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Volume 56, Issue 8
Displaying 1-28 of 28 articles from this issue
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Review
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Satoshi IchikawaArticle type: Review
2008 Volume 56 Issue 8 Pages 1059-1072
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSSynthetic nucleoside chemistry based on nucleoside natural products synthesis were described. First, a samarium diiodide (SmI2)-promoted aldol reaction with the use of α-phenylthioketone as an enolate was developed. The characteristics of this reaction are that the enolate can be regioselectively generated and the aldol reaction proceeds under near neutral condition. This reaction is proved to be a powerful reaction for the synthesis of complex nucleoside natural products, and herbicidin B and fully protected tunicaminyluracil, which were undecose nucleoside natural products, were synthesized. Next, the synthetic methodology of the caprazamycins, which are promising antibacterial nucleoside natural products, was also developed by the strategy including β-selective ribosylation without using a neighboring group participation. Our synthetic route provided a range of key analogues with partial structures to define the pharmacophore. Simplification of the caprazamycins was further pursued to develop diketopiperazine analogs.View full abstractDownload PDF (894K)
Regular Articles
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Takehisa Hanawa, Chikako Tsuchiya, Naoko Endo, Kazumi Hanawa, Masahiko ...Article type: Regular Article
2008 Volume 56 Issue 8 Pages 1073-1076
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSA formulation study of intravesical oxybutynin (OB) preparations was carried out in order to improve the effectiveness in intravesical instillation therapy for spastic neurogenetic bladder. Sodium hyaluronate (HYA) was introduced to enhance the muco-adhesiveness of the instillation preparation, and the physicochemical properties of the OB formulation were evaluated in comparison with a conventional formulation containing hydroxypropylcellulose (HPC). The viscous properties and in vitro adhesiveness increased with the amount of the polymeric additives, and retention properties of OB in rabbit bladder were comparable after addition of 0.4% HYA and 1.0% HPC. HYA was able to enhance the intravesical retention properties of OB instillation solution to a lesser degree than HPC, it seemed to be a useful additive in the OB instillation due to its safety and mucosal-protective effect.View full abstractDownload PDF (143K) -
Sanat Kumar Basu, Adhiyaman RajendranArticle type: Regular Article
2008 Volume 56 Issue 8 Pages 1077-1084
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSNateglinide loaded alginate-chitosan beads were prepared by ionic gelation method for controlling the drug release by using various combinations of chitosan and Ca2+ as cation and alginate as anion. IR spectrometry, scanning electron microscopy, differential scanning calorimetry and X-ray powder diffractometry were used to investigate the physicochemical characteristics of the drug in the bead formulations. The calcium content in beads was determined by atomic absorption spectroscopy. The swelling ability of the beads in different media (pH 1.2, 4.5, 6.8) has been found to be dependent on the presence of polyelectrolyte complex of the beads and the pH of the media. The ability to release the Nateglinide was examined as a function of chitosan and calcium chloride content in the gelation medium. It is evident that the rate of drug release and its kinetics could be controlled by changing the chitosan and the calcium chloride concentrations. Calcium alginate beads released more than 95% of drug with in 8 h; whereas coated beads sustained the drug release and released only 75—80% of drug. The drug release mechanism analyzed indicates that the release follows either “anomalous transport” or “case-II transport”.View full abstractDownload PDF (731K) -
Daniela Catarzi, Vittoria Colotta, Flavia Varano, Guido Filacchioni, P ...Article type: Regular Article
2008 Volume 56 Issue 8 Pages 1085-1091
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSIn this paper, we report a study on some new 4,5-dihydro-4-oxo-1,2,4-triazolo[1,5-a]quinoxaline-2-carboxylate derivatives (TQXs), bearing a nitrogen-containing heterocycle at position-9, and designed as (R,S)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptor antagonists. These compounds ensue from the structural modification of previously reported 8-heteroaryl-TQXs which were endowed with high affinity and selectivity for the AMPA receptor. All the newly synthesized compounds were biologically evaluated for their binding at the AMPA receptor. Gly/N-methyl-D-aspartic acid (NMDA) and kainic acid (KA) high-affinity binding assays were performed to assess the selectivity of the reported derivatives toward the AMPA receptor. This study produced some new TQXs which are less potent than the reference compounds, and endowed with a mixed AMPA and Gly/NMDA receptor binding affinity. To rationalize the experimental findings, a molecular modeling study was performed by docking some TQX derivatives to the AMPA receptor model.View full abstractDownload PDF (605K) -
Wafaa El-Sayed HassanArticle type: Regular Article
2008 Volume 56 Issue 8 Pages 1092-1096
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSThree rapid, simple, reproducible and sensitive extractive colorimetric methods (A—C) for assaying dothiepin hydrochloride (I) and risperidone (II) in bulk sample and in dosage forms were investigated. Methods A and B are based on the formation of an ion pair complexes with methyl orange (A) and orange G (B), whereas method C depends on ternary complex formation between cobalt thiocyanate and the studied drug I or II. The optimum reaction conditions were investigated and it was observed the calibration curves resulting from the measurements of absorbance concentration relations of the extracted complexes were linear over the concentration range 0.1—12 μg ml−1 for method A, 0.5—11 μg ml−1 for method B, and 3.2—80 μg ml−1 for method C with a relative standard deviation (RSD) of 1.17 and 1.28 for drug I and II, respectively. The molar absorptivity, Sandell sensitivity, Ringbom optimum concentration ranges, and detection and quantification limits for all complexes were calculated and evaluated at maximum wavelengths of 423, 498, and 625 nm, using methods A, B, and C, respectively. The interference from excipients commonly present in dosage forms and common degradation products was studied. The proposed methods are highly specific for the determination of drugs I and II, in their dosage forms applying the standard additions technique without any interference from common excipients. The proposed methods have been compared statistically to the reference methods and found to be simple, accurate (t-test) and reproducible (F-value).View full abstractDownload PDF (96K) -
Shigehiko Takegami, Keisuke Kitamura, Hiroto Kawada, Yu Matsumoto, Tat ...Article type: Regular Article
2008 Volume 56 Issue 8 Pages 1097-1102
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSA new lipid nano-emulsion (LNE) was prepared from soybean oil and phosphatidylcholine (PC) employing two cosurfactants, sodium palmitate (PA) for reduced droplet size and sucrose palmitate (SP) for stability enhancement. The mean droplet size of LNEs prepared at a PA/PC (w/w) ratio of larger than 1/10 was found to be ca. 50 nm by dynamic light scattering and atomic force microscopy. However, during the 12-month storage, the PA/PC (1/10)-LNE showed an increase in mean droplet size and broadening of the droplet size distribution due to coalescence of the LNE particles. In a saline solution, the coalescence proceeded very rapidly, i.e., the mean droplet size increased to more than 150 nm within 0.5 h. To suppress the coalescence of LNE particles, four sucrose fatty acid esters of different chain lengths were examined as candidate cosurfactants. The results showed that PA/SP/PC (1/4/10)-LNE could maintain a mean droplet size around 50 nm for 12 months. In a saline solution, the mean droplet size could be maintained within 100 nm even after 24 h. Slight formation of flocculation in the LNEs depending on the storage period was suggested by measurement of the 31P nuclear magnetic resonance line width of the LNEs.View full abstractDownload PDF (1510K) -
Yoshinori Onuki, Chihiro Hagiwara, Ko Sugibayashi, Kozo TakayamaArticle type: Regular Article
2008 Volume 56 Issue 8 Pages 1103-1109
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSTo understand more fully the effect of polyunsaturated fatty acids (PUFAs) on lipid bilayers, we investigated the effects of treatment with fatty acids on the properties of a model membrane. Three kinds of liposomes comprising dipalmitoylphosphatidylcholine (DPPC), dioleylphosphatidylcholine (DOPC), and cholesterol (Ch) were used as the model membrane, and the fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH) and detergent insolubility were determined. Characterization of the liposomes clarified that DPPC, DPPC/Ch, and DPPC/DOPC/Ch existed as solid-ordered phase (Lβ), liquid-ordered phase (lo), and a mixture of lo and liquid-disordered phase (Lα) membranes at room temperature. Treatment with unsaturated fatty acids such as oleic acid (OA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) markedly decreased the fluorescence anisotropy value and detergent insolubility. PUFAs and OA had different effects on the model membranes. In DPPC liposomes, the most prominent change was induced by PUFAs, whereas, in DPPC/Ch and DPPC/DOPC/Ch liposomes, OA had a stronger effect than PUFAs. The effect of PUFAs was strongly affected by the amount of Ch in the membrane, which confirmed a specific effect of PUFAs on the Ch-poor membrane domain. We further explored the effect of fatty acids dispersed in a water-in-oil-in-water multiple emulsion and found that unsaturated fatty acids acted on the membranes even when incorporated in emulsion form. These findings suggest that treatment with PUFAs increases the segregation of ordered and disordered phase domains in membranes.View full abstractDownload PDF (168K) -
Hiroshi Fukushima, Akira Hiratate, Masato Takahashi, Masako Saito-Hori ...Article type: Regular Article
2008 Volume 56 Issue 8 Pages 1110-1117
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSDipeptidyl peptidase IV (DPP-IV) inhibitors have attracted attention as potential drugs for use in the treatment of type 2 diabetes because they prevent the degradation of glucagon-like peptide-1 (GLP-1) and extend its duration of action. We previously reported that 2-cyano-4-fluoropyrrolidines act as potent DPP-IV inhibitors and have been modifying the 1-position of pyrrolidine to obtain more useful inhibitors. An L-tert-butylglycine derivative was found to be a stable and potent DPP-IV inhibitor that exhibits a glucose lowering effect in vivo. Here, we report the synthesis of and biological data on the aforementioned derivatives.View full abstractDownload PDF (356K) -
Li-Fang Fan, Wei He, Min Bai, Qing Du, Bai Xiang, Yong-Zhen Chang, De- ...Article type: Regular Article
2008 Volume 56 Issue 8 Pages 1118-1125
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSThe major objectives of this study were i) to evaluate the permeability and swelling characteristics of isolated films prepared by mixing of pectin with ethylcellulose; and ii) to assess the absorption and in vitro/in vivo correlation (IVIVC) of 5-FU film-coated colon-targeted pellets in dogs. Free films were prepared by casting and solvent evaporation method. These free films were evaluated by swelling experiment and permeability to 5-FU in different media. Pectin/ethylcellulose films had suitable characteristics for colonic delivery; and when the addition of pectin was up to the ratio of 30%, the swelling and permeability of the mixed films was significantly increased in the simulated colonic fluid (SCF). Pharmacokinetic study in dogs gave Tmax/Cmax of 14 h/1.6 μg/ml and 16 h/1.7 μg/ml for total weight gain (TWG)-22% and 18% coated pellets, respectively. The plasma 5-FU levels of the TWG-22% and 18% coated pellets were maintained at a much lower level with a mean residence time (MRT) of 18—20 h, longer than 2.1 h for 5-FU uncoated pellets, confirming delayed absorption. There was no statistically significant difference in the area under the plasma concentration vs. times curve (AUC) values between the uncoated pellets and the coated pellets. Moreover, a good linear regression relationship was observed between the percent in vitro dissolution in SCF and the percent absorption or percent AUC. It was concluded that i) pectin within the mixed films were susceptible to colonic enzymes, and the film-coated pellets are potentially useful for colonic drug delivery; and ii) in vitro dissolution testing in SCF could be used to establish certain IVIVC for the colon-specific drug delivery systems activated by microflora.View full abstractDownload PDF (220K) -
Seiji Miwatashi, Yasuyoshi Arikawa, Tatsumi Matsumoto, Keiko Uga, Naoy ...Article type: Regular Article
2008 Volume 56 Issue 8 Pages 1126-1137
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSTo investigate the potency of an adenosine A3 receptor (A3AR) antagonist as an anti-asthmatic drug, a novel series of 4-phenyl-5-pyridyl-1,3-thiazole derivatives was synthesized and evaluated in human adenosine A1, A2A and A3 receptor and rat adenosine A3 receptor binding assays. From investigation of the SAR study, compound 7af was identified as a highly potent human and rat A3AR antagonist. This compound inhibited IB-MECA-induced plasma protein extravasation in the skin of rats and showed good oral absorption. Also, compound 7af significantly inhibited antigen-induced hyper-responsiveness to acetylcholine in actively sensitized Brown Norway rats. These results show that 4-phenyl-5-pyridyl-1,3-thiazole derivatives are potential candidates to enable the evaluation of A3AR antagonists. Further evaluation of this class of compounds may afford a novel anti-inflammatory agent such as an anti-asthmatic drug.View full abstractDownload PDF (361K) -
Yuki Tsunoda, Masafumi Okawa, Junei Kinjo, Tsuyoshi Ikeda, Toshihiro N ...Article type: Regular Article
2008 Volume 56 Issue 8 Pages 1138-1142
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSFrom the whole plants and the roots of Gueldenstaedtia multiflora, which has been used in traditional Chinese medicine, five new oleanane glycosides and one lupane glycoside were isolated together with eight known oleanane glycosides and a medicarpin derivative. These structures were determined based on MS and 2D-NMR spectra.View full abstractDownload PDF (167K) -
Jian-Xin Pu, Xue-Mei Gao, Chun Lei, Wei-Lie Xiao, Rui-Rui Wang, Li-Bin ...Article type: Regular Article
2008 Volume 56 Issue 8 Pages 1143-1146
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSTwo new tetrahydrofuran lignans, kadlongirins A and B (1, 2), a new cadinane-type sesquiterpenoid, 2,7-dihydroxy-11,12-dehydrocalamenene (3), together with seven known lignans, grandisin, fragransin B1, vladirol F, kadsuralignan C, otobaphenol, isoanwulignan, and 4-[4-(3,4-dimethoxyphenyl)-2,3-dimethylbutyl]-2-methoxy-phenol, were isolated from the leaves and stems of Kadsura longipedunculata. The structures of these new compounds were elucidated by spectroscopic methods. Compound 2 exhibited weak anti-human immunodeficiency virus-1 activity with an EC50 value of 16.0 μg/ml, and therapeutic index (TI) value of 6.7.View full abstractDownload PDF (252K) -
Lijun Zhou, Qingang Yang, Yong Wang, Youhong Hu, Xiaomin Luo, Donglu B ...Article type: Regular Article
2008 Volume 56 Issue 8 Pages 1147-1152
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSNovel potential human immunodeficiency virus (HIV) protease inhibitors were designed by a combination of nelfinavir and amprenavir motifs. The designed compounds were prepared by a facile synthetic route and their stereochemistry was further confirmed by a stereospecific synthesis from commercially available (S)-2-oxiranylmethyl m-nitrobenzenesulfonate. All compounds were tested for their ability in inhibiting HIV type 1 protease activity with the published method of reference 19. Derivatives 1a—u exhibited moderate to significant inhibitory activities in preliminary bioassay. The best compound 1a has IC50 value of 0.02 μM, comparable to that of amprenavir. A docking study on compounds 1a—u was performed using the published X-ray crystal structure of HIV type 1 protease, all compounds bound to the HIV type 1 protease in an extended conformation and the scaffoldings of the binding conformations could be aligned quite well. Comparative molecular field analysis (CoMFA) study was performed to explore the specific contributions of electrostatic and steric effects in the binding of these new compounds to HIV type 1 protease and a predictive CoMFA model was built with thirteen compounds as training set. Test analysis of other five compounds as test set demonstrated that the CoMFA model has strong predictive ability to this series of compounds. It will be very useful to further optimize the designed inhibitors.View full abstractDownload PDF (641K) -
Zhimin Zhao, Katsuyoshi Matsunami, Hideaki Otsuka, Takakazu Shinzato, ...Article type: Regular Article
2008 Volume 56 Issue 8 Pages 1153-1158
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSFrom the 1-BuOH-soluble fraction of a MeOH extract of leaves of Tarenna gracilipes, collected in Okinawa, seven new cycloartane glycosides, named tareciliosides A—G (4—10), were isolated together with three known compounds, D-mannitol (1), (R)-linalool 6-O-α-L-arabinopyranosyl-β-D-glucopyranoside (2), and mussaenoside (3). Their structures were elucidated through a combination of spectroscopic analyses.View full abstractDownload PDF (163K) -
Tsutomu Warashina, Kimiko Shikata, Toshio Miyase, Satoshi Fujii, Tadat ...Article type: Regular Article
2008 Volume 56 Issue 8 Pages 1159-1163
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSThree new cardenolide glycosides and six new acylated lignan glycosides were obtained along with nineteen known compounds from the aerial parts of Asclepias curassavica L. (Asclepiadaceae). The structure of each compound was determined based on interpretations of NMR and MS measurements and chemical evidence.View full abstractDownload PDF (153K)
Notes
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Chika Hashida, Naonobu Tanaka, Yoshiki Kashiwada, Makoto Ogawa, Yoshih ...Article type: Notes
2008 Volume 56 Issue 8 Pages 1164-1167
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSTwo new prenylated phloroglucinol derivatives and 15 known compounds were isolated from the aerial parts of Hypericum perforatum var. angustifolium. Their structures were determined on the basis of spectroscopic evidence.View full abstractDownload PDF (85K) -
Myun-Ho Bang, Min-Woo Han, Myoung-Chong Song, Jin-Gyeong Cho, Hae-Gon ...Article type: Notes
2008 Volume 56 Issue 8 Pages 1168-1172
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSRepeated silica gel and octadecyl silica gel (ODS) column chromatography of the aerial parts of Artemisia princeps PAMPANINI (Sajabalssuk) led to the isolation of a new sesquiterpenoid, 3-((S)-2-methylbutyryloxy)-costu-1(10),4(5)-dien-12,6α-olide (2), along with two previously reported sesquiterpenoids: 8α-angeloyloxy-3β,4β-epoxy-6βH,7αH,8βH-guaia-1(10),11(13)-dien-12,6α-olide (1, carlaolide B) and 3β,4β-epoxy-8α-isobutyryloxy-6βH,7αH,8βH-guaia-1(10),11(13)-dien-12,6α-olide (3, carlaolide A). The structure of compound 2 was elucidated by spectroscopic data analysis, including one dimensional (1D) and two dimensional (2D) nuclear magnetic resonance (NMR) experiments. Of the isolates, compound 2 exhibited potent cytotoxicity against human cervix adenocarcinoma cells and induced apoptosis.View full abstractDownload PDF (184K) -
Shingo Sato, Akihito Yashiro, Naoki Tsushima, Kenta HosakaArticle type: Notes
2008 Volume 56 Issue 8 Pages 1173-1176
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSA method for the synthesis of calix[4 and 6]arenes with two or three alternately arranged phloroglucinols and p-tert-butylphenols was studied using “3+1” and “5+1” approaches, compared to a simple one-pot synthesis based on a “1+1” approach. By using Yb(OTf)3 as a catalyst, each calix[4 and 6]arenes was afforded, in an overall yield of 20.7% and 11.8% in the “3+1” and “5+1” approaches, respectively, and 24.6% and 19.9% using a “1+1” approach with chlorobenzene and toluene as refluxing solvents, respectively.View full abstractDownload PDF (266K) -
Takashi Fukasawa, Takao Orii, Masayo Tanaka, Noriko Suzuki, Yasushi Ka ...Article type: Notes
2008 Volume 56 Issue 8 Pages 1177-1180
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSThere are many reports that the drug-induced taste disorder is ascribable to the chelate reaction of a drug with zinc ion and the following zinc deficiency. As a quantitative measure of the chelating ability of drugs with zinc ions, the chelating ability was estimated from the electrode potential change of the Zn2+/Zn(Hg) system during the addition of a drug. The electrode potential was measured in a water–N,N-dimethylformamide mixed solution and in an aqueous solution depending on the solubility of the drugs. The observed electrode potential change showed a positive correlation to the frequency of the drug-induced taste disorder that was supplied from the manufacturer of the original drug. The regression analysis was carried out assuming that the frequency of the taste disorder and the electrode potential change was linear. The F-values, p-values, and R2-values were 4.29, 0.13, 0.589, and 4.15, 0.13, 0.580, respectively. The positive correlation between the drug-induced taste disorder and the electrode potential change appeared evident if the uncertainty in the frequency of the taste disorder was taken into consideration. Thus the assumption of the zinc ion chelating mechanism on the drug-induced disorder was also evident except for cisplatin. The frequency of the drug-induced taste disorder of bezafibrate was estimated to be 0.4—0.5 from the regression analysis.View full abstractDownload PDF (89K) -
Midori Nishide, Yutaka Yoshikawa, Eriko U. Yoshikawa, Kinuyo Matsumoto ...Article type: Notes
2008 Volume 56 Issue 8 Pages 1181-1183
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSWe prepared 4 new Zn(II) complexes with Zn(O4), Zn(N2O2), and Zn(S2O2) coordination modes and evaluated their insulinomimetic activities in an in vitro study. The insulinomimetic activities of bis(pyrrole-2-carboxylato)zinc (Zn(pc)2), bis(α-furonic acidato)zinc (Zn(fa)2), bis(thiophene-2-carboxylato)zinc (Zn(tc)2), and bis(thiophene-2-acetato)zinc (Zn(ta)2) complexes were found to be higher than that of zinc sulfate (ZnSO4). Zn(ta)2 showed the highest insulinomimetic activity among the Zn(II) complexes because of its high lipophilicity.View full abstractDownload PDF (77K) -
Fumihiro Nagashima, Kozue Wakayama, Yuki Ioka, Yoshinori AsakawaArticle type: Notes
2008 Volume 56 Issue 8 Pages 1184-1188
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSThree new ent-verticillane diterpenoids have been isolated from the Japanese liverwort Jackiella javanica, together with known sesqui- and diterpenoids. Their absolute configurations were established by X-ray crystallographic analysis and circular dichroism spectroscopy.View full abstractDownload PDF (1153K) -
Ying-shu Zou, Ke Wang, Yang Zhang, Yuan Li, Jie Meng, Jian-bo WuArticle type: Notes
2008 Volume 56 Issue 8 Pages 1189-1190
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSA new compound named 713A was isolated from the fermentation broth of a fungal strain 713. The structure of 713A was elucidated by spectroscopic methods. In the screening for interleukin-6 (IL-6) receptor antagonist, 713A exhibited inhibitory activity to the binding of IL-6 and IL-6 receptor with an IC50 value of 8.6 μM.View full abstractDownload PDF (72K) -
Hyukjae Choi, Sun Kwan Oh, Wonho Yih, Jungwook Chin, Heonjoong Kang, J ...Article type: Notes
2008 Volume 56 Issue 8 Pages 1191-1193
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSCyanopeptolin CB071 (1), a trypsin inhibitor, was isolated from the freshwater cyanobacterium Aphanocapsa sp. Its complete structure was determined by detailed NMR spectroscopy and MS analyses, along with chemical reactions. The compound showed inhibition of trypsin at a concentration of IC50=2.5 μM.View full abstractDownload PDF (68K) -
Emiko Sato, Takayuki Mokudai, Yoshimi Niwano, Masato Kamibayashi, Masa ...Article type: Notes
2008 Volume 56 Issue 8 Pages 1194-1197
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSWe investigated a hypoxanthine (HPX) and xanthine oxidase (XOD) reaction by using a luminol analog 8-amino-5-chloro-7-phenylpyrido[3,4-d]pyridazine-1,4-(2H,3H)dione sodium salt (L-012)-mediated chemiluminescence (CL) response. Addition of a high activity of superoxide dismutase (SOD), a potent O2−· scavenger, and of a high concentration of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), a potent spin trapping agent, diminished completely the CL response. Whereas a high concentration of dimethyl sulfoxide (DMSO), as a potent ·OH scavenger could not attain to the complete diminishment of the CL response. It has been reported that luminol monoanion reacts with ·OH to form luminol radical, and then resultant luminol radical reacts with O2−· to elicit CL response. Complete scavenging for ·OH is assumed to result in lack of luminol radical, which in turn induces lack of CL response. However, our results did not support the idea. Furthermore, we examined the effect of L-012 on the DMPO-OOH formation in the presence or absence of DMSO in the HPX-XOD system by applying an electron spin resonance (ESR)-spin trapping method. The DMPO-OOH formation was inhibited even in the presence of DMSO, and the rate constant (k2) between L-012 and O2−· obtained in the presence of DMSO was 9.77×102 M−1 s−1 and the constant in the absence of DMSO was 2.97×103 M−1 s−1. The data suggests that L-012 is converted to a radical form that reacts with O2−· even under the conditions of the absence of ·OH. From these, we postulate that the existence of a reactive intermediate oxygen species in the HPX-XOD system.View full abstractDownload PDF (137K) -
Hyi-Seung Lee, Su Young Park, Chung Ja Sim, Jung-Rae RhoArticle type: Notes
2008 Volume 56 Issue 8 Pages 1198-1200
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSPhorbasins G—I (1—3) were isolated from the sponge Phorbas gukulensis collected from Gagu-Do, Korea. The complete structure of the compounds was determined by NMR and MS spectroscopy, along with chemical reaction. Phorbasin G (1) was found to be a diterpene possessing a taurine residue.View full abstractDownload PDF (65K) -
Miyako Moriyama, Jian-Mei Huang, Chun-Shu Yang, Miwa Kubo, Kenichi Har ...Article type: Notes
2008 Volume 56 Issue 8 Pages 1201-1204
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSTwo new seco-prezizaane-type sesquiterpenoids 1, 2 and two new prenylated phenylpropanoids 4, 5 were isolated along with 15 known compounds from Illicium fargesii. The structures of 1, 2 were elucidated as 10-O-(E)- and 10-O-(Z)-cinnamoyl-2-oxo-6-deoxyneoanisatin by analysis of spectroscopic data and by comparison of their NMR data with those of previously reported 2-oxo-6-deoxyneoanisatin (3), respectively, whereas the structures of 4, 5 were identified as 4-allyl-2-(3-methylbut-2-en-1-yl)phenol and 4-allyl-2-(2-methylbut-3-en-2-yl)phenol, respectively, on the basis of spectroscopic data. Among the isolated compounds, macranthol (7) was found to have neuroprotective activity at 5—10 μM in rat cortical neurons cultured in DMEM/N2 medium.View full abstractDownload PDF (189K) -
Kiyosei Takasu, Yuta Miyakawa, Masataka Ihara, Hidetoshi TokuyamaArticle type: Notes
2008 Volume 56 Issue 8 Pages 1205-1206
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSWe describe here (2+2) cycloaddition reaction of alkyl enol ethers with acrylates catalyzed by triethylsilyl triflic imide (Et3SiNTf2), which was in situ generated from triethylsilane and triflic imide. The reaction efficiently provides substituted cyclobutanes bearing alkoxy function in a stereoselective manner.View full abstractDownload PDF (72K) -
Weihua Yuan, Yanghua Yi, Haifeng Tang, Mei Xue, Zenglei Wang, Guoquan ...Article type: Notes
2008 Volume 56 Issue 8 Pages 1207-1211
Published: August 01, 2008
Released on J-STAGE: August 01, 2008
JOURNAL FREE ACCESSTwo new holostan-type triterpene glycosides, 17-hydroxy fuscocineroside B (1) and 25-hydroxy fuscocineroside B (2), together with a known triterpene glycoside, fuscocineroside B (3) were isolated from the sea cucumber Bohadschia marmorata JAEGER. The structures of the new triterpene glycosides were elucidated on the basis of spectroscopic analyses and chemical reactions. Compounds 1 and 3 showed considerable antifungal activities against six strains.View full abstractDownload PDF (120K)
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