All issues
Volume 50, Issue 2
Displaying 1-33 of 33 articles from this issue
- |<
- <
- 1
- >
- >|
Regular Articles
-
Toshio Yajima, Yumiko Fukushima, Shigeru Itai, Yoshiaki KawashimaArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 147-152
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSThe degree of bitterness of clarithromycin (CAM) dry syrup was evaluated using several methods. Using the inversion method, shaking method, and paddle method, a reasonable correlation between the bitter taste and the amount dissolved was not observed. A mini-column with inner diameter of 0.76 cm and height of 5 cm packed with CAM dry syrup was used for the release test. The release rate of CAM in test solution, which passed through the mini-column, was then measured to evaluate bitterness. The release rate of CAM in the release test using the mini-column correlated well with the results of a sensory test for the bitterness of CAM dry syrup. The dissolution rate constant, defined as the percentage of CAM dissolved from the unit void surface multiplied by the void volume, was inversely proportional to the linear velocity of the test solution. The critical factors affecting evaluation of bitterness were the void volume of the column and linear velocity of the test solution. The optimum linear velocity and void volume were 0.048—0.021 cm/min and 0.27—0.12 cm3, respectively. In addition, the threshold of bitterness of CAM dry syrup was defined as the concentration at which half of the volunteers recognized bitterness in the sensory test. This threshold was found to be 135 μg/ml using the mini-column.View full abstractDownload PDF (202K) -
Shun-Li Wang, Shan-Yang Lin, Yen-Shan WeiArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 153-156
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSA novel Fourier transform infrared (FT-IR) microspectroscopy equipped with a micro hot stage (thermal FT-IR microscopic system) was used to quickly study the phase transformation of acetaminophen polymorphs by a one-step process. Acetaminophen was sealed in KBr disc on the first and second heating processes under this system. The results indicate that the contour IR profile of form I acetaminophen in the first heating process changed dramatically only near 165 °C, but in the re-heating process exhibited a considerable alteration in peak intensity, band width and position near the temperatures at 85, 118 and 153 °C. A glassy form of acetaminophen was obtained after rapidly cooling the melted acetaminophen from 200 to 25 °C. The glassy acetaminophen was recrystallized at 85 °C to transform to the form III of acetaminophen in the reheating process, and then transformed to its form II near 118 °C. The thermal FT-IR microscopic system is a simple, quick and timesaving tool for investigation of the thermo-dependent molecular structure of acetaminophen polymorphs in the processes of recrystallization and polymorphic transition.View full abstractDownload PDF (76K) -
Fu-Wen Lin, Jhi-Joung Wang, Tian-Shung WuArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 157-159
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSThree new pavine N-oxide alkaloids, (−)-isocaryachine-N-oxide B, (+)-caryachine-N-oxide, (−)-caryachine-N-oxide, and a new isoquinoline alkaloid, 6, 7-methylenedioxy-N-methylisoquinoline together with 11 known alkaloids were isolated and characterized from the stem bark of Cryptocarya chinensis. The structures of the isolated compounds were determined by spectral methods. The stereochemistry of pavine-N-oxide alkaloids is also discussed.View full abstractDownload PDF (57K) -
Atef Abdel-Monem Abdel-Hafez, Norio Nakamura, Masao HattoriArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 160-164
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSAnaerobic incubation of phorbol (1) from Croton tiglium with human intestinal bacteria afforded five metabolites: isophorbol (2), deoxyphorbol (3), 4β,9α,20-trihydroxy-13,15-seco-1,6,15-tigliatriene-3,13-dione (4), 4β,9α,20-trihydroxy-15,16,17-trinor-1,6-tigliadiene-3,13-dione (5) and 4β,9α,20-trihydroxy-14(13→12)-abeo-12αH-1,6-tigliadiene-3,13-dione (6). All these metabolites (2—6) were identified and characterized by spectroscopic means, including two-dimensional (2D)-NMR. Nine defined strains from the human intestine showed an ability to transform 1 to these metabolites.View full abstractDownload PDF (84K) -
Ioanna Andreadou, Androniki Tasouli, Elias Bofilis, Michael Chrysselis ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 165-168
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSNovel indole derivatives containing a triazole moiety (1a—d, 2a—c) were synthesized as lead compounds with interesting pharmacological profiles. Their antioxidant activity was investigated on in vitro non-enzymatic rat hepatic microsomal lipid peroxidation. All compounds showed significant effect in the above assay. The effect depended mainly on the attachment position of the triazole moiety on the indole nucleus. The most potent antioxidant derivatives 1a, 1c and 1d were tested for their protective ability against the oxidative damage of the myocardium after ischemia-reperfusion, in male rabbits which were subjected to 30 min regional ischemia followed by reperfusion. The tested antioxidant compounds 1a, 1c and 1d were continuously infused for 30 min starting at 10th min of ischemia and lasted at 10th min of reperfusion. The concentration of malondialdehyde (MDA, a marker of lipid peroxidation) and hemodynamic parameters (blood pressure and heart rate) were measured in the baseline, at 20th min of the sustained ischemia, 1st and 20th min of reperfusion. It was found that the examined compounds 1a, 1c and 1d reduced significantly the level of MDA in rabbits under ischemia-reperfusion and proved to be promising substances for further evaluation of anti-ischemic properties.View full abstractDownload PDF (57K) -
Hatsuo Maeda, Shinya Matsu-ura, Mari Nishida, Yuji Yamauchi, Hidenobu ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 169-174
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSPerhydrolysis of acetyl resorufin (AR) was reported previously to work as a fluorometric indicator reaction for glucose determination using only glucose oxidase. However, hydrolysis of AR in blank solution rendered the working concentration range of this method less than two orders of magnitude. To exclude or at least significantly reduce this interference, acyl groups and reaction conditions in the competition between perhydrolysis and hydrolysis of various acyl resorufins were assessed. Fluorometric evaluation of reactions in the presence or absence of H2O2 in phosphate buffer (pH 7.5, 100 mM)–CH3CN at 25 °C demonstrated that in tert-butylacetyl, isobutyryl, cyclohexanecarbonyl and pivaloyl resorufins (TBAR, IBR, CHR and PVR, respectively) among 10 acyl resorufins examined here, the competitive situation was shifted in a much more favorable way to perhydrolysis than in AR, although fluorometric responses due to their H2O2-dependent deacylation were suppressed in comparison with AR. Examination of the effects of pH, components and concentrations of buffers as well as reaction temperature established reaction conditions that not only allowed perhydrolysis of each of these four compounds to prevail over hydrolysis more effectively, but also improved the H2O2-based fluorometric responses. Thus, perhydrolysis of TBAR, IBR, CHR and PVR in phosphate buffer (pH 8.0, 20 mM)–CH3CN at 25 °C worked effectively as fluorometric indicator reactions for H2O2 analysis, affording a calibration curve over a concentration range of three orders of magnitude. Taking sensitivity, reproducibility and the response for blank solution into consideration, PVR seemed to be the best choice as a fluorochromogen for H2O2 determination under these conditions. For H2O2 analysis at lower pH, perhydrolysis of IBR in phosphate buffer (pH 7.5, 20 mM)–CH3CN was shown to effectively function as an indicator reaction. Applicability of the fluorometric methods with PVR and IBR to blood glucose determination was also discussed, comparing with Trinder's method with phenol, 4-aminoantipyrine and peroxidase (POD).View full abstractDownload PDF (89K) -
Hongshan Yu, Jinmei Gong, Chunzhi Zhang, Fengxie JinArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 175-178
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSIn this paper the ginsenoside-α-(1→2)-L-rhamnosidase from microorganisms was purified and characterized. The enzyme hydrolyzed the 6-C, α-(1→2)-L-rhamnoside of 20(S) and 20(R)-ginsenoside Rg2 to produce the 20(S) and 20(R)-ginsenoside Rh1, but hardly hydrolyzed the α-rhamnoside of pNPR. The enzyme molecular weight was about 53 kDa. The optimum temperature of enzyme reaction was 40 °C, and the optimum pH was 5.View full abstractDownload PDF (64K) -
Yukio Nohara, Tomomi Usui, Toshio Kinoshita, Mitsuo WatanabeArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 179-184
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSUremic toxins are accumulated in the blood of patients with chronic renal failure (CRF), although alteration of the toxicity by the interaction of various uremic retention products has not been precisely clarified. In this study, we found that cytochrome c added to incubation mixtures containing guanidino compounds and methylglyoxal in phosphate buffer solution (pH 7.4) resulted in reduction of cytochrome c. Superoxide anions were generated from incubation mixtures of each guanidino compound with methylglyoxal, because the reduction was inhibited by the addition of superoxide dismutase. The incubation mixture containing each guanidino compound and methylglyoxal had different rates of generation of the superoxide anion from other mixtures. A relatively higher superoxide anion formation rate was observed in the incubation mixture containing Arg and methylglyoxal (7.9±0.5 nmol·m−1·min−1), or in the incubation mixture containing methylguanidine and methylglyoxal (6.3±0.6 nmol·ml−1·min−1). These findings suggest that interactions of various uremic retention products which accumulate in the blood of uremic patients may generate reactive oxygen species and may be involved in the oxidative stress observed in CRF patients. The addition of aminoguanidine, which is known to inhibit the formation of advanced glycation end products, to a mixture of guanidino compounds and methylglyoxal inhibited reactions between guanidino compounds and methylglyoxal.View full abstractDownload PDF (73K) -
Genjirou Kusano, Shiho Orihara, Daisuke Tsukamoto, Makio Shibano, Maks ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 185-192
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSInvestigation of the constituents of the fruits of Morus alba LINNE (Moraceae) afforded five new nortropane alkaloids (1—5) along with nor-ψ-tropine (6) and six new amino acids, morusimic acids A—F (7—12). The structures of the new compounds were determined to be 2α,3β-dihydroxynortropane (1), 2β,3β-dihydroxynortropane (2), 2α,3β,6exo-trihydroxynortropane (3), 2α,3β,4α-trihydroxynortropane (4), 3β,6exo-dihydroxynortropane (5), (3R)-3-hydroxy-12-{(1S,4S)-4-[(1S)-1-hydroxyethyl]-pyrrolidin-1-yl}-dodecanoic acid-3-O-β-D-glucopyranoside (7), (3R)-3-hydroxy-12-{(1S,4S)-4-[(1S)-1-hydroxyethyl]-pyrrolidin-1-yl}-dodecanoic acid (8), (3R)-3-hydroxy-12-[(1R,4R,5S)-4-hydroxy-5-methyl-piperidin-1-yl]-dodecanoic acid-3-O-β-D-glucopyranoside (9), (3R)-3-hydroxy-12-[(1R,4R,5S)-4-hydroxy-5-methyl-piperidin-1-yl]-dodecanoic acid (10), (3R)-3-hydroxy-12-[(1R,4R,5S)-4-hydroxy-5-hydroxymethyl-piperidin-1-yl]-dodecanoic acid-3-O-β-D-glucopyranoside (11), and (3R)-3-hydroxy-12-[(1R,4S,5S)-4-hydroxy-5-methyl-piperidin-1-yl]-dodecanoic acid (12) on the basis of spectral and chemical data.View full abstractDownload PDF (111K) -
Toshifusa Shu, Hideshi Suzuki, Kenji Hironaka, Kunio ItoArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 193-198
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSWe attempted the development of rapid oral disintegration tablets by direct compression using co-ground mixture of D-mannitol and crospovidone. The co-ground mixture was prepared with a vibration rod mill. The tablets were formed by compression using a single punch-tableting machine after addition of the co-ground mixture to non-ground D-mannitol, crospovidone and magnesium stearate. Regarding the properties of tablets, hardness and the time of disintegration were measured. The particle diameter and specific surface area of the co-ground mixture were measured. The tablets manufactured from a physical mixture of 30% (w/w) co-ground mixture of D-mannitol and crospovidone (mixed ratio 9 : 1) with 65.5% (w/w) of non-ground mannitol, 4% (w/w) of crospovidone, and 0.5% (w/w) of magnesium stearate had good properties for rapidly disintegrating tablets in the oral cavity. They showed the hardness of 4.9 kg and disintegration time of 33 s. We found that adding co-ground mixture of D-mannitol and crospovidone is useful in enhancing hardness of the tablets that could not be achieved by addition of their individually ground mixture. The improvement in the hardness of the tablets was also observed when other saccharides and disintegrants were used. This method was proved to be applicable in the manufacture of tables of ascorbic acid, a water-soluble drug and nifedipine, a slightly water soluble drug; and the dissolution rate of nifedipine from the tablets in water was remarkably improved. The particle sizes of D-mannitol in the co-ground mixture were smaller than that of the individually ground mixture, resulting in a larger specific surface area of the co-ground mixture than that of the individually ground mixture. Therefore, it was presumed that crospovidone acted as a grinding assistant for D-mannitol in the co-grinding process, enhancing the hardness of tablets by increasing the contact area among powder particles.View full abstractDownload PDF (62K) -
Charles Descoins, Jr., Isabel López Bazzocchi, Angel Guti&eacut ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 199-202
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSA new sesquiterpene evoninate alkaloid (1), and two sesquiterpenes (2, 3) with a dihydro-β-agarofuran skeleton, along with three known sesquiterpenes (4—6), were isolated from the seeds of Euonymus europaeus. Their structures were elucidated by high resolution mass analysis, and one- and two-dimensional (1D and 2D) NMR spectroscopy, including homonuclear and heteronuclear correlation [correlation spectroscopy (COSY), rotating frame Overhauser enhancement spectroscopy (ROESY), heteronuclear single quantum coherence (HSQC), and heteronuclear multiple bond correlation (HMBC)] experiments.View full abstractDownload PDF (66K) -
Takao Ohyashiki, Akinori Kadoya, Katsumi KushidaArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 203-207
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSFe2+-dependent lipid peroxidation in phosphatidylcholine (PC) liposomes, assessed by thiobarbituric acid-reactive substances (TBARS) production, was stimulated in the presence of Fe3+ in a concentration-dependent manner. The rates of nitroblue tetrazolium (NBT) reduction and Fe2+ oxidation (Fe2+ disappearance and Fe3+ formation) were also enhanced by the addition of Fe3+ to the reaction mixture, and there is a good linear relationship between these parameters. These results suggest that the facilitation of reactive oxygen species (ROS) production via Fe2+ oxidation is closely related to the onset of the stimulatory effect of Fe3+ on Fe2+-dependent lipid peroxidation. On the other hand, results using the liposomes containing various concentrations of endogenous lipid hydroperoxides (LOOH) indicated that endogenous LOOH is not directly involved in the onset of the Fe3+ stimulatory effect on Fe2+-dependent TBARS production and ROS production. This hypothesis was further confirmed by the evidence that Fe2+-dependent ROS production and Fe2+ oxidation of dipalmitoylphosphatidylcholine liposomes were also stimulated by the addition of Fe3+. The results with several antioxidants and radical scavengers suggested that ROS related to Fe2+-dependent lipid peroxidation and its stimulation by Fe3+ are ferrous–oxygen complexes rather than superoxide anion, hydrogen peroxide and hydroxyl radicals. Based on these results, we proposed a possible mechanism for the onset of the Fe3+ stimulation in Fe2+-dependent lipid peroxidation.View full abstractDownload PDF (87K) -
Hisashi Matsuda, Toshio Morikawa, Jing Tao, Kazuho Ueda, Masayuki Yosh ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 208-215
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSThree new diarylheptanoid glycosides, named (+)-S-myricanol 5-O-β-D-glucopyranoside, myricanene A 5-O-α-L-arabinofuranosyl(1→6)-β-D-glucopyranoside, and myricanene B 5-O-α-L-arabinofuranosyl(1→6)-β-D-glucopyranoside, were isolated from the bark of Chinese Myrica rubra, together with twenty known compounds. The absolute stereostructures of the new diarylheptanoid glycosides were elucidated on the basis of chemical and physicochemical evidence, including the application of the modified Mosher's method. The inhibitory effects of isolated constituents on the release of β-hexosaminidase from RBL-2H3 cells were examined, and several diarylheptanoids, myricanol, (+)-S-myricanol, myricanone, and myricanenes A and B, and a flavonol, myricetin, were found to show the inhibitory activity.View full abstractDownload PDF (122K) -
Kuniharu Utsuno, Masamichi Tsuboi, Shunji Katsumata, Toschitake Iwamot ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 216-219
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSTertiary structure changes in DNA duplexes, induced by Hoechst 33258 binding, have been examined by the use of atomic force microscopy. Besides minor groove binding, which is an established mode of binding for this drug, Hoechst 33258 has now been found to show another binding mode, which causes an unwinding of the duplex. When the drug concentration is as high as 0.5 μg/ml, the Hoechst 33258 molecule seems to function as a clamp for two DNA chains and forms a condensate. The condensate was found to have a toroidal shape. By surveying more than 100 microscopic images of such condensates formed in 1 μg/ml drug solution, a mechanism of toroidal condensate formation has been proposed.View full abstractDownload PDF (244K) -
Yorinobu Yonezawa, Sumio Ishida, Shinobu Suzuki, Hisakazu SunadaArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 220-224
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSIn order to examine basic properties of release from and through wax matrix layer, reservoir device matrix tablet was prepared from a physical mixture of hydrogenated caster oil and drug that was the same one in the reservoir. Release process could be divided into two stages. The first stage was the formation process of water channel by dissolving the drug in the wax matrix layer, and dissolved drug was released from the matrix layer following the square-root-of-time law equation. Hence, the drug penetration coefficient and tortuosity in the matrix layer were estimated. The second stage was the zero order release process of drug in the reservoir through the wax matrix layer. The release rate constant was calculated from the slope of line. Hence, the drug permeability coefficient and tortuosity were estimated. Fundamentally, tortuosity can not be expressed by some meaningful factors, and is obtained as an experimental result. By preparing wax matrix system from a physical mixture other than melted granule method, it was suggested that the matrix structure was uniform three-dimensionally. As a result, tortuosity could be expressed by a function of porosity, because unrecognized factors such as the surface coverage and thickness of melted wax on the soluble component should not be involved.View full abstractDownload PDF (68K) -
Reiko Fujita, Noriyuki Watanabe, Hiroshi TomisawaArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 225-228
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESS2-Alkyl-1-alkylthioisoquinolinium salts were readily prepared from 2-alkyl-1(2H)-isoquinolones via 2-alkyl-1(2H)-thioisoquinolones in two steps. Under mild conditions, the reaction of 2-alkyl-l-alkylthioisoquinolinium salts with active methylene compounds in the presence of sodium hydride afforded 2-alkyl-1-(substituted methylene)iso-quinolines in good yields. Pyrrolo[2,1-a]isoquinolines were synthesized by the cyclization of 2-benzyl-1-(substituted methylene)isoquinolines using acetic anhydride.View full abstractDownload PDF (60K) -
Tetsuya Araki, Yukinori Kawai, Ikumi Ohta, Hiroaki KitaokaArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 229-234
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSSitafloxacin (STFX) hydrate, an antimicrobial agent, is photo-labile in aqueous solutions. The photodegradation rates (k) in neutral solutions were higher than those observed in acidic and alkaline solutions and maximum at the maximum absorption wavelength of STFX. The structures of photodegradation products were elucidated as 7-[7-amino-5-azaspiro[2.4]heptan-5-yl]-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid and 1-(1-amino-2-{[6-fluoro-1-(2-fluoro-1-cyclopropyl)-1,4-dihydro-4-oxo-3-quinolin-7-yl]-amino}ethyl)cyclopropanecarbaldehyde. This implies that dechlorination is the key step in the photodegradation of STFX. The effect of halide ions on the photodegradation of STFX was estimated by observing the increments in the photostability of STFX with the addition of chloride ions. In contrast, in the presence of bromide ions, instead of increased photostability of the STFX rate, a new photodegradation product in the presence of bromide ion was observed. The structure of this new photodegradation product was an 8-bromo form of STFX, which was substituted for chlorine at the 8-position, so the dissociation of C–Cl bond at the 8-position of STFX was the rate-limiting step in the initial process of the photodegradation. STFX generated ·C (carbon centered radical) and ·OH (hydroxyl radical) in the process of photodegradation in a pH 4.0 buffer. On the contrary, STFX did not generate ·C in the presence of chloride ion in a pH 4.0 buffer. The ·C was generated and then degraded into the above degradation products by photoirradiation in the absence of chloride ion, but the ·C immediately reacted with chloride when it was present. As a result, the C–Cl bond was recovered leading to a possible increase in the apparent photostability.View full abstractDownload PDF (81K) -
Akito Yasuhara, Yousuke Takeda, Naoyuki Suzuki, Takao SakamotoArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 235-238
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSThe reaction of ethyl 2-ethynylphenylcarbamate derivative with alkenes in the presence of a palladium(II) catalyst, copper dichloride and tetrabutylammonium fluoride (TBAF) produced 2-substituted 3-ethenylindoles during refluxing. The intramolecular cyclization reaction of ethyl 2-ethynylphenylcarbamates, which have an ethenyl part in the ethynyl group, was also used to produce carbazole derivatives.View full abstractDownload PDF (63K) -
Tetsunori Fujisawa, Shinjiro Odake, Yuji Ogawa, Junko Yasuda, Yasuo Mo ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 239-252
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSFibroblast collagenase (MMP-1), a member of the matrix metalloproteinases family, is believed to be a pathogenesis of arthritis, by cleaving triple-helical type II collagen in cartilage. From the similarity of the active site zinc binding mode with hydroxamate, we designed and synthesized α-mercaptocarbonyl possessing compounds (3—5), which incorporated various peptide sequences as enzyme recognition sites. The P4–P1 peptide incorporating compound (3) exhibited as potent inhibition as the hydroxamate (1) and the carboxylate (2) type inhibitors, with an IC50 of 10−6 M order against MMP-1. But the inhibitor (3) related compounds (6—8) displayed decreased or no inhibitory potencies. These results suggest that the existence of both the carbonyl and thiol groups might be critical for the inhibition, and the distance between the two functional groups is important for inhibitory potency. For Pn′ peptide incorporating compounds (4a—k), except for 4h and 4k, all compounds showed IC50 values under sub-nanomolar. Among them, for potent inhibition, Leu was better than Phe and Val as the P1′ amino acid, and the P2′ position amino acid was necessary, and preferentially Phe. Insertion of the Pn peptide into 4d or 4k, giving compounds 5a—c, did not increase the activities of 4d and 4k. Substitution of the mercapto group with other functional groups lost the activity of compound 4a. The stereochemical preference at the thiol-attached position was also determined by preparation of both isomers of 4a. It was found that the S configuration compound (36b) is approximately 100 times more potent than the corresponding R-isomer (36a).View full abstractDownload PDF (153K) -
Yoshie Horiguchi, Hirokazu Kodama, Masayoshi Nakamura, Tsuyoshi Yoshim ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 253-257
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSA synthesis of 1,1-disubstituted 1,2,3,4-tetrahydroisoquinolines (6) was achieved in a highly efficient manner via Pictet–Spengler reaction of arylethylamines (1) and acyclic and cyclic ketones (2) using titanium (IV) isopropoxide and acetic-formic anhydride. The cyclization of the in situ formed acyliminium ion (4) to N-formyl 1,2,3,4-tetrahydroisoquinoline (5) was greatly facilitated by using trifluoroacetic acid as an additional reagent. The Pictet–Spengler reaction was carried out by one pot procedure, providing a convenient and effective method for preparing various 1,2,3,4-tetrahydroisoquinolines.View full abstractDownload PDF (66K) -
Ying-Jun Zhang, Takashi Tanaka, Yayoi Betsumiya, Rie Kusano, Atsushi M ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 258-262
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSThe association of 10 different tannins and related polyphenols with gramicidin S, a cyclic peptide having a rigid β-turn structure, has been examined using 1H-NMR spectroscopy. In the presence of pentagalloylglucose and epigallocatechin-3-O-gallate, the proton signals due to proline and the adjacent phenylalanine moieties selectively shifted to up field, suggesting a regioselective association with the β-turn structure. The association was also supported by the observation of intermolecular nuclear Overhauser effects between epigallocatechin-3-O-gallate and the peptide. In contrast, ellagitannins, biogenetically derived from pentagalloylglucose, showed small and non-selective chemical shift changes, suggesting that interaction with these tannins is relatively weak. The hydrophobicity of the tannin molecules and the steric hindrance of the interaction site are thought to be important in the association.View full abstractDownload PDF (76K) -
Koji Urakami, Yasushi Shono, Atsuya Higashi, Kazuichi Umemoto, Masayuk ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 263-267
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSA novel method for thermodynamic stability studies of polymorphic drug substances has been developed. In order to estimate the transition temperature for an enantiotropic polymorphic pair, a formula for calculating the temperature at which the solubilities of each polymorph become equal has been derived with heat of solution and solubility as the variables. This formula is based on the assumption that van't Hoff plots (logarithmic solubility versus reciprocal of absolute temperature plots) of each polymorph show a straight line (heat of solution is independent of temperature) whose slope can be expressed as a function of heat of solution. The transition temperatures for seratrodast, acetazolamide and carbamazepine polymorphic pairs calculated by the formula were in good agreement with the results of previous studies. Furthermore, the calculated transition temperature for the indomethacin polymorphic pair was above the melting point, an unrealistic temperature range, suggesting that these polymorphs are monotropically related. Since this formula requires solubility data at only one arbitrary temperature other than heat of solution data for both polymorphs in a polymorphic pair, the proposed method is much faster than the conventional method requiring solubility data at five or more different temperatures for the preparation of van't Hoff plots.View full abstractDownload PDF (64K) -
Liva Rakotondraibe Romuald Harinantenaina, Ryoji Kasai, Kazuo YamasakiArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 268-271
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSSix new ent-kaurane diterpenoid glycosides, cussoracosides A (3), B (4), C (5), D (6), E (7), and F (8) were isolated from the dried leaves of Cussonia racemosa, along with two known compounds identified as β-D-glucopyranosyl ent-16β,17-dihydroxykauran-19-oate (1) and paniculoside IV (2). The structures of these new compounds were deduced on the basis of chemical and spectroscopic evidence.View full abstractDownload PDF (57K)
Notes
-
Guo-Hua Chu, Paula A. Witt-Enderby, Marla Jones, Pui-Kai LiArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 272-275
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSWe report the synthesis and radioligand binding analysis of a series of naphthalenic melatonin receptor ligands, N-[2-(7-alkoxy-2-methoxy-1-naphthyl)ethyl]propionamide. This series of ligands exhibits subpicomolar binding affinity to both MT1 and MT2 melatonin receptors expressed in chinese hamster ovary (CHO) cells.View full abstractDownload PDF (58K) -
Meei-Jen Liou, Pei-Lin Wu, Tian-Shung WuArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 276-279
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSFour new naphthohydroquinones, rubinaphthins A (1), B (2), C (3), and D (4), together with 11 known compounds were isolated and characterized from the roots of Rubia yunnanensis. The structures of 1—4 were elucidated by spectral analysis and chemical transformation.View full abstractDownload PDF (58K) -
Toshiko Tanimoto, Akiko Ikuta, Mayumi Sugiyama, Kyoko KoizumiArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 280-283
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSThe chromatographic behavior of manno-oligosaccharides derived from Saccharomyces cerevisiae mannan on two kinds of HPLC columns, an aminopropyl-silica column or a graphitized carbon column (GCC), was investigated. The order of elution of manno-oligosaccharides on both columns with acetonitrile–water was almost the same, that is, the retention increased with increasing molecular size. However, the GCC made it possible to isolate completely two isomers of mannotrioses (M3-1 and M3-2) with different linkage positions. We reinvestigated the structures of mannobiose (M2), M3s, and mannotetraose (M4) that were completely isolated by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and NMR spectroscopy.View full abstractDownload PDF (65K) -
Hitoshi Yoshimitsu, Makiko Nishida, Mitsuko Yoshida, Toshihiro NoharaArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 284-286
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSFrom the fresh roots of Solanum abutiloides, four new 26-aminocholesteryl glycosides were obtained, and their structures were characterized by analysis of their spectra data, including two-dimensional (2D) NMR spectroscopy. These compounds were regarded as key intermediates in the biogenesis of steroidal alkaloids.View full abstractDownload PDF (49K) -
Tadashi Shiraiwa, Keiji Fukuda, Motoki KuboArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 287-291
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSAn attempt was made to use a simple procedure to obtain D- and L-allothreonine (D- and L-aThr), which are non-proteinogenic α-amino acids and are useful as chiral reagents in asymmetric syntheses. DL-aThr that exists as a conglomerate was optically resolved by replacing crystallization with L-alanine (L-Ala) as an optically active co-solute. D-aThr was preferentially crystallized from an aqueous solution of DL-aThr in the presence of L-Ala, as was L-aThr in the presence of D-Ala. Furthermore, a diasteroisomeric mixture of D-aThr and L-threonine (L-Thr) and one of L-aThr and D-Thr were prepared, respectively, by epimerization of L- and D-Thr using salicylaldehyde as the catalyst in acetic acid. Based on the result of the replacing crystallization, D- and L-aThr were separated from aqueous solutions of the diastereoisomeric mixtures in the presence of L- and D-Ala. The partially resolved D- and L-aThr were recrystallized from water to yield the corresponding enantiomers in optically pure forms.View full abstractDownload PDF (67K) -
Susumu Sato, Teruo Komoto, Yoshihiko Kanamaru, Noriyuki Kawamoto, Tomo ...Article type: Note
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 292-297
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSNew μ-opioid receptor (MOR) agonists containing 4-hydroxypiperidine, piperidine and piperazine moieties were synthesized and evaluated to find a peripheral opioid analgesic. Among the synthesized compounds, [2-[1-[3-(N,N-dimethylcarbamoyl)-3,3-diphenylpropyl]-4-hydroxypiperidin-4-yl]phenoxy]acetic acid (8: SS620) having phenoxyacetic acid and 4-hydroxypiperidine moieties showed the highest agonist potency on the MOR in an isolated guinea-pig ileum preparation, and it also had selectivity to the human MOR expressed in Chinese hamster ovary (CHO)-K1 cells compared with the same types of δ- and κ-opioid receptors (DOR and KOR). In addition, compound 8 showed a 10 times more potent MOR agonist activity than loperamide. Furthermore, compound 8 showed a peripheral analgesic activity in vivo screening on rat.View full abstractDownload PDF (79K) -
Kunihiro Sumoto, Nobuko Mibu, Kazumi Yokomizo, Masaru UyedaArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 298-300
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSNew diphenylmethane-type 2,2′-dihydroxybisphenols (5a—d) were prepared regioselectively in good yields. We evaluated the antiviral activity of some bisphenol derivatives synthesized by the plaque reduction assay. Most of the compounds showed significant antiviral activity and the 4,4′-dihydroxybisphenol derivative (10) showed higher activity than 2,2′-bisphenol derivatives. This compound had EC50 value of 1.8 μg/m1.View full abstractDownload PDF (48K) -
Hisae KakoiArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 301-302
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESS2-Amino-3-benzyl-5-(p-hydroxyphenyl)pyrazine (2), a precursor of Watasenia preluciferin (coelenterazine) (1), is widely distributed in marine bioluminescent animals. It was prepared from p-hydroxyphenylglyoxal aldoxime (5) in two steps; by condensation with α-aminophenylpropiononitrile in the presence of TiCl4 in pyridine, followed by reduction of the resulting N-oxide (6) with Zn–AcOH in CH2Cl2 and produced 2, with an 89% overall yield. This procedure was linked with the facile one-step preluciferin synthesis reported in the previous paper. Thus, Watasenia preluciferin (1), frequently required for various chemiluminescent and bioluminescent studies, was coveniently synthesized in three steps from 5, with a 56% overall yield, overcoming the difficulty of obtaining it from natural sources.View full abstractDownload PDF (38K) -
Hiroshi Nakamura, Machiko Ono, Takeshi Yamada, Atsushi Numata, Hiroyuk ...Article type: Note
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 303-306
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSseco-Macrosphelide E has been isolated from a strain of Periconia byssoides originally separated from the sea hare Aplysia kurodai. Its absolute stereostructure, with the same configuration as that of macrosphelide E, have been elucidated on the basis of spectroscopic analyses and unambiguous synthesis.View full abstractDownload PDF (76K)
Communicatins to the Editor
-
One-Pot Preparation of Chiral β-Amino Esters by Rhodium-Catalyzed Three-Components Coupling ReactionToshio Honda, Hitoshi Wakabayashi, Kazuo KanaiArticle type: Communication to the Editor
Subject area: [not specified]
2002 Volume 50 Issue 2 Pages 307-308
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSChiral β-amino esters are synthesized in one-pot from three components, amines, aldehydes, and ethyl bromoacetate, under the rhodium-catalyzed Reformatsky-type reaction condition, where complete diastereoselection is achieved in the nucleophilic addition step of ethyl bromoacetate to the imines prepared in situ.View full abstractDownload PDF (44K)
- |<
- <
- 1
- >
- >|