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Volume 55, Issue 5
Displaying 1-28 of 28 articles from this issue
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Review
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Biswanath Dinda, Sudhan Debnath, Yoshihiro Harigaya2007 Volume 55 Issue 5 Pages 689-728
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSNaturally occurring new secoiridoids published during 1994—2005 are reviewed with available physical and spectral data: mp, [α]D, UV, IR, 1H- and 13C-NMR and plant source. The works on biological and pharmacological activity of naturally occurring iridoids and secoiridoids reported during 1998—2005 are also reviewed. Bioactivities like antiallergic, antiarthritis, antibacterial, anticancer, anticoagulant, anticomplement, antifungal, antiinflammatory, antioxidative, antiprotozoal, antispasmodic, antiviral, immunomodulatory, neuroprotective, nerve growth factor potentiating and wound healing activities are highlighted.View full abstractDownload PDF (1613K)
Regular Articles
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Miyoko Kamigauchi, Kazuko Kawanishi, Hirofumi Ohishi, Toshimasa Ishida2007 Volume 55 Issue 5 Pages 729-733
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe enhancing effects of α-, β-, and γ-cyclodextrins (CyDs) on the aqueous extraction of ephedrine and berberine from the natural medicines were investigated in HPLC analysis, and the greatest effect was observed for β- and γ-CyDs. To clarify the structural basis of such an increased extraction effect with β-CyD, possible interaction modes of (1R,2S)-ephedrine with α-, β-, and γ-CyDs were investigated using molecular dynamic simulations in an aqueous solution system. It was shown that the wrapping model of ephedrine by β-CyD is the most compact and thus increases the solubility most effectively, compared with those by other CyDs. The same mode could be possible for the greatest effect of γ-CyD on the extraction of berberine from natural medicines. This clearly shows that CyDs are useful additives for the effective extraction of bioactive alkaloids from natural medicines.View full abstractDownload PDF (1437K) -
Thomas Gaslonde, Sylvie Michel, Michel Koch, Bruno Pfeiffer, Sté ...2007 Volume 55 Issue 5 Pages 734-738
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSCoupling of 6-hydroxy-3,3-14-trimethyl-3,14-dihydro-7H-benzo[b]pyrano[3,2-h]acridin-7-one (6) with α,ω-diiodoalkanes of varying length under alkaline conditions gave dimers 7—10. Halogenated ethers 11—14, cyclization products 15—17, and compounds 18—22 were also isolated in small yield from the reaction mixtures. Compounds 7—10 were more potent than acronycine and benzo[b]acronycine in inhibiting L1210 cell proliferation. The length of the alkyl ether linkage between the two benzopyranoacridone units had a dramatic influence on the cytotoxic activity. Compound 9 (n=5) was the most active, with an IC50 value against L1210 cells within the same range of magnitude as diacetate 5, currently under clinical development.View full abstractDownload PDF (149K) -
Yoshimi Hashimoto, Chiharu Matsunaga, Emi Tokuyama, Eriko Tsuji, Takah ...2007 Volume 55 Issue 5 Pages 739-746
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe purpose of the present study was the quantitative prediction of the bitterness-suppressing effect of sweeteners (sucrose or sugar alcohols) on the bitterness of famotidine (or quinine sulfate as control) solutions using an artificial taste sensor. Firstly, we examined the response characteristics of the sensor response to sweetness. The sensor membrane is charged negatively in the presence of sweeteners, which tend to receive protons from one of the components of the sensor membrane. The magnitude of the sensor response was shown to increase in direct proportion to the concentration of the sweetener. Secondly, we used direct or indirect methods to evaluate and predict the bitterness-suppressing effect of sweeteners on 1 mg/ml famotidine and 81.4 μM quinine sulfate solutions. In direct method, a regression between the sensor output of the sweetness-responsive sensor and the bitterness intensity obtained in human gustatory tests of famotidine solutions containing sweeteners at various concentrations, was performed. As a result, we were able to predict directly the bitterness intensity of the mixed solution. Finally, we also evaluated the bitterness intensity of the dissolution media of commercially available, orally disintegrating tablets containing famotidine by the combined usage of bitterness- and sweetness-responsive sensor. We found that the sugar alcohols in the tablet seem to be effective in the bitterness-suppression of famotidine from these tablets, especially in the initial phase (within 30 s) of the disintegration process.View full abstractDownload PDF (237K) -
Anna Kusakiewicz-Dawid, Elżbieta Masiukiewicz, Barbara Rzeszotars ...2007 Volume 55 Issue 5 Pages 747-752
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSEthyl 3-amino-1H-pyrazole-4-carboxylate (1) was yielded through total synthesis and reacted with acetic anhydride to give the acetylated products 2—6. Compounds 1—6 were studied with HPLC, X-ray, FT-IR, 1H-NMR, 13C-NMR and MS. Acetylation was carried out in solvents of various polarity, namely; chloroform; dioxane; DMF; acetic anhydride, at room temperature and at boiling points; and in the presence and absence of DMAP. The acetylated products are mainly nitrogen atoms in the ring. The position of the ring proton in the solution was based on NOESY; multinuclear HMBC, HSQC spectra and calculations. For equivalent amounts (1—1.5 mol) of acetic anhydride at room temperature two products of monoacetylation are produced in the ring: 2 and 3, ca. 2 : 1 and at the same time only small amount of the third product of monoacetylated, 5 in DMF, as well the product diacetylated, 4. The greatest amount of the product 4 is produced during the reaction with chloroform. However, in this solvent and in dioxane no product 5 is produced. Compound 2 is, largely, formed in dimethylformamide, in the presence DMAP, 0.2 eq. In the presence of this catalytic base, for the first hour, there is a mixture 2 and 3 to the ratio ca. 95 : 5. With 8 eq of Ac2O at reflux, after another hour, the compounds 3, 4 and 6 appear about equal amounts. After a longer time, the compound, which appears most in this mixture is triacetylated derivative 6. The structural and spectroscopic characteristics of compounds 1—6 have been given and the methods for their preparation have been provided.View full abstractDownload PDF (449K) -
ShengJun Mao, Hui Jin, YueQi Bi, Zhen Liang, Hui Li, ShiXiang Hou2007 Volume 55 Issue 5 Pages 753-756
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe ion-pair reversed-phase HPLC method for determination of sodium tanshinone IIA sulfonate (STS) in various biological samples was for the first time developed and validated, and was applied for pharmacokinetics and tissue distribution studies of intravenously administrated STS in mice. A linear relation was found between peak area and STS concentrations within the ranges of 0.1—5 μg/ml for plasma, 0.1—5 μg/g of tissue for kidney homogenate, 0.1—20 μg/g of tissue for liver homogenate, 0.1—1 μg/g of tissue for heart, spleen and lung homogenates, respectively. In plasma and tissues, the limit of quantification (LOQ) and the limit of detection (LOD) for STS were 100 ng/ml and 20 ng/ml. In all biological specimens, the average inter- and intra-day precision of STS were within 4.9%. The recoveries were more than 92% at all concentration levels in each type of biological specimens. STS plasma concentration–time data were best fitted with a two-compartment model, characterized by an initial rapid phase of drug concentration decrease, and a slower terminal elimination phase. The pharmacokinetics of STS was characterized with a distribution half-life (t1/2α) of 1.2±0.18 min, a terminal half-life (t1/2β) of 21.6±2.4 min, a distribution volume (V) of 0.057±0.011 l/kg, a plasma clearance (CL) of 0.86±0.12 l/h/kg and an AUC0—∞ of 58.41±6.21 μg·h/ml. STS was widely distributed into most tissues and was obviously accumulated in liver. This results indicated that STS may be promising to treat liver disease.View full abstractDownload PDF (227K) -
Kur-Ta Cheng, Feng-Lin Hsu, Shih-Hui Chen, Peng-Ke Hsieh, Hsu-Shan Hua ...2007 Volume 55 Issue 5 Pages 757-761
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSA new biflavonoid, 2,3-dihydro-4′,4′′′-di-O-methylamentoflavone (5), and five known compounds, (−)-catechin (1), quercetin (2), 2,3-dihydrosciadopitysin (3), sciadopitysin (4), and isoginkgetin (6), were isolated from Podocarpus macrophyllus var. macrophyllus (Podocarpaceae). These compounds were evaluated their ability to inhibit cellular tyrosinase activity and for their melanin inhibitory activity in human epidermal melanocytes (HEMn). In the melanin synthesis assay, 2,3-dihydro-4′,4′′′-di-O-methylamentoflavone (5) showed a potent anti-tyrosinase effect with IC50=0.098 mM in HEMn. It also significantly decreased both protein and mRNA levels of the tyrosinase-related protein-2 (TRP-2) by Western blot and quantitative real-time PCR (qRT-PCR) analysis. These findings suggest that the new compound, 2,3-dihydro-4′,4′′′-di-O-methylamentoflavone (5), is the most active component of P. macrophyllus var. macrophyllus in inhibiting pigmentation and that this inhibition is exerted through inhibition of transcription of the genes encoding TRP2.View full abstractDownload PDF (219K) -
Shang-Kwei Wang, Chang-Yih Duh2007 Volume 55 Issue 5 Pages 762-765
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSSeven new nardosinane sesquiterpenoids, elongatols A—G (1—7) were isolated from the methylene chloride solubles of the Formosan soft coral Nephthea elongata. Their structures were elucidated by extensive spectroscopic analysis and their cytotoxicity against selected cancer cells was measured in vitro.View full abstractDownload PDF (116K) -
Li-Tang Wang, Shang-Kewi Wang, Keryea Soong, Chang-Yih Duh2007 Volume 55 Issue 5 Pages 766-770
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSEleven new cytotoxic cembranolides, michaolides A—K (1—11), and crassolide (12) were isolated from the CH2Cl2 extract of the Formosan soft coral Lobophytum michaelae. Their structures were established by extensive spectral analysis. The cytotoxicity of the isolates against selected cancer cells was measured in vitro.View full abstractDownload PDF (146K) -
Prasoon Gupta, Akanksha, Kiran Babu Siripurapu, Ausaf Ahmad, Gautam P ...2007 Volume 55 Issue 5 Pages 771-775
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSBioactivity-guided purification of n-BuOH soluble fraction from the ethanol extract of Evolvulus alsinoides resulted in the isolation of two new compounds, 2,3,4-trihydroxy-3-methylbutyl 3-[3-hydroxy-4-(2,3,4-trihydroxy-2-methylbutoxy)-phenyl]-2-propenoate (1) and 1,3-di-O-caffeoyl quinic acid methyl ester (2) along with six known compounds, caffeic acid (3), 6-methoxy-7-O-β-glucopyranoside coumarin (4), 2-C-methyl erythritol (5), kaempferol-7-O-β-glucopyranoside (6), kaempferol-3-O-β-glucopyranoside (7) and quecetine-3-O-β-glucopyranoside (8). The structure of new compounds 1 and 2 were elucidated by spectroscopic analysis, while known compounds were confirmed by direct comparison of their NMR data with those reported in literature. This is the first report of the presence of phenolic constituents in Evolvulus alsinoides. The isolated compounds 1—5 and 8 were screened for anti-stress activity in acute stress induced biochemical changes in adult male Sprague–Dawley rats. Stress exposure has resulted in significant increase of plasma glucose, adrenal gland weight, plasma creatine kinase (CK), and corticosterone levels. Compound 1 displayed most promising antistress effect by normalizing hyperglycemia, plasma corticosterone, CK and adrenal hypertrophy, while compounds 2 and 3 were also effective in normalizing most of these stress parameters, however compounds 4, 5 and 8 were ineffective in normalizing these parameters.View full abstractDownload PDF (121K) -
Mailavaram Raghu Prasad, Deb Pran Kishore2007 Volume 55 Issue 5 Pages 776-779
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSA novel, efficient, microwave assisted route for the synthesis of 6-substituted-2,3,4-trihydropyrimido[1,2-c]-9,10,11,12-tetrahydrobenzo[b]thieno[3,2-e]pyrimidines in good yields has been developed. The intermediates, 2-substituted-4-[3-hydroxy(propyl-1-amino)]5,6,7,8-tetrahydrobenzo[b]thieno[2,3-d]pyrimidines were obtained by irradiating 2-substituted-4-chloro-5,6,7,8-tetrahydrobenzo[b]thieno[2,3-d]pyrimidines with 1-amino-propanol under basic conditions in a microwave oven. 4-Chlorothieno[2,3-d]pyrimidines were synthesized by microwave irradiation of equimolar mixture of 4-hydroxythieno[2,3-d]pyrimidines and phosphorus oxychloride. The final compounds were screened for antibacterial activity by Kirby Bauer's method using amicacin as the standard against various gram positive and gram negative bacteria. All the compounds showed antibacterial activity comparable with the standard.View full abstractDownload PDF (87K) -
Kinzo Watanabe, Rina Tanaka, Hitomi Sakurai, Kazuo Iguchi, Yasuji Yama ...2007 Volume 55 Issue 5 Pages 780-783
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe structure of a new monomeric peptidoglycan-related compound with hypotensive and diuretic activities, cymbidine A (1) isolated from the orchid Cymbidium goeringii, was elucidated mainly by spectroscopic analysis. The structure of 1 was shown to involve four amino acids (D-alanin, meso-diaminopimelic acid, D-gultamic acid, and L-valine) and two amino sugars (N-acetylglucosamine and 1,6-anhydro-N-acetylmuramic acid). The sequence of the amino acids and amino sugars was determined by the analysis of 2D NMR data. The absolute stereochemistries of the three amino acids (D-Ala, D-Glu and L-Val) were determined by the modified Marfey's method, and the (6S,10R) configurations of meso-diaminopimelic acid in 1 were indicated on the basis of the CD analysis. The absolute stereochemistry of 1,6-anhydro-N-acetylmuramic acid was also determined by CD data.View full abstractDownload PDF (119K) -
Hiroshi Saimaru, Yutaka Orihara, Pimpimon Tansakul, Young-Hwa Kang, Ma ...2007 Volume 55 Issue 5 Pages 784-788
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSOlive (Olea europaea) contains large quantity of triterpene acids including oleanolic acid (6) as a major one. Varieties of biological activities exhibited by triterpene acids attracted our attentions, especially from pharmaceutical viewpoints. Cell culture of olive plant was induced and its triterpene constituents were studied. From the cell suspension cultures, six ursane type triterpene acids; ursolic acid (9), pomolic acid (10), rotundic acid (11), tormentic acid (12), 2α-hydroxyursolic acid (13) and 19α-hydroxyasiatic acid (14), and two oleanane type acids; oleanolic acid and maslinic acid (7), have been isolated. Quantity of ursane type triterpene acids produced by cell cultures was larger than that of oleanane type. Further, a multifunctional oxidosqualene cyclase (OSC) named OEA was cloned by homology based PCRs from the same cultured cells. Major product of OEA is α-amyrin (ursane skeleton), showing good accordance to higher content of ursane-type triterpene acids in the cultured cells, and strongly suggesting OEA to be a major contributor OSC for their production.View full abstractDownload PDF (221K) -
Hitoshi Yoshimitsu, Makiko Nishida, Toshihiro Nohara2007 Volume 55 Issue 5 Pages 789-792
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThree new 15,16-seco-cycloartane glycosides, which were constructed by a C–C bond cleavage in the D ring, have been isolated from Cimicifuga Rhizome for the first time. Their structures were determined by the use of 2D NMR techniques and chemical evidence.View full abstractDownload PDF (116K)
Notes
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Shouichi Hosaka, Takeshi Sadoshima, Mika Sato, Chikayuki Hamada, Yoshi ...2007 Volume 55 Issue 5 Pages 793-795
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe solid-state interaction between manidipine dihydrochloride (Man) or benidipine hydrochloride (Ben) and lactose monohydrate (Lac) was investigated. An endothermic peak area at 170 °C was observed when their mixtures were subjected to differential scanning calorimetry (DSC) measurement, and this interaction was accelerated by compression. In the present study, dependency on the particle size of Lac was examined in this solid-state interaction. The DSC peak area at 170 °C as a function of the compression force profile was influenced by different particle sizes of Lac in combination with the two medicinal compounds in a different manner. The profile of the onset temperature of Lac dehydration, which indicates the degree of crystalline structure disruption, changed with differing Lac particle size. Moreover, when the particle size of Lac was large, the dehydration onset temperature of Lac with Man decreased from the lower compression force than that of Lac with Ben. The reason for this is thought to be the difference in the powder properties between Man and Ben, although the physicochemical properties of Man and Ben are similar.View full abstractDownload PDF (119K) -
Marta Struga, Jerzy Kossakowski, Ewa Kedzierska, Sylwia Fidecka, Joann ...2007 Volume 55 Issue 5 Pages 796-799
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSA series of nineteen new thiourea and urea derivatives of 10-isopropyl-8-methyl-4-azatricyclo[5.2.2.02,6]undec-8-ene-3,5-dione, 1-isopropyl-7-methyl-4-azatricyclo[5.2.2.02,6]undec-8-ene-3,5-dione and 1,7,8,9,10-pentamethyl-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione have been prepared and studied by 1H-NMR. The compound k1a (1-(1,7,8,9,10-pentamethyl-3,5-dioxo-4-aza-tricyclo[5.2.1.02,6]dec-8-en-4-yl)-3-phenyl-urea) was tested for pharmacological activity on animal central nervous system (CNS). The activities of synthesized compounds were evaluated for their cytotoxicity and anti-HIV-1 activity in MT-4 cells. Antimicrobial activity of the newly obtained derivatives was tested against some Gram-positive and Gram-negative bacteria and fungi of the Candida species.View full abstractDownload PDF (102K) -
Studies on Preparation and Absolute Bioavailability of a Self-Emulsifying System Containing PuerarinDong-qin Quan, Gui-xia Xu, Xiang-gen Wu2007 Volume 55 Issue 5 Pages 800-803
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe purpose of the study was to develop an optimum formulation of self-emulsifying drug delivery systems (SEDDS) containing puerarin and to evaluate its absolute bioavailability. Using oleic acid as oil, Tween-80 as surfactant and propylene glycol as cosurfactant, a series of mixtures comprising oleic acid, propylene glycol and Tween 80 were prepared and their self-emulsifying properties were studied. Pseudo-ternary phase diagrams were constructed to identify the efficient self-emulsification region and particle sizes of the resultant emulsions were determined using a laser diffraction sizer. From these studies, an optimized formulation consisting of oil (17.5%), Tween-80 (34.5%) and cosurfactant (34.5%) was selected and its absolute bioavailability in beagle dogs after oral administration was about 24.8%. The data suggest the use of SEDDS to provide a potential way of puerarin administered orally.View full abstractDownload PDF (141K) -
Ming-An Ouyang, Yung-Shung Wein, Ren-Kuan Su, Yueh-Hsiung Kuo2007 Volume 55 Issue 5 Pages 804-807
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThree new cyclolignan esters and seven known compounds including two cyclolignan isolariciresinol, lynoiresinol, and five aromatic compounds methyl ferulate, vanillin, 4-hydroxy-3,5-dimethoxybenaldehyde, 4-methoxygallic acid, gallic acid were isolated from n-butanol extract of Rhus semialata (Anacardiaceae). The structural elucidations of rhusemialins A (1), B (2), and C (3) were based on FAB-MS, 1D and 2D NMR spectra.View full abstractDownload PDF (97K) -
Mohamed Elbandy, Tomofumi Miyamoto, Marie-Aleth Lacaille-Dubois2007 Volume 55 Issue 5 Pages 808-811
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSA new sulfated lupane triterpene, Gypsophilin (1), and its glucosyl ester, Gypsophilinoside (2) were isolated from the roots of Gypsophila repens whereas a new flavone C-glycoside (3) was obtained from the aerial parts. Their structures were established as (3β)-3-O-(sulfo)lup-20(29)-en-23,28-dioic acid (1), (3β)-3-O-(sulfo)lup-20(29)-en-23,28-dioic acid -28-O-β-D-glucopyranosyl ester (2) and luteolin-7-O-α-L-arabinopyranosyl-6-C-β-glucopyranoside (3) by spectroscopic methods such as 1D and 2D NMR, HR-ESI-MS and FAB-MS.View full abstractDownload PDF (93K) -
Virginia Torpocco, Haydee Chávez, Ana Estévez-Braun, &Aa ...2007 Volume 55 Issue 5 Pages 812-814
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSTwo new dammarane triterpenes have been isolated from the stem bark exudates of Maytenus macrocarpa. Their structures were determined by extensive 1D and 2D NMR spectroscopic studies as 24(Z)-3-oxodammara-20(21),24-dien-27-oic acid (1) and octa-nor-13-hydroxydammara-1-en-3,17-dione (2). These compounds were tested for antitumoral activity.View full abstractDownload PDF (74K) -
Bin Wu, Tsukasa Takahashi, Takehiro Kashiwagi, Shin-ichi Tebayashi, Ch ...2007 Volume 55 Issue 5 Pages 815-816
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSTwo new flavonoid glycosides kaempferol 3-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (1), and quercetin 3-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (2), together with six known flavonoid glycosides were isolated from the leaves of Solidago altissima L. grown in Kochi of Japan. The structure elucidation of the isolated compounds was performed by acid hydrolysis and spectroscopic methods including UV, IR, ESI-MS, 1D- and 2D-NMR experiments.View full abstractDownload PDF (64K) -
Marek Tadeusz Konieczny, Wojciech Konieczny, Michał Sabisz, Andrz ...2007 Volume 55 Issue 5 Pages 817-820
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSIsomeric oxathiolone fused chalcones were prepared by condensation of appropriate acetylbenzo[1,3]oxathiol-2-ones with benzaldehydes under acidic conditions. The synthesized compounds were screened for cytotoxic activity using HeLa cells, as well as for antibacterial activity against Micrococcus luteus, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli, Proteus vulgaris, antifungal activity against Candida albicans, and tuberculostatic activity against Mycobacterium tuberculosis H37Rv and Mycobacterium kansasii strains.View full abstractDownload PDF (110K) -
Hiroshi Suzuki, Nagwa S. M. Aly, Yusuke Wataya, Hye-Sook Kim, Ikumi Ta ...2007 Volume 55 Issue 5 Pages 821-824
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSQuinoline hexose analogs are expected to be useful as novel agents for treatment of chloroquine-resistant malaria. Here, we report preparation of 4-hydroxy quinoline-β-glucosides from anilines in 4 steps.View full abstractDownload PDF (114K) -
Kazuhito Hioki, Satomi Kameyama, Shohei Tani, Munetaka Kunishima2007 Volume 55 Issue 5 Pages 825-828
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSNew triazine-type dehydrocondensing reagents, such as ROMP-Trz-Cl and ROMP(OH)-Trz-Cl, were synthesized by a ring opening metathesis polymerization (ROMP) method, and these showed higher loading than conventional polymer-supported condensing reagents. These polymers effect the formation of amides in good yields by addition of a mixture of carboxylic acid, amine and NMM. ROMP(OH)-Trz-Cl, which contains hydroxyl groups in the polymer chain, gave amides in good yields even in MeOH.View full abstractDownload PDF (133K) -
Fumiko Fujisaki, Marumi Oishi, Kunihiro Sumoto2007 Volume 55 Issue 5 Pages 829-831
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe closure by cyclization with diethyl carbonate (EtO)2CO from aminoalcohols 1 as starting material can lead to the oxazolidinones 2a, b and 2c, respectively. In the reaction of trans-isomer (6) and (EtO)2CO, isolated products were also only 5-membered oxazolidinone derivative (7), containing its dehydrated derivative 8. The preferential formation of the 5-membered oxazolidinone ring system apparently indicated that this process (5-Exo-Trig ring closure) is more favorable than that of 6- or 7-membered ring derivative (3 or 9) by 6- or 7-Exo-Trig ring closure.View full abstractDownload PDF (90K) -
Yukiko Umeda, Toshiro Fukami, Takayuki Furuishi, Toyofumi Suzuki, Mizu ...2007 Volume 55 Issue 5 Pages 832-836
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSThe molecular complex formed between indomethacin (IDM) and lidocaine (LDC), which are typical external medicines, was studied. A thermal analysis, microscopic study and phase solubility technique suggested intermolecular interaction between IDM and LDC. The phase solubility profiles with IDM and LDC were classified as AL-type, indicating the formation of a 1 : 1 stoichiometric molecular complex. The apparent stability constant (KS), calculated from the slope and the intercept, was 4478.9 m−1. A molecular ion peak was detected at 592.2 (m/z) from fast-atom bombardment-MS measurements, which was in accordance with the sum of the molecular weight for IDM (MW: 357.81) and LDC (MW: 234.38). The changes of IR spectra in the C=O stretching region showed that each intact hydrogen bond network was collapsed in the IDM-LDC system and strong interaction between IDM and LDC formed after their kneading. From the 1H-NMR analyses, it was estimated that the dominant interactive site was the IDM carboxylic acid group which associated with the LDC diethyl amino group non-covalently.View full abstractDownload PDF (870K) -
Tomohiro Maegawa, Yuki Fujita, Ai Sakurai, Akira Akashi, Mutsumi Sato, ...2007 Volume 55 Issue 5 Pages 837-839
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSAromatic nitriles are not only important components of natural products, pharmaceuticals, herbicides and agrochemicals but also a synthetic equivalent of various functionalities. The development of synthetic methods of aromatic nitriles have been increasing in terms of its usefulness. Since aromatic nitriles are susceptible to the hydrogenation, it has been desired for the development of chemoselective hydrogenation method with retention of nitrile groups. Pd/C is one of the most popular catalysts for hydrogenation and many of reducible functional groups such as multiple bonds, benzyl ethers, N-Cbzs, nitro groups and so on could be easily reduced under the conditions. Therefore, it is very difficult to achieve the chemoselective hydrogenation of substrates containing two or more reducible functional groups. We have found that a Pd/C catalyst formed an isolable complex with ethylenediamine (en) employed as catalytic poison, and the complex [Pd/C(en)] catalyzed chemoselective hydrogenation of a variety of reducible functionalities distinguishing O-benzyl, N-Cbz and O-TBDMS protective groups, benzyl alcohols and epoxides. In the course of these investigations, we found the aryl nitriles could survive under the Pd/C(en)-catalyzed hydrogenation conditions in THF whose choice is important for the effective suppression. This methodology could be applied to the selective hydrogenation of alkene and alkyne functionalities in the presence of aromatic nitrile.View full abstractDownload PDF (108K)
Communications to the Editor
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Yosuke Demizu, Masakazu Tanaka, Masanobu Nagano, Masaaki Kurihara, Mit ...2007 Volume 55 Issue 5 Pages 840-842
Published: 2007
Released on J-STAGE: May 01, 2007
JOURNAL FREE ACCESSL-Leu hexapeptide containing α-aminoisobutyric acid (Aib) forms a right-handed (P) 310-helix, whereas that containing cyclic α,α-disubstituted amino acid Ac5cdOM assumes a right-handed (P) α-helix in the solid state.View full abstractDownload PDF (623K)
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