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Volume 44, Issue 11
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Katsuya FUKUMARU, Takashi SAWADA, Norihisa NISHINO, Hiromu SAKURAI1996 Volume 44 Issue 11 Pages 1989-1997
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSESR spectrometry is useful for studyin the coordination environment around lone pair electrons of paramagnetic metal ions, such as the copper(II) (Cu(II)) ion. To this purpose, X-band ESR spectrometry has generally been used. In the present study, along with the x-band ESR, we applied L-band ESR spectrometry first, which allows for the ESR measurements of Cu(II) complexes under lower dielectric loss by water molecules than that of X-band ESR. x- and L-band ESR parameters analyzed for Cu(II) complexes with CuN4 coordination mode were found to relate to the coordination structures of the Cu(II) complexes and to other physical parameters, such as stability constants and halfwave potentials of the complexes. Several important features were observed in both the X- and L-band ESR spectra of the Cu(II) complexes as follows : Coordination to the axial positions or tetrahedral distortion of the square-planar Cu(II) complexes decreased in the hyperfine coupling constant, A-value. The g-value decreased when the stability constants increase or when the halfwave potentials shift to become more negative. Both x- and L-band ESR spectrometries are proposed to be very useful for analyzing the coordination structures of Cu(II) complexes in aqueous solutions.View full abstractDownload PDF (1074K) -
Mariko TARUI, Noriko NOMOTO, Yoko HASEGAWA, Katsuhiko MINOURA, Mitsuno ...1996 Volume 44 Issue 11 Pages 1998-2002
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour kinds of X-Trp (X=adenine, guanine, cytosine, thymine) were synthesized as model compounds to investigate the effect of complementary hydrogen bond base pairing on the stacking interaction of Trp with nucleic acid base. Association constants (Ka) of these compounds with two guanine derivatives (9-ethylguanine and 9-ethyl-7-methylguanine) were determined by Eadie-Hofstee plots of 1H-NMR titration experiments, and the thermodynamic parameters (ΔH, ΔS and ΔG) for the respective complexes were obtained by van't Hoff analyses based on the temperature dependence of the Ka values. The complexes were characterized by enthalpy/entropy compensations, where the interaction of cytosine-Trp with guanine derivatives was largely enthalpy-driven, accompanied by a small entropy component, whereas those of remaining complexes were all associated with a large increase in entropy, accompanied by a small positive enthalpy component. The present insight on the binding of X-Trp with a guanine base provides a thermodynamic basis for the importance of cooperative hydrogen bond pairing and aromatic stacking interactions in the specific recognition of a nucleic acid base pair by protein.View full abstractDownload PDF (740K) -
Katsuhiko ISEKI, Satoshi OISHI, Yoshiro KOBAYASHI1996 Volume 44 Issue 11 Pages 2003-2008
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn the Oppolzer aldol reaction, aldehyde reacts exclusively on the Si face (C(α)-Si attack) of the double bond of the boryl enolate 2 derived from (1S, 2R)-N-propionylbornane-10, 2-sultam (1), providing only 3a stereoselectively. Hexafluoroacetone (4) caused complete reversal of the diastereo-face selectivity, reacting exclusively on the Re face (C(α)-Re attack) of 2 to give only 5. Trifluoroacetaldehyde (8) and 2, 2-difluoro-5-phenylpentanal (9) caused partial reversal of the diastereo-face selectivity, giving significant amounts of unexpected and unusual syn- (12c, 13c) and anti- (12d, 13d) aldols along with the normal syn-aldol (12a, 13a). This finding was applied to the reactions of the boryl enolate with phenylglyoxal (10) and ethyl glyoxylate (11).View full abstractDownload PDF (972K) -
Isao KITAGAWA, Taifo MAHMUD, Ko-ichi YOKOTA, Shinsaku NAKAGAWA, Tadano ...1996 Volume 44 Issue 11 Pages 2009-2014
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new quassinoids named samaderines X (1), Y (2), and Z (3), and indaquassin X (5), and a new C19 quassinoid glycoside, 2-O-glucosylsamaderine C (10), together with five known quassinoids, samaderines B (7), C (8), and E (4), indaquassin C (6), and simarinolide (9), were isolated from the stems of Quassia indica (Simaroubaceae), an Indonesian medicinal plant. The chemical structures of these quassinoids have been elucidated on the bases of their chemical and physicochemical properties. Samaderines X (1), Z (3), E (4), and B (7) were shown to exhibit significant growth-inhibitory activity against the cultured malarial parasite Plasmodium falciparum (a chloroquine- resistant K1 strain), and 1-8 were shown to exhibit in vitro cytotoxicity (IC50 : 0.04-1.00 μg/ml) against KB cells. Samaderines X (1), B (7), and C (8), as well as indaquassin X (5), exhibited inhibitory activity in the in vitro endothelial cell-neutrophil leukocyte adhesion assay, whereas samaderines X (1) and B (7) were found to exhibit significant anti-inflammatory activity.View full abstractDownload PDF (871K) -
Ming-hua QUI, Rui-lin NIE, Norio NAKAMURA, Tohru KIKUCHi1996 Volume 44 Issue 11 Pages 2015-2019
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new steroidal alkaloids, paxillarines A (1) and B (2), were isolated from Pachysandra axillaris. Their structures were determined by means of spectrometric methods as 3α-N-methylbenzoylamino-4β-acetoxy-16β-hydroxy-20α-dimethylamino-5α-pregnane and 3α-N-methylbenzoylamino-4β-acetoxy-12β-hydroxy-20α-dimethyl-amino-5α-pregnane, respectively. Some of the expected characteristic 1H-NMR signals were not observed due to hindered rotation when the spectra were measured on a 400 MHz spectrometer, although all of the signals appeared clearly on a 90 MHz machine. The conformation of the ring A moiety of these alkaloids is discussed.View full abstractDownload PDF (638K) -
Shigeko OZAKI, Shizue MITOH, Hidenobu OHMORI1996 Volume 44 Issue 11 Pages 2020-2024
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSCycloalkano[α]pyrroles were obtained by reductive radical cycloaddition of 1-(2-iodoethyl)pyrrole and activated olefins or by cyclization of 1-(ω-iodoalkyl)pyrroles, through electroreduction of the iodides using nickel(II) complex as an electron-transfer catalyst.View full abstractDownload PDF (841K) -
Taisuke ITAYA, Yasutaka TAKEDA, Tozo FUJII1996 Volume 44 Issue 11 Pages 2025-2032
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS7-Alkoxy-3-alkyladenine perchlorates (9) were prepared from 3-alkyladenines (4) by N-oxidation followed by alkylation with alkyl halides in N, N-dimethylacetamide. The 7-methoxy derivatives 9d, g, j thus obtained afforded 3-methyl-8-hydroxyadenine (7a), 3-ethyl-8-hydroxyadenine (7b), and 3-benzyl-8-hydroxyadenine (7c) in 74%, 72%, and 39% yields, respectively, on treatment with boiling 0.1 N aqueous sodium hydroxide, whereas treatment of 9d, g, j with sodium methoxide in methanol at room temperature afforded 3-alkyl-8-methoxyadenines (10m, p, q) in 91%-98% yields. Similar treatment of 9d with sodium ethoxide in ethanol afforded 8-ethoxy-3-methyladenine (10n) in 89% yield. Compounds 10m, q were alternatively prepared from 9d, j in 77% and 84% yields, respectively, by treatment with 0.1 N aqueous sodium hydroxide in the presence of methanol. This method was suitable for the synthesis of the 8-benzyloxy compound 10o : it was obtained in 60% yield by treating 7-benzyloxy-3-methyladenine perchlorate (9f) with a mixture of aqueous sodium hydroxide and benzyl alcohol. Compounds 7 were alternatively prepared from 9 through 10. For example, 7c was obtained in 84% overall yield by treatment of 9j with sodium methoxide, followed by hydrolysis of the resulting 10q with boiling 1 N hydrochloric acid.On the other hand, methylation of 3-methyladenine 7-oxide (8a) with dimethyl sulfate in 0.1 N aqueous sodium hydroxide in the absence or presence of added methanol afforded N6, 3-dimethyladenine 7-oxide (14) in 13% or 14% yield, together with 7a (4% yield) or 10m (11%).View full abstractDownload PDF (1274K) -
Tadashi HASHIMOTO, Kazuhiro OHKI, Naoki SAKURA1996 Volume 44 Issue 11 Pages 2033-2036
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA method for highly selective cleavage of pGlu-peptide linkages in 70% methanesulfonic acid (MSA) is described. When pGlu-Ala-Phe-OH, pGlu-His-Pro-OH and dog neuromedin U-8 (d-NMU-8) (1-7)-OH (pGlu-Phe-Leu-Phe-Arg-Pro-Arg-OH) were hydrolyzed in 70% MSA at 60°C for 3 h or at 25°C for 3 d, the pGlu-peptide linkage was predominantly cleaved to give H-Ala-Phe-OH, H-His-Pro-OH and H-Phe-Leu-Phe-Arg-Pro-Arg-OH, in high yields. The results indicated that pGlu-peptide linkages are highly susceptible to 70% MSA, whereas the amide bond of the pyrrolidone moiety of the pGlu residue and other internal peptide bonds are extremely resistant.View full abstractDownload PDF (629K) -
Hiroaki TAGUCHI, Toshio YOKOI, Yoshio OKADA1996 Volume 44 Issue 11 Pages 2037-2041
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe carboxyl function was easily introduced into a pyrazinone ring by means of a newly developed procedure for pyrazinone ring formation from Asp- or Glu-containing dipeptidyl chloromethyl ketones : during the reaction, rapid decarboxylation from a carboxymethyl group at position 3 of 2(1H)-pyrazinone occurred due to the low electron density at position 3 of 2 (1H)-pyrazinone.View full abstractDownload PDF (782K) -
Kazuya YOSHIZUMI, Shoji IKEDA, Katsumi GOTO, Tominori MORITA, Noriyasu ...1996 Volume 44 Issue 11 Pages 2042-2050
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS3, 5-Di-substituted phenylcyanoguanidine derivatives with halogen, cyano, and/or nitro groups at the 3- and 5-positions of the benzene ring exhibited very strong smooth muscle relaxation activity in vitro, as compared to pinacidil. Among them, N-(3-chloro-5-cyanophenyl)-N'-cyano-N"-tert-pentylguanidine (5s) showed 27-fold more potent activity than pinacidil, and exhibited a stronger and more lasting antihypertensive effect than pinancidil by oral administration to spontaneously hypertensive rats. We propose a new pharmacophore model in which the essential factors for binding to the potassium channel are an NH and a bulky alkyl group.View full abstractDownload PDF (1077K) -
Takanobu KUROITA, Nobuhiro MARUBAYASHI, Mitsuharu SANO, Kouji KANZAKI, ...1996 Volume 44 Issue 11 Pages 2051-2060
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of 3, 4-dihydro-2H-1, 4-benzoxazine-8-carboxamide derivatives was synthesized and evaluated for serotonin-3 (5-HT3) receptor antagonistic activities by means of assays of 5-HT3 receptor binding and the ability to antagonize the von Bezold-Jarisch reflex in rats. Replacement of the 1, 4-benzoxazine ring with a 1, 4-benzthiazine ring or seven-membered ring (i.e., 1, 5-benzoxepine or 1, 5-benzthiepine) resulted in decreased affinity for 5-HT3 receptor. Introduction of substituents at the 2 position of the 1, 4-benzoxazine ring increased the antagonistic activities (dimethyl>methyl>dihydro>phenyl). The compounds bearing a 9-methyl-9-azabicyclo[3.3.1]non-3-yl moiety as the basic part of 3, 4-dihydro-2H-1, 4-benzoxazine-8-carboxamide derivatives were equipotent to those bearing 1-azabicyclo[2.2.2]oct-3-yl moiety. The 9-methyl-9-azabicyclo[3.3.1]non-3-yl moiety was confirmed to adopt a boat-chair conformation on the basis of both NMR studies and X-ray analysis. In this series, endo-6-chloro-3, 4-dihydro-N-(9-methyl-9-azabicyclo[3.3.1]non-3-yl)-2, 2, 4-trimethyl-2H-1, 4-benzoxazine-8-carboxamide showed the highest affinity for 5-HT3 receptors (Ki=0.019 nM), and a long-lasting 5-HT3 receptor antagonistic activity as evidenced by antagonism to the von Bezold-Jarisch reflex in rats. Such a long-lasting 5-HT3 receptor antagonism would be attributed to the introduction of both two methyl groups at the 2 position of the benzoxazine ring and the 9-methyl-9-azabicyclo[3.3.1]non-3-yl moiety, which adopts the boat-chair conformation.View full abstractDownload PDF (1378K) -
Toshimi SEKI, Tomio NAKAO, Takeshi MASUDA, Kohichi HASUMI, Kotaro GOTA ...1996 Volume 44 Issue 11 Pages 2061-2069
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of novel pyridazinone derivatives (II) having a phenoxypropanolamine moiety was synthesized. Their hypotensive and β-blocking activities were evaluated after intravenous administration of the compounds to anesthetized rats. Among them, the 5-chloro-2-cyanophenoxy derivative (29) showed the promising dual activities and was selected for further studies.View full abstractDownload PDF (1293K) -
Osamu UCHIKAWA, Kohji FUKATSU, Masahiro SUNO, Tetsuya AONO, Takayuki D ...1996 Volume 44 Issue 11 Pages 2070-2077
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFor the development of novel antioxidants having therapeutic utility, a new series of condensed 4- and 5-aminothiazole derivatives has been synthesized using simple methods. Condensed 4-aminothiazoles were prepared by the reaction of α-bromolactams with thioamides in ethanol and 5-aminothiazole derivatives were obtained by the treatment of 3-(acylamino)lactams with a thiating agent such as phosphorus pentasulfide and Lawesson's reagent in pyridine. In vitro assay of the condensed 5-aminothiazole derivatives showed them to be potent inhibitors of lipid peroxidation. In order to evaluate these compounds in an in vivo system, we devised a simple and reproducible method in which the inhibition of characteristic behaviors induced by spinal injection of FeCl2 was expressed numerically. Compounds having strong in vitro activity protected the central nervous system from injury caused by iron-dependent lipid peroxidation. The results suggest that the in vivo assay developed in this study should be useful as a screening method for antioxidants and also that condensed 5-aminothiazole derivatives are promising candidates for the treatment of traumatic and ischemic injury of the central nervous system.View full abstractDownload PDF (1004K) -
Akiko KUSANO, Makio SHIBANO, Genjiro KUSANO, Toshio MIYASE1996 Volume 44 Issue 11 Pages 2078-2085
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSEight new glycosides were isolated from Cimicifuga simplex (Ranunculaceae), and their structures were determined to be 23-O-acetyl-7, 8-didehydroshengmanol-3-O-α-L-arabinopyranoside (1), 24-epi-24-O-acetyl-7, 8-didehydrohydroshengmanol-3-O-β-D-galactopyranoside (2), 7, 8-didehydrocimigenol-3-O-β-D-galactopyranoside (3), 24-epi-24-O-acetylhydroshengmanol-3-O-β-D-galactopyranoside (4), cimigenol-3-O-β-D-galactopyranoside (5), 25-O-methylcimigenol-3-O-β-D-galactopyranoside (6), 25-O-acetylcimigenol-3-O-β-D-galactopyranoside (7) and 25-O-acetylcimigenol-3-O-β-D-glucopyranoside (8). Genuine aglycones were obtained by the hydrolysis of 1-7 with lactase F[Amano] and of 8 with cellulase T[Amano]4. Acerinol was prepared from 7, 8-didehydrocimigenol and showed antilipemic effects.View full abstractDownload PDF (1109K) -
Masayuki YOSHIKAWA, Hiromi SHIMADA, Hiroshi SHIMODA, Nobutoshi MURAKAM ...1996 Volume 44 Issue 11 Pages 2086-2091
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo bioactive cyanoglycosides, rhodiocyanosides A and B, and two oligoglycosides, rhodioflavonoside [gossypetin 7-O-β-D-glucopyranosyl(1→3)-α-L-rhamnopyranoside] and rhodiooctanoside [octyl α-L-arabinopyranosyl(1→6)-β-D-glucopyranoside), were isolated from the Chinese natural medicine "Si Lie Hong Jing Tian" (Shiretsukoukeiten in Japanese), the underground part of Rhodiola quadrifida (PALL.) FISCH. et MEY., together with four known compounds : rhodioloside, n-hexyl β-D-glucopyranoside, gossypetin 7-O-α-L-rhamnopyranoside, and tricetin. The chemical structures of new glycosides were determined on the basis of chemical and physicochemical evidence. Rhodiocyanosides A and B exhibited inhibitory activity on the histamine release from rat peritoneal exudate cells sensitized with anti-2, 4-dinitrophenyl IgE. Additionally, rhodiocyanoside A, the major constituent of this natural medicine, was also found to show antiallergic activity in a passive cutaneous anaphylaxis test in rat.View full abstractDownload PDF (964K) -
Dongming ZHANG, Toshio MIYASE, Masanori KUROYANAGI, Kaoru UMEHARA, Hir ...1996 Volume 44 Issue 11 Pages 2092-2099
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNine new oleanate-type saponins, polygalasaponins XXXIII-XLI, along with seven known saponins were isolated from the roots of Polygala fallax HEMSL. Polygalasaponins XXXIII-XLI were elucidated as 3-O-β-D-glucopyranosyl presenegenin 28-O-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-(4-O-acetyl)-β-D-fucopyranosyl ester, 3-O-β-D-glucopyranosyl presenegenin 28-O-β-D-galactopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-(4-O-acetyl)-β-D-fucopyranosyl ester, 3-O-β-D-glucopyranosyl presenegenin 28-O-β-D-galactopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-(3, 4-di-O-acetyl)-β-D-fucopyranosyl ester, 3-O-β-D-glucopyranosyl presenegenin 28-O-β-D-galactopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-[(5-O-acetyl)-β-D-apiofuranosyl-(1→3)]-α-L-rhamnopyranosyl-(1→2)-(3, 4-di-O-acetyl)-β-D-fucopyranosyl ester, 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl presenegenin 28-O-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-(3-O-acetyl)-β-D-fucopyranosyl ester, 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl presenegenin 28-O-β-D-galactopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-(4-O-acetyl)-β-D-fucopyranosyl ester, 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl presenegenin 28-O-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-(4-O-acetyl)-β-D-fucopyranosyl ester, 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl presenegenin 28-O-β-D-galactopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-[β-D-apiofuranosyl-(1→3)]-α-L-rhamnopyranosyl-(1→2)-(3, 4-di-O-acetyl)-β-D-fucopyranosyl ester and 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl presenegenin 28-O-β-D-galactopyranosyl-(1→4)-β-D-xylopyranosyl-(1→4)-[(5-O-acetyl)-β-D-apiofuranosyl-(1→3)]-α-L-rhamnopyranosyl-(1→2)-(3, 4-di-O-acetyl)-β-D-fucopyranosyl ester, respectively, on the basis of spectroscopic and chemical evidence.View full abstractDownload PDF (930K) -
Tenji KONISHI, Shiu KIYOSAWA, Takao KONOSHIMA, Yasuhiro FUJIWARA1996 Volume 44 Issue 11 Pages 2100-2102
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new diterpenes, excoecarins A (2), B (3) and C (4) have been isolated from the wood of Excoecaria agallocha LINN. The structures of excoecarins A, B and C were established as (13R, 14R)-ent-8α, 13;14, 15-diepoxy-13-epi-labda-3-one (2), (13R, 14S)-ent-8α, 13;14, 15-diepoxy-13-epi-labda-3-one (3), (13R, 14R)-ent-8α, 13;14, 15-diepoxy-13-epi-labda-3β-ol (4), respectively, on the basis of spectroscopic data and chemical evidence.View full abstractDownload PDF (508K) -
Hiroyuki MINAMI, Atsuko KUWAYAMA, Toyokichi YOSHIZAWA, Yoshiyasu FUKUY ...1996 Volume 44 Issue 11 Pages 2103-2106
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new prenylated xanthones, garciniaxanthones F (1), G (2) and H (3), have been isolated as antioxidative substances from the wood of Garcinia subelliptica (Guttiferae). Their structures have been elucidated on the basis of spectroscopic data involving comparison of their 13C-NMR data with those of previously known xanthones. The antioxidant properties of the new compounds have been evaluated by three assay systems : anti-lipid peroxidation, α, α-diphenyl-β-picrylhydrazyl radical scavenging activity and superoxide radical scavenging activity.View full abstractDownload PDF (677K) -
keisuke KOJIMA, Iclal SARACOGLU, Motoh MUTSUGA, Yukio OGIHARA1996 Volume 44 Issue 11 Pages 2107-2110
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new oleanane-type saponins, papyrioside LA-LD, were isolated from the leaves of Tetrapanax papyriferum. The structures of these new compounds were elucidated as 11α-hydroxy-3, 21-dioxo-olean-12-en-28-oyl-α-L-rhamnopyranosyl-(1→4)-(6-O-acetyl-β-D-glucopyranosyl)-(1→6)-β-D-glucopyranoside, 11α-methoxy-3, 21-dioxo-olean-12-en-28-oyl-α-L-rhamnopyranosyl-(1→4)-(6-O-acetyl-β-D-glucopyranosyl)-(1→6)-β-D-glucopyranoside, 3α-hydroxy-11α-methoxy-21-oxo-olean-12-en-28-oyl-α-L-rhamnopyranosyl-(1→4)-(6-O-acetyl-β-D-glucopyranosyl)-(1→6)-β-D-glucopyranoside and 21α-hydroxy-11α-methoxy-3-oxo-olean-12-en-28-oyl-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside, respectively, on the basis of spectroscopic and chemical evidence.View full abstractDownload PDF (510K) -
Yuji CHIKARAISHI, Makoto OTSUKA, Yoshihisa MATSUDA1996 Volume 44 Issue 11 Pages 2111-2115
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe dissolution phenomenon of piretanide amorphous form and form C was investigated in various pH buffers at 37°C and at pH 5 at various temperatures by a dispersed-amount method. Their initial dissolution rates were investigated at pH 5 at various temperatures (30-45°C) by a stationary-disk method. The solubility of the amorphous form and form C was temperature dependent at pH 5 and pH dependent at 37°C. The amorphous form was more soluble than form C under acidic conditions. However, it was as soluble as form C in JP XII second fluid (pH 6.8). The amorphous form showed characteristic convex dissolution curves with maximal concentration at 30 and 35°C, whereas the amorphous form at 40 and 45°C and the form C at 30-45°C showed only normal dissolution curves.The initial dissolution process of form C obtained by the stationary-disk method followed the Noyes-Whitney-Nernst equation, but that of the amorphous form did not. The initial dissolution process of the amorphous form was analyzed by a dissolution kinetics equation involving phase transformation from the amorphous form to form C. The maximal concentration, the dissolution rate constant, and the rate constant of the phase transition process were estimated. The thermodynamic parameters for the dissolution process of the amorphous form and form C were obtained from van't Hoff and Arrhenius plots, respectively. The results of the intrinsic solubility and dissolution parameters of the two forms suggested that the difference in the dissolution rates between them affects the bioavailability of piretanide preparations.View full abstractDownload PDF (634K) -
Kazuhiko OZAKI, Masahiro HAYASHI1996 Volume 44 Issue 11 Pages 2116-2120
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSCycloinulohexaose (CF-6) maintained the membrane structure of the liposomes during freeze-thawing, and thus CF-6 was very effective in inhibiting both drug leakage from liposomes and the size change of liposomes during freezing and freeze-drying. As the ratio of CF-6 to lipid increased from 1 to 5, calcein retention in the liposomes increased from 70% up to 85% and a maximum retention was obtained at a ratio of more than 2. The addition of glycerol enhanced the above cryoprotective effect of CF-6 and improved calcein retention up to 90%. Neither detectable leakage of calcein nor particle size change was observed after the storage of liposomes freeze-dried with CF-6 for 6 months at 4 and 25°C.View full abstractDownload PDF (685K) -
Yunxia BI, Hisakazu SUNADA, Yorinobu YONEZAWA, Kazumi DANJO, Akinobu O ...1996 Volume 44 Issue 11 Pages 2121-2127
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn order to make a compressed tablet which can rapidly disintegrate in the oral cavity, microcrystalline cellulose and low-substituted hydroxypropylcellulose were used as disintegrants, and ethenzamide and ascorbic acid were chosen as poorly and easily water soluble model drugs, respectively.The mixture of microcrystalline cellulose and low-substituted hydroxypropylcellulose was compressed at 100-500 kgf in the absence of an active ingredient. The properties of these tablets, such as hardness, porosity, the time required for complete wetting of a tested tablet (wetting time), water uptake and disintegration time determined by a new disintegration apparatus, were investigated to elucidate the wetting and disintegration characteristics of these tablets. When the MCC/L-HPC ratio was in the range of 8 : 2 to 9 : 1, the shortest disintegration time was observed. The disintegration of tablets containing ethenzamide or ascorbic acid was examined next. Tablet disintegration time in the oral cavity was also tested, and good correlation between the disintegration behaviors in vitro and in the oral cavity was recognized.View full abstractDownload PDF (1161K) -
Satoru WATANO, Atsuko YAMAMOTO, Kei MIYANAMI1996 Volume 44 Issue 11 Pages 2128-2131
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn this contribution, an organic solvent-based enteric coating was made using an agitation fluidized bed. Core spherical particles containing an aqueous pigment were coated with an enteric methacrylate-methyl methacrylate copolymer dissolved in an ethanol solution using an agitation fluidized bed under various spray mist sizes. Physical properties of coated granules such as the drug release properties, the specific surface are and the coating efficiency were investigated. The effect of spray mist size on the properties of coated granules was investigated and the film forming mechanism in agitation fluidized bed coating was discussed. The optimum operating conditions were also determined.View full abstractDownload PDF (570K) -
Akihiko ITO, Masayasu SUGIHARA1996 Volume 44 Issue 11 Pages 2132-2136
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSRapidly disintegrating tablets as an oral dosage form for elderly patients with impaired swallowing were investigated using agar powders (AG) or treated agar powders (TAG).When the compression pressure was changed from 0.4 to 2.0 ton/cm2, the disintegration time of AG tablets increased from about 60 to about 160 s, and the hardness significantly increased from 3 to 13 kgw. The disintegration time and hardness of the TAG tablets were scarcely affected by the compression pressure : the disintegration time was 5-6 s, and the hardness was 2-3 kgw. The rapid disintegration of the TAG tablets seemed due to the rapid water penetration into the tablet resulting from the large pore size and large overall pore volume.It was found that rapidly disintegrating oral tablets with proper hardness can be prepared using TAG.View full abstractDownload PDF (763K) -
Noriko N. MIURA, Naohito OHNO, Yoshiyuki ADACHI, Toshiro YADOMAE1996 Volume 44 Issue 11 Pages 2137-2141
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSoluble (SSG, β-1, 3-D-glucan obtained from the culture filtrates of a fungus, Sclerotinia sclerotiorum IFO 9395) and particulate (zymosan) β-glucans were oxidized by sodium hypochlorite (NaClO), and the oxidized products were analyzed by gel filtration and ion-exchange chromatographies and by limulus G-test to study the metabolism of β-glucans in vivo. By oxidative degradation, SSG was gradually oxidized to anionic polymers, which decreased the molecular weight and reduced the content of the sidechain at the same time. Zymosan, a particle from fungi cell wall, was easily solubilized to a high molecular weight polysaccharide by oxidative degradation. The elution profiles on ion exchange columns and the limulus G-test reactivity of the products were similar to those of polysaccharides obtained by in vivo experiments using SSG and zymosan. These results suggest that oxidative degradation is the main metabolic pathway of β-glucans in vivo, and that the sidechains would be oxidized faster than the main chain.View full abstractDownload PDF (687K) -
Motomasa KOBAYASHI, Shunji AOKI, Katsuhiko GATO, Isao KITAGAWA1996 Volume 44 Issue 11 Pages 2142-2149
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAltohyrtins A (1), B (2), and C (3) and 5-desacetylaltohyrtin A (4), extremely potent cytotoxic macrolides, have been isolated from the Okinawan marine sponge Hyrtios altum. The absolute stereostructures of these macrolides have been elucidated on the bases of detailed NMR analysis, application of the modified α-methoxy-α-(trifluoromethyl)phenylacetic acid (MTPA) method to the hexa-MTPA esters, and application of the circular dichroism (CD) exciton chirality method.View full abstractDownload PDF (988K) -
Yueh-Hsiung KUO, Ming-Tsang YU1996 Volume 44 Issue 11 Pages 2150-2152
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe following constituents were isolated from the heartwood of Juniperus formosana HAY. var. concolor HAY. : (-)-sesquichamaenol, (-)-7-hydroxycalamenene, (-)-15-hydroxycalamenene, and (-)-1-hydroxy-1, 3, 5-bisabolatrien-10-one. The latter two compounds are new candinane- and bisabolane-type sesquiterpenes, and their structures were elucidated on the basis of spectral and chemical evidence.View full abstractDownload PDF (461K) -
Cheng Yu CHEN, Shinji NAGUMO, Hiroyuki AKITA1996 Volume 44 Issue 11 Pages 2153-2156
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSOptically pure (3R, 7R)-3, 7, 11-trimethyldodecan-1-ol (16), corresponding to the α-tocopherol side chain, was synthesized by the coupling reaction of a chiral isoprene unit (3S)-9 derived from an enzymatically hydrolyzed product (2S, 3S)-2 and a ten-carbon alkylating reagent (R)-13 derived from (R)-(+)-pulegone.View full abstractDownload PDF (619K) -
Carlos A. M. FRAGA, Ana L. P. MIRANDA, Eliezer J. BARREIRO1996 Volume 44 Issue 11 Pages 2157-2161
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS(±)-5-[5β-(((E)-1-Octen-3-ol)-1)-2-oxabicyclo[3.3.0]octan-3-yl]-4-oxapentanoic acid (±)-(1a, b), designed as a chemically and biologically stable prostacyclin analogue, was synthesized in 15% yield overall, via the (±)-3-hydroxymethyl-5-carbethoxy-2-oxabicyclo[3.3.0]octane (4) as the key intermediate.View full abstractDownload PDF (777K) -
Naoyuki KOIZUMI, Shigehiro TAKEGAWA, Mamoru MIEDA, Kenyu SHIBATA1996 Volume 44 Issue 11 Pages 2162-2164
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe preparation of 6- and/or 7-substituted 3-oxo-2-oxasteroids having a spirotetrahydrofuran ring at the 17-position is described. These compounds showed high antiandrogenic potency in the castrated male rat.View full abstractDownload PDF (581K) -
Abdelhakim ELOMRI, Alexios-Leandros SKALTSOUNIS, Sylvie MICHEL, Franco ...1996 Volume 44 Issue 11 Pages 2165-2168
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNitration of acronycine (1) and 6-demethoxyacronycine (3) afforded 2-nitroacronycine (2) and 2-nitro-6-demethoxyacronycine (4), respectively. Reduction of 2-nitroacronycine yielded, depending on the conditions, 2-nitro-1, 2-dihydroacronycine (5), 2-oxo-1, 2-dihydroacronycine oxime (7) or 2-amino-1, 2-dihydroacronycine (6). This latter was readily converted into 2-dimethylamino-1, 2-dihydroacronycine (8), 2-acetylamino-1, 2-dihydro-acronycine (9) and 2-benzoylamino-1, 2-dihydroacronycine (10).The cytotoxicity of these compounds was evaluated against L1210 leukemia cells. Compounds 2 and 7 were 300- and 10-fold more potent than acronycine in inhibiting L1210 cell proliferation, respectively. Compound 2 was devoid of antitumor activity against P388 leukemia and C38 colon adenocarcinoma.View full abstractDownload PDF (664K) -
Corinne LANDRAS, Richard JASZTOLD-HOWORKO, Alain PIERRE, Stephane LEON ...1996 Volume 44 Issue 11 Pages 2169-2172
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSStarting from 2-(6-methoxy-1-methylcarbazol-2-yl)ethylamine and diethyl-2, 6-pyridine dicarboxylate, the title compounds were obtained through five or six steps. The new compounds retained significant cytotoxicity towards various tumor cell lines, but in vivo studies on murine P388 leukemia, B16 melanoma and Lewis lung carcinoma showed a lowered antitumor activity with respect to that of the related ovivacine lead compound 1.View full abstractDownload PDF (655K) -
Toshiyuki FUKUDA, Yoshio KiTADA, Xin-Min CHEN, Lei YANG, Toshio MIYASE1996 Volume 44 Issue 11 Pages 2173-2176
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new monoterpene glycosides, kudingosides A and B, were isolated from Ku-Ding-Cha (Ligustrum pedunculare REHD.), together with a known monoterpene glycoside, (S)-lipedoside B-III, and three known phenylethanoid glycosides. Their structures were elucidated by spectroscopic and chemical means. Kudingosides A and B, and (S)-lipedoside B-III inhibited acyl-CoA : cholesterol acyltransferase (ACAT) with IC50 values of 2.70×10-3 M, 2.88×10-3 M, and 2.69×10-4 M, respectively.View full abstractDownload PDF (594K) -
Hiroshi MORITA, Takashi KAYASHITA, Koichi TAKEYA, Hideji ITOKAWA1996 Volume 44 Issue 11 Pages 2177-2180
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSRestrained molecular dynamics calculation in vacuo using AMBER force field implemented in MacroModel/Batchmin showed a major solution conformation in dimethyl sulfoxide-d6 of pseudostellarin D, cyclo(-Gly-Tyr-Gly-Pro-Leu-Ile-Leu-). This is a cyclic heptapeptide isolated from Pseudostellaria heterophylla possessing characteristics of a β-bulge motif with three intramolecular hydrogen bonds, two β-turns (one type I at Pro4 and Leu5 residues, and one type II at Leu7 and Gly1 residues) and all trans amide bonds. The solution form of pseudostellarin D, which was homologous to that observed in the solid state, was also supported by Monte Carlo simulation study.View full abstractDownload PDF (618K) -
Mineo SHIMIZU, Nobuo UEMITSU, Masayuki SHIROTA, Kazuhiro MATSUMOTO, Ya ...1996 Volume 44 Issue 11 Pages 2181-2182
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new triterpene ester, 3-O-trans-feruloyl euscaphic acid, was isolated from the leaves of Eriobotrya japonica. The structure of this compound was elucidated by means of chemical and spectroscopic studies.View full abstractDownload PDF (405K) -
Hai-Xue KUANG, Hui SUN, Ning ZHANG, Yoshihito OKADA, Toru OKUYAMA1996 Volume 44 Issue 11 Pages 2183-2185
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new triterpenoidal saponins, congmuyenosides A and B, were isolated from the leaves of Aralia elata collected in Heilongjiang Province, China, and established as 3-O-[β-D-glucopyranosyl(1→2)][β-D-glucopyranosyl-(1→3)]-β-D-glucopyranosyl hederagenin and 3-O-[β-D-glucopyranosyl(1→2)][β-D-glucopyranosyl(1→3)-β-D-glucopyranosyl(1→3)]-β-D-glucopyranosyl hederagenin, respectively, on the basis of chemical and spectral evidence.View full abstractDownload PDF (475K) -
Hisao NEMOTO, Junya KIKUISHI, Masayuki SHIBUYA1996 Volume 44 Issue 11 Pages 2186-2188
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSConversion of the phthalide derivative 5 to the enediynes 6 and 11 are described. Treatment of 5 with 1, 8-diazabicyclo[5.4.0]undec-7-ene in hexamethylphosphoric triamide stereoselectively gives 6, which can be used as an efficient DNA-damaging biradical.View full abstractDownload PDF (411K) -
SYNTHESIS OF ω-TERT-BUTYL ESTERS OF ASPARTIC ACID AND GLUTAMIC ACID VIA B, B-DIFLUOROBOROXAZOLIDONESJidong WANG, Yoshio OKADA, Zongmu WANG, Yuhong WANG, Wei LI1996 Volume 44 Issue 11 Pages 2189-2191
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSB, B-Difluoroboroxazolidones (DFBONs) were synthesized for the first time from salts of amino acid and BF3·Et2O, and their properties were examined. DFBONs were used in selective preparation of Glu(OBut) and Asp(OBut) in good yields under catalysis with BF3·Et2O and H3PO4. Amberlite XAD-2 resin was successfully employed to purify the above amino acid derivatives.View full abstractDownload PDF (515K) -
Hiromitsu TAKAYAMA, Yuhko MIYABE, Toshiaki SHITO, Mariko KITAJIMA, Nor ...1996 Volume 44 Issue 11 Pages 2192-2194
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSBased on a biogenetic consideration, a Nauclea alkaloid, naucleidinal (6), and its 3-epimer (7) were stereoselectively prepared from the aglycones of strictosamide and the vincoside lactam, and their absolute stereochemistry was confirmed.View full abstractDownload PDF (457K) -
Mariko KITAJIMA, Seiichiro SHIRAKAWA, Samia G. A. ABDEL-MOTY, Hiromits ...1996 Volume 44 Issue 11 Pages 2195-2197
Published: November 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe structure of a new chiral β-carboline derivative, Compound D, which was found during the chemical investigation of metabolites formed by cultured hybrid cells of two Apocynaceae plants, Rauwolfia serpentina Benth. and Rhazya stricta Decaisne, was rigorously confirmed by chemical synthesis starting from tryptamine and D-glucose.View full abstractDownload PDF (418K)
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