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Volume 43, Issue 8
Displaying 1-29 of 29 articles from this issue
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Shuji KITAGAWA, Takeshi SAKUMA, Seiichi YONEMURA1995 Volume 43 Issue 8 Pages 1263-1266
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSEffects of pyrocatechol and six of its monosubstituents on oxidation of soybean phosphatidylcholine liposome induced by hydophilic free radical initiator, 2, 2'-azobis(2-amidinopropane)dihydrochloride (AAPH), and hydrophobic free radical initiator, 2, 2'-azobis(2, 4-dimethylvaleronitrile) (AMVN), were determined and relationships with their redox potentials and hydrophobic parameters were studied for their inhibitory effects by regression analysis. Inhibitory potencies of the catechol compounds on hydrophilic AAPH-induced oxidation clearly correlated with their redox potentials, whereas no significant effects of the hydrophobicities of the compounds were found. These results indicated that scavenging activities of these compounds on AAPH-initiated radical chain reactions were controlled by their electron donor activities. Inhibitory potencies of these compounds on hydrophobic AMVN-induced oxidation of liposome, in contrast, were significantly correlated with their hydrophobicity, although regression analysis revealed that their electron donor activities were also important.View full abstractDownload PDF (666K) -
Yueh-Hsiung KUO, Chien-Huang WU, Rong-En WU, Sheng-Tsai LIN1995 Volume 43 Issue 8 Pages 1267-1271
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe BF3-, TsOH- or HCOOH-catalyzed dimerization of 3, 4-dioxygenated cinnamate or 1-arylpropene offers a route to arylindane lignans. The structures of the products were elucidated and a mechanism is proposed for the reactions. The structures of the dimeric products assigned as aryltetralin lignans by Botta et al.View full abstractDownload PDF (722K) -
Tohru SUGAWARA, Kyoko KOBAYASHI, Shigeha OKAMOTO, Chieko KITADA, Masah ...1995 Volume 43 Issue 8 Pages 1272-1280
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAn automated synthesis system, which is suitable for repetitive syntheses using similar reaction procedures, was used to synthesize systematically a library of all possible dipeptides (25) and tripeptides (125) from 5 protected amino acids. The apparatus has also been applied to the automated synthesis of 10 fragment tripeptide derivatives that are constituents of the hormone PACAP-27. The measured molecular optical rotation values of the library of 125 tripeptides were found to correlate well with calculated values obtained by summation of the molecular optical rotation values for the constituent amino acids.View full abstractDownload PDF (1146K) -
Yasuoki MURAKAMI, Toshiko WATANABE, Takao HAGIWARA, Yohko AKIYAMA(nee ...1995 Volume 43 Issue 8 Pages 1281-1286
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe Fischer indolization of ethyl pyruvate 2-[2-(trifluoromethyl)phenyl]phenylhydrazone (5) gave two indolic products, ethyl 7-(trifluoromethyl)-1-phenylindole-2-carboxylate (12) as a minor product and ethyl 1-[2-(trifluoromethyl)phenyl]indole-2-carboxylate (13) as a major product. This result shows that the Fischer indolization occurred on the more electron-rich phenyl group. In the Goldberg reaction to prepare 13 from ethyl indole-2-carboxylate (15) and o- (21) or m-bromo-α, α, α-trifluotoluene (23), it was found that Goldberg reaction proceeds via a benzyne mechanism, at least in part, in a sterically crowded situation.View full abstractDownload PDF (969K) -
Yasuoki MURAKAMI, Toshiko WATANABE, Tomoko OTSUKA, Tsutomu IWATA, Yuri ...1995 Volume 43 Issue 8 Pages 1287-1293
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn connection with studies on the direction of cyclization in the Fischer indolization of substituted diphenylhydrazones, the Fischer indolization of ethyl pyruvate 2-bis(2-methoxyphenyl)hydrazone (6) was carried out. The result showed that cyclization in Fischer indolization of diphenylhydrazone does not always proceed to the electron-richer nucleus, but depends on the conformation of the enehydrazine. Thus, the Fischer indolization should proceed via a [3, 3] sigmatropic route, with an electronic effect.View full abstractDownload PDF (950K) -
Shunsaku OHTA, Masayuki YAMASHITA, Kazuo ARITA, Takahiro KAJIURA, Ikuo ...1995 Volume 43 Issue 8 Pages 1294-1301
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSCyclic ketone O-trimethylsilylcyanohydrins (2) were prepared and converted to various compounds : α-hydroxyketones (3), dehydroxylated ketones (4), α, β-unsaturated ketones (9), tricyclic ketones (10), 1-ethoxycarbonyl-4-phenyl-1, 2, 4a, 5, 6, 7, 8, 8a-octahydro-2-naphthalenone (13), 1-phenylperhydroisocoumarin (18) and 1, 2, 3, 4, 4a, 10, 11, 11a-octahydro-5H-benzo[a, d]cyclohepten-10-one (20).View full abstractDownload PDF (1121K) -
Shigeyuki YOSHIFUJI, Mamoru KANAME1995 Volume 43 Issue 8 Pages 1302-1306
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS(R)- and (S)-Baclofen and (R)- and (S)-PCPGABA [4-amino-2-(4-chlorophenyl)butyric acid] were stereospecifically synthesized via (R)- and (S)-3-(4-chlorophenyl)pyrrolidines, starting from trans-4-hydroxy-L-proline. The syntheses involve two key operations, namely, 1) a stereoselective hydrogenation of dehydroproline derivatives controlled by the C-2 carboxyl function and 2) an effective ruthenium tetroxide oxidation to prepare chiral 3- and 4-(4-chlorophenyl)pyrrolidin-2-ones, which are dehydrated precursors of the target molecules.View full abstractDownload PDF (872K) -
Eiji YOSHIDA, Haruhiro FUJIMOTO, Miyuki BABA, Mikio YAMAZAKI1995 Volume 43 Issue 8 Pages 1307-1310
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new azaphilones, named helicusins A, B, C, and D, were isolated from an Ascomycete, Talaromyces helicus. Helicusins A and B were deduced to be (7S, 13S)-7-deacetyl-7-epi-sclerotiorin-7-yl hydrogen 3'-methyl-2'E-pentenedioate and its 2'Z isomer, and helicusins C and D were deduced to be (7S, 13S)-7-deacetyl-7-epi-sclerotiorin-7-yl hydrogen 3'-methyl-3'Z-pentenedioate and its 3'E isomer, respectively, on the basis of chemical and spectral data.These four new azaphilones showed weak monoamine oxidase-inhibitory effects.View full abstractDownload PDF (700K) -
Takeo OKAZAKI, Masahiro KAJIWARA1995 Volume 43 Issue 8 Pages 1311-1317
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe biosynthetic pathway of bacteriochlorophyll-a in Rhodopseudomonas spheroides was investigated by administration of [2-13C]glycine, L-[methyl-13C]methionine, L-[1-13C]glutamic acid and 13C- or 15N-labeled δ-aminolevulinic acid (ALA). The origin of the hydrogen atoms was studied by following the incorporation into bacteriochlorophyll of 13C-labeled ALA in a medium containing 50% D2O and that of 2H-, 13C-labeled ALA. The labeled bacteriochlorophylls were converted into more stable methyl bacteriopheophorbides, which were subjected to 13C-NMR analyses to obtain information about the biosynthetic origin of the hydrogen atoms. The use of 13C-enriched bacteriochlorophylls and methyl bacteriopheophorbides allowed us to make 13C-NMR signal assignments for all carbons of the porphyrin nucleus.View full abstractDownload PDF (749K) -
Mika YASUDA, Shigehisa SAITO, Yasushi ARAKAWA, Shigeyuki YOSHIFUJI1995 Volume 43 Issue 8 Pages 1318-1324
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNew amino acids, (±)-t-3, t-4-bis(carboxymethyl)-r-2-pyrrolidinecarboxylic acid (1d) and (±)-t-3a, t-6a-perhydro-r-1, t-4, t-6-cyclopenta[c]pyrroletricarboxylic acid (2), which possess relatively similar configurations to kainic acid, were synthesized from readily available Diels-Alder adducts.View full abstractDownload PDF (1094K) -
Regioselective Synthesis of 14-Membered Biaryl Ethers : Total Synthesis of RA-VII and DeoxybouvardinTsutomu INOUE, Takashi INABA, Isao UMEZAWA, Masayuki YUASA, Hideji ITO ...1995 Volume 43 Issue 8 Pages 1325-1335
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn order to obtain a key compound (22a") for synthesis of RA-VII (1) and deoxybouvardin (2), construction of the 14-membered ring system was performed by means of thallium trinitrate-mediated oxidation of the tetrahalogeno amides 5-7. The dibromo dichloro amide 6 or the bromo trichloro amide 7 gave a natural type of 14-membered ring dienone (23a or 23c), whereas the tetrabromo amide 5 gave an unnatural type of product, 19a. The formation of the latter product 19a could be understood on the basis of energy calculations on plausible intermediates 26a-c and 27a-c in the transition state in the oxidaive coupling reaction. Compound 23a was further converted to 22a" through conventional procedures (aromatization; methylation; catalytic hydrogenation). This intermediate was readily converted to 1 and 2. Thus, total synthesis of RA-VII (1) and deoxybouvardin (2) was achieved for the first time.View full abstractDownload PDF (1596K) -
Hiroaki TAGUCHI, Kenichi HIRANO, Toshio YOKOI, Keiichi ASADA, Yoshio O ...1995 Volume 43 Issue 8 Pages 1336-1339
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS2-Acetoxy-3-benzyl-5-methyl-6-isobutylpyrazine was prepared by cyclization of H-Phe-Leu-CH2Cl, followed by acetylation with acetic anhydride. This pyrazine derivative can react with amino groups of amino acids or peptides to produce acetyl amino acids or acetyl peptides without acetylation of hydroxy group of Tyr, Ser and Thr. Using this acetylating reagent, Ac-Tyr-Val-Ala-Asp-MCA, which is a specific substrate of the interleukin-I (IL-I) processing enzyme, was prepared.View full abstractDownload PDF (748K) -
Yuko TAKEMURA, Yoko MATSUSHITA, Noriko NAGAREYA, Masami ABE, Junko TAK ...1995 Volume 43 Issue 8 Pages 1340-1345
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree novel dimeric acridone alkaloids named citbismine-A (1), -B (3) and -C (5) have been isolated from the roots of Marsh grapefruit (Citrus paradisi) and Hirado-buntan (C. grandis). The structure of citbismine-A was elucidated as 1 by spectroscopic studies and single crystal X-ray analysis. Structure assignments of citbismine-B (3) and -C (5) were based on spectroscopic data including two dimensional (2D)-NMR (correlation spectroscopy (COSY) and heteronuclear multiple bond correlation (HMBC)) experiments. The common structural characteristic is the presence of a C-C bond between the aromatic ring and the dihydrofuran ring of each acridone nucleus.View full abstractDownload PDF (876K) -
Masayuki KATO, Shigetaka NISHINO, Kiyotaka ITO, Hisashi TAKASUGI1995 Volume 43 Issue 8 Pages 1346-1350
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS(+)-8, 9-Dihydro-10-methyl-7-[(5-methyl-1H-imidazol-4-yl)methyl]pyrido[1, 2-a]indol-6(7H)-one hydrochloride (FK 1052, 1) is a highly poten 5-HT3 (serotonin-3) receptor antagonist. For the study of the metabolism and disposition of FK 1052 (1), we synthesized carbon 14-labeled FK 1052 in three steps from 10-demethyl FK 1052 (8). The Mannich reaction and subsequent hydrogenolysis of the dimethylaminomethyl group enabled the efficient introduction of one carbon atom at the 10-position of the pyrido[1, 2-a]indol-6(7H)-one ring. The Mannich reaction of (+)-8, 9-dihydro-7-[(5-methyl-1H-imidazol-4-yl)methyl]pyrido[1, 2-a]indol-6(7H)-one (8) with [14C]paraformaldehyde and dimethylamine hydrochloride gave the [14C]-10-dimethylaminomethyl compound (20). Subsequent hydrogenolysis of 20 with palladium on carbon and ammonium formate, followed by recrystallization of the salt with (+)-di-p-toluoyl-D-tartaric acid, gave[14C]FK 1052 with a radiochemical purity of 99.4% and an enantiomeric excess of more than 97%.View full abstractDownload PDF (788K) -
Masayuki KATO, Kiyotaka ITO, Shigetaka NISHINO, Hisashi YAMAKUNI, Hisa ...1995 Volume 43 Issue 8 Pages 1351-1357
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe synthesis and structure-activity relationships of a series of new azabicycloalkanes as 5-HT3 (serotonin-3) receptor antagonists are described. Our study on the azabicycloalkaneacetamide derivatives showed that 2, 3-dihydroindole as the aromatic ring moiety afforded potent 5-HT3 receptor antagonist activity, as judged by blockade of bradycardia induced by i.v. injection of 2-methylserotonin in anesthetized rats. 7-Azaindole as the aromatic moiety afforded weak 5-HT3 receptor antagonists activity. The best 5-HT3 antagonists in this study were endo-3, 3-diethyl- (9k) and 3, 3-dimethyl-2, 3-dihydro-1-[(8-methyl-8-azabicyclo[3.2.1]oct-3-yl)acetyl-1H-indole (9d), being approximately 10-fold more potent than ondansetron (1). This study shows that the azabicycloalkaneacetyl group is a new pharmacophoric element as a basic nitrogen and a linking carbonyl moiety.View full abstractDownload PDF (1024K) -
Masayuki KATO, Shigetaka NISHINO, Kiyotaka ITO, Hisashi YAMAKUNI, Hisa ...1995 Volume 43 Issue 8 Pages 1358-1363
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThis paper describes the discovery of structurally novel heterocyclic carboxamides which are highly potent 5-HT3 (serotonin-3) receptor antagonists. Pyrrolo[2, 1-c][1, 4]benzoxazine-6-carboxamides (12 and 20) were found to possess potent 5-HT3 receptor antagonist activity on the von Bezold-Jarisch reflex in anesthetized rats. Structure-activity studies showed that compounds with small and lipophilic substituents such as chloro and methyl at the 8-position of the aromatic ring portion retained high potency, whereas those with bulky substituents showed essentially no activity. A dimethyl group at the 4-position slightly decreased the potency. 1-Azabicyclo[2.2.2]octan-3-amine as the amine part afforded the most potent activity. From this series, 20a was found to be the most potent 5-HT3 receptor antagonist, being 40-fold more potent than ondansetron (1).View full abstractDownload PDF (872K) -
Hiroshi HARADA, Toshiya MORIE, Yoshimi HIROKAWA, Naoyuki YOSHIDA, Shir ...1995 Volume 43 Issue 8 Pages 1364-1378
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new series of 2-alkoxy-4-amino-5-chlorobenzamide derivatives bearing five- to seven-membered heteroalicyclic rings in the amine moiety was synthesized and evaluated for serotonin-3 (5-HT3) receptor antagonistic activity by assaying the ability to antagonize the von Bezold-Jarisch reflex in rats. The five- to seven-membered heteroalicycles comprise pyrrolidine, morpholine, 1, 4-thiazine, piperidine, piperazine, 1, 4-oxazepine, 1, 4-thiazepine, azepine, and 1, 4-diazepine rings. Among them, some benzamide derivatives having a 1, 4-diazepine ring showed a potent 5-HT3 receptor antagonistic activity. In particular, 4-amino-5-chloro-N-(1, 4-dimethylhexahydro-1H-1, 4-diazepin-6-yl)-2-ethoxybenzamide (96) and the 1-benzyl-4-methylhexahydro-1H-1, 4-diazepine analogue 103 showed potent 5-HT3 receptor antagonistic activity without 5-HT4 receptor binding affinity.View full abstractDownload PDF (2001K) -
Kazutake SHIMADA, Katsuko SUGAYA, Hidefumi KAJI, ITO NAKATANI, Kuniko ...1995 Volume 43 Issue 8 Pages 1379-1384
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS25-Hydroxyvitamin D3 (D2) 3- and 25-monoglucuronides were synthesized from the corresponding provitamin D or its derivatives with the Koenigs-Knorr reaction using silver carbonate as a catalyst, followed by photochemical reaction, thermal isomerization and then alkali hydrolysis. The obtained glucuronides were subjected to enzymatic hydrolysis using β-glucuronidase, and substrate specificities were found in the examined enzymes originating from different sources.View full abstractDownload PDF (945K) -
Yoshihito OKADA, Noriaki MIYAUCHI, Katsuhisa SUZUKI, Toshimitsu KOBAYA ...1995 Volume 43 Issue 8 Pages 1385-1387
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAn EtOAc extract of Artemisiae Capillari Spica inhibited both bovine lens aldose reductase (bovine-LAR) and rabbit platelet aggregation. Two simple coumarins, scoparone (1) and scopoletin (2), and three flavonoids, capillarisin (21), cirsimaritin (22) and rhamnocitrin (23), were isolated from this extract. Scoparone (1) and scopoletin (2) exhibit a potent inhibitory effect on rabbit platelet aggregation induced by four types of agent, ADP, PAF, sodium arachidonate and/or collagen. Capillarisin (21) exhibits a potent inhibitory effect on bovine-LAR.In addition, thirteen simple coumarins, five coumarin glycosides and two flavonoids were tested for their inhibitory effect against bovine-LAR and rabbit platelet aggregation.View full abstractDownload PDF (491K) -
Yoshikazu YAMAMOTO, Yasutaka MIURA, Yasuhiro KINOSHITA, Masako HIGUCHI ...1995 Volume 43 Issue 8 Pages 1388-1390
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSInhibition of tumor promoter-induced Epstein-Barr virus (EBV) activation was screened using tissue culture and thallus extracts of lichens. Usnea longissima ACH. thallus and Cetraria ornata MULL. ARG. tissue culture showed strong inhibitory activity. We identified (+)-usnic acid (1), barbatic acid (2), diffractaic acid (3), 4-O-demethylbarbatic acid (4), and evernic acid (5) as inhibitors of EBV activation from the U. longissima thallus. Of these compounds, (+)-usnic acid exhibited the highest inhibitory activity (IC50=1.0 μM).View full abstractDownload PDF (543K) -
Yoshiyasu FUKUYAMA, Yuuko KIRIYAMA, Mitsuaki KODAMA, Hideyuki IWAKI, S ...1995 Volume 43 Issue 8 Pages 1391-1394
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNew 1, 4-benzoquinone derivatives, ardisiaquinones D (2), E (4), and F (5) along with the known ardisiaquinones A (1) and B (3) have been isolated from the leaves of Ardisia sieboldii (Myrsinaceae) and shown to be 5-lipoxygenase inhibitors. Their structures have been elucidated by spectroscopic analysis and chemical degradation. The degree of inhibition of 5-lipoxygenase activity by the ardisiaquinones and some derivatives of ardisiaquinone A is reported.View full abstractDownload PDF (734K) -
Hiroshi MORITA, Shinji NAGASHIMA, Koichi TAKEYA, Hideji ITOKAWA1995 Volume 43 Issue 8 Pages 1395-1397
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSConformational analysis of antitumor cyclic pentapeptides, astins A (1) and C (3), was made by a combination of NMR and computational techniques. These results indicated that the backbone conformations of 1 and 3, with lower activity than astin B (2), were different from that of 2. The backbone conformation together with a cis 3, 4-dichlorinated proline residue was considered to play an important role in the antitumor activities of astins.View full abstractDownload PDF (570K) -
Masato TAKAHASHI, Hiroshi YUASA, Yoshio KANAYA, Mitsuru UCHIYAMA1995 Volume 43 Issue 8 Pages 1398-1401
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe prepared soft gelatin capsules (SC) containing ibuprofen (IB), a widely used phenylpropionic acid-derived antiphologistic-analgesic drug. To evaluate the SC, in vitro dissolution tests were performed both by the paddle (PD) method described in the Japanese Pharmacopoeia (JP XII) and by the rotating dialysis cell (RDC) method which we previously developed and evaluated for application. In vivo, the blood IB concentration was determined after administration to beagles. Higher bioavailability was observed after administration of the SC containing IB than after administration of the bulk IB powder. A higher correlation was observed between the in vitro dissolution behavior and in vivo results by the RDC method than by the PD method, suggesting the usefulness of the RDC method in the dissolution test of SC.View full abstractDownload PDF (652K) -
Hiroyasu KOKUBO, Shinichiro NAKAMURA, Hisakazu SUNADA1995 Volume 43 Issue 8 Pages 1402-1406
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA model system consisting of lactose-cornstarch was used to examine the effect of five cellulosic binders [hydroxypropylcellulose (HPC) (6 cP), hydroxypropylmethylcellulose 2910 (HPMC) (3, 6, 15 cP) and methylcellulose (MC) (15 cP)] on the particle size distribution of granules prepared in a fluidized bed under fixed operating conditions. The distribution of binder in different size fractions of granules was also determined by measuring the contents of methoxyl and hydroxypropoxyl groups. When the binders were added by the solution method, higher solution viscosity resulted in the granule size being increased without any increase in the percentage of coarse (>500 μm) particles generated. The granules prepared by the dry mixing method with HPC (6 cP) or HPMC (3 cP) also showed a good correlation between median particle size and binder level. The other binders did not show such a correlation, as higher concentrations of the binders were present in the medium-sized particle fractions of the granules at higher binder levels, and partly aggregated was the observed binder in these granules. The results support our previous conclusion, in a study of wet granulation with a high-speed mixer, that analysis of granule size dependency of binder content is useful for evaluating the effectiveness of binders added by dry mixing.View full abstractDownload PDF (724K) -
Tetsuaki TANAKA, Osamu OKUDA, Kazuo MURAKAMI, Hitoshi YOSHINO, Hidenor ...1995 Volume 43 Issue 8 Pages 1407-1411
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFormal total synthesis of (±)-aphidicolin (1) was achieved via a Lewis acid-mediated stereoselective spiroannelation reaction as a key step. The bisbenzyl acetal (2) was synthesized from the readily available dimethyl acetal (4). Treatment of 2 with trimethylsilyl trifluoromethanesulfonate (TMSOTf) afforded a 69 : 31 mixture of the spirocyclic enones (9 and 10) in excellent yield. The tricyclic ketal-ketone (3) corresponding to the B/C/D rings of 1 was easily generated from the enone (9) by intramolecular alkylation and catalytic hydrogenation as principal steps. The A-ring construction was performed by a procedure similar to one used previously. Barbier reaction of 14, followed by oxidative rearrangement, stereoselective 1, 4-addition of a methyl group, and subsequent intramolecular aldol-condensation afforded the tetracyclic enone (18), which has already been transformed into (±)-aphidicolin (1).View full abstractDownload PDF (748K) -
Hiroaki KOMATSU, Aya KITAJIMA, Satoshi OKADA1995 Volume 43 Issue 8 Pages 1412-1415
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSParticle profiles such as the average diameter, size distribution and dispersion, as well as the zeta potential, of commercially available intravenous fat emulsions of high-calorie nutrient fluids (6 products) and drug carriers (4 products) were examined using photon correlation spectroscopy (dynamic light scattering). Wide variations were observed in number-weighted (dn), weight-weighted (dw) and z-average diameters, and dw/dn ratios as a measure of polydispersity. Average size is not sufficient for the pharmaceutical characterization of particles and the determination of size distribution or dw/dn value is essential for more precise information. Although measuring the zeta potential of fat emulsions is of considerable value in estimating their stability on long-term storage, a medium which accurately reflects the environment of the droplets in the system of interest should be chosen when diluting the emulsion.View full abstractDownload PDF (657K) -
Toshinobu KORENAGA, Yuko TOYODA, Masuo MORISAKI, Yoshinori FUJIMOTO1995 Volume 43 Issue 8 Pages 1416-1418
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA postulated intermediate of bile acid biosynthesis, 24-oxo-3α, 7α, 12α-trihydroxy-5β-cholestan-26-oyl CoA was chemically synthesized from cholic acid.View full abstractDownload PDF (411K) -
Akimori WADA, Masako TSUTSUMI, Yuka INATOMI, Hiroo IMAI, Yoshinori SHI ...1995 Volume 43 Issue 8 Pages 1419-1421
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn order to clarify the conformation of chromophore in rhodopsin, especially the torsional angle around the C6-C7 single bond, 8, 18-propano- and methano-retinals were prepared from 2, 2-dimethylcyclohexanone via the palladium-catalyzed coupling reaction of vinyl triflates with methyl E-3-trimethylstannyl-2-butenoate, and their interaction with bovine opsin was investigated.View full abstractDownload PDF (436K) -
Yasuko KAMOCHI, Tadahiro KUDO1995 Volume 43 Issue 8 Pages 1422-1424
Published: August 15, 1995
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSPyridines were rapidly reduced to piperidines with Sm or Yb-HCl system at room temperature in quantitative yields. Quinolines and isoquinolines were similarly reduced to the corresponding 1, 2, 3, 4-tetrahydro-derivatives with Sm-HCl system in good yields.View full abstractDownload PDF (435K)
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