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Volume 38, Issue 9
Displaying 1-50 of 58 articles from this issue
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Daisuke YAMAMOTO, Hirofumi OHISHI, Toshimasa ISHIDA, Masatoshi INOUE, ...1990 Volume 38 Issue 9 Pages 2339-2343
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTo investigate the possible binding mode of E-64 (N-[N-(L-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl]agmatine), a potent cysteine protease inhibitor, to papain active site, molecular dynamics simulations were applied to two complex forms : R- and S- configurational forms of E-64 C2 atom for the covalent bond formation with the papain Cys-25 SH group. The tertiary structures of the papain-E-64 complexes were built by visual interactive modelling and the energy minimization technique, and were subjected to the dynamics simulations of 10 ps. Although no significant difference was observed between the potential energies of energy-minimized R- and S-complex forms, the molecular dynamics simulations suggested that the hydrogen bonding mode of the former form is more advantageous than that of the latter one. Comparing with the hydrogen bonds observed in the papain-E-64 complex crystal, it could be concluded that the present molecular dynamics simulation reflects well the three-dimensional structure concerning the interaction of E-64 with the papain active site. The conformational characteristics of E-64 and its possible interaction mode with papain were also discussed.View full abstractDownload PDF (685K) -
Yoshio SASAKI, Hideko KAWAKI, Tatsuya TAKAGI1990 Volume 38 Issue 9 Pages 2344-2346
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe quantitative structure-activity relationship descriptor σS°, representing the contributions from dispersion and repulsion interactions can be expressed as follows : (1) for disubstituted benzene derivatives, σS°(1, 2)=0.831ΣσS°(mono)-0.004, σS°(1, 3)=0.855ΣσS°(mono)-0.007, and σS°(1, 4)=0.874ΣσS°(mono)-0.018; (2) for trisubstituted benzene derivatives, σS°(1, 3, 5)=0.752 ΣσS°(mono)-0.017, σS°(1, 2, 4)=0.715ΣσS°(mono)+0.006, and σS°(1, 2, 3)=0.723×ΣσS°(mono)-0.006.These are revealed to be successful for the estimation of the descriptors σS° for optional di- and tri-substitued benzene derivatives, and meet the needs of the practical quatitative structure-activity relationships.View full abstractDownload PDF (502K) -
Shoko YOKOYAMA, Tadao FUJIE1990 Volume 38 Issue 9 Pages 2347-2351
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe heats of dissolution (ΔHd) of B polymorph of 1-tetradecanoic acid (C14), 1-pentadecanoic acid (C15), 1-hexadecanoic acid (C16), 1-heptadecanoic acid (C17) and 1-octadecanoic acid (C18) were measured at 310.15 K in ethanol using a calorimetric technique. In ethanol, no concentration dependence of ΔHd was found within the concentration range of at least 1×10-3-2×10-2 moldm-3. At a concentration of 1×10-2 moldm-3, the values of ΔHd were 60.6, 66.0, 69.4, 75.6 and 79.1 kJ mol <-1> for C14, C15, C16, C17 and C18, respectively. ΔHd increased linearly by increasing the number of carbon atoms (n) in the fatty acid (FA), so that the (CH2)-increment was obtained as 4.40±0.10 kJ mol-1.ΔHd was compared with the heats of fusion (ΔHf). ΔHd was higher than ΔHf, and the difference between ΔHd and ΔHf for odd-numbered FA was larger than that for even-numbered FA. This is related to the phenomena that the plots of ΔHf vs. n indicate a zig-zag pattern and those of ΔHd vs. n indicate a single line pattern.View full abstractDownload PDF (813K) -
Alain GUEIFFIER, Jean Claude MILHAVET, Yves BLACHE, Olivier CHAVIGNON, ...1990 Volume 38 Issue 9 Pages 2352-2356
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe reaction of nitrosyl chloride with 6- and 8-acetamido-7-methylimidazo[1, 2-a]pyridine (7g-i) reveal clear differences of reactivity of these isomeric structures. After bifunctionalization of the imidazolic moiety, the 6-acetamido derivatives do not yield the 1H-imidazo[1, 2-a]pyrazolo[4, 5-d]pyridine (4) system, but undergo a Gomberg-Bachman reaction complicated by Dimroth rearrangement. In contrast, upon similar treatment, the 8-acetamido compounds (17, 19) yielded the N-nitrosoacetamides (18a, b), which were converted into 1H-imidazo[1, 2-a]pyrazolo[3, 4-c]pyridines (20a, b) in 22 and 34% yields, respectively, without rearrangement.View full abstractDownload PDF (909K) -
Kanoko TSUBOYAMA, Kazuyoshi TAKEDA, Katsumi TORII, Haruo OGURA1990 Volume 38 Issue 9 Pages 2357-2363
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAllylic sulfides were synthesized from allylic alcohols 1 using S, S'-bis(1-phenyl-1H-tetrazol-5-yl) dithiocarbonate (2) by means of a single-step reaction. The allylic sulfides were coupled with a Grignard reagent or carbanion in the presence of a catalytic amount of copper(I) bromide or palladium(0).View full abstractDownload PDF (905K) -
Yoshikazu MATSUMOTO, Yoshio OKADA, Kyong-Son MIN, Satomi ONOSAKA, Keii ...1990 Volume 38 Issue 9 Pages 2364-2368
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSPhytochelatin (PC)-related peptides were prepared by a conventional solution method and their heavy metal-binding properties were examined. Different from the Cu2+ and Cu+-binding properties of metallothionein (MT)-related peptides, the Cu2+ and Cu+-binding properties of PC-related peptides were fairly dependent on structure. It is of interest that γ-Glu-Cys-Gly (glutathione) exhibited quite different Cu2+ and Cu+-binding properties from those of other PC-related peptides and its binding abilities were comparable to those of MT-related peptides. The Cd 2+-binding properties of glutathione were similar to those of Cys, and the Cd2+-binding abilities of PC-related peptides increased in proportion to the increase of γ-Glu-Cys peptide unit.View full abstractDownload PDF (717K) -
Satoshi TSUBOI, Kazunori NAKABAYASHI, Yoshikazu MATSUMOTO, Naoki TENO, ...1990 Volume 38 Issue 9 Pages 2369-2376
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSVarious peptide fragments related to eglin c, which consists of 70 amino acid residues, were synthesized by a conventional solution method and their inhibitory effects on leukocyte elastase, cathepsin G and α-chymotrypsin were examined. Among them, H-Arg-Glu-Tyr-Phe-OMe (eglin c 22-25) and H-Ser-Pro-Val-Thr-Leu-Asp-Leu-Arg-Tyr-OMe (eglin c 41-49) inhibited cathepsin G and α-chymotrypsin but not leukocyte elastase, while H-Thr-Asn-Val-Val-OMe (eglin c 60-63) inhibited leukocyte elastase but not cathepsin G or α-chymotrypsin, although eglin c potently inhibited leukocyte elastase, cathepsin G and α-chymotrypsin. These results indicated that the interaction sites of eglin c with leukocyte elastase, cathepsin G and α-chymotrypsin might be different.View full abstractDownload PDF (1501K) -
Hiroyuki AKITA, Harutami YAMADA, Hiroko MATSUKURA, Tadashi NAKATA, Tak ...1990 Volume 38 Issue 9 Pages 2377-2380
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSDehydration of the four diastereomers of tetrahydropyran 8-11 involving the 4-hydroxyl and 5-methyl groups with diethylazodicarboxylate-PPh3-toluene was undertaken to clarify the relation between the configurations of these substituents and the direction of dehydration. Compound 8 with 4β(equatorial)-hydroxyl and 5β(axial)-methyl groups was found to give the trisubstituted olefin 12 exclusively, and the isomers 13 and 14 were shown to be produced from 9 and 11, respectively, with high selectivity. The mechanisms involved are discussed.View full abstractDownload PDF (636K) -
Fumiko NISHIDA, Yuji MORI, Naoko ROKKAKU, Sayuri ISOBE, Takeyuki FURUS ...1990 Volume 38 Issue 9 Pages 2381-2389
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe structures of three aglycones of glykenins, produced by Basidiomycetes sp., were determined to be (2S, 16R, 17S, 21R)-2, 16, 17, 21-, (2S, 17R, 18S, 22R)-2, 17, 18, 22-, and (2S, 17S, 18S, 22R)-2, 17, 18, 22-tetrahydroxyhexacosanoic acids (3a-c). The absolute configurations of two of the four hydroxy groups in 3a-c were established by chiral synthesis of the degradation products (6a-c and 7a-c). Chemical transformation of 3a-c to 6, 8-dioxabicyclo[3.2.1]octane derivatives (18-c) revealed the relative and absolute configurations of the acyclic 1, 2-diol moieties in 3a-c.View full abstractDownload PDF (1165K) -
Koh-ichiro SHIBAMORI, Hiroshi EGAWA, Teruyuki MIYAMOTO, Yoshiro NISHIM ...1990 Volume 38 Issue 9 Pages 2390-2396
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe displacement reactions of ethyl 1-cyclopropyl-5, 6, 7, 8-tetrafluoro-4(1H)-oxoquinoline-3-carboxylate (7) and its carboxylic acid 8 with amine nucleophiles were examined. The nucleophilic displacement occurred regioselectively at the C-5 or C-7 position depending on the substrate (7 or 8) and solvent selected; this finding permitted the introduction of an optional nucleophile preferentially into the required position at either C-5 or C-7, or into both positions with a desired combination of nucleophiles. Taking advantage of this regioselectivity, we prepared various 5-substituted 6, 7, 8-trifluoro- and 7-substituted 5, 6, 8-trifluoro-1-cyclopropyl-4(1H)-oxoquinoline-3-carboxylic acids. Furthermore, the use of the boron-chelated derivative of the carboxylic acid 8 was favorable for the regioselective synthesis of 7-substituted 5, 6, 8-trifluoroquinolones.View full abstractDownload PDF (990K) -
Taiko ODA, Yoshihiro SATO, Masahiko KODAMA, Hazime SAITO1990 Volume 38 Issue 9 Pages 2397-2399
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe mode of incorporation of 2H-labeled trans-diethylstilbestrol (DES) (1b) and its methyl ether derivatives (2a, 2b, and 3) into multibilayers of egg phosphatidylcholine was analyzed by means of deuterium nuclear magnetic resonance. A clear distinction was found between DES or its methyl ether derivatives incorporated into lipid bilayers and those precipitated in the aqueous phase, by taking into account the extent of the motionally averaged quadrupole interaction. Thus, it was found that the relative proportion of these compounds incorporated into multibilayers decreased in the following order : DES (1b)>DES monomethyl ether (2a and 2b)>DES dimethyl ether (3). In addition, we demonstrated that the mode of intercalation in the multibilayers differs greatly among these compounds.View full abstractDownload PDF (559K) -
Masaru KOBAYASHI, Fuyuko KANDA, Srinivasa Rao DAMARLA, Desaraju Venkat ...1990 Volume 38 Issue 9 Pages 2400-2403
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS3β, 7β-Dihydroxy-24-methylenecholesterol (1) and three new polyhydroxysterol glycosides (2a, 3a and 4) were isolated from the lipid extract of an Alcyonium sp. soft coral which was collected in the Andaman and Nicobar Islands. Isolation of steroidal glycosides from soft corals is rare, if not unprecedented. Spectroscopic and chemical degradation studies indicated the new glycosides to be 24-methylenecholest-5-ene-3β, 16β-diol-3-O-α-L-fucoside (2a) and its 7β- (3a) and 7α-hydroxy (4) derivatives.View full abstractDownload PDF (745K) -
Yoshio TAKEUCHI, Hironobu OGURA, Yohko ISHII, Toru KOIZUMI1990 Volume 38 Issue 9 Pages 2404-2408
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAs a part of our work on synthetic studies of chiral monofluoro compounds and molecular design of efficient reagents for optical purity determination, we focused on novel α, α-disubstituted α-fluoroacetic acids (8a-d) (R1=Me, Ph; R2=C≡CPh, Me, Bu). The ethyl esters (13a-d) were prepared by introduction of alkyl groups into the appropriate α-keto acids (9a, b) followed by fluorination of the corresponding hydroxy-esters (12a-d) with diethylaminosulfur trifluoride (DAST). For comparison with Mosher's reagent (2-methoxy-2-trifluoromethylphenylacetic acid, (MTPA)), the ethyl esters (13a-d) were converted into three representative diastereoisomers, (14a-d), (15a-d), and (16a-d), and 19F-nuclear magnetic resonance (19F-NMR) chemical shift differences between pairs of diastereoisomers (Δδ) were obtained. These α, α-disubstituted α-fluoroacetate derivatives have much larger Δδ values than the corresponding derivatives of MTPA, which strongly indicates that the acids (8a-d) can potentially be better reagents for ee determination than MTPA. The influence on the Δδ values of the steric effects which arise upon introduction of the two substituents (R1 and R2) on the fluorine-bearing chiral center is also discussed.View full abstractDownload PDF (808K) -
Motomasa KOBAYASHI, Jun-ichi TANAKA, Taketo KATORI, Miki MATSUURA, Meg ...1990 Volume 38 Issue 9 Pages 2409-2418
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA potent cytotoxic dimeric macrolide, swinholide A (1), was isolated from the Okinawan marine sponge Theonella swinhoei. The absolute stereostructure of 1, having a dimeric dilactone structure with a 44-membered ring, has been determined on the basis of its chemical behavior and an X-ray crystallographic analysis.View full abstractDownload PDF (1374K) -
Takeaki NAITO, Okiko MIYATA, Natsuko KIDA, Keiko NAMOTO, Ichiya NINOMI ...1990 Volume 38 Issue 9 Pages 2419-2423
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFuropyridones 4a-c were shown to be available as synthons for alkaloid synthesis by their facile conversion to the key intermediates 13a, b, and 16 for the synthesis of quinine, ajmalicine, and 7-demethyltecomanine.View full abstractDownload PDF (962K) -
Takashi TANAKA, Gen-ichiro NONAKA, Itsuo NISHIOKA1990 Volume 38 Issue 9 Pages 2424-2428
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSome novel reactions of dehydrohexahydroxydiphenic acid esters [e.g., geraniin (1)] with bases are presented. Namely, treatment of 1 with triethylamine or sodium benzenesulfinate in acetonitrile caused a benzylic acid-type rearrangement to yield a brevifolin carboxylic acid derivative (3). On the other hand, treatment of 1 with pyridine gave a tetrahydroxydibenzofuran derivative (8), whereas reaction with aqueous sodium hydroxide cleaved the carbon-carbon linkage to yield a dehydrochebulic acid ester (10).The application of these reactions to granatins A and B, the major tannins in pomegranate, unequivocally established their structures (13 and 11, respectively).View full abstractDownload PDF (778K) -
Hiroshi TAKAHASHI, Bor Chyu-an HSIEH, Kimio HIGASHIYAMA1990 Volume 38 Issue 9 Pages 2429-2434
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe configuration at the 2-position of 2-(p-bromophenyl)-N-methyl-4-phenyl-1, 3-oxazolidine (2a) was determined by X-ray analysis. The reactions of 2, 4-diphenyl- and 2-methyl-4-phenyl-1, 3-oxazolidines (2b-d and 2e-g) with methyl and phenylmagnesium bromides were investigated.View full abstractDownload PDF (824K) -
Hideo NAKAMURA, Kazushi ARATA, Takeshi WAKAMATSU, Yoshio BAN, Masakats ...1990 Volume 38 Issue 9 Pages 2435-2441
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSLevoglucosan (8) has been found to be a useful material for the synthesis of chiral compounds having five contiguous chiral centers (14). Conversion of 8 to 14 involves two trans-diaxial openings of epoxides by nucleophilic reagents. Among 14, 14c was successfully transformed into the intermediate 5 for the total synthesis of elaiophylin (1). Efficient lactonization of the carboxylic acid 33 has been achieved by use of Yamaguchi's method.View full abstractDownload PDF (1081K) -
Masaru KOBAYASHI, Takumi HIRASE1990 Volume 38 Issue 9 Pages 2442-2445
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe cembranoids of a Sarcophyton sp. soft coral, collected in Okinawa, were found to be composed predominantly of dihydrofuranocembranoid derivatives (2, 3, 5a, 6 and 7) together with a hydrocarbon cembrene C (1) and a lactonic cembranoid, sarcophytonin B (4). The major constituents sarcophytonin A (2), deoxosarcophine (5a), and sarcophytonin C (6) were shown to be mixtures having similar enantiomeric ratios. The structures of the new compounds (3, 4, 6 and 7) were derived on the basis of spectroscopic studies and chemical correlations. Compounds 3 and 7 were supposed to be artefacts derived from 5a or 6 (3), and from 5a (7) respectively.View full abstractDownload PDF (644K) -
Atsuyuki ASHIMORI, Taizo ONO, Takeshi UCHIDA, Yutaka OHTAKI, Chikara F ...1990 Volume 38 Issue 9 Pages 2446-2458
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of 4-(substituted pyridyl)-1, 4-dihydropyridine derivatives were synthesized and their hypotensive effects examined. Several compounds, 2-(N-benzyl-N-methylamino)ethyl methyl 1, 4-dihydro-2, 6-dimethyl-4-(3-nitro-2-pyridyl)-3, 5-pyridinedicarboxylate (2b), its 4-(4-nitro-2-pyridyl) analogue (2g), 4-(3-trifluoromethyl-2-pyridyl) analogue (2c), 4-(2-trifluoromethyl-3-pyridyl) analogue (3e), 4-(4-cyano-2-pyridyl) analogue (2e), 4-(2-cyano-3-pyridyl) analogue (3d), and 4-(6-bromo-2-pyridyl) analogue (2i), were found to have a hypotensive activity parallel to that of nicardipine; 2c and 3e, in particular, had approximately twice the duration of nicardipine, and 2e had the most potent hypotensive activity of all the derivatives synthesized.View full abstractDownload PDF (1642K) -
Hiroshi ISHIKAWA, Tetsuyuki UNO, Hisashi MIYAMOTO, Hiraki UEDA, Hisash ...1990 Volume 38 Issue 9 Pages 2459-2462
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of substituted 1, 2-dihydro-6-oxo-pyrrolo[3, 2, 1-ij]quinoline-5-carboxylic acids for the treatment of systemic infections was synthesized via 7-bromo-3-ethylthio-4, 5-difluoro-2-methylindole (3), which was prepared by Gassman's indole synthesis in excellent yield. The synthesized pyrroloquinolines were tested for their antibacterial activities. 8-Fluoro-1, 2-dihydro-2-methyl-9-(4-methyl-1-piperazinyl)-6-oxo-6H-pyrrolo[3, 2, 1-ij]quinoline-5-carboxylic acid showed a potent antibacterial activity against gram-positive and gram-negative bacteria.View full abstractDownload PDF (591K) -
Keiichi NOGUCHI, Katsurou MATSUO, Noriya OHTA1990 Volume 38 Issue 9 Pages 2463-2466
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFive kinds of oligopeptides H-Asp-Ser-Asp-OH (1), H-Asp-Gly-Lys-OH (2), H-Ser-Asp-Gly-Lys-OH (3), H-Asp-Ser-Asp-Gly-Lys-OH (4), and H-Ala-Asp-Ser-Asp-Gly-Lys-OH (5) related to immunoglobulin E (IgE) were synthesized by the conventional solution method with the objective of obtaining a new type of antiallergic agent. Their pharmacological activity was examined by measuring the inhibition of the production of IgE and relaxation of the smooth muscle contraction of rabbit aorta. H-Ala-Asp-Ser-Asp-Gly-Lys-OH (5) displayed potent inhibition against the production of IgE antibody (69.6%) and relaxation against the contraction of rabbit aorta.View full abstractDownload PDF (629K) -
Yuji NOMOTO, Hiroyuki OBASE, Haruki TAKAI, Tadashi HIRATA, Masayuki TE ...1990 Volume 38 Issue 9 Pages 2467-2471
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of 1-[1-(6, 7-dimethoxy-4-quinazolinyl)-4-piperidinyl]-3-substituted 2-imidazolidinone and 2-imidazolidinethione derivatives was synthesized and examined for cardiotonic activity in anesthetized dogs. Alkylation of the 2-imidazolidinone (1) afforded the N-alkylated products, while alkylation of the 2-imidazolidinethione (12) afforded the S-alkylated derivatives accompanied with a small quantity of the N-alkylated products. The N-alkylated derivatives showed generally potent activity, and the S-alkylated ones exhibited weak activity. Insertion of an alkyl group between the piperidine and the imidazolidinone moiety generally resulted in a fall in activity.View full abstractDownload PDF (612K) -
Hisashi MIYAMOTO, Hiraki UEDA, Tatsuya OTSUKA, Sinji AKI, Hisashi TAMA ...1990 Volume 38 Issue 9 Pages 2472-2475
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of substituted 4-oxoquinoline-3-carboxylic acids having a methyl group at the 8-position was prepared and tested for their antibacterial activity. 7-(trans-3-Amino-4-methyl-1-pyrrolidinyl)-1-cyclopropyl-1, 4-dihydro-6-fluoro-8-methyl-4-oxoquinoline-3-carboxylic acid (21) exhibited highly potent antibacterial activity against both gram-positive and gram-negative bacteria, including Pseudomonas aeruginosa.View full abstractDownload PDF (691K) -
Toshiyuki KONOSU, Yawara TAJIMA, Noriko TAKEDA, Takeo MIYAOKA, Mayumi ...1990 Volume 38 Issue 9 Pages 2476-2486
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTriazole compounds with an oxazolidine ring were designed and synthesized as a potential inhibitor of the fungal cytochrome P450 14α-demethylase. In testing for antifungal activity against a mouse systemic Candida albicans infection, (4R, 5R)-3-acyl-4-methyloxazolidine derivatives 4 exhibited remarkably high efficacy after oral or parenteral dosing. The potent activity of 4 is hypothesized to be a consequence of a structural similarity between 4 and lanosterol, a target molecule of the cytochrome P450 14α-demethylase. Highly stereoselective synthesis of these oxazolidines is also described.View full abstractDownload PDF (1487K) -
Kinji IIZUKA, Tetsuhide KAMIJO, Hiromu HARADA, Kenji AKAHANE, Tetsuhir ...1990 Volume 38 Issue 9 Pages 2487-2493
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe synthesis and the structure-activity relationships of renin inhibitors designed from the angiotensinogen transition state are described. These inhibitors contained residues modified at P1-P1, , P2, and P4-P3. Decrease in the size of side chain alkyl group in norstatine analog at P1 diminished the inhibitory activities of the compounds. Compound 5j, which contained valine residue instead of histidine residue at P2, inhibited potently cathepsin D (IC50=6.0×10-9 M) and pepsin (IC50=3.5×10-7 M) to the same extent as renin (IC50=8.5×10-10 M), and thus was not specific for renin. The reduction of the β-carbonyl group to methylene group in β-carbonylpropionyl residue at P4-P3 decreased the potency about 2 orders against human renin (5i : IC50=1.1×10-7 M vs. 1 : IC50=2.4 ×10-9 M). These results confirmed the rationality of our analysis of the interaction between an orally potent human renin inhibitor 1 and the active site of human renin using modeling techniques, showing that 1 fits the active site of renin favorably. The experimental details of the synthesis are presented.View full abstractDownload PDF (1162K) -
Toshiyuki KAJI, Kayoko KAGA, Miezi NSIMBA, Tomohiro HAYASHI, Naoko EJI ...1990 Volume 38 Issue 9 Pages 2494-2497
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTo investigate the possible mechanism of the stimulatory effect of a hot water extract from Artemisia leaf (Artemisia princeps PANPANINI) (AFE) on the proliferation of endothelial cells, cells from bovine aorta were cultured for 72 h in RPMI1640 medium supplemented with 10% fetal calf serum in the presence of 5 μg/ml AFE. The AFE treatment significantly increased the cell number after culture, while in the presence of 10 μg/ml unfractionated heparin, AFE conversely decreased it. This implied that AFE enhanced the cell growth promotion by basic fibroblast growth factor (bFGF). The accumulation of bFGF was significantly increased in the culture medium, in the low-affinity (glycosaminoglycans-binding) fraction, and in the cell extract fraction, but was unchanged in the high-affinity (receptor-binding) fraction. The contents of [35S]sulfate-labeled glycosaminoglycans in both cell layer and the medium were not increased by AFE treatment. The proliferation of A10 cells, an established cell line of smooth muscle cells from murine aorta, was not stimulated by AFE. A10 cells did not produce a significant amount of bFGF in the presence or absence of AFE. Thus, the production of bFGF was considered to be involved in AFE stimulation of cell proliferation. In conclusion, it was suggested that AFE stimulated endothelial cell proliferation by increasing the production of bFGF rather than by an increase in the number of bFGF receptors and the content of glycosaminoglycans in the cell layer. The enhanced reserve of bFGF in the low-affinity fraction of cell layer and in the medium would cause the AFE-stimulated proliferation of endothelial cells.View full abstractDownload PDF (673K) -
Zhe-ming GU, De-xi ZHANG, Xiu-wei YANG, Masao HATTORI, Tsuneo NAMBA1990 Volume 38 Issue 9 Pages 2498-2502
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom the ether extract of the underground part of Notopterygium forbesii, two new coumarin glycosides, bergaptol-O-β-D-glucopyranoside and 6'-O-trans-feruloylnodakenin, were isolated along with known compounds including seven furanocoumarins, two dihydrofuranocoumarins, a sterol glucoside and two phenolic compounds. Analysis of their contents by high-performance liquid chromatography (HPLC) revealed that the underground part of N. forbesii contained large amounts of p-hydroxyphenethyl anisate (0.7%), bergaptol glucoside (0.2%), nodakenin (2%) and 6'-O-trans-feruloylnodakenin (0.7%) and a lesser amount of notopterol (0.08%), while that of N. incisum contained a large amount of notopterol (1.2%) and less amounts of the others. The characteristic difference in chemical composition between the two species enabled us to identify the respective botanical sources of a Chinese crude drug, Qiang-huo derived from N. incisum and N. forbesii by HPLC.View full abstractDownload PDF (780K) -
Sadanobu TACHIBANA, Saori NISHIURA, Sadahiro ISHIDA, Kazuaki KAKEHI, S ...1990 Volume 38 Issue 9 Pages 2503-2506
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe quality of commercial heparin injections was examined by 400-MHz proton nuclear magnetic resonance (1H-NMR) spectroscopy using several measuring modes. The signals of the N-acetyl protons, as well as the sugar-ring protons, attached to the sulfamino and sulfato group-bearing carbons could be easily distinguished from other proton signals and quantified. Measuring at a high temperature (60°C) enabled clear isolation of the H-5 proton signal in the sulphated iduronic acid residue (Is-5) from other proton signals including that of water. The heparin contents of various heparin injections were estimated by using this signal as an index. However, the signal intensity was not parallel with anticoagulant activity. On the other hand, the N-acetyl proton signal was highly correlated to anticoagulant activity. The present method was also useful for concurrent identification of additives in heparin injections.View full abstractDownload PDF (553K) -
Michiaki YONEDA, Yasushi OHKAWA1990 Volume 38 Issue 9 Pages 2507-2512
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNileprost is a new prostacyclin analogue stabilized by introduction of the cyano group at its 5-position. The acidic and alkaline degradation and the structure determination of the degradation products were investigated. The degradation of nileprost is very slow in comparison with that of prostacyclin. Although prostacyclin is easily decomposed to 6-keto-prostaglandin F1α (6-keto-PGF1α) through the hydrolysis of a vinyl ether moiety, nileprost gives little of such hydrolysis product but many isomers and dehydrates. The structures of the products were determined by high-per-formance liquid chromatography (HPLC), negative ion fast atom bombardment mass spectra (N-FABMS) and nuclear magnetic resonance (NMR) studies. It was found that the vinyl ether moiety of nileprost is converted from 5Z form to 5E form in both media, and that the ω-side chain also undergoes transfer of hydroxyl group or dehydration in acid medium. These results indicate that introduction of the cyano group into the 5-position of prostacyclin is extremely effective for the stabilization of the vinyl ether moiety. Furthermore, on the basis of the structural elucidation, the reaction mechanism of nileprost in both media was clarified.View full abstractDownload PDF (840K) -
Masahiro YAGI, Akimasa SHIBUKAWA, Terumichi NAKAGAWA1990 Volume 38 Issue 9 Pages 2513-2517
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA high-performance liquid chromatography system was developed for the stereoselective determination of ketoprofen enantiomers in human plasma following direct sample injection. The system comprised of a pretreatment column and a chiral separation column connected in a series via a switching valve. When a 200 μl portion of human plasma containing a therapeutic level of ketoprofen was directly applied to the system, ketoprofen was adsorbed in the pretreatment column, while plasma proteins were excluded. After the elution of proteins from the pretreatment column, the valve was switched and ketoprofen was desorbed and transferred to the chiral separation column where the enantiomers were separated and determined by ultraviolet-absorption. The mobile phase conditions for the pretreatment and chiral separation were optimized, which enabled rapid and complete recovery followed by satisfactory separation of the enantiomers. The calibration line for each enantiomer showed good linearity in the range of 0.25-5 μg/ml with a detection limit of 0.02 μg/ml (signal to noise ratio (S/N)>3), which was sufficient for practical demands. The precision test indicated that the coefficient of variation for five repeated determinations of (-) ketoprofen was 5.4% at 0.1 μg/ml and 1.4% at 1 μg/ml.View full abstractDownload PDF (778K) -
Osamu FUJISHITA, Kazuhiro NAKASHIMA, Masaaki HIRAKAWA, Kenji OTSUBO, S ...1990 Volume 38 Issue 9 Pages 2518-2522
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe correlative equations between the molecular volume and the qualitative indication (hR) for β-lactam antibiotics, the reaction products between β-lactam antibiotics and kanamycin, and the degradation products of β-lactam antibiotics were hR=0.32+0.080 V2/3A/|Z|(N=15, r=0.972 for penicillins) and hR=0.04+0.072 V2/3A/|Z|(N=12, r=0.987 for cephems). Where VA is van der Waals volume (Å3/molecule), hR is The relative step height in The isotachopherogram, and Z is the electric change, respectively.According to these equations, the molecular volumes of the reaction products between β-lactam antibiotics and the other aminoglycoside antibiotics, and those of the degradation products of β-lactam antibiotics can be estimated from the value of hR. Also according to the step height in the isotachopherogram, the reaction products or the degradation products may be estimated directly when the electric charge is known.It was confirmed that a molecule of aminoglycoside antibiotics reacted with a molecule of β-lactam antibiotics. Therefore, the inactivation of aminoglycoside antibiotics is much greater than for β-lactam antibiotics when the clinical doses of these antibiotic combinations are used.View full abstractDownload PDF (785K) -
Masakazu TSUCHIYA, Haruki OISHI, Aya TAKAOKA, Masaji HUSAMOTO, Shuji M ...1990 Volume 38 Issue 9 Pages 2523-2526
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA procedure for the Limulus amebocyte lysate (LAL) test discriminating between endotoxin and (1→3)-β-D-glucan based on the turbidimetric kinetic method was proposed. Endotoxin and (1→3)-β-D-glucan, which are elicitors of the activation of LAL, showed different reaction courses with this lysate. To analyze the difference in the reaction, two parameters, the maximum differential coefficient of the reaction (Dmax) and the reaction time required to botain Dmax (Tp) were defined. The logarithmic plottings of Tp versus Dmax (Tp-Dmax plot) discriminated between endotoxin and (1→3)-β-D-glucan. Endotoxin was measured with a standard curve plotting logarithmic endotoxin concentration versus Dmax (ET-Dmax plot). The endotoxin calculated from Dmax was less influenced by (1→3)-β-D-glucan than that calculated from the usual gelation time. A small amount of endotoxin in a sample could be concealed by the addition of polymyxin B, which inhibited the activation of LAL by endotoxin. (1→3)-β-D-glucan was measured without being affected by the presence of a small amount of endotoxin using LAL with polymyxin B. The following procedure is proposed as a LAL test to discriminate between endotoxin and (1→3)-β-D-glucan.(1) Identify the main substance (endotoxin or (1→3)-β-D-glucan) triggering the activation of LAL using the Tp-Dmax plot. (2) Use the appropriate method to measure the main substance : the ET-Dmax plot for endotoxin or the LAL with polymyxin B for (1→3)-β-D-glucan.View full abstractDownload PDF (659K) -
Kazuya KURACHI, Naohito OHNO, Toshiro YADOMAE1990 Volume 38 Issue 9 Pages 2527-2531
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSSG is an antitumor branched (1→3)-β-D-glucan obtained from the culture filtrate of Sclerotinia sclerotiorum IFO 9395. Hydroxyethylation of SSG higher than MS 0.45 (MS value represents molar ratio of hydroxyethyl group vs. glucosyl group) by ethyleneoxide in aqueous sodium hydroxide lose the antitumor activity. Degradation of branching point of hydroxyethylated SSG (HE-SSG) by the sequential treatments of periodate oxidation, borohydride reduction, and mild acid hydrolysis of these derivatives regenerated the antitumor activity. These results directly demonstrated that the branching point covered, at least a part of, the dormant active site of SSG.View full abstractDownload PDF (751K) -
Fumie HASHIMOTO, Chishio SUGIMOTO, Hidenori HAYASHI1990 Volume 38 Issue 9 Pages 2532-2536
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS3-Amino-1, 2, 4-triazole (aminotriazole) is an irreversible inhibitor of catalase which is a marker enzyme of peroxisomes. We studied the effect of aminotriazole treatment on biosyntheses of cholesterol and bile acid in vivo. When catalase activity of peroxisomes of rat liver was inhibited by aminotriazole treatment, bile acid content in the bile was significantly decreased to about 70% of the control, but that in the liver was not changed. Cholesterol content in the bile was significantly decreased to about 80% of the control, while in the liver and serum the content was not significantly changed. When [2-14C]mevalonate was administered to rats, radioactivities of cholesterol in the liver, serum and bile were all drastically decreased by aminotriazole treatment, and an unidentified radioactive product was detected. Radioactivity of bile acid in the bile was also greatly decreased. In a similar experiment with [4-14C]cholesterol, aminotriazole treatment had no effect on the radioactivity of either cholesterol or bile acid in the liver, serum and bile. In this case, the unidentified product could not be detected.These results indicate that when catalase activity of liver peroxisomes is suppressed by aminotriazole treatment, biosynthesis of bile acid from exogenous cholesterol is not inhibited, but a step in the pathway of biosynthesis of endogenous cholesterol from mevalonate is inhibited.View full abstractDownload PDF (934K) -
Masumi UEDA, Yasuhiko NAKAMURA, Hirokazu MAKITA, Yu IMASATO, Yoshiaki ...1990 Volume 38 Issue 9 Pages 2537-2541
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAgglomerated crystals of enoxacin were prepared by a novel spherical crystallization technique using ammonia diffusion system (ADS). This technique made it possible to agglomerate amphoteric drugs like enoxacin which could not be agglomerated by the conventional means. When an ammonia water solution of enoxacin was poured into the mixture of acetone and a water-immiscible solvent such as dichloromethane under agitation, a small amount of ammonia water was liberated in the system. The ammonia water played a role both as a good solvent for enoxacin and a bridging liquid, which collected fine crystals precipitated into spherical agglomerates in one step. Moreover, agglomerates of the stable crystalline form were obtained by selecting the proper solvents. It was proved that the agglomeration mechanism follows these steps : acetone in the crystallization solvents enters into droplets of ammonia water and consequently enoxacin dissolved in the ammonia water is precipitated, while the droplets collect the crystals; simultaneously, a part of the ammonia in the agglomerates diffuses to the outer organic solvent phase.View full abstractDownload PDF (923K) -
Kazuhiko BABA, Yoh'ichiro TAKEICHI, Yoshinobu NAKAI1990 Volume 38 Issue 9 Pages 2542-2546
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSGround mixtures containing uracill were prepared using various additives such as celluloses, proteins, cyclodextrins, enteric coating agents and inorganic compounds in a planetary ball mill. The amorphous state of uracil was observed in the X-ray diffraction patterns of some of the ground mixtures. The results of infrared spectral analysis indicated deprotonation of uracil after 30 h of (30-h) grinding with sodium polyglutamate. All ground mixtures showed the transient supersaturation of uracil in dissolution studies. The initial amount of uracil dissolved from the 30-h ground mixtures with sodium benzoate derivatives, ethylcellulose, hydroxypropylmethylcellulose acetate succinate and proteins was 2.5 to 9-times that dissolved from intact uracil. The crystallinity and solubility of uracil in the ground mixtures were affected by the mixing ratio, grinding time and moisture content of the additive.View full abstractDownload PDF (782K) -
Yoh'ichiro TAKEICHI, Kazuhiko BABA, Yoshihito KINOUCHI, Yuichi IIDA, Y ...1990 Volume 38 Issue 9 Pages 2547-2551
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAn improvement of the rectal absorption of uracil was examined by the application of absorption enhancers in addition to the increased solubility of uracil.Uracil was ground with additives such as MgO, sodium 2, 6-dihydroxybenzoate, human serum albumin or hydroxypropylmethylcellulose acetate succinate. Aqueous, oily and powdery formulations, which consisted of the ground mixtures, nicotinamide, urea and absorption enhancers such as polyoxyethylene (23) cetylether (BC-23) or sodium caprate, were prepared.Uracil solubility in the aqueous formulations was increased about 4-13 times that in the corresponding control formulations. When rectally administered to beagle dogs, marked increases in the plasma uracil level were observed in some of the cases of aqueous and oily formulations, In the powdery formulations and formulations containing macromolecular additives, however, absorption improvement was not observed.The results indicated that an improvement in the absorption of uracil was caused by the combinative improving effect of the increased uracil solubility and the promoting effect of absorption enhancers.View full abstractDownload PDF (751K) -
Ichimaro YAMADA, Hiroaki MIZUTA, Kenji OGAWA, Tetsuya TAHARA1990 Volume 38 Issue 9 Pages 2552-2555
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe pharmacokinetics of a new lipophilic substituted benzamide N-[(1-butyl-2-pyrrolidinyl)methyl]-2-methyl-5-sulfamoyl-2, 3-dihydrobenzofuran-7-carboxamide hydrochloride (1) and sulpiride in both plasma and brain were investigated in rats.The octanol-water partition coefficients of the base of 1(2) and sulpiride were 6.3 and 0.2, respectively. The eliminations of 2 from plasma and brain were similar to those of sulpiride. The systemic bioavailabilities of 1 and sulpiride after oral administration of 200 mg/kg were 60.9±10.9 and 18.2±6.4%, respectively. The brain concentrations of 2 were about 2-3 times higher than those of sulpiride until 4 h after oral administration of 100 mg/kg. The brain/plasma ratios of 2 were about 2 times higher than those of sulpiride. These results indicate that the penetration of 2 through the gastrointestinal membrane and/or the blood-brain barrier are higher than those of sulpiride.View full abstractDownload PDF (627K) -
Hideo TAKAHATA, Yoshiyuki KOIDA, Masao KOBAYASHI, Masayoshi SAMEJIMA1990 Volume 38 Issue 9 Pages 2556-2560
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSucceeding our previous study on enteric microencapsulation by surface neutralization method for acidic drugs, a new means of application was developed for the encapsulation of non-acidic drugs. Indomethacin was chosen as a model drug in this study because of its low solubility in water and non-acidicity. Carboxymethylethylcellulose (CMEC) was used as enteric polymer as previously.Indomethacin was not encapsulated as it was, but the encapsulation could be done using its core granules added with an organic acid. Thus, the influences of preparation temperature, species of organic acid and its concentration in the cores as well as the species of binder on the properties of resultant microcapsules (MCs) were examined.CMEC content in MCs increased as the temperature increased. The CMEC content prepared using maleic acid was higher than that prepared using fumaric acid. These phenomena were correlated with the dissolution rate of organic acid from the cores during the manufacturing process and the phase separation of CMEC determined at various temperatures and pH.MCs having thick films prepared at high temperatures did not always have high resistance to the dissolution of indomethacin in the 1st fluid. The most effective membrane was obtained when MCs were prepared at around 20°C.Binders used in the cores affected the CMEC content in MCs and the dissolution rate of indomethacin. Hydrophobic ethylcellulose (EC) depressed the dissolution more strongly than did hydrophilic polyvinylalcohol (PVA).View full abstractDownload PDF (871K) -
Mitsuo NAKAO, Yukiko GOTO, Yasuhiko MATSUKI, Akira HIRATSUKA, Tadashi ...1990 Volume 38 Issue 9 Pages 2561-2566
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSRegioselectivity in N-acetylation of nitro-p-phenylenediamine, a widely used hair dye component, by rat liver cytosolic N-acetyltransferases was studied in relation to its substituent effects on enzymatic N-acetylation of mono-substituted anilines. Nitro-p-phenylenediamine was acetylated specifically at the N4-position to afford the N4-monoacetate, a major urinary metabolite in the rat, when incubated with rat liver cytosol fortified with acetyl-coenzyme A. N1-Acetylation of nitro-p-phenylenediamine did not take place even when the N4-monoacetate was used as a substrate, suggesting a strong steric hindrance effect of the ortho nitro group on the enzymatic N1-acetylation. The steric hindrance effect of the nitro group on the cytosolic N-acetylation of the ortho amino group was revealed by a comparative study carried out by using aniline, three respective regioisomers of nitroanilines and phenylenediamines as model substrates. The comparative study also indicated the enzymatic N-acetylation of the mono-substituted anilines to be strongly influenced by the electronic effect of the substituents.Regioselective N-acetylation in the hepatic cytosol was also investigated with N1- and N4-monoacetates of 1, 2, 4-triaminobenzene. The monoacetates yielded the N1, N4-diacetate, another major urinary metabolite of the hair dye component, in the rat, without concomitant formation of the N2, N4-diacetate or the N1, N2, N4-triacetate. The triacetate was formed only from the N1, N2-diacetate in the enzymatic reactions. A comparative study, carried out by using N-mono-acetates of three regioisomeric phenylenediamines, indicated that the N-acetyl group had a potent steric hindrance effect on the primary amino group at the ortho position.Thus, the present in vitro study strongly suggested that the two major urinary metabolites, nitro-p-phenylenediamine N4-acetate and 1, 2, 4-triaminobenzene N1, N4-diacetate, of the hair dye component could be formed, at least in the rat liver, by the enzymatic N-acetylation of the corresponding amines.View full abstractDownload PDF (879K) -
Mercedes GARRIDO, Maria L. Lopez RODRIGUEZ, M. Jose MORCILLO1990 Volume 38 Issue 9 Pages 2567-2569
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS4-(Benzoylaminomethyl)pyridine 1-oxides (1) react with indan-1, 3-dione in the presence of acetic anhydride to give 2-(benzoylamino-4-pyridylmethylene)indan-1, 3-diones (4) and 4-benzoylaminomethyl-2-(3-hydroxy-1-oxo-2-indenyl)-pyridines (5) as enol forms. The reaction mechanism is discussed.View full abstractDownload PDF (454K) -
Atsushi NUMATA, Kenzo KAWAI, Chika TAKAHASHI1990 Volume 38 Issue 9 Pages 2570-2573
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new juvabione analogs (4 and 5) were isolated, together with (+)-epijuvabione and (+)-dehydroepijuvabione, from the wood of Abies sachalinensis (FR. SCHM.) MAST. (Pinaceae) grown in the southern base of the Taisetsu mountain range of Hokkaido, Japan. The structures of 4 and 5 were respectively established to be methyl 4(S)-[1(S), 5-dimethyl-3-oxohexyl]-3-oxo-1-cyclohexene-1-carboxylate and methyl 4(R)-[1(S), 5-dimethyl-3-oxohexyl]-3-oxo-1-cyclohexene-1-carboxylate on the basis of chemical and spectral evidence. Juvabione-type compounds had been isolated from the wood of this species, whereas this time the epijuvabione-type compounds alone were obtained. This evidence suggests the existence of a tree-to-tree variation in constituents of the A. sachalinensis wood.View full abstractDownload PDF (582K) -
Yuji MORI, Hitomi KAGEYAMA, Makoto SUZUKI1990 Volume 38 Issue 9 Pages 2574-2576
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe coupling reaction of the chiral building block (2) with the chiral epoxide (3) and highly syn-1, 3-stereoselective reduction of the resulting β-hydroxy ketone (5) allowed us to achieve the stereoselective synthesis of tarchonanthuslactone (1).View full abstractDownload PDF (585K) -
Mitsuaki MAEDA1990 Volume 38 Issue 9 Pages 2577-2580
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSQuaternary quinolinium salts, 1-methyl-, 1, 3-dimethyl-, and 1, 4-dimethylquinolinium iodide, react with trichloromethyl carbanion, which is generated from chloroform and sodium hydroxide in methanol, to give the 1, 2-dihydro adducts, 1-methyl-2-trichloromethyl-1, 2-dihydroquinolines. 1, 2-Dimethylquinolinium salt gives a different type of addition product and further reaction also occurs with dichlorocarbene to give a dichlorocyclopropane-fused compound under similar reaction conditions. Reduction of the 1, 2-dihydro adduct gives 1-methyl-2-trichloromethyl-1, 2, 3, 4-tetrahydroquinoline or 1-methyl-2-dichloromethyldecahydroquinoline depending on the catalyst used. These adducts are useful intermediates for synthesis of chlorine-containing heterocycles.View full abstractDownload PDF (689K) -
Hiroshi KASHIHARA, Hiroshi SUEMUNE, Naomi TSUNEHIRO, Kiyoshi SAKAI1990 Volume 38 Issue 9 Pages 2581-2582
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe enones (II), which were obtained from dimethyl 4, 5-isopropylidenedioxy-2-oxopentylphosphonate (Ia) and various aldehydes, were easily converted to 2-alkenylfurans (III) by treatment with p-TsOH in MeOH. In a similar manner, the furfuryl phosphonate (IVa) and the 3-methylfurfuryl phosphonate (IVb) were obtained from Ia and its 3-methylated analogue (Ib), respectively.View full abstractDownload PDF (459K) -
Tokujiro KITAGAWA, Megumi KAWAGUCHI, Keiko IWASAKI1990 Volume 38 Issue 9 Pages 2583-2585
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSUnder essentially neutral conditions, alkyl, aryl, and heteroaryl aldoximes (4) readily react with 2, 2'-oxalyldi(o-sulfobenzimide) (ODS; 6) in refluxing acetonitrile to give the corresponding nitriles (5) in good yields.View full abstractDownload PDF (435K) -
Chihiro ITO, Shiho TANAHASHI, Youko TANI, Motoharu JU-ICHI, Mitsuo OMU ...1990 Volume 38 Issue 9 Pages 2586-2588
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new coumarin and a new acridone-coumarin dimer named trans-grandmarin (1) and acrimarine-H (5), respectively, were isolated from roots of some Citrus plants (Rutaceae) and their structures are proposed on the basis of spectrometric analyses. Citaldoxime (7) was also isolated from roots of some Citrus plants and its structure was found to be identical with that of a γ-radiation-induced antifungal stress metabolite isolated from Citrus fruit.View full abstractDownload PDF (517K) -
Katsuyuki KURUMAYA, Masahiro KAJIWARA1990 Volume 38 Issue 9 Pages 2589-2590
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTo clarify the origin of amide-nitrogen of vitamin B12, [1-13C]aminolevulinic acid (ALA) and L-[amide-15N]glutamine were administered to P. shermanii. The 13C-nuclear magnetic resonance spectrum of the vitamin B12 subsequently isolated showed distinct 13C-15N coupling and isotope shift at six amide carbons. However, the C-57 amide carbon showed neither coupling, nor shift. Thus, it was concluded that the nitrogens of 6 amides of the side chain were derived from glutamine and the C-57 amide nitrogen was from threonine.View full abstractDownload PDF (384K) -
Tozo FUJII, Tohru SAITO, Shigeji MORI1990 Volume 38 Issue 9 Pages 2591-2594
Published: September 25, 1990
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe reaction rates in the Dimroth rearrangements of the marine sponge base 1, 9-dimethyl-8-oxoadenin (1) and related compounds such as 1, 9-dimethyladenine (6a) and 8-bromo-1, 9-dimethyladenine (6b) were measured in H2O at various pH's and ionic strength 1.0 at 40°C. In all cases, attack of hydroxide ion on the protonated species of the substrate at the 2-position was faster than that on the neutral species by a factor of 100-1400. In the reaction of the protonated species, the relative ease of undergoing Dimroth rearrangement was in the order of 6b>6a>1. The same order of reactivity was found to hold for the neutral species.View full abstractDownload PDF (574K)