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Volume 48, Issue 1
Displaying 1-31 of 31 articles from this issue
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Seiichiro TABUCHI, Harunobu ITO, Hajime SOGABE, Masako KUNO, Takayoshi ...2000 Volume 48 Issue 1 Pages 1-15
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn our continuing research for dual CCK-A and -B antagonists, according to our hypothesis that dual CCK-A and -B antagonists should be more efficacious than selective CCK-A antagonists for the treatment of panreatitis, we have prepared various 5-alkyl-9-methyl-1, 4-benzodiazepines. From the compounds prepared, 1-cyclo-hexyl-carbonylmethyl-5-ethyl-9-methyl-3-(m-tolylureido)-2-oxo--1, 4-benzodiazepine, (40) was selected as a candidate for development due to its well-balanced high affinity for both receptors. The R-enantiomer of 40, (R)-40 (FR 208419), had 27-fold higher affinity for the CCK-A receprot and 8-fold more potent CCK-B receptor binding activity than (S)-40.The biological activity after p.o.administration of (R)-40, estimated from the ID50 value (0.23 mg/kg p.o.) obtained by preliminary evaluation by gastric emptying effects, is considered to be high enough for further development. This compound is now undergoing further biological evaluations with a view to clinical development.View full abstractDownload PDF (2005K) -
Toshiyuki HATA, Yukio ONO2000 Volume 48 Issue 1 Pages 16-20
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSMonte Carlo simulations are systematically presented to demonstrate the influence of the hydrophobic group's steric bulk on hydration structure. We have simulated a dimethyl ether (DME), two conformations for ethyl methyl ether (0°EME and 180°EME), and 0°ethanol solutions. Spatial distribution function (SDF), gOO(x, y, z) and difference SDF (DSDF), △gOO(x, y, z), obtained from MC simulation in an infinitely dilute aqueous solution of ether show the three-dimensional probability of an atom-atom pair distribution between solute and solvent atoms. Based on the results of SDF in an infinitely dilute aqueous solution of ether, the distribution of hydration water molecules can be divided into hydrogen acceptor (HA) and hydrophobic hydration (HH) regions, and the spatial orientation of the hydrogen-bonded water in the HA region is found to form a triple-layer structure, as it does in alcohol solutions. From the results of an analysis of the DSDF △gOO(x, y, z) between the SDFs of EME and DME, it is apparent that the distribution changes of hydration water molecules in ether solutions are essentially similar to those in the alcohol solutions. Further, we show that the hydration water molecules are distributed mainly in the stable area in the binding energy's (BE) contour maps for each region.View full abstractDownload PDF (929K) -
Akira MATSUHISA, Nobuaki TANIGUCHI, Hiroyuki KOSHIO, Takeyuki YATSU, A ...2000 Volume 48 Issue 1 Pages 21-31
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSArginine vasopressin (AVP) has a dual action mainly in the periphery, i.e., vasoconstriction and water reabsorption via V1A and V2 receptors; it may play a role in a number of diseases, including congestive heart failure (CHF), hypertension, renal discase, edema, and hyponatremia. We have attempted to develop a new series of orally active AVP antagonists for both V1A and V2 receptors based on the hypothesis that the blockade of both V1A and V2 receptors might be beneficial to CHF patients. In this report, a series of compounds structurally related to 4'-(1, 4, 5, 6-tetrahydroimidazo[4, 5-d][1]benzoazepine-6-carbonyl)benzanilide and 4'-(5, 6-dihydro-4H-thiazolo[5, 4-d][1]benzoazepine-6-carbonyl)benzanilide were synthesized and examined for AVP antagonist activity for both V1A and V2 receptors. As a result, it was found that the 4'-(1, 4, 5, 6-tetrahydroimidazo[4, 5-d][1]benzoazepine-6-carbonyl)-2-phenylbenzanilide derivatives showed potent binding affinity for both V1A and V2 receptors. Especially, 4'-(2-methyl-1, 4, 5, 6-tetrahydroimidazo[4, 5-d][1]benzoazepine-6-carbonyl)-2-phenylbenzanilide monohydrochloride (18, YM087=conivaptan hydrochloride) exhibited potent binding affinity and AVP antagonist activity, after intravenous administration, for both V1A and V2 receptors. Furthermore, YM087 exhibited the most potent oral activity for the V2 receptor. Details of the synthesis and pharmacological properties of this series are presented.View full abstractDownload PDF (1311K) -
Kiyoshi IKEDA, Keisuke MIYAJIMA, Tadayosi SHIMIZU, Kazuo ACHIWA2000 Volume 48 Issue 1 Pages 32-40
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFor the determination of favorable binding linkages of lipid A analog as a synthetic immunoadjuvant to the antigen moiety for synthetic vaccines, new N-acylated L-serine-containing D-glucosamine analogs (Type A, B, C) were synthesized and their mitogenicities were examined. Among chemically synthesized compounds (6-15, 30), compound 8 for Type B exhibited the most potent mitogenicity.View full abstractDownload PDF (1324K) -
A.A. El-ASMY, M.E. KHALIFA, T.H. RAKHA, M.M. HASSANIAN, A.M. ABDALLAH2000 Volume 48 Issue 1 Pages 41-44
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSComplexes of several transition metal ions with α-oximinoacetoacetyl pyridine-4-phenylthiosemicarbazone (H3OAPT) have been prepared. Attempts were made to elucidate their geometries by elemental analysis, molar conductance, magnetic measurements and by some spectroscopic (IR, ESR and electronic)techniques. All the investigated metal ions form mononuclear complexes except for CuII, which forms mononuclear and trinuclear complexes with its chloride and acetate salts, respectively. The IR spectra show that the ligand behaves as a mono or binegative tridentate. Moreover, it acts as a trinegative hexadentate in the trinuclear CuII complex. The protonation constants (log KH1=9.9 and log KH2=6.0), as well as the stability constants of the metal complexes, are determined by the pH-titration of H3OAPT and its metal(II) complexes against 0.01 M NaOH. CuII complexes possess square-planar stereochemistry while Co11 and NiII have an octahedral one. The crystal field parameters of CoII and NiII complexes are evaluated.View full abstractDownload PDF (686K) -
Ehab A. ABOURASHED, Farouk S. EL-FERALY, Ikhlas A. KHAN, Charles D. HU ...2000 Volume 48 Issue 1 Pages 45-47
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe use of microbial models for biotransformation of the natural benzoquinone, maesanin (1), resulted in the isolation of an ethanolamine conjugate (5) from the culture broth of Debaryomyces polymorphus ATCC 20280. Metabolite 5 was characterized as 2-hydroxy-5-(ethanolamino)-3-(10'-Z-pentadecenyl)-1, 4-benzoquinone. The production of 5 represents a new type of phase II conjugation reaction in microbial systems. The results of preliminary mammalian metabolism of 1 in rats were incondlusive.View full abstractDownload PDF (604K) -
Juziro NISHIJO, Sachiko SHIOTA, Kaori MAZIMA, Yukiko INOUE, Hitomi MIZ ...2000 Volume 48 Issue 1 Pages 48-52
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe interaction of cyclodextrins (CDs) with L-α-dipalmitoyl phopsatidyl choline (DPPC), L-α-distearoyl phosphatidyl choline (DSPC), and L-α-dimyristoyl phosphatidyl choline (DMPC) unilamellar liposomes was investigated by the leakage of carboxylfluorescein (CF) entrapped in the inner aqueous phase of liposomes, at 25°C(DPPC and DSPC liposomes) and at 5°C (DMPC liposomes). The efficiency of CDs for CF leakage was remarkable in the order of heptakis (2, 6-di-O-methyl)-β-CD (DOM-β-CD)>α-CD>heptakis (2, 3, 6-tri-O-methy)-β-CD (TOM-β-CD) from DPPC liposomes, in the order of DOM-β-CD> TOM-β-CO> : α-CD from DSPC liposomes and in the order of α-CD>DOM-β-CD<TOM-β-CD from DMPC liposomes. The other CDs used in the present studies, β-CD, 2-hydroxylpropyl β-CD, and γ-CD scarcely induced the CF leakage from above the three liposomes.From the profiles of % CF leakage, together with measurements of differential scanning calorimetry, it was found that hydrophobic DOM-β-CD penetrates the matrix of the liposomes to interact with them as well as TOM-β-CD, and that less hydrophobic α-CD exists at the surface of the membrane to interact with the liposomes. Further, it was found that the interaction of CDs with liposomes changes depending not only on the length of fatty acid chain of phospholipid (condensation force and hydrophobicity) but also the hydrophobicity and the cavity size of CD.View full abstractDownload PDF (798K) -
Taiju KURAMOTO, Yuri KAMEYAMA, Miyuki KANEDA, Motoo SHIRO, Takahiko HO ...2000 Volume 48 Issue 1 Pages 53-55
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe structure and stereochemistry of the higher bile acid, tetrahydroxyisosterocholanic acid (TISA), which was previously isolated from the bile of Amyda japonica (turtle) and proposed as a tetrahydroxyisosterocholanic acid, have been established as (22S, 25R)-3α, 12α, 15α, 22-tetrahydroxy-5β-cholestan-26-oic acid by X-ray crystal-lographic analysis of its ethyl ester.View full abstractDownload PDF (511K) -
Chang-Sheng LU, Chuan-Jiang HU, Yan YU, Qing-Jin MENG2000 Volume 48 Issue 1 Pages 56-59
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSInclusion compounds of some 4-substituted benzoic acid and benzaldehyde drugs with β-cyclodextrin were prepared and characterized by IR spectroscopy, powder X-ray diffraction, thermogravimetry, and 1H-NMR spectroscopy. The thermal stability and chemical stability of these drugs were strikingly improved after inclusion. The effect of inclusion on the chemical-shifts of protons H-3 and H-5 in the NMR spectroscopy is discussed. Using the relative shift theory, the preferred inclusion mode was proposed. The center of the aromatic ring of the drug molecule was considered to be located in the cavity 1.2Å inside from the H-5 plane of β-cyclodextrin.View full abstractDownload PDF (647K) -
Kimihiko HORI, Akira SAKAGUCHI, Michinari KUDOH, Koichi ISHIDA, Yuri A ...2000 Volume 48 Issue 1 Pages 60-64
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFungicidal activity of widely used imidazole antifungal drugs in topical applications is not so strong in spite of their potent fungistatic activities against dermatophytes and pathogenic yeasts. In order to improve fungicidal activity of imicazole antifungal agents, a series of novel imidazole derivatives having a hydrophobic substituent derived from isoprenoid were synthesized. The efficacy of these compounds was evaluated with respect to direct cell-membrane damaging activity, ergosterol biosynthesis inhibition, minimum growth-inhibitory concentration (MIC) and therapeutic effect for experimental dermatophytosis of guinea pigs. Among the newly synthesized compounds, the geranyl derivative named AFK-108 (2a) showed the highest in vivo fungicidal activity with both cell membrane damaging activity and ergosterol biosynthesis inhibition in vitro.View full abstractDownload PDF (903K) -
Chihiro ITO, Yuichi KONDO, Tian-Shung WU, Hiroshi FURUKAWA2000 Volume 48 Issue 1 Pages 65-70
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe structures of two new dimeric acridone alkaloids, glycobismine-D (1) and -E (2), having a novel linkage as binary acridones, three monomeric acridones, glycocitrine-IV (3), -V (4), and -VI (5), and three quinolone alkaloids, glycocitlone-A (6), -B (7), and -C (8) from Glycosmis citrifolia (WILLD.) LINDL. (Rutaceae) have been elucidated by spectrometric studies.View full abstractDownload PDF (885K) -
Yoshiko NAGATA, Chie MIYAMOTO, Yoshikazu MATSUSHIMA, Shigenobu MATSUMO ...2000 Volume 48 Issue 1 Pages 71-76
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSα-Tocopherol (α-Toc) was solubilized in aqueous solutions using 13 solubilizing agents and the products of oxidation by oxygen in the presence and the absence of Cu(II) were analyzed by HPLC. In the presence of Cu(II), the oxidation was accelerated and 5-formyl-7, 8-dimethyltocol and α-tocoquinone were the major oxidation products. Their yields greatly increased in the presence of Cu(II). The yields and the rates of formation of the products were dependent on the properties of solubilizing agents and other conditions as well as the presence of Cu(II) or other metal ions. It is suggested that slight changes in the structure of the solubilizing agents affect the course of the reaction.View full abstractDownload PDF (764K) -
Junichi KITAJIMA, Kaoru KIMIZUKA, Yasuko TANAK2000 Volume 48 Issue 1 Pages 77-80
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAs the glycosyl constituents of Ficus pumila L. fruits (Moraceae), three new sesquiterpenoid glucosides, pumilasides A, B and C were isolated together with benzyl β-D-glucopyranoside, (E)-2-methyl-2-butenyl β-D-glucopyranoside and rutin. Their structures were characterized as (1S, 4S, 5R, 6R, 7S, 10S)-1, 4, 6-trihydroxyeudesmane 6-O-β-D-glucopyranoside, (1S, 4S, 5S, 6R, 7R, 10S)-1, 4-dihydroxymaaliane 1-O-β-D-glucopyranoside and 10α, 11-dihydroxycadin-4-ene 11-O-β-D-glucopyranoside by spectral and chemical methods.View full abstractDownload PDF (605K) -
Masayuki MURASE, Kazuhiro WATANABE, Takuji YOSHIDA, Seisho TOBINAGA2000 Volume 48 Issue 1 Pages 81-84
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe nucleophilic addition reaction of N-tosyl-4-oxo-4, 5, 6, 7-tetrahydroindole (12) with the lithium salt of 1-methoxyindole (5), followed by dehydration with 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ) gave the derivative of 2, 4'-bi-1H-indole (9) which provides a new concise synthetic method of an indole pigment of the slime mould, arcyriacyanin A. The compound was first demonstrated here to have unique inhibitory activity to a panel of human cancer cell lines and to inhibit protein kinase C and protein tyrosine kinase.View full abstractDownload PDF (587K) -
Tian-Shung WU, Chien-Mao CHEN2000 Volume 48 Issue 1 Pages 85-90
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSEight new acridone alkaloids, buxifoliadines-A-H together with nine known acricone compounds, were isolated and characterized from the root bark of Severinia buxifolia which was collected in Hainan province, China. Their structures were determined by spectroscopic methods. The relationship between acridone alkaloids with collecting area is discussed. The 13C-NMR spectra of the prenyl substituents at C-2 and/or C-4 of N-unsubstituted acridone alkaloids are also discussed.View full abstractDownload PDF (864K) -
Jun TODA, Shinobu MATSUMOTO, Toshiaki SAITOH, Takehiro SANO2000 Volume 48 Issue 1 Pages 91-98
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour stereoisomers of 1, 3-dimethyl-1, 2, 3, 4-tetrahydroisoquinoline, an inducer of Parkinson-like syndrome, were synthesized by applying a new method of 1, 2, 3, 4-tetrahydroisoquinoline (TIQ) synthesis utilizing the Pummerer reaction as a key step. The chiral centers at C-1 and C-3 were constructed by two routes starting from alaninol (3) and 1-phenylethylamine (4) as a chiral source. Enantiomerically pure 1, 3-dimethyl-TIQs (1R, 3S)-(1), (1S, 3R)-(ent-1), (1S, 3S)-(2), and (1R, 3R)-(ent-2) were prepared in a stereochemically unambiguous manner from 3 in 11 steps (route I) and from 4 in 6 steps (route II). The conformations of tetrahydroisoquinoline ring in 1-methyl, 3-methyl, and 1, 3-dimethyl-TIQs were discussed on the basis of their CD, 1H-NMR spectra, and steric energies.View full abstractDownload PDF (1263K) -
Tsutomu WARASHINA, Tadataka NORO2000 Volume 48 Issue 1 Pages 99-107
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThirty new steroidal glycosides were obtained from the aerial part of Asclepias incarnata L. (Asclepiadaceae). These glycosides were confirmed to have lineolon, isolineolon, 12-O-acetyllineolon, 12-O-(Z)-cin-namoyllineolon, metaplexigenin, 15β-hydroxylineolon, 15β-hydroxyisolineolon, 16α-hydroxyisolineolon, 12-O-tigloyl-16α-hydroxyisolineolon as the aglycone and 2, 6-dideoxyhexoprranose as the sugar sequence by spectroscopic methods and chemical evidence.View full abstractDownload PDF (1207K) -
Tominari CHOSHI, Takeshi KUWADA, Miyako FUKUI, Yuhji MATSUYA, Eiichi S ...2000 Volume 48 Issue 1 Pages 108-113
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new type of β-carboline nucleus, N-methoxymethyl-4-methyl-β-carboline (4) was synthesized by thermal electrocyclic reaction of a 1-azahexatriene system, involving the indole 2, 3-bond. The key compound N-methoxymethyl-1-methoxycarbonyl-4-methyl-β-carboline (2) was then prepared in a four-step sequence. The total synthesis of oxopropaline G (1e) was achieved from this key compound in four steps. Furthermore, the enantioselective total syntheses of (+)-oxopropaline D (1c) and its enantiomer were also achieved by application of the Sharpless oxidation-procedure in nine steps from 2.View full abstractDownload PDF (943K) -
Masami KAWASE, Michitaka HIRABAYASHI, Hiroko KUMAKURA, Setsuo SAITO, K ...2000 Volume 48 Issue 1 Pages 114-119
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe Dakin-West reaction of N-alkoxycarbonyl-N-alkyl-α-amino acids (1a-j) with trifluoroacetic anhydride in the presence of pyridine gave α-amido trifluoromethyl ketones (2a-j), in which probable intermediates were mesoionic 1, 3-oxazolium-5-olates (munchnones). The diastereoselective reduction of 2a-f with NaBH4 gave the threo-aminoalcohols (5a-f), which may be explained by the Felkin-Anh model. This was confirmed by converting 5a-f into trans-5-trifluoromethyl-2-oxazolidinones (6a-f) in good yields.View full abstractDownload PDF (1000K) -
Iwao OKAMOTO, Tetsuya TAKEYA, Yoshiki KAGAWA, Eiichi KOTANI2000 Volume 48 Issue 1 Pages 120-125
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe reaction of oleanane triterpenoid 1b with a FeIII(PA; picolinate)3/H2O2/MeCN system (reagent system A), a simple model system for mono-oxygenase, gave the 11α-hydroxyl derivative 3 as major product, along with 11-oxo derivative 4 and 12-oxo derivative 6. The reaction of lupane triterpenoid 2b with reagent system A gave only oxidative rearrangement compounds, (20R)-aldehyde 8 and (20S)-aldehyde 9 were epimeric isomers. Then, we have found that iron(III) picolinate complex, FeIII(PA)3 is efficient in effecting the rearrangement of triterpenoid epoxides 5 and 7 into the corresponding cargonyl compounds, 6, 8 and 9 with 1, 2-shift of the hydride.View full abstractDownload PDF (986K) -
Makoto MORI, Sadao OIDA2000 Volume 48 Issue 1 Pages 126-130
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAn orally bioavailable carbapenem CS-834, which is a pivaloyloxymethyl (POM) ester-type prodrug and has (R)-5-oxopyrrolidin-3-ylthio moiety at the C-2 position of the 1β-methylcarbapenem skeleton, is currently under clinical trial. We accomplished a short-step synthesis of CS-834 by using phosphorus ylide from the intramolecular Wittig-type reaction in the key step for cyclization to the bicyclic carbapenem system. The POM ester group was found to be suitable for the cyclization conditions.View full abstractDownload PDF (897K) -
Takihiro INABA, Keiichi TANAKA, Ryuko TAKENO, Hideyoshi NAGAKI, Chosak ...2000 Volume 48 Issue 1 Pages 131-139
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA group of derivatives of 7-methanesulfonylamino-6-phenoxychromone (1) at the pyrone and phenoxy rings was synthesized with 4-chloro-3-nitroanisole and evaluated against acute and chronic inflammations in oral administration in animals. Significant potency in the rat models of carrageenin-induced edema (CPE) and adjuvant-induced arthritis (AA) was realized with 2'-fluoro and 2', 4'-difluoro derivatives (9a and 9d), and 3-formylamino derivative (19a) and its 2'-fluoro and 2', 4'-difluoro compounds (22a and 22d), displaying AA therapeutic effect of ED40=2.5-7.1mg/kg/d for 7d and AA prophylactic effect of 53-70% inhibition at the dosage of 3 mg/kg/d for 22 d. To identify a candidate for further pharmacological study, the five compounds were subjected to evaluation of their gastro-ulcerogenic liability, leading to selection of the fluorine-free compound 19a which did not cause acute ulceration at 300 mg/kg in oral administration in rats. Compound 19a (ED40=3.6mg/kg in established AA) possessed good therapeutic efficacy against type II collagen-induced arthritis in DBA/1J mice with doses of 30 and 100 mg/kg, suggesting the development of 19a (designated T-614) as a prospective diseasemodifying antirheumatic agent. In addition, a preparative-scale synthetic route to T-614 has been established.View full abstractDownload PDF (1424K) -
Shinji AOKI, Taku MIZUTANI, Kazumi DANJO2000 Volume 48 Issue 1 Pages 140-141
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe studied a method of estimating the number of contacts in a solid dosage form using thermal analysis. Ibuprofen (IB) and Ethenzamide (ET) were used as model actives. IB and ET were granulated and sieved with each other. We prepared mixtures of IB and ET using different diameter granules. The number of contacts between the samples was calculated by the expression method of Ouchiyama and Tanaka. By thermal analysis, we measured the quantity of endotherm up to 60-63°C from 56°C. The quantity of endotherm up to 61°C from 56°C was in good proportion to the number of contacts calculated by the expression.View full abstractDownload PDF (384K) -
Tadamasa TERAI, Daisuke ARAHO, Kanehiro OSAKABE, Masaaki KATAI, Isao N ...2000 Volume 48 Issue 1 Pages 142-144
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe structure of iso-trayanotoxin II, a new diterpenoid from Leucothoe grayana MAX., has been determined as 3β, 5β, 6β, 14β, 16α-pentahydroxygrayanotox-9(10)-ene by spectroscopic and X-ray crystallographic analysis. The lethal dosage level of iso-grayanotoxin II in mice was lower than that of grayanotoxin III.View full abstractDownload PDF (479K) -
Mitsuhiro YOSHIMATSU, Sayaka KINOSHITA2000 Volume 48 Issue 1 Pages 145-147
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe direct lithiation and alkylation of β-sulfur-α-triflutromethyl substituted enol thers 1-3 proceeded to give the alkylated products 4a-f, 5, 6a-c in moderate to high yields.View full abstractDownload PDF (580K) -
Hong-Min LIU, Xuebin YAN, Fumiyuki KIUCHI, Zhenzhong LIU2000 Volume 48 Issue 1 Pages 148-149
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new ent-kaurene β-D-glucoside was isolated from Rabdosia rubescens, together with the known compounds oridonin, ponicidin, and pedalitin. The structure of new compound was determined, on the basis of spectral date and X-ray crystallographic analysis, to be ent-7β, 20-epoxy-kaur-16-ene-1β, 6α, 7α, 14α, 15α-pentanol 1-O-β-D-glucopyranoside.View full abstractDownload PDF (437K) -
Nectarios ALIGIANNIS, Nicole POULI, Panagiotis MARAKOS, Sofia MITAKU, ...2000 Volume 48 Issue 1 Pages 150-153
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe synthesis and pharmacological evaluation of 7-O-(4-O-acetyl-3-iodo-2, 3, 6-trideoxy-α-L-arabino-hexopy-ranosyl)daunomycinone and 7-O-(3-chloro-2, 3, 6-trideoxy-4-O-propanoyl-α-L-lyxo-hexopyranosyl)daunomycinone are described. Their cytotoxic activity was evaluated against normal and resistant cell lines. Both compounds exhibited activity against the adriamycin resistant cell line KB-A1. These results support the hypothesis that the increased lipophilicity of the sugar part of anthracyclines is associated with their ability to overcome multidrug resistance (MDR).View full abstractDownload PDF (808K) -
Fumiko ABE, Tatsuo YAMAUCHI, Keiichi HONDA, Nanao HAYASHI2000 Volume 48 Issue 1 Pages 154-156
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThirteen pregnane glycosides were isolated from fresh leaves of Marsdenia tomentosa collected in the Fukuyama district. Of these, six were glycosides previously obtained from the same plant collected in the Fukuoka district and one from another Asclepiadaceous plant. The structures of the six new glycosides were determined by spectrometric method.View full abstractDownload PDF (558K) -
Koji YAMADA, Yasuo HARADA, Tomofumi MIYAMOTO, Ryuichi ISOBE, Ryuichi H ...2000 Volume 48 Issue 1 Pages 157-159
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new ganglioside molecular species, HPG-7 (1) was obtained from the polar fraction of the chloroform/methanol extract of the sea cucumber, Holothuria pervicax. On the basis of chemical and spectroscopic evidence, the structure of 1 was determined, and the major component was 1-O-[α-L-fucopyranosyl-(1→4)-(N-aceryl-α-D-neuraminosyl)-(2→11)-(N-glycolyl-α-D-neuraminosyl)-(2→4)-(N-acetyl-α-D-neuraminosyl)-(2→6)-β-D-glucopyranosyl]-(2S, 3S, 4R)-2-[(2R)-2-hydroxytetracosanoylamino]-14-methyl-hexadecane-1, 3, 4-triol. This is the first report on the isolation and structure elucidation of trisialo-ganglioside from sea cucumber. 1 showed neuritogenic activity toward the rat pheochromocytoma cell line, PC-12 cell.View full abstractDownload PDF (569K) -
Tsuneo IWAKAWA, Hiroshi NAKAI, Giichi SUGIMORI, Akira MURABAYASHI2000 Volume 48 Issue 1 Pages 160-162
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTreatment of 3-acetonyl-5-cyano-1, 2, 4-thiadiazole (1) with 4-methyl or 4-methoxyphenylhydrazine hydrochloride provided 5-cyano-3-(2, 5-dimethylindol-3-yl)-1, 2, 4-thiadiazole (2) or 5-cyano-3-(5-methoxy-2-methylindol-3-yl)-1, 2, 4-thiadiazole (3) as the sole product, respectively. In contrast, treatment of 1 with phenylhydrazine hydrochloride resulted in the formation of 5-cyano-3-(2-methylindol-3-yl)-1, 2, 4-thiadiazole (4) and the unexpected 5-cyano-3-(3, 5-dimethyl-1-phenylpyrazol-4-yl)-1, 2, 4-thiadiazole (5). In a similar manner, when 1 was treated with 4-chiorophenylhydrazine hydrochloride, indolization was suppressed by phenylpyrazolation giving rise to 5-cyano-3-(5-chloro-2-methylindol-3-yl)-1, 2, 4-thiadiazole (6) and 5-cyano-3-[1-(4-chlorophenyl)-3, 5-dimethylpyrazol-4-yl]-1, 2, 4-thiadiazole (7). The reaction mechanism is discussed. Compounds 4, 5 and 6 exhibited weak antimicrobial activity against Helicobacter pylori.View full abstractDownload PDF (525K) -
Kiyoshi IKEDA, Koji KONISHI, Kimihiko SANO, Kiyoshi TANAKA2000 Volume 48 Issue 1 Pages 163-165
Published: January 01, 2000
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe 2-thio- or 2-selenoglycosides of N-acetylneuraminic acid methyl ester were transformed by successive treatment with dimethyl(methylthio)sulfonium triflate (DMTST) and 1, 8-diazabicyclo[5.4.0]-7-undecene (DBU) to give the correponding methyl 2-deoxy-2, 3-didehydroneuraminates in excellent yields. Their acids and thier analogues are sialidase inhibitors of pharmaceutical interest.View full abstractDownload PDF (515K)
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