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Volume 48, Issue 6
Displaying 1-27 of 27 articles from this issue
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Rolf HUISGEN2000 Volume 48 Issue 6 Pages 757-765
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSElucidation of mechanisms and discovery of novel reactions are interconnected, as four research chapters from the Munich laboratory demonstrate. 1) In a new poening of the furan ring, 2-methoxyfuran and tetra-acceptor-substituted ethylenes furnish methyl acrylates, which are cis-3-substituted by a cyclopropyl ring that bears the four acceptor groups. Experiments with trans- and cis-1, 2-bis(trifluoromethyl-1, 2-dicyanoethylenes(BTE) clarify the role of zwitterionic intermediates. 2) The concerted nature of 1, 3-dipolar cycloaddition is well established. On reacting thiocarbonyl S-ylides as electron-rich 1, 3-dipoles with tetra-acceptor-substituted ethylenes, the switchng to a two-step pathway via zwitterion was diagnosed from a loss of stereopecificity and the formation of strained 7-membered cyclic ketene imines. 3) Stable as crystals, these ketene imines rearrange to 5-membered thiolanes in solution. In contrast to open-chain ketene imines, the cyclic representatives and vinyl ether at the C=N bond and show a novel pathway of dimerization. 4) Cycloadducts of isoquinolinium N-phenylimide with ethylenic dipolarophiles undergo an acid-catalyzed [3.3] sigmatropic hydrazo rearrangement. An exception is the conversion of the dimethyl maleate adduct (C21H20N2O4) by acid into a yellow compound C24H22N2O6; the structure and the astounding mechanism were clarified.View full abstractDownload PDF (1323K) -
Yueh-Hsiung KUO, Wen-Chin CHEN, Ching-Kuo LEE2000 Volume 48 Issue 6 Pages 766-768
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new monoterpene, platydiol (1), and three new diterpenes, platyclolactonic acid (2), 14, 15-bisnor-8(17)-labdene-16, 19-dioic acid (3), and 6, 7-dehydrosandaracopimaric acid (4), were isolated from the pericarp of Platycladus orientalis. Their structures were elucidated by spectral and chemical methods.View full abstractDownload PDF (566K) -
Tomokatsu TSUKAMOTO, Cheng Yu CHEN, Hirokazu OKAMOTO, Kazumi DANJO2000 Volume 48 Issue 6 Pages 769-773
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSYoung's moduli (E) of three representative tableting excipients and their mix powders were measured for compressed rectangular beam specimens over a range of porosities using a three-point bending technique. We also examined the effects of the amount of water adsorbed on the tensile strentgh of these specimens. The maximal tensile strength (σmax) decreased with increasing water vapor adsorption for microcrystalline cellulose(MCC) and mixed powders of lactose and MCC. σmax increased with increasing compression stress and specimen weitht for all samples. σmax of an α-lactose and cornstarch mixture with a ratio of 7 : 3 showed a large value. Young's modules (E) and the crushing energy (CE) of MCC were larger than those of the other samples.Young's modulus of specimens decreased as the proportion of α-lactose increased.Disintegration time (DT) of tablets comprised of lactose and MCC mixture was much faster than those of tablets comprised of individual powders. This appeared to demonstrate the effect of MCC swelling on the disintegration time of the tablet. The disintegration time of the lactose/cornstarch series increased only when Young's modulus increased sharply.View full abstractDownload PDF (696K) -
Akiko NISHIMURA, Mitsutomo TSUHAKO2000 Volume 48 Issue 6 Pages 774-778
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSingle strand conformation polymorphism (SSCP) analysis of the N-ras oncogene was achieved by capollary electrophoresis with a laser-induced fluorescence detector (CE-LIF) using methylcellulose as a molecular sieving agent. The PCR-amplified N-ras oncogene, which is known to have a point mutation at codon 61 in the neuroblastome, was investigated by CE-LIF combined with SSCP (SSCP-CE-LIF). A mixture of wild- and mutant-type single strand DNA fragments (103 bp) of the N-ras oncogene was separated by buffer solution containing 1.0% methylcellulose and 0.2μm fluorescent dye (YO-PRO-1) at 25°C.The SSCP-CE-LIF technique gave good resolution for wild- and mutant-type single strand DNA fragments with separation completed within 7 min. SSCP analysis using a CE system with a LIF detector was successfully applied to the detection of the one point mutation on the N-ras oncogene.View full abstractDownload PDF (720K) -
Shouhong XU, Junpei YAMANAKA, Shizuko SATO, Isamu MIYAMA, Masakatsu YO ...2000 Volume 48 Issue 6 Pages 779-783
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSComplexes composed of sodium hyaluronate (NaHA) and bovine serum albumin (BSA) were studied to elucidate the exact composition of the complex, the phase separation, the electrophoretic mobility and the size uisng dynamic light scattering (DLS) and electrophoretic ligth scattering (ELS), etc. The phase diagram of the mixed solutions was determined. The complexes were soluble in neutral or weakly acidic pH regions and showed phase separation in the more acidic pH region. From the concentration of Na+ released from NaHA when it binds to BSA, the ratios of BSA to NaHA of the complexes were determined. In the region of soluble complexes, one BSA molecule was determined to bind with 15 carboxylic groups of NaHA and in the region of isoluble complexes to bind with 6 carboxylic groups. At the phase separation point, 117 BSA molecules bound with one NaHA molecule and 17% of the carboxylic groups of NaHA did not contribute to the binding of BSA. The sizes of the complexes decreased form several μm to several hundred nm as the binding ratio of BSA increases. Decreases in the viscosities of the mixed solutions were consistent with the decreases of the sizes. From these results, a model of complex formation is proposed.View full abstractDownload PDF (733K) -
Morio MURAKAMI, Kohji FUKATSU, Shigenori OHKAWA, Fumiko KASAHARA, Tohr ...2000 Volume 48 Issue 6 Pages 784-792
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTAK-218 has a 2, 3-dihydrobenzofuran-5-amine (coumaran) structure which resembles α-tocopherol, and is a promising candidate as an agent for central nervous system (CNS) trauma and ischemia. The radical scavenging activity of TAK-218 was studied using electron spin resonance (ESR) spectroscopy.TAK-218 exhibited a more potent scavenging activity towards the hydroxyl radical than did the well-known hydroxyl radical scavengers, mannitol and dimethylsulfoxide. Towards the superoxide radical, TAK-218 showed equal potency to glutathione. TAK-218 reacted rapidly with stable radicals, such as galvinoxyl and 2, 2-diphenyl-1-picrylhydrazyl hydrate (DPPH), and gave the quinone as a two-electron oxidized product in analogy with α-to-copherol.To exhibit an excellent antioxidative activity in living systems, the compounds should not only have the intrinsic radical scavenging activity but also good distribution in the biological lipid-bilaver membrane. To examine the antioxidant activity of TAK-218, the inhibition of lipid peroxidation by α-tocopherol and TAK-218 in liposomal membranes was studied usign an ESR spin-label technique.Both α-tocopherol and TAK-218 completely inhibited lipid peroxidation by radicals generated in an aqueous layer using a water-soluble radical initiator, 2, 2'-azobis-(2-amidinopropane) hydrochloride (AAPH). At a high incubation temperature (45°C), α-tocopherol scavenged radicals more effectively than TAK-218 on the surface of the membrane, while TAK-218 scavenged radicals more effectively in the interior of the membrane. The difference between TAK-218 and α-tocopherol for radical scavenging in the membrane system derives from the different distribution pattern of these compounds. TAK-218 can penetrate the membrane freely and can scavenge the radical in the membrane interior.Furthermore, TAK-218 was shown to inhibit lipid peroxidation initiated by a lipid soluble radical initiator, 2, 2'-azobis-(2, 4-dimethylvaleronitrile)(AMVN), in a membrane more effectively than α-tocopherol.View full abstractDownload PDF (1189K) -
Maria-Dolores VEIGA, Fakhrul AHSAN2000 Volume 48 Issue 6 Pages 793-797
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTolbutamide-hydroxypropyl-γ-cyclodextrin (TBM-HPGCD) interaction has been investigated in an aqueous environment and in the solid state. The solubility of TBM was increased in accord with the amount of HPGCD added to the aqueous medium forming a soluble inclusion compound. The phase solubility diagram obtained was of AL type. Physical mixtures and kneaded systems of the drug and cyclodextrin derivative were prepared in 1 : 1 and 1 : 2 drug/cyclodextrin mol/mol ratio. All solid binary systems were characterised by hot-stage microscopy (HSM), differential scanning calorimetry (DSC), thermogravimetry (TG) and X-ray powder diffractometry (XRD). An inclusion complex was formed in both of the kneaded systems. In the 1 : 2 kneaded system, the entire drug was included in the cyclodextrin cavity, while in the 1 : 1 kneaded system only a part of the drug formed an inclusion complex with the cyclodextrin. A significant improvement in the dissolution of the drug was botained from the kneaded systems in comparison with that of the pure TBM and physical mixtures. However, there was no significant difference between the dissolution profiles of the two kneaded systems. The study suggests that an inclusion complex was obtained both in aqueous solution and in solid state.View full abstractDownload PDF (796K) -
Sun Dong YOO, Eunhee KANG, Hun JUN, Beom Soo SHIN, Kang Choon LEE, Kyu ...2000 Volume 48 Issue 6 Pages 798-801
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThis study examined the pharmacokinetic disposition, oral absorption and hepatic extraction of itraconazole and its active metabolite, hydroxyitraconazole, in rats. After i.v.injection, serum itraconazole concentrations decreased biexponentially, with an average terminal elimination half-life, volume of distribution and systemic clearance of 4.9h, 6.0l/kg and 14.2ml.min.kg, respectively. When given orally, its absorption was low, with a mean absolute bioavailability of 16.6%. The metabolite to parent drug area under the curve (AUC) ratio was higher after oral administration compared with i.v. injection (mean ratio, 2.7 vs. 0.9). The hepatic drug extraction ratio determined after femoral and portal vein administration averaged 18.5%. When hydroxyitraconazole was injected i.v., the elimination half-life, volume of distribution and systemic clearance of itraconazole averaged 10.0h, 2, 4l/kg and 3.4ml/min/kg, respectively. The fraction of the systemically available itraconazole that was metabolized to hydroxyitraconazole was 21.0% and 76.0% after i.v. and oral administration, respectively. In summary, this study is the first reporting the hepatic extraction of itraconazole and the i.v. disposition characteristics of hydroxyitraconazole in rats. Itraconazole is a drug with a low hepatic extraction ratio and its systemic clearance appears to be largely accounted for by hepatic metabolism.View full abstractDownload PDF (653K) -
Hideko INOUE, Mari WATANABE, Hirokazu NAKAYAMA, Mitsutomo TSUHAKO2000 Volume 48 Issue 6 Pages 802-807
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe phosphorylation of several D-glucose derivatives has been achieved using inorganic sodium cyclotriphosphate hexahydrate (P3m), Na3P3O9·6H2O, in aqueous solution. In the phosphorylation of D-glucuronic acid, 6-phosphoryl-D-glucose and D-xylose, β-D-glucuronic and 1-triphosphate, 6-phosphoryl-β-D-glucose 1-triphosphate and β-D-xylose 1-triphosphate were synthesized stereoselectively with maximum yields of 43.5, 32.8 and 41.9% respectively. In the case of D-glucosamine and 2-deoxy-D-glucose, the main phosphorylated products were assigned to β-D-glucosamine 1-triphosphate and 2-deoxy-β-D-glucose 1-triphosphate by 1H-, 13C- and 31P-NMR, and the yields were 13.9 and 13.4%, respectively.View full abstractDownload PDF (816K) -
Li MU, Si-shen FENG, Mei Lin GO2000 Volume 48 Issue 6 Pages 808-816
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of hydrid molecules incorporating the furoxan and nicorandil moieties were designed as potential NO donors with cardiovascular and cerebrovascular activities. Thirty-six target molecules were successfully synthesized by conventional methods and characterized by infrared spactroscopy, 1H-NMR spectroscopy and highresolution mass spectra. The compounds were tested for their effects on KCl-induced contraction of rabbit thoracic aorta whose endothelium was denuded. Eight compounds were found to reduce KCl-induced contraction by more than 30% at 10μM. All except one of these compounds are characterized by the presence of electron withdrawing groups in the phenyl ring attached via an amide or ester linkage to the furoxan moiety. The nature of the terminal carbonyl linkage (ester or amide) and the length or type of the alkyl chain bridging the two carbonyl functions have little effect on the activity. One of the active compounds, N-(4-methoxy-benzoyl)-N'-[3-methylfuroxanyl-4-carbonyl)piperazine (17i) was tested for hypotensive effects on anaesthesized rats at 1.5mg/kg, and found to demonstrate a gradual and sustained hypotensive effect. The results suggest that the furoxan-nicoradil derivatives are a useful lead in the design of NO-donor compounds for hypertension.View full abstractDownload PDF (1241K) -
Shoji KAMIYA, Hiroaki SHIRAHASE, Akihisa YOSHIMI, Shohei NAKAMURA, Mam ...2000 Volume 48 Issue 6 Pages 817-827
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe synthesized a series of indoline derivatives with an amide or urea moiety and examined their inhibitory effects on acyl-CoA : cholesterol acyltransferase (ACAT) activity, lipid-peroxidation and serum cholesterol levels in experimental animals. Among the derivatives synthesized, a series of N-(1-alkyl-4, 6-dimethylindolin-7-yl)-2, 2-dimethylpropanamides potently inhibited rabbit intestinal ACAT activity and lipid-peroxidation of rat brain homogenate. The effect on ACAT activity was related to the length of the alkyl chain at the 1-position of indoline. N-(4, 6-Dimethyl-1-octylindolin-7-yl)-2, 2-dimethylpropanamide hydrochloride (55) showed inhibitory effects on intestinal and hepatic ACAT activity slightly weaker than those of YM-750, and an inhibitory effect on low density lipoprotein (LDL)-peroxidation similar to that of probucol. Compound 55 also reduced serum cholesterol at 10mg/kg/d in hyperlipidemic rats and 20 mg/kg/d in normolipidemic hamsters. The plasma concentration of 55 reached 716ng/ml in dogs (10mg/kg, p.o.), which is an effect concentration against hepatic ACAT activity and LDL-peroxidation. In conclusion, compound 55 is a novel bioavailable ACAT inhibitor with anti-peroxidative activity and is thus a promising anti-atherosclerotic and anti-hyperlipidemic drug. Indoline proved to be a useful pharmacophore for molecular design of new anti-peroxidative drugs.View full abstractDownload PDF (1650K) -
Hitoshi YOSHIMITSU, Makiko NISHIDA, Zhong-Zhi QIAN, Zhen-Huan LEI, Tos ...2000 Volume 48 Issue 6 Pages 828-831
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new triterpene glycosides were isolated from the dried aerial parts of Thalictrum squarrosum (Ranunculaceae). They were designated as squarroside I, being a cycloartane-type glycoside, and squarrosides II, III and IV, being oleanene-type glycosides. Their structures were established by using two dimensional (2D) NMR techniques.View full abstractDownload PDF (710K) -
Masanori KUROYANAGI, Kenichi YOSHIDA, Atsushi YAMAMOTO, Masao MiWA2000 Volume 48 Issue 6 Pages 832-837
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom the ethyl acetate soluble fraction of twigs of Magnolia denudata (Magnoliaceae), seven new neolignan derivatives, 1-7, were isolated along with eighteen known lignan and neolignan derivatives, 8-25. The structures of the new neolignans were elucidated by means of spectral methods, especially by 1H-NMR and 13C-NMR spectra, and two dimensional NMR methods such as 1H-detected heteronuculear multiple bond connectivity(HMBC), 1H-detected multiple quantum coherence (HMQC) and 1H-1H-correlation spectroscopy (COSY). Compounds 1-4 have novel structures possessing a 6-oxabicyclo[3.2.2]nonane skeleton and compounds 5-8 also have novel structures possessing a bicyclo[3.2.1]octane skeleton. The anti-platelet-activating factor (PAF) activity of these compounds was tested by measurement of inhibition activity against acetyl transferase to/lyso-PAF.View full abstractDownload PDF (823K) -
Shao-jiang SONG, Norio NAKAMURA, Chao-mei MA, Masao HATTORI, Sui-xu XU2000 Volume 48 Issue 6 Pages 838-842
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new saponins, 3-O-[β-D-glucopyranosyl(1→3)-α-L-arabinopyranosyl]-16α-hydroxyolenolic acid 28-O-β-D-glucopyranosyl ester (called aralia-saponin I), 3-O-[β-D-glucopyranosyl(1→3)-α-L-arabinopyranosyl]-16α-hydroxyhederagenin 28-O-β-D-glucopyranosyl ester (aralia-saponin II), 3-O-[β-D-glucopyranosyl(1→3)-β-D-glucopyranosyl(1→3)-α-L-arabinopyranosyl]-16α-hydroxyloleanolic acid 28-O-β-D-glucopyranosyl ester (araliasaponin III), 3-O-[β-D-glucopyranosyl(1→3)-β-D-glucopyranosyl(1→3)-β-D-glucopyranosyl]-16α-hydroxyoleanolic acid 28-O-β-D-glucopyranosyl ester (aralia-saponin IV), were isolated form the root bark of Aralia elata (Miq.)Seem., together with nineteen known compounds including glycosides of (20S)-protopanaxadiol and (20S)-pro-topanaxatriol. Their structures were determined on the basis of chemical and spectrocopy methods.View full abstractDownload PDF (778K) -
Takeshi YAMAMOTO, Manabu HORI, Ikuo WATANABE, Kengo HARADA, Shoji IKED ...2000 Volume 48 Issue 6 Pages 843-849
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe have previously reported that N-(4-isopropyl-2, 2-dimethyl-3-oxo-3, 4-dihydro-2H-benzo[1, 4]oxazine-6-carbonyl)guanidine (4b) methanesulfonate salt (KB-R9032) is a potent and highly water-soluble Na/H exchange inhibitor. In a series of studies on Na/H exchange inhibitors, we designed and synthesized N-(3-oxo-3, 4-dihydro-2H-benzo[1, 4]thiazine-6-carbonyl)guanidines (5) as more potent inhibitors with high water-solubility. The design strategy for 5 was based on a quantitative structure-activity relationship (QSAR) study, involving the proportional relationship between the biological activity and hydrophobicity of the ring structure of compounds 4. As expected, compounds 5 showed more potent activity than 4. It was found by using the QSAR analysis that 4 were about five-fold more potent than 4. The increase in potency of compounds 5 well agreed with our previous QSAR analysis result. The most potent derivative was the methanesulfonate salt 5d of the 4-isopropyl derivative(IC50=0.0091μM). And in addition to the in vitro study, 5d showed significant protective activity against a rat acute myocardial infraction model.View full abstractDownload PDF (915K) -
Masao INUKAI, Yu JIN, Chikako YOMOTA, Masakatsu YONESE2000 Volume 48 Issue 6 Pages 850-854
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSHyaluronate-hydroxyethyl acrylate blend hydrogels were investigated as matrices for controlled release devices. Glycidyl methacrylate (GMA) derivatized HA (GMA-HA) was synthesized by coupling of GMA to HA in the presence of a suitable catalyst. These hydrogels were prepared by a free radical copolymerization of GMA-HA and hydroxyethyl acrylate. The water content of these hydrogels at equilibrium swelling in water(Ww) was 0.978±0.0073 (n=18); however, these hydrogel was mechanically tough and could be used as disk shape. The hydrogels swelling were found to depend on ionic strength and pH. The dried hydrogels quickly regained their original condition in water, and they swelled to more than 90% of its initial water contents after 30 min. This swelling-deswelling behavior was reproducible. The release of chlorpromazine HCl as a model cationic drug from the gels was suppressed significantly in water. The release increased with increasing the ionic strength and decreasing pH of bulk solutions.View full abstractDownload PDF (851K) -
Tomohiro MATSUSHIMA, Noriyuki NAKAJIMA, Bao-Zhong ZHENG, Osamu YONEMIT ...2000 Volume 48 Issue 6 Pages 855-860
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA stereoselective synthesis is described of the 18-membered lactone (2) via an efficient macrolactonization of the conformation-controlled seco-acid (3); this was designed with the aid of molecular mechanics (MM)-calculation and synthesized by coupling between the C1-C12 (4) and C13-C23 (5) fragments.View full abstractDownload PDF (939K) -
Takashi HARAYAMA, Hirotake YASUDA, Toshihiko AKIYAMA, Yasuo TAKEUCHI, ...2000 Volume 48 Issue 6 Pages 861-864
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS6H-Dibenzo[b, d]pyran-6-one, 6H-benzo[d]naphtho[1, 2-b]pyran-6-one, and their derivatives were prepared via the palladium mediated aryl-aryl coupling reaction of aryl ortho-halobenzoate. The short step synthesis of arnottin I (1) was achieved this method.View full abstractDownload PDF (699K) -
Akikazu KAKEHI, Suketaka ITO, Kazuyuki HIRATA, Peng ZUO2000 Volume 48 Issue 6 Pages 865-869
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe title compounds, together with 3-vinylindolizine-1-carbonitriles (4-56%), were prepared in 1-18% yields from the S-alkylation of pyridinium 1-[3-ethoxycarbonyl-1-[cyanomethylthio(thiocarbonyl)]]allylides with alkyl halides, followed by treatment of the resulting pyridinium salts with a base and then a dehydrogenating agent. In several reactions of pyridinium salts obtained from reaction of the allylides with benzylic halides, trace amounts of bis[1-cyano-9-(ethoxycarbonyl)thieno[3, 4-b]indolizin-3-yl] disulfides with an interesting superimposed structure were also isolated. The structures of these compounds were confirmed by X-ray analyses.View full abstractDownload PDF (871K) -
Naciye TURKEL, Ulviye OZER2000 Volume 48 Issue 6 Pages 870-872
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe stability constants of 5-nitrosalicylic acid (5-NSA ) and 5-sulfosalicylic acid (5-SSA) complexes of Sc(III)were determined by potentiomeric pH titration. ML and ML2 type first and second complexes were observed in the solutions of 5-NSA and 5-SSA with Sc(III) at 25°C in I=0.1M ionic medium. The stability constants of Sc(III)-5NSA and Sc(III)-5SSA systems were also investigated by spectrophotometry to determine the stoichiometries of the complexes formed in the reactions. Our results showed that Sc(III)-5SSA complexes are more stable than the Sc(III)-5NSA complexes in aqueous solutions.View full abstractDownload PDF (488K) -
Junko KOYAMA, Izumi MORITA, Akari KINO, Kiyoshi TAGAHARA2000 Volume 48 Issue 6 Pages 873-875
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe separation of nine furanonaphthoquinones by micellar electrokinetic chromatography (MEKC) is described. The running electrolytes used in this method were 0.03M sodium dodecyl sulphate (SDS) in 0.09M borate buffer (pH 9) containing 10% methanol, with an applied voltage of 20kV. Application of this technique in the determination of the main furanonaphthoquinones, 5-hydroxy-2-(1-hydroxyethyl)naphtho[2, 3-b]furan-4, 9-dione, 8-hydroxy-2-(1-hydroxyethyl)naphtho[2, 3-b]furan-4, 9-dione, and 2-(1-hydroxyethyl)naphtho[2, 3-b]furan-4, 9-dione, of Tabebuia impetiginosa is demonstrated in this paper.View full abstractDownload PDF (462K) -
Sadaaki TAMURA, Narihiko FUKAMIYA, Xiao-Yang MOU, Teruo MUKAINAKA, Hru ...2000 Volume 48 Issue 6 Pages 876-878
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIntroduction of a senecioyl group into shinjulactones B and C, and esterification of the diosphenol moiety in brusatol and brucein A enhanced inhibitory effect against Epstein-Barr virus early antigen activation.View full abstractDownload PDF (611K) -
O-Jin OH, Seung-Yeup CHANG, Chang-Soo YOOK, Ki-Sook YANG, Sang-Yong PA ...2000 Volume 48 Issue 6 Pages 879-881
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo 3, 4-seco-lupane triterpenoids (1, 2) were isolated from the leaves of Acanthopanax divaricatus var. albeofructus (Araliaceae). Based on the spectroscopic data, the chamical structures of 1 and 2 were characterized as 24-hydroxychiisanogenin and 22α-hydroxychiisanogenin, respectively. 1 was a new compound and 2 was isolated for the first time from the natural source, although it had been obtained as an enzymatically hydrolyzed artifact form 22α-hydroxychiisanoside.View full abstractDownload PDF (473K) -
Kazunori TSUBAKI, Koichiro MUKOYOSHI, Tadamune OTSUBO, Kaoru FUJI2000 Volume 48 Issue 6 Pages 882-884
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSeveral homoxacalix[3]arenes possessing different substituents on their upper rims were synthesized in yields of 7-20% by a condensation reaction between the p-substituted phenol dimer and monomer under acidic high-dilution conditions.View full abstractDownload PDF (534K) -
Masayuki KIRIHARA, Tomofumi TAKUWA, Maiko OKUMURA, Takahiro WAKIKAWA, ...2000 Volume 48 Issue 6 Pages 885-888
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe palladium catalyzed nucleophilic substitution ofα-bromo-α, α-difluoroallyl derivatives turned out to be an efficient method for the preparation of several fluorinated organic molecules. Several soft carbon nucleophiles regioselectively reacted with 3-bromo-3, 3-difluoropropene (BDFP) to give the 3-substituted 1, 1-difluoroalkenes. Phenylzinc chloride and tributylphenyltin afforded 1-fluoro-1, 3-diphenylpropene. The radical bromination of 3-substituted 1, 1-difluoroalkenes provided 1-substituted BDFPs, and a 1-substituted BDFP reacted with carbon nucleophiles to give 1, 3-disubstituted 3, 3-difluoroalkenes. For the reaction of nitrogen nucleophiles with BDFP, an amine and the sodium salts of the carbamates reacted with BDFP at the γ-position. However, the sodium salts of the sulfoneamide predominantly attacked at the α-position.View full abstractDownload PDF (636K) -
Osamu TANAKA, Eyong-Chae HAN, Hiroyuki YAMAGUCHI, Hiromichi MATSUURA, ...2000 Volume 48 Issue 6 Pages 889-892
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSPanax pseudo-ginseng subsp. pseudo-ginseng has a carrot like root with a small rhizome. It was shown that the saponin composition of roots and rhizomes of this subspecies collected in Tibet and China was extremely poor. From the roots and rhizomes collected in Central Nepal, (specimen-PNct), only a small amount of an oleanolic acid saponin, β-D-glucopyranosyl-oleanolate (2) was isolated together with a polyacetylene-alcohol, panaxynol (3). In another specimen (specimen-PNs), also collected in Central Nepal, two oleanolic acid saponins, stipleanoside R2 (4) and chikusetsusaponin IV (5) were detected. No dammarane saponin was identified in either specimen. P. pseudo-ginseng subsp. himalaicus (Subsp-H) has a big rhizome with a small round root. From rhizomes and roots of this subsp. collected in Central Nepal (specimen-HNct), a fairly large amount of dammarane saponins, ginsenosides-Rb1 (6), -Rd (7), -Re (9) and -Rg1 (10), gypenoside XVII (8), notoginsenoside-R1 (11), majonoside-R2 (12) and pseudo-ginsenoside-F11 (13) were isolated, while no oleanane saponin (oleanolic acid saponin) was identified in this subsp. Based on the present and previous studies, medicinal evaluation and chemogeographical correlation of Himalayan Panax spp. are discussed.View full abstractDownload PDF (753K) -
Vania BERNARDES GENISSON, Pascal NEBOIS2000 Volume 48 Issue 6 Pages 893-894
Published: June 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe cycloaddition reactions of o-indoloquinone 4 to azadienes are described. With 1-azadiene 2, quinone 4 works as a dienophile to give the directly aromatized cycloadduct 6. In contrast, when 2-azadiene 3 is used, the cycloaddition occurs with CO-4, indicating that this system functions as a heterodienophile.View full abstractDownload PDF (454K)
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