All issues
Volume 54, Issue 3
Displaying 1-28 of 28 articles from this issue
- |<
- <
- 1
- >
- >|
Regular Articles
-
Sang Joon Ahn, Mamoru Koketsu, Hideharu Ishihara, Soo Min Lee, Sang Ke ...2006 Volume 54 Issue 3 Pages 281-286
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSThis study reports depigmenting potency of selenium-containing carbohydrates, which would be based upon the finding of direct inhibition to mushroom tyrosinase. Two selenoglycosiede, SG-3 (bis(2,3,4-tri-O-acetyl-β-D-arabinopyranosyl) selenide) and SG-8 (4′-methylbenzoyl 2,3,4,6-tetra-O-acetyl-D-selenomanopyranoside) among eleven selenium-containing compounds examined, were discovered to be effective depigmenting compounds on a mushroom tyrosinase inhibitory assay. SG-3 exhibited a competitive inhibition effect that was similar to kojic acid, well-known tyrosinase inhibitor. At 100 μM and 150 μM, SG-8 had an uncompetitive inhibitory effect that was higher than kojic acid. A study of a melan-a cell originated-tyrosinase inhibition assay showed that SG-8 had a lower inhibitory effect than kojic acid. SG-3 showed a similar inhibition effect to kojic acid on the melan-a cell-originated tyrosinase inhibitory assay. SG-8 showed dose-dependently cytotoxicity in a study of inhibition melanin synthesis by melan-a cells. Most melan-a cells did not survive after being treated with 20 μM of SG-8. At 10 μM, SG-3 inhibited melanin synthesis in the melan-a cells, and the effect was similar to phenylthiourea, which is a well-known inhibitor of melanin synthesis. Therefore, SG-3 is a new candidate for depigmenting reagents.View full abstractDownload PDF (657K) -
Ryuichi Higuchi, Shinichi Inoue, Kouji Inagaki, Maki Sakai, Tomofumi M ...2006 Volume 54 Issue 3 Pages 287-291
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSA ganglioside molecular species GP-3 (1) has been obtained from the water-soluble lipid fraction of the chloroform/methanol extract of the starfish Asterina pectinifera. The structure of the ganglioside has been determined on the basis of chemical and spectroscopic evidence. Compound 1 represents new ganglioside molecular species possessing two moles of sialic acids at the inner part of the sugar moiety. Partial hydrolysis by hot water and an enzymatic hydrolysis by means of endoglycoceramidase (EGCase) have proved useful for structure elucidation of the complex oligosaccharide moiety. Moreover, 1 exhibits neuritogenic activity toward the rat pheochromocytoma cell line, PC-12 cells, in the presence of nerve growth factor (NGF).View full abstractDownload PDF (170K) -
Jean Duplex Wansi, Jean Wandji, Luc Mbaze Meva'a, Alain Françoi ...2006 Volume 54 Issue 3 Pages 292-296
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSThe CH2Cl2/MeOH extract of the stem bark of Oriciopsis glaberrima ENGL. afforded four new acridone alkaloids namely oriciacridone C, D, E and F along with six known compounds: atalaphyllidine, oleanolic acid, butulinic acid, β-sitosterol, stigmasterol, glucoside of stigmasterol and one synthetically known acridone: 1,3,5-trihydroxy-4-prenylacridone. The structures were established on the basis of MS, 1D and 2D NMR experiments. The acridones 1, 4 and 5 showed potent activity against α-glucosidase, while the acridones 1—5 showed moderate free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH).View full abstractDownload PDF (101K) -
Bin Li, Dong-Ming Zhang, Yong-Ming Luo, Xiao-Guang Chen2006 Volume 54 Issue 3 Pages 297-300
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSThree new anthraquinone glycosides, lasianthuoside A (1), B (2), and C (3), were isolated from the root of Lasianthus acuminatissimus MERR., The structural elucidation of these anthraquinones was mainly established on the basis of 1D and 2D NMR and HR-MS spectroscopic analysis. Ten known compounds, damnacanthol (4), damnacanthol 11-methyl ether (5), damnacanthol-3-O-β-D-primeveroside (6), asperuloside (7), asperulosidic acid (8), deacetyl asperulosidic acid (9), a nonglycosidic iridoid (10), 2,6-dimethoxy-4-hydroxyphenol-1-O-β-D-glucopyranoside (11), tachioside (methoxyhydroquinone-4-O-β-D-glucopyranoside) (12), and isotachioside (methoxyhydroquinone-1-O-β-D-glucopyranoside) (13) were also identified for the first time from this plant in the course of the phytochemical and spectroscopic investigation. In addition to this report, a preliminary evaluation of 13 compounds in treating rheumatoid arthritis and antitumor effects of six anthraquinones are presented.View full abstractDownload PDF (104K) -
Sunit Suksamrarn, Orapin Komutiban, Piniti Ratananukul, Nitirat Chimno ...2006 Volume 54 Issue 3 Pages 301-305
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSThree new prenylated xanthones, mangostenones C (1), D (2), and E (3), together with 16 known xanthones 4—19, were isolated from the young fruit (7-week maturity stage) of Garcinia mangostana. The structural elucidation of the new compounds was mainly established on the basis of 1D and 2D NMR and HR-MS spectroscopic analysis. Compound 1 showed cytotoxic properties against three human cancer cell lines, epidermoid carcinoma of the mouth (KB), breast cancer (BC-1), and small cell lung cancer (NCI-H187), with IC50 values of 2.8, 3.53, and 3.72 μg/ml, respectively. Among the isolates, α-mangostin (12), the major metabolite, exhibited the most potent effects against the BC-1 cells with an IC50 value of 0.92 μg/ml, an activity greater than that of the standard drug ellipticine (IC50=1.46 μg/ml). Compound 12 also showed the highest activity against KB cells, while gartanin (10) displayed the strongest activity against the NCI-H187 cells at the respective IC50 values of 2.08 μg/ml and 1.08 μg/ml.View full abstractDownload PDF (144K) -
Jungui Dai, Jiao Bai, Toshiaki Hasegawa, Shigenori Nishizawa, Junichi ...2006 Volume 54 Issue 3 Pages 306-309
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSA new taxoid, 5α,13α-diacetoxy-10β-cinnamoyloxy-4(20),11-taxadien-9α-ol (1) along with its 9,10-isomer, taxinine NN-11 (2) were isolated from the callus cultures of Taxus cuspidata. The structures were identified by the analyses of the spectral data and chemical method. Their in vitro cytotoxicity against 3 cell lines (HepG2, WI-38 and VA-13) and multidrug resistance (MDR) reversal activity toward 2780AD tumor cells were preliminarily evaluated, the low cytotoxicities and potent MDR reversal activities suggested that they might be good lead compounds of tumor MDR reversal agent.View full abstractDownload PDF (73K) -
Eriko Tsuji, Takahiro Uchida, Atsuko Fukui, Ryuta Fujii, Hisakazu Suna ...2006 Volume 54 Issue 3 Pages 310-314
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSThe purpose of this study was to evaluate the bitterness-suppressing effect of three jellies, all commercially available on the Japanese market as swallowing aids, on two dry syrups containing the macrolides clarithromycin (CAM) or azithromycin (AZM). The bitterness intensities of mixtures of the dry syrups and acidic jellies were significantly greater than those of water suspensions of the dry syrups in human gustatory sensation tests. On the other hand, the mixture with a chocolate jelly, which has a neutral pH, was less bitter than water suspensions of the dry syrups. The bitterness intensities predicted by the taste sensor output values correlated well with the observed bitterness intensities in human gustatory sensation tests. When the concentrations of CAM and AZM in solutions extracted from physical mixtures of dry syrup and jelly were determined by HPLC, concentrations in the solutions extracted from mixtures with acidic jellies were higher than those from mixtures with a neutral jelly (almost 90 times higher for CAM, and almost 7—10 times higher for AZM). Thus, bitterness suppression is correlated with the pH of the jelly. Finally, a drug dissolution test for dry syrup with and without jelly was performed using the paddle method. There was no significance difference in dissolution profile. It was concluded the appropriate choice of jelly with the right pH is essential for taste masking. Suitable jellies might be used to improve patient compliance, especially in children. The taste sensor may be used to predict the bitterness-suppressing effect of the jelly.View full abstractDownload PDF (267K) -
Kazuko Yoshikawa, Toshinori Tanaka, Akemi Umeyama, Shigenobu Arihara2006 Volume 54 Issue 3 Pages 315-319
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSThree new abietane diterpenes, sugikurojins D (1), E (2), and F (3), and two new abietanes which incorporate cadinane, sugikurojins G (4) and H (5) were isolated from the bark of Cryptomeria japonica. These structures were elucidated primarily by extensive NMR experiments. The structure of sugikurojin D (1) was deduced to be 6α-acetoxy-7β,11-dihydroxy-12-methoxy-8,11,13-abietatriene. Sugikurojin E (2) was deduced to be 6α-acetoxy-7β,12-dihydroxy-8,11,13-abietatriene. Sugikurojin F (3) was 7α-methoxy-8,13-abietadien-11,12-dione. Sugikurojins G (4) and H (5) had a unique skeleton incorporating an α-cadinol or a 1α-hydroxy-T-cadinol in ferruginol, respectively. Also obtained in this investigation were the known diterpenes (6—14). An antibacterial activity of ten among these against Staphylococcus aureus and Escherichia coli was inactive at the (MIC: 125 μg/ml) level. Meanwhile, in the cytotoxic activity against HL-60, compounds 4, 8, and 11 showed moderate (IC50: 4, 35.4; 8, 28.0; 11, 52.4 μM) though weak (IC50: 4, 100; 8, 80.8; 11, 100 μM) activity against HCT-15.View full abstractDownload PDF (183K) -
Wimal Herath, Julie Rakel Mikell, Amber Lynn Hale, Daneel Ferreira, Ik ...2006 Volume 54 Issue 3 Pages 320-324
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSFermentation of 3-hydroxyflavone (1) with Beauveria bassiana (ATCC 13144) yielded 3,4′-dihdroxyflavone (3), flavone 3-O-β-D-4-O-methylglucopyranoside (4) and two minor metabolites. 7-Hydroxyflavone (2) was transformed by Nocardia species (NRRL 5646) to 7-methoxyflavone (5) whilst Aspergillus alliaceus (ATCC 10060) converted it to 4′,7-dihydroxyflavone (6). Flavone 7-O-β-D-4-O-metylglucopyranoside (7) and 4′-hydroxyflavone 7-O-β-D-4-O-methylglucopyranoside (8) were the metabolic products of 7-hydroxyflavone (2) when fermented with Beauveria bassiana (ATCC 7159). One of the minor metabolites of 3-hydroxyflavone (1) was tentatively assigned a β′-chalcanol structure (9). Compounds 4, 7 and 8 are reported as new compounds. Structure elucidation of the metabolites was based on spectroscopic data.View full abstractDownload PDF (95K) -
Tokumi Maruyama, Shigetada Kozai, Yosuke Demizu, Myriam Witvrouw, Chri ...2006 Volume 54 Issue 3 Pages 325-333
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESS3-(3,5-Dimethylbenzyl)uracil (3) was treated with alkyl halides in the presence of alkali to give 1-substituted congeners. Condensation of 3 with alcohols using the Mitsunobu reaction was also employed as an alternative method. The anti-HIV-1 activity of 1-substituted analogues of 3-(3,5-dimethylbenzyl)uracil was evaluated according to previously established procedures. It appeared that the nitrogen of the 1-cyanomethyl group is important for anti-HIV-1 activity, suggesting interaction with the amino acid residue of HIV-1 reverse transcriptase. 1-Arylmethyl derivatives also showed good anti-HIV-1 activity; and that of 2- and 4-picolyl derivatives was particularly excellent. These results were confirmed by Docking Studies using the program, Glide ligand docking jobs, which suggests hydrogen bonding between amide N–H of Lys 101 and nitrogen of the cyanomethyl and picolyl group.View full abstractDownload PDF (1120K) -
Reiko Fujita, Masato Hoshino, Hiroshi Tomisawa2006 Volume 54 Issue 3 Pages 334-337
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESS1-Alkyl-2-alkylthioquinolinium salts were prepared from 1-alkyl-2(1H)-quinolones via 1-alkyl-2(1H)-thioquinolones in two steps. Under mild conditions, the reaction of 1-alkyl-2-alkylthioquinolinium iodides with active methylene compounds in the presence of sodium hydride afforded 1-alkyl-1,2-dihydro-2-(substituted methylene)quinolines in good yields. The cyclization of 1-benzylquinolines using acetic anhydride produced the corresponding pyrrolo[1,2-a]quinoline derivatives.View full abstractDownload PDF (132K) -
Kazuhiro Nojima, Hiroshi Miyamae, Yasuko Yamaashi2006 Volume 54 Issue 3 Pages 338-343
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSHexachlorocyclopentadiene (HCCP, 1), one of the starting materials in the synthesis of aldrin (3), was found to be able to epoxidize aldrin (3) to give dieldrin (4) when exposed to artificial light at wavelengths longer than 290 nm. In this photochemical reaction, heptachloro-3′-cyclopentenyldioxy heptachloro-2-cyclopentene (2) was isolated as a key intermediate, which appears to be derived from the interaction between the triplet state of photo-excited HCCP (1) and triplet oxygen (3Σg−), but not from that between the ground state of HCCP (1) and singlet oxygen (1Δg). The peroxide (2) plays an important role in the formation of dieldrin (4), because it utilized oxygen atom derived from oxygen in air for the epoxidation.View full abstractDownload PDF (873K) -
Takumi Hara, Fumitoshi Hirayama, Hidetoshi Arima, Yoshihiro Yamaguchi, ...2006 Volume 54 Issue 3 Pages 344-349
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESS2-(N-Cyanoimino)-5-{(E)-4-styrylbenzylidene}-4-oxothiazolidine (FPFS-410) is a newly synthesized thiazolidine derivative having not only antidiabetic but also lipid-lowering activities. However, this compound has an extremely low aqueous solubility (2.8 (±0.33)×10−8 M (0.0094±0.0011 μg/ml) in 1.0 M phosphate buffer (pH 7.0) at 25 °C). In this study, we investigated the effect of various hydrophilic cyclodextrins (CyDs) on the solubility of FPFS-410 to select a CyD suitable for formulations of the compound. Among various CyDs, 2-hydroxypropyl-β-CyD (HP-β-CyD) had the highest solubilizing ability to FPFS-410, e.g., the solubility of the compound was increased 200000-fold by the addition of 40 mM HP-β-CyD, which was attributable to the formation of the 1 : 2 (guest : host) inclusion complexes. The interaction of HP-β-CyD with FPFS-410 was studied using 1H-nuclear magnetic resonance (NMR) spectroscopies including ROESY spectroscopy and a molecular modeling calculation. These results suggested that HP-β-CyD forms a 1 : 2 (guest : host) inclusion complex with FPFS-410 by including both the stilbene and thiazolidine moieties. FPFS-410/HP-β-CyD solid complexes with various stoichiometries were prepared by the spray drying and cogrinding methods, and confirmed by powder X-ray diffractometry that these complexes are in an amorphous state. The dissolution of FPFS-410 in water was significantly accelerated by the complexation with HP-β-CyD. In vivo studies revealed that HP-β-CyD markedly increases the bioavailability of FPFS-410 after oral administration in dogs. The present results suggest that HP-β-CyD is useful for improvement of the extremely low bioavailability of FPFS-410.View full abstractDownload PDF (235K) -
Marek Tadeusz Konieczny, Wojciech Konieczny, Soko Okabe, Hiroaki Tsuji ...2006 Volume 54 Issue 3 Pages 350-353
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSBiological activity of thioaurones was not tested so far and the group constitute completely unexplored source of new molecules of pharmacological interest. We report synthesis and evaluation of cytotoxic activity of thioaurone derivatives bearing p-hydroquinone system in ring A. Their activity was found to depend strongly on substitution pattern, so eventually both the activity and pharmacokinetic parameters of the molecules could be tailored by further structural modifications.View full abstractDownload PDF (87K) -
Masashi Yamada, Ken-ichiro Hayashi, Hiroshi Hayashi, Ryota Tsuji, Kazu ...2006 Volume 54 Issue 3 Pages 354-358
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSFour new resveratrol oligomers, nepalensinols D—G, were isolated from the stem of Kobresia nepalensis (Cyperaceae). The structures were determined by detailed NMR spectral analysis. The compounds were assessed for their inhibitory activity against human topoisomerase II, a potential target of anti-tumor agents. These stilbenoids showed potent inhibitory activity against human topoisomerase II with IC50 values of 5—15 μM.View full abstractDownload PDF (238K)
Notes
-
Kenta Yamamoto, Hiraku Onishi, Akihiko Ito, Yoshiharu Machida2006 Volume 54 Issue 3 Pages 359-362
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSAdsorption characteristics of medicinal carbon powder (JP 14) for acetaminophen were examined at 37 °C using conventional incubation in an attempt to obtain an effective oral dosage form. Hydroxypropyl cellulose (HPC) and maltitol (MT), being able to act as a binding agent, were tested as additives. Tablets of medicinal carbon were produced by the wet granulation method. The rate and extent of adsorption of the medicinal carbon powder were roughly similar in water, JP 14 1st fluid (pH 1.2) and JP 14 2nd fluid (pH 6.8). The relationship between concentrations of free and adsorbed acetaminophen indicated that the adsorption followed the Langmuir mode. The maximal adsorption of acetaminophen in water was 0.219 g per gram medicinal carbon powder, little influenced by the addition of MT, but slightly reduced by the addition of HPC. The tablet prepared using MT as a binding agent displayed a favorable hardness and adequate disintegration time. The tablet showed good adsorption potential for acetaminophen, though the adsorption rate and extent of the tablet were reduced to some extent as compared with powder.View full abstractDownload PDF (190K) -
Tetsuro Ito, Zulfiqar Ali, Miyuki Furusawa, Ibrahim Iliya, Toshiyuki T ...2006 Volume 54 Issue 3 Pages 363-367
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSThree new resveratrol oligomers, cotylelophenol C (1) (resveratrol tetramer) and cotylelosides A (2) and B (3) (O-glucosides of resveratrol trimer), together with four known glucosides of resveratrol oligomers (vaticasides A, B, C, D) and piceid, were isolated from an acetone soluble part of stem of Cotylelobium lanceolatum (Dipterocarpaceae). The structures of new compounds were determined by spectral data analysis. The characteristic properties observed in the NMR spectra of 1 were also discussed.View full abstractDownload PDF (230K) -
Sang Hoon Jung, Soo Young Park, Youngmi Kim-Pak, Hong Kyu Lee, Kyong S ...2006 Volume 54 Issue 3 Pages 368-371
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSFifteen chalcones and three thiazolidinedione (TZD) chalcones were prepared to evaluate their peroxisome proliferator-activated receptor-γ (PPAR-γ) ligand-binding activities. Among the three TZDs, one compound possessed PPAR-γ transactivation potential, while the others showed antagonistic activity against PPAR-γ transactivation. Among the chalcones, compound 5 was the most potent, and structure–activity relationship studies indicated that a methoxyl group in position C-4 and hydroxyl group in position C-4′ or 5′ in chalcone plays a key role in determining the potency of PPAR-γ activation.View full abstractDownload PDF (242K) -
Feng Wang, Jing Chen, Xuejun Liu, Xu Shen, Xuchang He, Hualiang Jiang, ...2006 Volume 54 Issue 3 Pages 372-376
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSIn search of small molecule compounds as the ligands of cyclophilin A, a series of quinoxalines were prepared, and their Kd values of cyclophilin A and IC50 values for peptidyl-prolyl isomerase activity of cyclophilin A were tested. The results suggest that some quinoxalines are promising ligands of cyclophilin A.View full abstractDownload PDF (125K) -
Hwa Jin Lee, Ji Sun Kim, Joung Wha Yoon, Hee-Doo Kim, Jae-Ha Ryu2006 Volume 54 Issue 3 Pages 377-379
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSAnalogues of yakuchinones were synthesized as inhibitors of nitric oxide production in lipopolysaccharide-activated macrophage cell line, RAW 264.7 cells. We prepared stronger inhibitors than the original natural molecules, yakuchinones A and B reported from Alpinia oxyphylla. From the limited structural activity relation study of analogues, we concluded that the optimal length of linker between two aryl groups and the presence of enone moiety in the linker were identified as essential for the activity. The IC50 value of the most potent structure was 0.92 μM. The active analogues suppressed the expression of inducible nitric oxide synthase protein and mRNA.View full abstractDownload PDF (149K) -
Minh Giang Phan, Tong Son Phan, Katsuyoshi Matsunami, Hideaki Otsuka2006 Volume 54 Issue 3 Pages 380-383
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSFour new natural neolignans and lignans, which were given the trivial names odoratisols A—D (1—4), together with (−)-licarin A, kachirachirol B, obovatifol, and machilin-I were isolated from the air-dried bark of the Vietnamese medicinal plant Machilius odoratissima NEES (Lauraceae). Their absolute structures were determined on the basis of spectroscopic analyses including circular dichroism spectra.View full abstractDownload PDF (124K) -
Tao Yi, Xian-Cheng Zhan, Cheng-Rong Li, Ning He2006 Volume 54 Issue 3 Pages 384-386
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSA highly accurate nephelometric titration method was developed for the quantitative analysis of phenytoin sodium injection and tablets. The titration operating conditions and the validation of the method were studied. Five batches of phenytoin sodium injection and tablets were determined by the proposed method and the control experiment methods, respectively. The results of the titration are comparable to those of control experiments. The proposed method is accurate and reproducible, which is considered suitable for the quantitative analysis of a large number of samples.View full abstractDownload PDF (146K) -
Eiji Kawahara, Mikio Fujii, Yoshiteru Ida, Hiroyuki Akita2006 Volume 54 Issue 3 Pages 387-390
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSDirect β-glucosidation between (−)-myrtenol and nerol and D-glucose (3) using the immobilized β-glucosidase from almonds with the synthetic prepolymer ENTP-4000 gave myrtenyl O-β-D-glucoside (4) and neryl O-β-D-glucoside (10), respectively. The coupling of the myrtenyl or neryl O-β-D-glucopyranoside congeners (7 or 13) and 2,3,4-tri-O-benzoyl-β-L-arabinopyranosyl bromide (8) afforded the coupled products (9 or 14), respectively. Deprotection of the coupled products (9 or 14) afforded the synthetic myrtenyl 6-O-α-L-arabinopyranosyl-β-D-glucopyranoside (Sacranoside A, 1) or neryl 6-O-α-L-arabinopyranosyl-β-D-glucopyranoside (Sacranoside B, 2), respectively.View full abstractDownload PDF (136K) -
Jun Mori, Makoto Iwashima, Makoto Takeuchi, Haruo Saito2006 Volume 54 Issue 3 Pages 391-396
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSAn efficient synthesis of the antiviral and antioxidative chromene (1) was achieved. A small amount of chromene 1 could be derived from plastoquinones 2 and 3, the major constituents of the brown alga, Sargassum micracanthum. By the following synthetic scheme involving its application, many kinds of analogs can be synthesized for evaluation of their biological activity and mechanistic study. The total synthesis of 1, started from geranyl acetate and protected 2-bromo-6-methylhydroquinone, was executed with Sharpless asymmetric dihydroxylation for introduction of the terminal diol system and base-catalyzed sigmatropic rearrangement for construction of the chromene skeleton as the crucial steps. The stereochemistry at C-11′ was reconfirmed by this synthesis.View full abstractDownload PDF (199K) -
Yoshimasa Fukuda, Yuka Maeda, Kazuhiro Kondo, Toyohiko Aoyama2006 Volume 54 Issue 3 Pages 397-398
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSThe first method for cyano-phosphorylation of aldehydes with diethyl cyanophosphonate in the presence of N-heterocyclic carbene prepared from 1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride and KOt-Bu, as a nucleophilic catalyst, is described.View full abstractDownload PDF (68K) -
Hiroyuki Kimura, Toshio Fujiwara, Takahiro Katoh, Kiyoharu Nishide, Te ...2006 Volume 54 Issue 3 Pages 399-402
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESS(−)-Epibatidine, an excellent candidate of non-opioidal anesthesia, was formally synthesized in short steps from di-(l)-menthyl (R)-allene-1,3-dicarboxylate that was facilely prepared as a single isomer by means of crystallization-induced asymmetric transformation from a diastereomer mixture of (R)- and (S)-allene-1,3-dicarboxylates. Taking advantage of the chiral synthesis, derivatives of (−)-epibatidine were also prepared for targeting diagnostic agents that could bind nicotinic acetylcholine receptors (nAChRs) in the mammalian central nerve system.View full abstractDownload PDF (109K) -
Biswanath Das, Anjoy Majhi, Joydeep Banerjee, Nikhil Chowdhury, Harish ...2006 Volume 54 Issue 3 Pages 403-405
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESS2-Benzoxepines have efficiently been synthesized from Morita–Baylis–Hillman adducts, alkyl 3-aryl-3-hydroxy-2-methylenepropanoates by treatment with HCHO catalyzed by silica supported perchloric acid (HClO4·SiO2) or Amberlyst-15 in CH2Cl2 under reflux for a short period of time (1.5—2.5 h). The catalyst can be recovered and recycled. The antibacterial properties of the new 2-benzoxepines were studied but no activity was found.View full abstractDownload PDF (68K) -
Ding-Wa Zhang, Zheng-Yin Yang, Shi-Ping Zhang, Ru-Dong Yang2006 Volume 54 Issue 3 Pages 406-408
Published: 2006
Released on J-STAGE: March 01, 2006
JOURNAL FREE ACCESSA novel ligand, diethylenetriamine-N,N″-bis(acetyl-p-hydroxybenzoyl hydrazine)-N,N′,N″-triacetic acid (H3L) was synthesized and characterized on the basis of elemental analysis, molar conductivity, 1H-NMR spectrum, FAB-MS, TG-DTA analysis and IR spectrum. Its complex of Gd(III) holding promise of magnetic resonance imaging (MRI) was synthesized, and relaxivity (R1) of complex and Gd(DTPA)2− used as a control was determined in water solution, respectively. The relaxivity of GdL (R1=6.39 l·mmol−1·s−1) was larger than that of Gd(DTPA)2− (R1=4.34 l·mmol−1·s−1). The relaxivity of GdL has also been investigated in human serum albumin (HSA) solution, the relaxivity of GdL was enhanced from 6.39 l·mmol−1·s−1 in water solution to 7.69 l·mmol−1·s−1 in HSA solution. In addition, thermodynamics stability constant of GdL was determined. The results showed that complex of GdL is a prospective MRI contrast agent, although the thermodynamic stability constant of GdL complex (KGdL=1019.56) was a little less than that of Gd(DTPA)2− (KGd-DTPA=1020.73).View full abstractDownload PDF (124K)
- |<
- <
- 1
- >
- >|