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Volume 51, Issue 8
Displaying 1-26 of 26 articles from this issue
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Regular Articles
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Katsumasa Aoki, Yoshinobu Ishikawa, Miyuki Oyama, Yoshikazu Tomisugi, ...Article type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 899-903
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSA series of tentacle porphyrins having four aminoalkyl groups at the periphery was synthesized, and the DNA binding properties were investigated by absorption and circular dichroism (CD) spectroscopic methods. The aminopropyl chain was found to facilitate binding, and bisignate induced CD spectra revealed that the porphyrins are self-stacked on the DNA surface. The photonuclease activity of the tentacle porphyrins was also studied, and the aminopropylporphyrin showed the highest activity. The activity increased in proportion to the porphyrin load, but higher loads resulted in the decrease of activity. This inhibitory step corresponded to aggregation of the porphyrin. Thus, the aggregation was suggested to shield the inner porphyrin from the solvent, the production of active oxygen species being suppressed.View full abstractDownload PDF (182K) -
Yorinobu Yonezawa, Sumio Ishida, Hisakazu SunadaArticle type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 904-908
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSTo obtain basic and clear release properties, wax matrix tablets were prepared from a physical mixture of drug and wax powder at a fixed mixing ratio. Properties of release from the single flat-faced surface, curved side surface, and/or whole surface of the wax matrix tablet were examined. Then tortuosity and the applicability of Higuchi's square-root time law equation were examined. The Higuchi equation well analyzed the release processes of different release manners. However, the region fitted to the Higuchi equation differed with the release manner. Tortuosity obtained with release from the single flat-faced surface and curved side surface was comparable with that obtained with the release from a reservoir device tablet, whereas tortuosity obtained with release from the whole surface was larger. As the wax matrix tablets were prepared at a fixed mixing ratio, their internal structures should be similar. Therefore changes in the matrix volume or volume fraction with release were examined, and an extra volume where dissolved drug stray becomes large with release time in the case of release from the whole surface. These factors should be taken into account for evaluation of applicability and release properties. Furthermore, the entire release process should be analyzed using a combination of the square-root time law and other suitable equations in accordance with release manner or condition.View full abstractDownload PDF (100K) -
Kinzo Watanabe, Miyuki Sekine, Kazuo IguchiArticle type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 909-913
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSThree marine prostanoids, 1, 2, and 3, were isolated from the extract of the Okinawan soft coral Clavularia viridis. The structures of these compounds were assigned based on the results of spectroscopic analysis. Compound 1 was shown to be preclavulone-A methyl ester, and this is the first isolation of the ester of preclavulone-A as a natural product. Preclavulone-A is proposed to be the key intermediate in the biosynthesis of marine prostanoids exemplified by clavulones in C. viridis. The new prostanoid 3 was suggested to be a biosynthetic intermediate from preclavulone-A to clavulones, and a possible biogenetic pathway via 3 is proposed.View full abstractDownload PDF (83K) -
Laura Ribeiro, Thorsteinn Loftsson, Domingos Ferreira, Francisco VeigaArticle type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 914-922
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSThe purpose of this study was to investigate the interactions between vinpocetine (VP), sulfobutyl ether beta-cyclodextrin (SBEβCD) and the water-soluble polymers polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose (HPMC). The water-soluble polymers were shown to improve the complexation efficiency of SBEβCD, and thus less SBEβCD was needed to prepare solid VP–SBEβCD complexes in the presence of the polymers. The interactions between VP and SBEβCD, with or without PVP or HPMC, were thoroughly investigated in aqueous solutions using the phase-solubility method as well as in the solid state. The amount of VP solubilized in water or aqueous polymer solution increased linearly with increasing SBEβCD concentration, demonstrating AL-type plots. We estimated the apparent stability constant (Kc) at room temperature of VP–SBEβCD binary complex to be 340 M−1 and this value increased to 490 M−1 or 390 M−1, respectively, with the addition of PVP and HPMC, assuming a 1 : 1 VP–SBEβCD molar ratio. Improvement in the Kc values for ternary complexes clearly confirmed the benefit of the addition of water-soluble polymers to promote higher complexation efficiency. Solid VP–SBEβCD binary and ternary systems were prepared by physical mixing, kneading, coevaporation, and lyophilization methods and fully characterized by scanning electron microscopy, differential scanning calorimetry, and X-ray diffractometry. The results obtained suggest that coevaporation and lyophilization methods yield a higher degree of amorphous entities and indicated formation of VP–SBEβCD binary and ternary complexes.View full abstractDownload PDF (411K) -
Hiroyuki Nojima, Mayuko Takeda-Shitaka, Youji Kurihara, Kenshu Kamiya, ...Article type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 923-928
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSClass II major histocompatibility complex (MHC) has tolerance for binding longer antigen peptides than those bound by class I MHC. In this paper, a normal mode analysis on HLA-DR1 class II MHC involving an antigen peptide indicated that the peptide-binding groove had some different dynamic characteristics from that of HLA-A2 class I MHC. The dynamic changes in the class I groove with removal of the bound peptide were limited primarily to the central region and the C-terminal side (corresponding to the C-terminal side of the bound peptide) of the groove, while the dynamic changes in the class II groove with removal of the bound peptide extended to the whole of the groove, and were especially remarkable around a strand located in the N-terminal side (corresponding to the N-terminal side of the bound peptide) of the groove. These results suggest that the N-terminal side of the class II groove is more flexible than the same side of the class I groove, and this flexibility may allow some N-terminal residues of the bound peptide to extend outside the class II groove. Definite anti-correlative motions with removal of the bound peptide appeared between two α-helical regions of class II MHC as in the case of class I MHC. These motions of the class II groove may play an important role in obtaining “a flexible dynamic fit” against diverse longer peptides both of whose terminals extend outside the groove.View full abstractDownload PDF (219K) -
María Luisa Jimeno, Ibon Alkorta, Carolina Cano, Nadine Jagerov ...Article type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 929-934
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSThe oxalate salts and free bases of fentanyl and N-[1-(2-phenylethyl)-4-piperidyl]-N-(1-phenyl-4-pyrazolyl)propanamide, a new lead compound for long-acting analgesia, have been characterized by 1H- and 13C-NMR spectroscopy. The crystal structure of the hydrochloride of N-[1-(2-phenylethyl)-4-piperidyl]-N-(1-phenyl-4-pyrazolyl)propanamide monohydrate has been determined. Two centrosymmetrically related cations, joined through C(phenyl)-H…π contacts, encapsulate a large void that contains pairs of anions and bridged water molecules into a zero-dimensional (0D) supramolecular motif. The cations are linked to this framework via N+H…Cl− contacts. GIAO/B3LYP calculations have been carried out to compare the experimental 13C chemical shifts with the absolute shieldings thus calculated. The protonation of both molecules takes place on the piperidine ring (axial protonation), as has been verified both in the solid state (X-ray) and in solution (NMR).View full abstractDownload PDF (109K) -
Li-Yan Wang, Nai-Li Wang, Xin-Sheng Yao, Syohei Miyata, Susumu Kitanak ...Article type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 935-941
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSFour new ingenane-type diterpenes, 3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoyl-20-O-acetylingenol (1), 3-O-(2,3-dimethylbutanoyl)-13-O-dodecanoyl-20-deoxyingenol (2), 3-O-(2E,4Z-decadienoyl)-20-deoxyingenol (3), and 3-O-(2E,4E-decadienoyl)-20-deoxyingenol (4), two new jatrophane-type diterpenes, kansuinins D (9) and E (10), and four known ingenane-type diterpenes were isolated from the root of Euphorbia kansui. Their structures were elucidated by spectroscopic and chemical analysis, and individual Xenopus cells at the blastular stage were cultured with the diterpenes to test for biological activity. 20-Deoxyingenol diterpenes 3 and 4 induced the greatest cell cleavage arrest (0.5 μg/ml of each compound resulted in >75% cleavage arrest), but cell cleavage inhibitory activity became weak when C-16 had an acyl residue. In contrast, the jatrophane diterpene kansuinin D (9) showed no activity.View full abstractDownload PDF (85K) -
Toshihiro Shimizu, Yoshinori Nakano, Shuji Morimoto, Tetsuro Tabata, N ...Article type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 942-947
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSLansoprazole fast-disintegrating tablet (LFDT) is a new patient-friendly formulation of lansoprazole. Since lansoprazole is an antiulcer agent and is unstable under acidic conditions, we have developed LFDT as an orally disintegrating tablet containing enteric-coated microgranules. The effect of compression on dissolution behavior was investigated, as compression affected cleavage and crushing of the enteric layer. To decrease cleavage and crushing of the enteric layer, the effects of the combined ratio of methacrylic acid copolymer dispersion to ethyl acrylate–methyl methacrylate copolymer dispersion and the concentration of triethyl citrate on the dissolution in the acid stage and the dissolution in the buffer stage were evaluated. By adjusting the ratio of methacrylic acid copolymer dispersion to ethyl acrylate–methyl methacrylate copolymer dispersion to 9 : 1 and adding a 20% triethyl citrate concentration, sufficient flexibility of the enteric layer and sufficient stability against compression forces were achieved. Agglomeration of enteric-coated microgranules during the coating process was decreased at the optimized concentration of triethyl citrate and glyceryl monostearate. We compared the absorption properties of LFDT and lansoprazole capsules in dogs. The absorption profiles of LFDT were similar to those of lansoprazole capsules.View full abstractDownload PDF (80K) -
Tian-Shung Wu, Dau-Min Lin, Li-Shian Shi, Amooru Gangaiah Damu, Ping-C ...Article type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 948-950
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSFrom the stems of Rubia wallichiana DECNE, thirty-four structurally related compounds were isolated and identified. Three of them, namely rubiawallin-A (1), -B (2), and -C (3), constitute the first report of their occurrence from the natural source. Their structures were determined by comprehensive analyses of their 1D and 2D NMR, and electron impact (EI) mass spectral data. Furthermore, an in vitro screening of cytotoxicity of the isolated compounds was also evaluated. Among the testing compounds, 1-hydroxy-2-hydroxymethyl-3-methoxyanthraquinone (4) demonstrated most effective cytotoxicity towards Hepa-3B and Colo-205 cells.View full abstractDownload PDF (57K) -
Takashi Itoh, Kazuhiro Nagata, Masashi Yokoya, Michiko Miyazaki, Keiko ...Article type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 951-955
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSChiral 1-substituted isoquinoline derivatives, which were obtained by the reaction using alanine derivatives as chiral auxiliaries, were transformed to (S)-2,3,9,10,11-pentamethoxyhomoprotoberberine (7) and a synthetic intermediate for O-methylkreysigine (9) in good yields and high stereoselectivity. The corresponding chiral allyl derivative of isoquinoline was transformed to a pyrrolidinoisoquinoline (16) in a highly enantioselective manner.View full abstractDownload PDF (91K) -
Makiko Nishida, Hitoshi Yoshimitsu, Masafumi Okawa, Toshihiro NoharaArticle type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 956-959
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSFour new cycloartane glycosides, named aquilegiosides G—J, were isolated from the dried aerial parts of Aquilegia vulgaris. Their structures were determined by spectroscopic analysis and chemical evidence.View full abstractDownload PDF (74K) -
Yoshihiro Mimaki, Minpei Kuroda, Akihito Yokosuka, Hiroshi Harada, Mas ...Article type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 960-965
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSTo characterize the stems of Akebia trifoliata chemically, a detailed phytochemical examination was carried out on A. trifoliata stems, with particular attention to the triterpene and triterpene saponin constituents, and resulted in the isolation of three new triterpenes (1—3) and three new triterpene saponins (11—13), together with seven known triterpenes (4—10) and 12 known triterpene saponins (14—25). The structures of the new compounds were determined on the basis of spectroscopic analysis, including two-dimensional NMR spectroscopic data, and the results of hydrolysis. Four saponins (22—25), which were obtained in good yields and were not isolated from Akebia quinata stems, are concluded to be applicable as marker compounds in chemically distinguishing between A. trifoliata and A. quinata by conventional TLC examination. To the best our knowledge, the current work is the first chemical investigation of A. trifoliata.View full abstractDownload PDF (96K) -
Tsuyoshi Satoh, Tatsuya Sakamoto, Masanori Watanabe, Koji TakanoArticle type: Regular Article
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 966-970
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSTreatment of 1-chlorovinyl p-tolyl sulfoxides, which were synthesized from ketones and chloromethyl p-tolyl sulfoxide, with ethylmagnesium chloride or isopropylmagnesium chloride at below −78 °C gave magnesium alkylidene carbenoids in about 90% yields. The reaction of the generated carbenoids with lithium α-sulfonyl carbanions was found to afford tri- and tetra-substituted allenes. Both cyclic ketones and acyclic ketones were useful in this procedure. However, the 1-chlorovinyl p-tolyl sulfoxides derived from aldehydes gave only rearranged products, acetylenes, under the reaction conditions. The magnesium alkylidene carbenoid derived from an optically active 1-chlorovinyl p-tolyl sulfoxide was treated with lithium α-carbanion of 1-naphthyl phenyl sulfone; however, the obtained allene was found to be racemic. The mechanism of this reaction is also discussed.View full abstractDownload PDF (97K)
Notes
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Carmela Saturnino, Mariafrancesca Buonerba, Gianpiero Boatto, Maria Pa ...Article type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 971-974
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSThe therapy of human cancer is one of the more pursued goals by medicinal chemistry research. Most of the compounds clinically used as a treatment owe their efficacy to their cytotoxic interaction (direct or indirect) with nuclear DNA. This interaction results in the inhibition of DNA synthesis and the degradation of nucleic strands. Ellipticine is a naturally occurring 6H-pyrido[4,3-b]carbazole alkaloid endowed with antitumor activity, and several ellipticine derivatives have been used in clinical trials. We previously reported some 1,4-dimethyl-9H-carbazole derivatives structurally related to ellipticine. The purpose of our research was to transform the pyridocarbazole in a prodrug so that it would have more penetration in the tumor cells and block their replication. Our prodrug is slowly hydrolyzed in human plasma in the corresponding acid. From these preliminary results, we deduce that our compound can block cellular replication. Our hypothesis is that the antitumoral activity is probably related to the induction of damage to DNA, without cellular lysis in the short term.View full abstractDownload PDF (123K) -
Laura Hernández Franco, Jorge Alejandro PalermoArticle type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 975-977
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSThe synthesis of 2-substituted isomers of the meridianins, a familiy of bioactive indole alkaloids isolated from the tunicate Aplidium meridianum, was undertaken. The synthetic route comprises six steps, with a microwave promoted Fischer cyclization as the key reaction.View full abstractDownload PDF (61K) -
Muniyandy Saravanan, Kalakonda Sri Nataraj, Kettavarampalayam Swaminat ...Article type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 978-983
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSThe object of this study was to develop hydroxypropyl methylcellulose (HPMC) based cephalexin extended release tablet, which can release the drug for six hours in predetermined rate. Twenty-one batches of cephalexin tablets were prepared by changing various physical and chemical parameters, in order to get required theoretical release profile. The influences of HPMC, microcrystalline cellulose powder (MCCP), granulation technique, wetting agent and tablet hardness on cephalexin release from HPMC based extended release tablets were studied. The formulated tablets were also characterized by physical and chemical parameters. The dissolution results showed that a higher amount of HPMC in tablet composition resulted in reduced drug release. Addition of MCCP resulted in faster drug release. Tablets prepared by dry granulation was released the drug slowly than the same prepared with a wet granulation technique. Addition of wetting agent in the tablets prepared with dry granulation technique showed slower release. An increase in tablet hardness resulted in faster drug release. Tablets prepared with a wet granulation technique and having a composition of 9.3% w/w HPMC with a hardness of 10—12 kg/cm2 gave predicted release for 6 h. The in vitro release data was well fit in to Higuchi and Korsmeyer–Peppas model. Physical and chemical parameters of all formulated tablets were within acceptable limits. One batch among formulated twenty-one batches was successful and showed required theoretical release. The effect of storage on in vitro release and physicochemical parameters of successful batch was studied and was found to be in acceptable limits.View full abstractDownload PDF (92K) -
Alaa Mohamed Nafady, Mohamed Ahmed El-Shanawany, Mahmoud Hamed Mohamed ...Article type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 984-985
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSBy using β-cyclodextrin-inclusion as a unique technique, an efficient separation of pharmacologically active phenolic compounds from Brazilian propolis was achieved to provide one new compound, 3-(3-hydroxy-3-methyl-butyl)-5-prenyl-4-hydroxycinnamic acid, together with two common cinnamic acid derivatives, artepillin C and capillartemisin A, and two known flavanols, aromadendrin and 3,5,7-trihydroxy-4′-methoxyflavanol.View full abstractDownload PDF (47K) -
Yueh-Hsiung Kuo, Chiou-Fung Chyu, Hsiu-Chuan LinArticle type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 986-989
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSFive new cadinane-type sesquiterpenes, 15-acetoxy-T-muurolol (1), isokhusinodiol (2), cadin-10(14)-ene-4β,5α-diol (3), cadinane-4β,5α,10β-triol (4), and muurolane-4β,5β,10β-triol (5), together with five known compounds, T-cadinol (6), T-muurolol (7), α-cadinol (8), δ-cadinol (9), and khusinodiol (10), were isolated from the roots of Taiwania cryptomerioides. The structure of the new constituents were elucidated through chemical and spectral studies.View full abstractDownload PDF (69K) -
Thirumani Venkateshwar Goud, Masuna Srinivasulu, Vanimireddy Lakshmi N ...Article type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 990-993
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSTwo new bromotyrosine-derived metabolites (1, 2) have been isolated along with the known compounds 3,5-dibromo-4-methoxyphenylacetonitrile, 3-bromo-4-methoxyphenylacetonitrile, 3-bromo-4-hydroxyphenylacetonitrile, 1-hydroxyuracil, 1-methoxyhemibastadin 2, purpuramine H and a steroid 5α,8α-epidioxycholest-6-en-3β-ol from the sponge Psammaplysilla purpurea. Compounds 1 and 2 were characterized by interpretation of their spectral data. The antibacterial activity of these compounds is summarized.View full abstractDownload PDF (58K) -
Tokujiro Kitagawa, Mizuki Nakamura, Katunori MasaiArticle type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 994-998
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSA convenient synthesis of 2- and 3-(chloroacetylamino)-3-(2-furyl)propanoic acids (6a, 7a) and their fluoro analogs were developed. Both 6a and 7a showed 51—55% root growth-inhibitory activity towards rape seedlings at the concentration of 1.0×10−4 M.View full abstractDownload PDF (75K) -
Sang Hee Shim, Ju Sun Kim, Sam Sik KangArticle type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 999-1002
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSFour new and five known norditerpenoid alkaloids were isolated from the processed tubers of Aconitum carmichaeli. The new alkaloids are 14-O-cinnamoylneoline (3), 14-O-anisoylneoline (4) 14-O-veratroylneoline (5), and lipo-14-O-anisoylbikhaconine (8). The known alkaloids are neoline (1), 14-O-acetylneoline (2), foresaconitine (6), crassicauline A (7), and lipohypaconitine (9). Alkaloids 2, 6, and 7 were isolated from this plant for the first time. The structures of the new alkaloids were established by spectroscopic and chemical methods.View full abstractDownload PDF (72K) -
Yasunori Yaoita, Hitomi Ono, Masao KikuchiArticle type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 1003-1005
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSRussulanorol (1), a new norsesquiterpenoid with a novel carbon skeleton, was isolated from the fruiting bodies of Russula delica FR. (Russulaceae) together with three known sesquiterpenoids. The structure of 1 was elucidated on the basis of spectral data and chemical transformation. Compound 1 is an equilibrium mixture of two stereoisomers (1a, b) on the C-11 acetal carbon.View full abstractDownload PDF (64K) -
Yoshitane Kojima, Yutaka Yoshikawa, Eriko Ueda, Rie Ueda, Shuhei Yamam ...Article type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 1006-1008
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSIn vitro insulinomimetic activities of Zn(II) complexes with three natural products, betaine, L-lactic acid, and D-(−)-quinic acid (qui), were found in rat adipocytes treated with epinephrine in terms of the inhibition of free fatty acid release. Based on the results, the blood glucose lowering effect in KK-Ay mice with type 2 diabetes mellitus was observed by daily i.p. injections of a monomeric zinc(II) complex, Zn(qui)2, for 13 d.View full abstractDownload PDF (63K) -
Weihan Zhang, Wing Keung Liu, Chun-Tao CheArticle type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 1009-1011
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSPolyhydroxylated steroids and other metabolites were isolated from the soft coral Nephthea chabroli collected in South China Sea. The structures of two new compounds were determined to be 24-methylcholesta-9(11), 24(28)-diene-3β,12α,19-triol and 4α-methyl-3β,14β-dihydroxy-5α-ergost-24(28)-en-23-one on the basis of spectroscopic analysis. Cytotoxic activities of the polyhydroxylated sterols were evaluated on prostate carcinoma LNCaP cell line.View full abstractDownload PDF (52K) -
Hye Sook Kang, Hae Young Chung, Jee Hyung Jung, Byeng Wha Son, Jae Sue ...Article type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 1012-1014
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSA new phlorotannin, named eckstolonol (1), was isolated from the EtOAc soluble fraction of the methanolic extract of the brown alga, Ecklonia stolonifera OKAMURA, along with three known phlorotannins, eckol (2), phlorofucofuroeckol A (3), and dieckol (4). The structure of eckstolonol was identified as 5,8,13,14-tetraoxa-pentaphene-1,3,6,9,11-pentaol on the basis of spectroscopic evidence. The new compound was found to be a radical scavenger on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical.View full abstractDownload PDF (58K) -
Yasushi Arakawa, Masafumi Ohnishi, Norikazu Yoshimura, Shigeyuki Yoshi ...Article type: Note
Subject area: [not specified]
2003 Volume 51 Issue 8 Pages 1015-1020
Published: 2003
Released on J-STAGE: August 01, 2003
JOURNAL FREE ACCESSSynthesis of (1R,2S,5S,6R,8S)-3-azabicyclo[3.3.0]octane-2,6,8-tricarboxylic acid (2) from trans-4-hydroxy-L-proline (5) was attempted. A Diels–Alder reaction of 3,4-dehydroproline derivative 9 and cyclopentadiene afforded a single stereoisomer 11. The Diels–Alder adduct was smoothly converted to the hydrochloride of 2 (24) via RuO4 oxidation. Although some racemization of the material or product was observed during the synthetic processes, the amino acid 24 proved to be optically pure.View full abstractDownload PDF (101K)
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