, Magdy M. BEKHEIT2000 Volume 48 Issue 7 Pages 914-919
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSMononuclear and polynuclear chelates of potassium picolinoyldithiocarbazate (KHPcDC) with Mn(II), Fe(III), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Pd(II) and U(VI)O2 have been prepared and characterized by chemical and thermal (TG, DTG, DTA) analyses, molar conductivities, spectral (UV-Visible, IR, NMR, ESR) and magnetic moment measurements. The molar conductivities of the complexes lie in the non-electrolyte range whilst KHPcDC is a 1 : 1 electrolyte. Changes in selected vibrational absorption of the ligand upon coordination indicate that KHPcDC behaves as monoanionic and coordinates in a bidentate, tridentate and/or bridging tetradentate manner. Trans-form structure is proposed for [Pd(HPcDC)2]·2H2O and [Cd(HPcDC)2] complexes on the basis of NMR data. An octahedral structure is proposed for Fe(III), Fe(II) and Ni(II) complexes, a square-planar structure for Co(II) and Pd(II) complexes and a tetragonally distorted octahedral structure for the Cu(II) chelate on the basis of spectroscopic and magnetic data. The ligand field parameters (B, Dq, β) for the Fe(III) and Ni(II) chelates were calculated. TG, DTG and DTA studies support the different modes of chelation of KHPcDC. The solid metal acetate chelates have a unique decomposition exotherm profile which can be used as a rapid and sensitive tool for the detection of acetate-containing complexes.View full abstractDownload PDF (913K) -
Shigeki KOBAYASHI, Hiroki KOBAYASHI, Takatoshi YAMAGUCHI, Miharu NISHI ...2000 Volume 48 Issue 7 Pages 920-934
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTo investigate the chemical conformations and functions of the -Phe-Phe-Val- or -Phe-Phe- sequences contained in the Alzheimer's disease related β-amyloid peptide, a series of mini parallel double-stranded peptides conjugated with two peptide residues to one spacer were designed and prepared. The structure of the compounds was elucidated by circular dichroism (CD) spectrum and NMR two dimensional (2D) nuclear Overhauser enhancement and exchange spectroscopy (NOESY) measurments. The structure of 1, 2-ethano-bis(L-Phe-L-Phe-L-Leu), 1, 12-dodecano-bis(L-Phe-L-Phe-L-Leu), 1, 12-dodecano-bis(L-Phe-L-Phe-L-Val), and 1, 12-dodecano (D-Phe-D-Phe-D-Leu) conjugated with L-Leu and L-Val residues show a β-turn-like nucleation. The dihedral angles (θ=+75°, +180°, ω=+90°, φ=-87°, ψ=+180°) obtained from experimental coupling constant (J) data, etc. support that 1, 12-dodecano-bis(L-Phe-L-Phe) adopts β-turn mimic nucleation. The 1, 12-dodecano-bis(L-Leu-L-Leu-L-Phe), 1, 12-dodecano-bis(L-Ile-L-Phe-L-Leu), and 1, 12-dodecano-bis(L-Phe-L-Val-L-Leu), etc. adopt most probably a random structure by CD studies.It was found by titration spectrum that an inclusion complex of 1 : 1 ratio (association constant;Ka=1.0×104M-1) is formed between 1, 12-dodecano-bis(L-Phe-L-Phe-L-Leu) and azobenzene (guest, [L0]=1.758×10-5M-1). Moreover, the stability of the complexes was increased in order of 1, 12-dodecano-bis(L-Phe-L-Phe-L-Leu)·azobenzene>1, 12-dodecano-bis(L-Phe-L-Phe-L-Val)·azobenzene>1, 12-dodecano-bis(L-Phe-L-Val-L-Leu)·azobenzene. The data show that X-Phe-L-Phe-L-spacer(S)-L-Phe-L-Phe-X (X=amino acids;S=1, 2-ethano- and 1, 12-dodecano-) plays an important role as a binding site of the artificial receptor. The hydrophobic interaction of the four Phes in the two strands is a very interesting issue in the physiological action of proteins as well as the conformation of the backbone of X-L-Phe-L-Phe-spacer(S)-L-Phe-L-Phe-X.View full abstractDownload PDF (2016K) -
Cecile ENGUEHARD, Jean-Louis RENOU, Hassan ALLOUCHI, Jean-Michel LEGER ...2000 Volume 48 Issue 7 Pages 935-940
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom a pharmacophore model of bicyclic heterocycles as aromatase inhibitors we have designed three series of imidazo[1, 2-a]pyridine derivatives. The synthesis and the spectroscopy determination of various compounds are reported. The crystal data of one of these compounds (10b) was obtained. The aromatase inhibition potency was evaluated in vitro and no activity was found.View full abstractDownload PDF (901K) -
Xiaoliang YAN, Eugene KHOR, Lee-Yong LIM2000 Volume 48 Issue 7 Pages 941-946
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSChitosan-alginate polyelectrolyte complex (PEC) have been prepared in situ in beads and microspheres. This study examines the preparation of suitable chitosan-alginate coacervates for casting into homogeneous PEC films for potential applications in packaging, controlled release systems and wound dressings. Coacervation between chitosan and alginate was rapid, but the rate may be controlled with the addition of water miscible organic solvents. Compared with ethanol and PEG200, acetone was the more promising solvent moderator. Suspensions of fine, uniformly dispersed coacervates were produced by a dropwise addition of 0.25% w/v chitosan solution (solvent : 1 : 1 v/v of 2% acetic acid and acetone) into 0.25% w/v sodium alginate solution in water under rapid agitation. The PEC films were transparent and flexible. They exhibited high permeability to water vapor, but resisted complete dissolution in 0.1 M HCl, distilled water and pH 7.4 phosphate buffer solution. Microscopic heterogeneity in the films could be reduced by immersion in aqueous media, but this was accompanied by modifications in the thickness, permeability and mechanical property of the films.View full abstractDownload PDF (1805K) -
Teruko NOMURA, Yasuyuki ASAI, Naokazu MURAHASHI, Kiyoshi IWAMOTO2000 Volume 48 Issue 7 Pages 947-950
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSE5880, a novel platelet activating factor receptor antagonist, was dispersed in water for the preparation of injectable formulation and the physicochemical properties of the micelles were characterized. The critical concentration for formation of micelles was 0.12 mM. Using the area per molecule results, the critical packing parameter was calculated and showed that the structure was composed of spherical micelles and the number of the molecules per micelle was 88. The diameter of a micelle was 8.1 nm. The fluidity and micropolarity around the hydrocarbon region of the micelles were evaluated and compared to the surfactants, stearyltrimethylammmonium chloride and cetyltrimethylammonium chloride.View full abstractDownload PDF (614K) -
Irene CHIWELE, Brian E. JONES, Fridrun PODCZECK2000 Volume 48 Issue 7 Pages 951-956
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe shell dissolution properties of gelatine, gelatine/polyethylene glycol (PEG) and hydroxypropyl methylcellulose (HPMC) capsules were studied as a function of temperature, dissolution medium, and after different storage conditions. In any dissolution medium with a pH below or equal to 5.8, HPMC capsule shells dissolved rapidly, and there was no difference in the time in which dissolution occurred in the tested temperature interval of 10 to 55°C. Gelatine and gelatine/PEG capsule shells, generally, did not dissolve at temperatures below 30°C. The shell dissolution time of all capsules tested was prolonged and more variable in mixed phosphate buffer pH=6.8. The addition of enzymes (pepsin, pancreatin) to any dissolution medium was found not to enhance the differences between the different types of capsules investigated. In practical terms, the results indicated that capsule formulations should not be taken with drinks from the carbonated Cola-type. Gelatine containing capsules should preferably be administered with a warm drink, whereas HPMC capsules could be given with cold or warm drinks. The latter type of capsules should also be preferred for preparations to be taken in the fasted state. A short storage of gelatine containing capsules under hot humid tropical conditions appeared not to alter the dissolution properties of the shells, and changes in disintegration times and dissolution times of formulations filled in such capsules might be a reflection of changes of the powders incorporated rather than of the capsule shells. However, a short storage of HPMC capsules under such conditions appeared to influence the capsule shell matrix.View full abstractDownload PDF (982K) -
Toshiyuki HATA, Yukio ONO2000 Volume 48 Issue 7 Pages 957-963
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSpatial distribution functions (SDFs), gOO(x, y, z) and gOH(x, y, z), obtained from Monte Carlo simulations at 298 K were applied to characterize the anisotropic structure of infinitely dilute aqueous solutions of alcohols and ethers having straight chain and branched alkyl groups. In spite of the different size and shape of the hydrophobic groups, the spatial orientation of the hydrogen-bonded water molecules was found to be of linear type with a triple layer structure in the hydrogen acceptor (HA) region and a double layer structure in the hydrogen donor (HD) region. The volumes and the coordination number (CN) in the HA region were essentially identical for all alcohol and ether solutions, but the volumes for the isopropyl alcohol (IPA) and isopropyl methyl ether (IPE) solutions were greater than those for the other solutions. In the hydrophobic hydration (HH) region, these values increased with increasing size and shape of hydrophobic groups, except in the case of IPA and IPE solutions. These results indicated that the hydration structures around the isopropyl group in alcohol and ether solutions differed from those in other solutions. From the results of the difference SDF (DSDF), ΔgOO(x, y, z), between SDFs gOO(x, y, z) for the two states, it was apparent that the distribution of hydration water molecules in the HA region for ether solution was characterized by the increase of the distribution in the direction of lone pair electrons on the oxygen atom of the solute molecule with increasing hydrophobicity.View full abstractDownload PDF (1454K) -
Chiung-Yun CHANG, Li-Jiau HUANG, Jih-Pyang WANG, Che-Ming TENG, Sheng- ...2000 Volume 48 Issue 7 Pages 964-973
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn a continuation of our search for novel anti-platelet agents, isoflavone quinone and isoflavanquinone were selected as lead compounds and the synthesis of their methoxy derivatives was carried out. Among them, the 4'-and 7-methoxy derivatives were successfully prepared, whereas the attempt to obtain 3'-methoxy derivatives resulted in their isomers, 3'-methoxyflavone quinone and 3'-methoxyflavanquinone, instead.After screening for their anti-platelet, anti-inflammatory and anti-allergic activities, a preliminary structure-activity relationship was established.Compounds 6c, 7a-c, 8c and 9a-c were found to exhibit significant activities. In particular, compound 7c demonstrated very potent anti-platelet, anti-inflammatory and anti-allergic activities and was then recommended for further pharmacological investigation.View full abstractDownload PDF (1206K) -
Keiko HIRANO, Takaaki KUBOTA, Masashi TSUDA, Yuzuru MIKAMI, Jun'ichi K ...2000 Volume 48 Issue 7 Pages 974-977
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNew bis-pyridine alkaloids, pyrinodemins B-D (1-3), have been isolated together with pyrinodemin A (4) and related 3-alkyl pyridine alkaloids 5-8 from the Okinawan marine sponge Amphimedon sp. and the structures were elucidated from spectroscopic data. Pyrinodemins B-D (1-3) showed potent cytotoxicity, while compounds 5-8 exhibited antimicrobial activity.View full abstractDownload PDF (636K) -
Yoshiteru HONDA, Masahiro NAKANO2000 Volume 48 Issue 7 Pages 978-981
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe adsorption characteristics of various bile acids and methotrexate to a new type of anion-exchange resin, colestimide, were studied in vitro and compared with those to cholestyramine. For bile acids, colestimide was shown to have a higher capacity than cholestyramine. For example, approximately 1.4-fold higher for cholic acid and 2.0-fold for deoxycholic acid in water. In the presence of physiological anions, the degree of adsorption of cholic acid to both resins was greatly reduced, whereas adsorption of deoxycholic acid was only slightly reduced. Furthermore, the bed-volume of colestimide swelled about 6.8-fold in water, hence the anion-exchange groups of this resin are expected to be able to function effectively in adsorption of bile acids in the gut. In addition, colestimide was found to have high adsorption capacity for methotrexate, not only in water but also in media containing various physiological anions, and thus it is suggested that colestimide is a potential oral antidote to reduce possible toxicity by methotrexate through interruption of enterohepatic circulation.View full abstractDownload PDF (713K) -
Hiromichi ETO, Yasushi KANEKO, Takao SAKAMOTO2000 Volume 48 Issue 7 Pages 982-990
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNew 1, 2, 4-triazoles (1) having a difluoro(heteroaryl)methyl moiety were designed and synthesized via 1-aryl-2, 2-difluoro-2-(heteroaryl)ethanones (2), which were prepared by two routes starting from the reaction of ethyl 2, 2-difluoro(heteroaryl)acetate with phenyllithiums (Route A) and from the reaction of chlorodifluoro(heteroaryl)methane with benzaldehydes (Route B). The compounds 1 except for 1g show antifungal activities against yeasts and filamentous fungi in vitro, especially (+)-1f have equal or superior activities compared to those of itraconazole.View full abstractDownload PDF (1326K) -
Fumiko ABE, Tatsuo YAMAUCHI2000 Volume 48 Issue 7 Pages 991-993
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSteroidal compounds in the roots of Asclepias tuberosa were investigated and 17α-hydroxyandrosta-4, 6, 15-trien-3-one 17-O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranoside, termed ascandroside, was isolated from the CHCl3-soluble fraction. Among five doubly-linked cardenolide glycosides, two were identified as 3'-spiro-linked thiazolidinone (4) and S-oxythiazolidinone derivatives (5) of Δ5-calotropin. The stereochemistry at the C-3' in these two cardenolides is discussed. 3'-O-β-D-Glucopyranosyl-Δ5-calotropin (3) was also isolated along with Δ5-calotropin and its 3'-acetate. Nine glycosides of uzarigenin, coroglaucigenin and corotoxigenin were identified.View full abstractDownload PDF (559K) -
Toshiyuki MURAKAMI, Akinobu KISHI, Hisashi MATSUDA, Masayuki YOSHIKAWA2000 Volume 48 Issue 7 Pages 994-1000
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSix new furostanol-type steroid saponins called trigoneosides Xa, Xb, XIb, XIIa, XIIb, and XIIIa were isolated from the seeds of Egyptian Trigonella foenum-graecum L. (Leguminosae) together with six known furostanol-type steroid saponins : trigoneosides Ia, Ib, and Va, glycoside D, trigonelloside C, and compound C. The structures of trigoneosides Xa, Xb, XIb, XIIa, XIIb, and XIIIa were determined on the basis of chemical and physicochemical evidence as 26-O-β-D-glucopyranosyl-(25S)-5α-furostane-2α, 3β, 22ξ, 26-tetraol 3-O-α-L-rhamnopyranosyl(1→2)-β-D-glucopyranoside, 26-O-β-D-glucopyranosyl-(25R)-5α-furostane-2α, 3β, 22ξ, 26-tetraol 3-O-α-L-rhamnopyranosyl(1→2)-β-D-glucopyranoside, 26-O-β-D-glucopyranosyl-(25R)-5α-furostane-2α, 3β, 22ξ, 26-tetraol 3-O-β-D-xylopyranosyl(1→4)-β-D-glucopyranoside, 26-O-β-D-glucopyranosyl-(25S)-furost-4-ene-3β, 22ξ, 26-triol 3-O-α-L-rhamnopyranosyl(1→2)-β-D-glucopyranoside, 26-O-β-D-glucopyranosyl-(25R)-furost-4-ene-3β, 22ξ, 26-triol 3-O-α-L-rhamnopyranosyl(1→2)-β-D-glucopyranoside, and 26-O-β-D-glucopyranosyl-(25S)-furost-5-ene-3β, 22ξ, 26-triol 3-O-α-L-rhamnopyranosyl(1→2)-[β-D-glucopyranosyl(1→3)-β-D-glucopyranosyl(1→4)]-β-D-glucopyranoside, respectively.View full abstractDownload PDF (978K) -
Tetsuro ITO, Toshiyuki TANAKA, Yoshimi IDO, Ken-ichi NAKAYA, Munekazu ...2000 Volume 48 Issue 7 Pages 1001-1005
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new stilbene glucosides [(+)-α-viniferin 13b-O-β-glucopyranoside and resveratrol 12-C-β-glucopyranoside] and two new resveratrol oligomers, hemsleyanols A and B, were isolated from the bark of Shorea hemsleyana along with four known reseveratrol oligomers. The structures of the isolates, including the relative configurations, were established by spectroscopic data involving long-range coupling and nuclear Overhauser effect experiments.View full abstractDownload PDF (709K) -
Tian-Shung WU, Yu-Yi CHAN, Yann-Lii LEU2000 Volume 48 Issue 7 Pages 1006-1009
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new compounds, three phenanthrene derivatives, aristolochic acid-III methyl ester (1), cepharanone C (2), and sodium 7-hydroxyl-8-methoxyaristolate (3), and the benzoate derivative, sodium 3, 4-dimethoxybenzoate (4), together with 53 known compounds were isolated and characterized from the fresh root and stem of Aristolochia cucurbitifolia. Their structures were elucidated by spectral analyses and chemical transformations. The cytotoxicity and antiplatelet activity of the isolated compounds are also discussed.View full abstractDownload PDF (700K) -
Nobuyuki TANAKA, Tsuyoshi MIURA, Yukio MASAKI2000 Volume 48 Issue 7 Pages 1010-1016
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSPolymeric dicyanoketene acetals (DCKA) were synthesized by copolymerization of styrene and divinylbenzene or ethylene glycol dimethacrylate. These novel polymers could be used successfully as recyclable π-acid catalysts in monothioacetalization or carbon-carbon bond forming reaction of acetals.View full abstractDownload PDF (932K) -
Fumiko ABE, Tatsuo YAMAUCHI2000 Volume 48 Issue 7 Pages 1017-1022
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSixteen glycosides of pregnanes, including ikemagenin, lineolon, and a new pregnane, 3β, 8β, 14β, 15β, 16α-pentahydroxy-5α-pregnan-20-one, termed pleurogenin, were isolated from the roots of Asclepias tuberosa. Among ikemagenin and lineolon glycosides, one (1) was a known glycoside, and eight (2-7, 10, 13) were glycosides with new combinations of ikemagenin or lineolon and known sugar sequences composed of D-cymarose, D-oleandrose, D-thevetose and D-glucose. The structures of four new glycosides of ikemagenin (8, 9, 11, 12) and three of pleurogenin (14-16) were determined. The new glycosides have sugar sequences ranging from tetraoside to heptaosides.View full abstractDownload PDF (859K) -
Kazuyuki SATO, Misato TAMURA, Kei TAMOTO, Masaaki OMOTE, Akira ANDO, I ...2000 Volume 48 Issue 7 Pages 1023-1025
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe have reported that the reaction of ethyl bromodifluoroacetate (1) with alkenyl iodides in the presence of copper powder gives ethyl alkenyldifluoroacetates. As an extension of this reaction, reaction of 1 with Michael acceptors in the Presence of copper powder was examined and found to give 1, 4-addition products selectively, unless the acceptor has a group stabilizing a radical intermediate, such as a phenyl group.View full abstractDownload PDF (551K) -
Byung-Sun MIN, Jiang-Jing GAO, Norio NAKAMURA, Masao HATTORI2000 Volume 48 Issue 7 Pages 1026-1033
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSix new highly oxygenated lanostane-type triterpenes, called ganoderic acid γ(1), ganoderic acid δ(2), ganoderic acid ε(3), ganoderic acid ζ(4), ganoderic acid η(5) and ganoderic acid θ(6), were isolated from the spores of Ganoderma lucidum, together with known ganolucidic acid D (7) and ganoderic acid C2 (8). Their structures of the new triterpenes were determined as (23S)-7β, 15α, 23-trihydroxy-3, 11-dioxolanosta-8, 24(E)-diene-26-oic acid (1), (23S)-7α, 15α, 23-trihydroxy-3, 11-dioxolanosta-8, 24(E)-diene-26-oic acid (2), (23S)-3β, 7β, 23-trihydroxy-11, 15-dioxolanosta-8, 24(E)-diene-26-oic acid (3), (23S)-3β, 23-dihydroxy-7, 11, 15-trioxolanosta-8, 24(E)-diene-26-oic acid (4), (23S)-3β, 7β, 12β, 23-tetrahydroxy-11, 15-dioxolanosta-8, 24(E)-diene-26-oic acid (5) and (23S)-3β, 12β, 23-trihydroxy-7, 11, 15-trioxolanosta-8, 24(E)-diene-26-oic acid (6), respectively, by chemical and spectroscopic means, which included the determination of a chiral center in the side chain by a modification of Mosher's method. The cytotoxicity of the compounds isolated from the Ganoderma spores was carried out in vitro against Meth-A and LLC tumor cell lines.View full abstractDownload PDF (1153K) -
Hiroyuki NAKAMURA, Hiroshi FUKUDA, Frank GIRALD, Tooru KOBAYASHI, Jun' ...2000 Volume 48 Issue 7 Pages 1034-1038
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe evaluation of the Gd-carborane complex 2 as an MR imaging and boron carrier agent was carried out in vivo using tumor-bearing Donryu rats, MRI, ICP-AES, and α-autoradiography. The MR imaging revealed that the carborane Gd-DTPA 2 was metabolized slower in the body than Gd-DTPA 1. The results of the ICP-AES method indicated that compound 2 was incorporated into normal tissues and metabolized quickly, whereas it was not accumulated into tumor or brain tissue. The α-autoradiography showed that a high level of boron was obtained in the internal organs and in the necrosis of tumor tissue.View full abstractDownload PDF (1447K) -
Masayuki YOSHIKAWA, Toshiaki UEMURA, Hiroshi SHIMODA, Akinobu KISHI, Y ...2000 Volume 48 Issue 7 Pages 1039-1044
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn the course of our screening for natural estrogenic compounds from Occidental medicinal herbs, the extracts of several herbs were found to show proliferative activity in MCF-7 (an estrogen-sensitive breast cancer cell line). Among these active herbs, the methanolic extract from the aerial parts of Petroselinum crispum (parsley) showed potent estrogenic activity, which was equal to that of isoflavone glycosides from soybean. Through bioassay-guided separation, we isolated several flavone glycosides and a new flavone glycoside, 6"-acetylapiin, with estrogenic activity together with a new monoterpene glucoside, petroside. The structures of 6"-acetylapiin and petroside were characterized by the chemical and physicochemical evidence. Estrogenic activities of these flavone glycosides were found to be enhanced by removal of their glycoside moieties. The EC50 values (concentration needed to enhance the MCF-7 proliferation 50% compared to non-estrogen treated cell) of their aglycones are as follows, apigenin (1.0 μM), diosmetin (2.9 μM), and kaempferol (0.56 μM). The estrogenic activities of these flavones are nearly equal to those of the isoflavones, daidzein (0.61 μM) and genistein (0.60 μM). The methanolic extract of parsley, apiin, and apigenin restored the uterus weight in ovariectomized mice when orally administered for consecutive 7 days.View full abstractDownload PDF (949K) -
Masayuki YOSHIKAWA, Toshiyuki MURAKAMI, Hideo OOMINAMI, Hisashi MATSUD ...2000 Volume 48 Issue 7 Pages 1045-1050
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe saponin fraction from the fresh leaves of Euptelea polyandra SIEB. et ZUCC. was found to exhibit potent gastroprotective activity. Fourteen new nortriterpene saponins called eupteleasaponins were isolated from the saponin fraction with gastroprotective activity. The structures of eupteleasaponins I, II, III, IV, V, and V acetate were determined on the basis of chemical and physicochemical evidence as 3-O-α-L-rhamnopyranosyl(1→2)-β-D-glucopyranosyl(1→3)-β-D-xylopyranosylakebonoic acid 28-O-β-D-glucopyranosyl ester, 3-O-α-L-rhamnopyranosyl(1→2)-[α-L-rhamnopyranosyl(1→4)]-β-D-glucopyranosyl(1→3)-β-D-xylopyranosylakebonoic acid 28-O-β-D-glucopyranosyl ester, 3-O-α-L-rhamnopyranosyl(1→2)-[α-L-arabinopyranosyl(1→4)-α-L-rhamnopyranosyl(1→4)]-β-D-glucopyranosyl(1→3)-β-D-xylopyranosylakebonoic acid 28-O-β-D-glucopyranosyl ester, 3-O-α-L-rhamnopyranosyl(1→2)-[α-L-arabinopyranosyl(1→4)-α-L-rhamnopyranosyl(1→4)]-β-D-glucopyranosyl(1→3)-β-D-xylopyranosylakebonoic acid, 3-O-α-L-rhamnopyranosyl(1→2)-β-D-glucopyranosyl(1→3)-β-D-xylopyranosyleupteleogenin, and 3-O-α-L-rhamnopyranosyl(1→2)-6"-O-acetyl-β-D-glucopyranosyl(1→3)-β-D-xylopyranosyleupteleogenin.View full abstractDownload PDF (939K) -
Dae-Yeon SUH, Junichi KAGAMI, Kazuki FUKUMA, Naoko IWANAMI, Yasuyo YAM ...2000 Volume 48 Issue 7 Pages 1051-1054
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSChalcone synthase (CHS) and stilbene synthase (STS) catalyze different cyclization reactions of the common tetraketide to give different products, naringenin chalcone and resveratrol, respectively. We have previously observed in vitro cross-reaction of CHS and STS overexpressed in Escherichia coli, resveratrol production by CHS and chalcone production by STS. When expressed in eucaryotic cells, or in E. coli as thioredoxin-fusion proteins, CHS and STS exhibited reduced cross-reaction. STS refolded from inclusion bodies also showed reduced cross-reaction. While addition of bovine serum albumin and pH in the reaction were without noticeable effect, addition of glycerol decreased the cross-reaction of CHS likely due to its stabilizing effect on enzyme conformation. These results were interpreted to provide supporting evidence to our earlier proposition (Yamaguchi T. et al., FEBS Lett., 460, 457-461 (1999)) that the in vitro cross-reaction of CHS and STS is due to intrinsic capability of these enzymes to catalyze different types of cyclization, which, in turn, is endowed by conformational flexibility of their active sites.View full abstractDownload PDF (900K) -
Wenzhe FAN, Yasuhiro TEZUKA, Shigetoshi KADOTA2000 Volume 48 Issue 7 Pages 1055-1061
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSProlyl endopeptidase (PEP, EC 3.4.21.26) is an enzyme playing a role in the metabolism of proline-containing neuropeptides which have been suggested to be involved in learning and memory processes. In screening for PEP inhibitors from fourteen traditional Kampo formulas, we found that Tokaku-joki-to( ?? ?? ?? ?? ?? ) shows a significant inhibitory activity. Examination of the constitutents of the Kampo formula resulted in the isolation of two new compounds, cis-3, 5, 4'-trihydroxystilbene 4'-O-β-D-(6-O-galloyl)glucopyranoside (10) and 4-(4-hydroxyphenyl)-2-butanone 4'-O-β-D-(6-O-galloyl-2-O-cinnamoyl)glucopyranoside (16), along with twenty-five known compounds, cinnamic acid (1), protocatechuic acid (2), gallic acid (3), torachrysone 8-O-β-D-glucoside (4), emodin (5), emodin 8-O-β-D-glucoside (6), 3, 5, 4'-trihydroxystilbene 4'-O-β-D-glucopyranoside (7), 3, 5, 4'-trihydroxystilbene 4'-O-β-D-(2-O-galloyl)glucopyranoside (8), 3, 5, 4'-trihydroxystilbene 4'-O-β-D-(6-O-galloyl)glucopyranoside (9), 4-(4-hydroxyphenyl)-2-butanone 4'-O-β-D-glucopyranoside (11), isolindleyin (12), lindleyin (13), 4-(4-hydroxyphenyl)-2-butanone 4'-O-β-D-(2, 6-di-O-galloyl)glucopyranoside (14), 4-(4-hydroxyphenyl)-2-butanone 4'-O-β-D-(2-O-galloyl-6-O-cinnamoyl)glucopyranoside (15), 1-O-galloylglucose (17), 1, 2, 6-tri-O-galloylglucose (18), gallic acid 4-O-β-D-(6-O-galloyl)glucopyranoside (19), liquiritigenin (20), liquiritigenin 4'-O-β-D-glucoside (21), liquiritigenin 7, 4'-diglucoside (22), liquiritigenin 4'-O-β-D-apiofuranosyl-(1→2)-β-D-glucopyranoside (23), licuroside (24), (-)-epicatechin (25), (-)-epicatechin 3-O-gallate (26) and (+)-catechin (27). Among these compounds, twelve (7-10, 14-16, 18, 19, 24-26) showed noncompetitive inhibtion with an IC50 of 22.9, 3.0, 14.9, 2.8, 10.5, 0.69, 8.2, 0.44, 9.39, 26.5, 28.1 and 0.052μM, respectively.View full abstractDownload PDF (939K) -
Tsuyoshi IKEDA, Hidetsugu TSUMAGARI, Toshihiro NOHARA2000 Volume 48 Issue 7 Pages 1062-1064
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new steroidal saponins, named nigrumnins I and II, together with two known saponins were obtained from the whole plant of Solanum nigrum L. On the basis of spectroscopic analysis (1H-NMR, 13C-NMR, 1H-1H COSY, TOCSY, HMQC, HMBC and FAB-MS), nigrumnin I was established as (25R)-5α-spirostan 3β-ol 3-O-β-D-xylopyranosyl-(1→3)-[α-L-arabinopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-β-D-galactopyranoside (1), and nigrumnin II was elucidated as (25R)-3β, 17α-dihydroxy-5α-spirostan-12-one 3-O-β-D-xylopyranosyl-(1→3)-[α-L-arabinopyranosyl-(1→2)]-β-D-glucopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-β-D-galactopyranoside (2).View full abstractDownload PDF (539K) -
Koji WADA, Takao MORI, Norio KAWAHARA2000 Volume 48 Issue 7 Pages 1065-1074
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSHigh-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS) was successfully applied to seven stereoisomeric diterpenoid alkaloids at position 1 or 12. Comparison of the breakdown curves, observed by changing the potential difference between the first electrode and the second electrode of the APCI ion source, revealed stereochemical dependence of different fragmentations. The APCI spectra of alkaloids were predominantly the [M+H]+ ion and the major fragment ion, corresponding to the [M+H-H2O]+ ion or the [M+H-CH3COOH]+ ion, and comparison of the APCI spectra showed that the abundance of fragment ions was significantly higher for C-1 β-form alkaloids than for C-1 α-form alkaloids, and for C-12 β-form alkaloids than for C-12 α-form alkaloids. The characteristic fragment ions were formed due to the loss of an acetic acid or a water molecule at position 12. The fragmentation mechanisms depending on the stereochemisry of the precursor ion could be discerned by recording the spectra in a deuterated solvent system of 0.05 M ammonium acetate in D2O-acetonitrile-tetrahydrofuran. Loss of CH3COOD or D2O from the precursor ion gave the fragment ion. This result indicated that the proton of protonation was included in the leaving acetic acid and water molecule, respectively. The peak intensity ratio for R=[M+H]+/[M+H-H2O]++[M+H-CH3COOH]+ manifested the stereochemical differentiation of alkaloids at position 1 or 12.View full abstractDownload PDF (1186K) -
Jianjun GAO, Kiharu IGARASHI, Manabu NUKINA2000 Volume 48 Issue 7 Pages 1075-1078
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new phenylethanoid glycosides, incanoside C, incanoside D and incanoside E were isolated together with one known glycoside, β-D-fructofuranosyl-α-D-(6-O-[E]-sinapoyl) glucopyranoside from the whole plant of Caryopteris incana (THUNB.) MIQ. On the basis of chemical and spectral analyses, the structures of the new compounds were elucidated to be 1-O-(3, 4-dihydroxyphenyl)ethyl-O-β-D-glucopyranosyl(1→2)-α-L-rhamnopyranosyl(1→3)-4-O-feruloyl-β-D-glucopyranoside (incanoside C), 1-O-(3-hydroxy-4-methoxyphenyl)ethyl-O-β-D-glucopyranosyl(1→2)-α-L-rhamnopyranosyl(1→3)-4-O-feruloyl-β-D-glucopyranoside (incanoside D) and 1-O-(3-methoxy-4-hydroxyphenyl)ethyl-O-β-D-glucopyranosyl(1→2)-α-L-rhamnopyranosyl(1→3)-4-O-feruloyl-β-D-glucopyranoside (incanoside E). The three new phenylethanoid glycosides exhibited radical scavenging activities against DPPH radical and inhibitory activities against the oxidation of linoleic acid.View full abstractDownload PDF (642K) -
Hui-Chi HUANG, Chien-Chang SHEN, Chieh-Fu CHEN, Yang-Chang WU, Yao-Hau ...2000 Volume 48 Issue 7 Pages 1079-1080
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA novel agarofuran sesquiterpene polyol ester, 1β, 2β, 6α, 15β-tetracetoxy-8β, 9α-dibenzoyloxy-β-dihydroagarofuran (celahin D) (1), two known analogues of 1, 1β-acetoxy-8β, 9α-dibenzoyloxy-4α, 6α-dihydroxy-2β(α-methylbutanoyloxy)-β-dihydroagarofuran (2) and 1β-acetoxy-8β, 9α-dibenzoyloxy-6α-hydroxy-2β(α-methylbutanoyloxy)-β-dihydroagarofuran (3), and a known cytotoxic sesquiterpene pyridine alkaloid, emarginatine E (4) were isolated from the stems of Celastrus hindsii BENTH. Three known triterpenes, loranthol (5), lupenone (6) and friendelinol (7) were also obtained from the titled plant. Structural elucidation of compound 1 was established by 2D NMR spectra.View full abstractDownload PDF (440K) -
Erdal BEDIR, Ihsan CALIS, Ikhlas A. KHAN2000 Volume 48 Issue 7 Pages 1081-1083
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSMacrophyllosaponin E, a novel cycloartane-type triterpene, has been isolated from the roots of Astragalus oleifolius. The structure elucidation of the compound was achieved by a combination of one- and two-dimensional NMR techniques [1H-1H-correlation spectroscopy (COSY), 1H-13C-heteronuclear multiple guantum correlation spectroscopy (HMQC), and 1H-13C-heteronuclear multiple-bond correlation spectroscopy (HMBC)] and high resolution electrospray ionization Fourier transformation mass spectrometry (HR-ESI-FT-MS).View full abstractDownload PDF (477K) -
Hideaki OTSUKA, Eiji HIRATA, Takakazu SHINZATO, Yoshio TAKEDA2000 Volume 48 Issue 7 Pages 1084-1086
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSix lignan and neolignan derivatives (1-6) were isolated from the n-BuOH-soluble fraction of a MeOH extract of the leaves of Glochidion zeylanicum. On the basis of spectral data, their structures were elucidated to be (+)-isolarisiresinol 3a-O-β-D-glucopyranoside (1), dihydrodehydrodiconiferyl alcohol 4-, 9- and 9'-O-β-D-glucopyranosides (2-4, respectively), (+)-isolarisiresinol 2a-O-β-D-glucopyranoside (5), and dihydrodehydrodiconiferyl alcohol 9-O-sulfate (6), and 5 and 6 were new compounds.View full abstractDownload PDF (437K) -
Hui DONG, Yu-Lin GOU, R.Manjunatha KINI, Hong-Xi XU, Shao-Xing CHEN, S ...2000 Volume 48 Issue 7 Pages 1087-1089
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new cytotoxic polyhydroxysterol, 23, 24, -dimethylcholest-16(17)-E-en-3β, 5α, 6β, 20(S)-tetraol (2), together with nine known compounds was isolated from the soft coral Sarcophyton trocheliophorum. Their structures were determined by spectroscopic methods. Compound 2 showed potent growth inhibitory activity against human HL60 leukemia, M14 skin melanoma, and MCF7 breast carcinoma cells with EC50 values of 2.8, 4.3, and 4.9 μg/ml, respectively, and exhibited minimal toxicity to normal human peripheral blood lymphocytes.View full abstractDownload PDF (577K) -
Fumiko ABE, Tatsuo YAMAUCHI, Keiichi HONDA, Nanao HAYASHI2000 Volume 48 Issue 7 Pages 1090-1092
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSConduritol F 3-O- and 4-O-glucosides were obtained from Cynanchum liukiuense, along with conduritol F which was identified in all Asclepiadaceous plants examined, Tylophora tanakae, Asclepias curassavica and A. fruticosa, as well as in Marsdenia tomentosa. The pattern of the glucosidic linkage to conduritol F differed between individual species, 2-O-glucoside from T. tanakae and M. tomentosa, 3-O-glucoside from A. curassavica, but none from A. fruticosa. Along with conduritol F glucosides, an 11-glucosyloxy-megastigmane and a monoterpenoid glucoside were isolated from C. liukiuense.View full abstractDownload PDF (621K) -
Kazuko YOSHIKAWA, Hiromichi HIRAI, Masami TANAKA, Shigenobu ARIHARA2000 Volume 48 Issue 7 Pages 1093-1096
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom the fresh fruits of Styrax japonica SIEB. et ZUCC., four new triterpenoid glycosides, named jegosaponins A-D (1-4), were isolated. Their structures were determined on the basis of spectroscopic data and chemical evidence. Compounds 1-4 are 3-O-tetraglycosides of barringtogenol C having an acetyl and a tigloyl or a (2Z)-hexenoyl groups at C-21, 22 and 28. The acylated saponins, 1-4, all showed antisweet activity.View full abstractDownload PDF (582K) -
Sunao TAKEDA, Yasushi KANEKO, Hiromichi ETO, Minoru TOKIZAWA, Susumu S ...2000 Volume 48 Issue 7 Pages 1097-1100
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe α, α-gem-difluorination of 2', 4'-difluoro-α-(methylthio)acetophenone (1a) with N-fluoropyridinium salts gave 2', 4', α, α-tetrafluoro α-(methylthio)acetophenone (3a). This reaction was accelerated by the addition of zinc chloride, zinc bromide or anhydrous iron(III) chloride, and higher yields than the reaction without additives were obtained. The gem-difluorination reaction using FP-T300 in the presence of zinc bromide was applicable to other α-(alkylthio)acetophenone derivatives (1).View full abstractDownload PDF (643K) -
Naoe KOJIMA, Worapan SITTHITHAWORN, Ekapop VIROONCHATAPAN, Dae-Yeon SU ...2000 Volume 48 Issue 7 Pages 1101-1103
Published: July 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESScDNAs encoding geranylgeranyl diphosphate synthase (GGPPS) of two diterpene producing plants, Scoparia dulcis and Croton sublyratus, were isolated using the homology-based polymerase chain reaction method. Both cloned genes showed high amino acid sequence homology (60-70%) to other plant GGPPSs and contained highly conserved aspartate-rich motifs. The obtained clones were functionally expressed in Escherichia coli and showed sufficient GGPPS activity to catalyze the condensation of farnesyl diphosphate (FPP) and isopentenyl diphosphate to form geranylgeranyl diphosphate. To investigate the factor determining the product chain length of plant GGPPSs, S. dulcis GGPPS mutants in which either the small amino acids at the fourth and fifth positions before the first aspartate-rich motif (FARM) were replaced with aromatic amino acids or in which two additional amino acids in FARM were deleted were constructed. Both mutants behaved like FPPS-like enzymes and almost exclusively produced FPP when dimethylallyl diphosphate was used as a primer substrate, and failed to accept FPP as a primer substrate. These results indicate that both small amino acids at the fourth and fifth positions before FARM and the amino acid insertion in FARM play essential roles in product length determination in plant GGPPSs.View full abstractDownload PDF (743K)
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