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Volume 41, Issue 12
Displaying 1-28 of 28 articles from this issue
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Toshio KINOSHITA, Hiroshi OHISHI, Youko TANIMOTO1993 Volume 41 Issue 12 Pages 2073-2076
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe reaction of 5-bromo-6-bromomethyl-1, 3-dimethyl- (1a) and 5-bromo-6-bromomethyl-1-(3-bromopropyl)-3-methyl-2, 4(1H, 3H)-pyrimidinedione (4a) with 1.0 and 2.0 eq of the sodium salt of 2-nitropropane yielded a mixture of 6-formyl (2 and 5a) and carbon-carbon bond-cleavage products (3 and 6a). When a large excess of the sodium salt of 2-nitropropane was used, 3 and 6a were obtained as sole products, respectively. The nitrates [(5-bromo-1, 3-dimethyl-2, 4-dioxo-1, 2, 3, 4-tetrahydropyrimidin-6-yl)methyl nitrate (1b) and the dinitrate of 5-bromo-6-hydroxymethyl-1-(3-hydroxypropyl)-3-methyl-2, 4(1H, 3H)-pyrimidinedione (4b)] were exclusively converted to 6-formylpyrimidines (2 and 5b) or 6-unsubstituted pyrimidinediones (3 and 6b) by reaction with 1.0 or 2.0 eq of sodium methoxide, respectively. The dinitrate of 5-bromo-1-(2-hydroxyethyl)-6-hydroxymethyl-3-methyl-2, 4(1H, 3H)-pyrimidinediones (7) was treated with sodium methoxide to yield 2-(5-bromo-6-formyl-3-methyl-2, 4-dioxo-1, 2, 3, 4-tetrahydropyrimidin-1-yl)ethyl nitrate (8), a 3, 4-dihydropyrimido[6, 1-c][1, 4]oxazine derivative (9) and 2-(5-bromo-3-methyl-2, 4-dioxo-1, 2, 3, 4-tetrahydropyrimidin-1-yl)ethyl nitrate (10). A plausible reaction mechanism is presented.View full abstractDownload PDF (672K) -
Hiroko SEKI, Hiromitsu TAKAYAMA, Norio AIMI, Shin-ichiro SAKAI, Dhavad ...1993 Volume 41 Issue 12 Pages 2077-2086
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSComplete assignments of the proton and carbon signals as well as conformational analysis of eleven basic heteroyohimbine-type oxindole alkaloids were performed by using modern NMR techniques.View full abstractDownload PDF (1100K) -
Yoshisuke TSUDA, Shinzo HOSOI, Nobuya KATAGIRI, Chikara KANEKO, Takehi ...1993 Volume 41 Issue 12 Pages 2087-2095
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS(S)-(+)-3, 4-Dimethoxyphenylalanine methyl ester (1b) was converted, in 3 steps, into (5S)-(-)-8, 9-dimethoxy-1, 5-dimethoxycarbonyl-2, 3-dioxo-2, 3, 5, 6-tetrahydropyrrolo[2, 1-a]isoquinoline (2b). Diels-Alder reaction of 2b with 1-methoxy-3-trimethylsilyloxybutadiene under extremely high pressure (10 kbar), followed by desilylation, gave moderate yields of erythrinan derivatives (11), which were converted, in several steps, into (+)-erysotramidine (23b) and (+)-erysotrine (4), thus accomplishing the first total synthesis of natural Erythrina alkaloids in chiral forms.View full abstractDownload PDF (1274K) -
Chihiro ITO, Yukiko THOYAMA, Mitsuo OMURA, ICHIRO KAJIURA, Hiroshi FUR ...1993 Volume 41 Issue 12 Pages 2096-2100
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAlkaloidal constituents of root and stem bark of Murraya koenigii (L.) SPRENG. (Rutaceae) grown in the green-house of Okitsu Branch, Fruit Tree Research Station, Shizuoka, were studied. Three new monomeric and five novel binary carbazole alkaloids named mukoenine-A (1), -B (2), and -C (4), and murrastifoline-F (8), bis-2-hydroxy-3-methylcarbazole (9), bismahanine (11), bikoeniquinone-A (12), and bismurrayaquinone-A (13), respectively, were isolated, as well as 16 kinds of known carbazoles and carbazolequinones, and their structures were elucidated by spectrometric methods. Among the new binary carbazoles, bikoeniquinone-A (12) and bismurrayaquinone-A (13) were found to contain a carbazole-1, 4-quinone skeleton as a basic structural unit. These are the first examples of binary carbazolequinone alkaloids to be found in nature, and also the first carbazolequinone alkaloids to be isolated from Murraya plants except for M. euchrestifolia.View full abstractDownload PDF (797K) -
Masayuki YOSHIKAWA, Emiko HARADA(nee UCHIDA), Shunji AOKI, Johji YAMAH ...1993 Volume 41 Issue 12 Pages 2101-2105
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new quassinoids named picrajavanins A and B were isolated, together with known β-carboline alkaloids and picrasidine G, from the bark of Picrasma Javanica BL. (Simaroubaceae), an Indonesian folk medicine, collected on Flores Island. The absolute stereostructures of picrajavanins A (6) and B (7) have been elucidated on the basis of chemical and physicochemical evidence, together with the application of the modified Mosher's method.View full abstractDownload PDF (702K) -
Kazuhiro NOJIMA, Chiho ISOGAMI, Masaaki HIROBE1993 Volume 41 Issue 12 Pages 2106-2108
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSDiels-Alder reaction of methyl-substituted 1, 3-butadienes (1) with 1, 2-dibromoethylene gave dibromomethylcyclo-hexenes (2), which were subjected to epoxidation, followed by dehydrobromination of the resultant dibromo oxides (3) to afford 3-methylbenzene oxide (4a) and 1-methylbenzene oxide (4b). However, 4-methylbenzene oxide (4c) could not be obtained in this way.View full abstractDownload PDF (586K) -
Masayuki YOSHIKAWA, Shoko HATAKEYAMA, Nobumitsu TANAKA, Toshiro MATSUO ...1993 Volume 41 Issue 12 Pages 2109-2112
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new protostane-type triterpenes named 11-deoxyalisols B and B 23-acetate were isolated from the fresh rhizome of Alisma orientale JUZEP. originating from Japan, Taiwan, and China, together with known triterpenes and sesquiterpenes. The absolute stereostructures of 11-deoxyalisols B and B 23-acetate have been determined on the basis of chemical and physicochemical evidence. Sesquiterpene compositions in fresh rhizomes of Alisma orientale of the three different origins were examined and it was found that Japanese rhizome contained germacrene D as a major constituent, while fresh rhizomes from plants of Taiwanese and Chinese origin contained germacrene C and small amounts of alismol and alismoxide.View full abstractDownload PDF (711K) -
Hirotaka SHIBUYA, Kazuyoshi OHASHI, Norihiko NARITA, Kazuyuki HORI, Hi ...1993 Volume 41 Issue 12 Pages 2113-2120
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo diastereomeric macrocyclic lactone epoxides, i.e., a 13-membered-ring monomeric lactone diepoxide (FL1, E2, 7) and a 26-membered-ring dimeric lactone tetraepoxide (FL2E4, 8), were synthesized from E, E-farnesol by employing a new lactonization reaction with sodium hydride. Examinations by using a W-07 apparatus (liquid-membrane type) and by means of the human erythrocyte membrane method, have shown that FL2E4 (8) exhibits not only ion-transport activity for K+ ion but also ion-permeation activity for K+ ion across the human erythrocyte membrane, while FL1E2 (7) decreases the Na+ ion concentration inside human erythrocytes. Furthermore, we studied the dependence of the ionophoretic activities for K+ ion upon the epoxide configurations by using six distereomers of FL2E4 (8).View full abstractDownload PDF (1100K) -
Mariko MORITA, Tetsuo NAGANO, Masaaki HIROBE1993 Volume 41 Issue 12 Pages 2121-2124
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSN-Aminopyridinium iodide (NAPI) turned a bluish purple color upon the addition of NaOH. The NMR spectral data of the NAPI-NaOH system indicate that N-1-pyridinio amidate (NPA) is the species responsible for the coloration, which is probably due to intramolecular charge transfer transition. The intensity of the coloration increased remarkably with addition of benzaldehyde derivatives, especially p-nitrobenzaldehyde, to the NAPI-NaOH system. NAPI reacted with the benzaldehyde derivatives to form the corresponding Schiff bases. The mechanism of the coloration in the NAPI-NaOH-benzaldehyde derivative system is proposed to involve the formation of betaines, which can also be formed by adding NaOH to the isolated Schiff bases. Furthermore, there was a good correlation between the enhancing effects on the coloration and the redox potentials of the benzaldehyde derivatives. This indicates that benzaldehyde derivatives with an electron-withdrawing substituent group can enhance the coloration intensity much more effectively.View full abstractDownload PDF (585K) -
Hideki SAITOH, Toshio MIYASE, Akira UENO1993 Volume 41 Issue 12 Pages 2125-2128
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom the roots of Polygala senega var. latifolia TORR. et GRAY four new oligosaccharides, called senegoses F-I, were isolated and their structures were elucidated by spectroscopic and chemical means. These oligosaccharides were esterified with acetic, benzoic and ferulic acids.View full abstractDownload PDF (571K) -
Chikage MURAKAMI, Keiko MYOGA, Ryoji KASAI, Kazuhiro OHTANI, Tomonori ...1993 Volume 41 Issue 12 Pages 2129-2131
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe effect of plant extracts on D-glucose uptake by Ehrlich ascites tumour cells was examined. Among the 23 exracts of medicinal plants, five samples inhibited, and six samples activated, the uptake significantly. From one of the active plants, Lagerstroemia speciosa, two triterpenoids, colosolic acid and maslinic acid were isolated. Colosolic acid was shown to be a glucose transport activator. Scince this compound was known to have hypoglycemic activity, our simple in vitro bioassay method can at least be used as a first screening for anti-diabetic activity.View full abstractDownload PDF (590K) -
Tadahiro TAKEDA, Takatoshi NAKAMURA, Shigeki TAKASHIMA, Osamu YANO, Yu ...1993 Volume 41 Issue 12 Pages 2132-2137
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo novel triterpenoidal saponins, called calliandra saponins A and E, were isolated from the branches of Calliandra anomala (KUNTH) MACBR. On the basis of the chemical and physicochemical evidence, their structures were defined as 3-O-α-L-arabinopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→6)-2-acetamido-2-deoxy-β-D-glucopyranosyl echinocystic acid 28-O-{β-D-glucopyranosyl-(1→3)-[β-D-xylopyranosyl-(1→3)-β-D-xylopyranosyl-(1→4)]-α-L-rhamnopyranosyl-(1→2)-[(6S)-2-trans-2, 6-dimethyl-6-O-β-D-xylopyranosyl-2, 7-octadienoyl-(1→6)]-β-D-glucopyranosyl} ester (4) and 3-O-α-L-arabinopyranosyl-(1→2)-α-L-arabinopyranosyl-(1→6)-2-acetamido-2-deoxy-β-D-glucopyranosyl echinocystic acid 28-O-{β-D-glucopyranosyl-(1→3)-[β-D-xylopyranosyl-(1→3)-β-D-xylopyranosyl-(1→4)]-α-L-rhamnopyransoyl-(1→2)-[(6'S)-2'-trans-2', 6'-dimethyl-6'-O-(2-O-(6S)-2-trans-2, 6-dimethyl-6-hydroxy-2, 7-octadienoyl)-β-D-xylopyranosyl-2', 7'-octadienoyl-(1→6)-β-D-glucopyranosyl} ester (5), respectively.View full abstractDownload PDF (792K) -
Kiyotada YASUI, Hiroshi FUJIOKA, Yasuhiko NAKAMURA1993 Volume 41 Issue 12 Pages 2138-2140
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA search for a cryoprotective agent of a liposome containing recombinant human tumor necrosis factor (rHuTNF) was undertaken. Various additives were added and liposomes were freeze-thawed. As a result of these studies, albumin and gelatin were found to suppress the leakage of rHuTNF from liposome. This cryoprotective effect was only observed when the additives were added to the inside of the liposomal membrane; their addition to the outside of the membrane stimulated the leakage. This characteristic was clearly different from well-known cryoprotective agents, such as saccharides which have the cryoprotective effect on both sides of the liposomal membrane. Although this cryoprotective effect was also observed for recombinant human interleukin-1α (rHuIL-1α), it was not observed for fluorescein sodium. These effects of gelatin and albumin were restricted to macromolecular proteins such as rHuTNF and rHuIL-1α, but both substances were very effective cryoprotectants for a liposome containing protein.View full abstractDownload PDF (540K) -
Hideo TAKAHATA, Masao KOBAYASHI1993 Volume 41 Issue 12 Pages 2141-2146
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSConcerning the microencapsulation method based on surface neutralization of enteric polymers, the effect of plasticizer was studied using methacrylic acid-methacrylic acid methyl ester copolymer (Eudragit S). This did not form an effective film on the surface of particles when used with the general surface neutralization method. Microcapsules (MCs) were prepared by suspending crystal aspirin in aqueous Eudragit S solution containing triethyl citrate (TEC) as plasticizer, and the effects of the preparation conditions on the MC properties were investigated.The dissolution of aspirin from the MCs prepared at 60°C in the artificial gastrointestinal fluid (JP XII 1st fluid) was increasingly suppressed as TEC concentration increased. Most effective suppression of the dissolution required a preparation temperature above 40°C using 40% TEC, and 60°C using 20% TEC. With the increase in preparation temperature, the polymer content in MCs increased, but the recovery percent of aspirin and the single nuclear percent of MCs decreased. The polymer content in MCs increased with decreasing crystal size of aspirin, while the membrane thickness and permeability constant were almost the same irrespective of crystal size.The phase separation behaviors of Eudragit S solutions containing TEC were observed at various pHs and temperature and the state of the polymer phase at low pH was recognized to reflect the effect of plasticizer on the microencapsulation.View full abstractDownload PDF (1313K) -
Kazumi DANJO, Hironobu KATO, Akinobu OTSUKA, Takeshi WAKIMOTO1993 Volume 41 Issue 12 Pages 2147-2150
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSChanges in the size and tensile strength of tablets were investigated after storage at several levels of relative humidity (R.H.). Sucrose has a critical relative humidity (CRH) of 84.0%. The diameter and thickness of the tablets decreased with storage at increasing R.H., and then suddnely increased above the CRH. The relationship between the rates of the volume change and moisture adsorption was linear (R2=0.963).The diametral tensile strength increased with storage at 84% R.H., above which it decreased. This was due to the increase in the radii of curvature of the water films and smoothing of the particulate surface by dissolution of surface asperities. It was therefore assumed that slippage and transfer of particles easily occurs between contacting surfaces.Diametral tensile strength increased with increasing water evaporation.View full abstractDownload PDF (542K) -
Hiroyasu KOKUBO, Shinichiro NAKAMURA, Hisakazu SUNADA1993 Volume 41 Issue 12 Pages 2151-2155
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA model system consisting of lactose-cornstarch-microcrystalline cellulose was used to study the effect of five cellulosic binders [hydroxypropylcellulose (HPC) (6 cP), hydroxypropylmethylcellulose 2910 (HPMC) (3, 6, 15 cP), and methylcellulose (MC) (15 cp)] on particle size distribution of granules prepared by a high-speed mixer under fixed operating conditions. The distribution of binder in different size fractions of granules was determined by measuring the contents of methoxyl and hydroxypropoxyl groups. When the binders were added by the solution method, higher solution viscosity resulted in the percentage of coarse particles generated in the granules being increased without an increase in the median particle size. The granules prepared by the dry mixing method with HPC (6 cP) or HPMC (3 cP) showed a good correlation between their median particle size and binder level. Other binders did not show such a correlation, as higher concentrations of the binders were present in smaller particle fractions of the granules with an increase in binder level. When binders were dissolved completely in the dry mixing method, a good correlation between median particle size and binder level was observed. The analysis of granule size dependency of binder content appeared to be useful for evaluating the effectiveness of binders in the dry mixing method.View full abstractDownload PDF (709K) -
Yoshiaki KAWASHIMA, Hirofumi TAKEUCHI, Tomoaki HINO, Toshiyuki NIWA, T ...1993 Volume 41 Issue 12 Pages 2156-2160
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA controlled-release matrix filler was prepared by spray-drying a heated aqueous hydroxypropymethylcellulose (HPMC) solution suspending microcrystalline cellulose (MCC, PH101). Acetaminophen tablets (used as model drug, content=50%) were prepared by directly compressing the mixture of drug and spray-dried matrix filler. When HPMC was formulated with more than 10% of the matrix filler, drug release from the tablets was satisfactorily sustained. To obtain a similar sustained-release pattern with unmodified original HPMC, more than 50% of the matrix filler was required in the formulation. Whereas, when the tablet formulation was less that 5% modified HPMC, the drug was rapidly released from the tablets. Uniformly distributed HPMC in the spray-dried filler should lead to such drug-releasing behaviors. The micromeritic properties of HPMC in the matrix filler, viz. particle size, size distribution and the loading amount of HPMC, were main factors in determining the drug-release properties of the tablets. The drug-release rate of the tablets was determined by the erosion rate of the gelled HPMC formed on the surface of the tablets. The drug-release kinetics were described as a function of the cube root of the tablet weight. The drug was tabletted directly with the modified matrix filler by a rotary tabletting machine.View full abstractDownload PDF (831K) -
Hisao TOMIDA, Chie NAKAMURA, Hironori YOSHITOMI, Setsuo KIRYU1993 Volume 41 Issue 12 Pages 2161-2165
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA method for the preparation of theophylline-loaded alginate gel capsules was developed, and their drug release characteristics were investigated. A dispersion containing theophylline and wheat starch suspended in a calcium chloride solution was dropped into a sodium alginate solution. The calcium ions then diffused out of the droplets and reacted with the alginate, resulting in the formation of a water-insoluble calcium alginate gel membrane around each droplet. In subsequent drying, spherical, glossy capsules with a smooth surface were obtained (as average diameter of 3.1 mm). The coat thickness increased with coating time, and the CaCl2 concentration in the core dispersion increased. The efficiency of drug encapsulation (EE) decreased with an increase of the coating time, and increased with an increase of the CaCl2 concentration and the theophylline loading dose in the core dispersion. The coat thickness and EE were almost independent of the sodium alginate concentration in coating fluids (1% and 2%). The theophylline release from the gel capsules followed zero-order kinetics, and the release rates were significantly reduced as the coat thickness increased. Furthermore, the release rates were greatly reduced compared with those of the matrix type alginate gel beads.View full abstractDownload PDF (1081K) -
Eihei FUKUOKA, Midori MAKITA, Shigeo YAMAMURA1993 Volume 41 Issue 12 Pages 2166-2171
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA pattern fitting procedure for the characterization of crystals and/or crystallites in tablets using X-ray powder diffraction data has been described. Observed X-ray diffraction intensities were fitted to the analytic expression, and the fitting parameters, such as the lattice parameters, the peak-width parameters and the preferred orientation parameter(s), were optimized by a non-linear least-squares procedure. Orthorhombic crystals of isoniazid and D-mannitol were used for the samples.Lattice parameters were found to increase slightly with an increase in compression pressure. In isoniazid, the peak-width broadened with an increase of compression pressure, and a marked broadening at a relatively high scattering angle was observed. It is indicated that both a decrease of the crystallite size and the lattice disorder occurred simultaneously with compression. In D-mannitol, the peak-width broadened with compression and the broadening was independent of the scattering angle. It is indicated that although the crystallite size decreased, the lattice disorder did not increase with compression. The strength of the preferred orientation of the crystallites increased with compression in both crystals.View full abstractDownload PDF (757K) -
Mizuho OGASAWARA, Tomomi NAKAMURA, Ikuo KOYAMA, Masami NEMOTO, Tsuguch ...1993 Volume 41 Issue 12 Pages 2172-2175
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSChemical reactions of the amino group of taurine with aldehyde were investigated. Glucose, acetaldehyde, and malondialdehyde (MDA) were used as aldehydes. After taurine was reacted with the aldehydes, the amounts of remaining taurine and aldehydes were measured, and thereby the reactivity was evaluated. The amino acids such as glycine, α-alanine, and β-alanine were compared because of their structural resemblance to each other. Taurine showed a high reactivity with each one of the aldehydes tested.It is known that protein is altered through reactions of the amino group with various aldehydes. Low density lipoprotein (LDL) was used as a model protein, and the inhibiting effect of taurine against the modification of LDL by MDA was examined. Our results indicate that taurine inhibited the production of LDL modified by MDA. It was shown that the inhibiting effects correlated with the reactivity of MDA with the amino acids.Further, the taurine-glucose reaction product showed an antioxidative effect on the peroxidation of liposomes made of yolk phosphatidylcholine as a biomemebrane model. The results suggest the possibility of an inhibiting effect of taurine against the modification of protein, as well as an antioxidative effect through the reactions of taurine with aldehydes in vivo.View full abstractDownload PDF (744K) -
Naotake OGAWA, Hiroyuki TAGUCHI, Takatoshi SATO1993 Volume 41 Issue 12 Pages 2176-2179
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe interaction of α-chloromaleic anhydride (ClMAn) and allylcyclohexane (ACH) was studied. These monomers were found to make a charge-transfer (CT) complex at a 1 : 1 ratio. Copolymerization of ClMAn and ACH in solution gave a white powder in about 50% yield of which analytical data suggested that ClMAn and ACH are copolymerized in a 1 : 1 ratio. By heating the copolymer at 190°C for 1 h under reduced pressure, dehydrochlorination occurred quantitatively to generate a double bond in the polymer chain at the position of maleic anhydride moiety. The dehydrochlorinated copolymer was found to make a CT complex with acetone but the value of the formation constant was smaller than that of monomeric maleic anhydride.View full abstractDownload PDF (565K) -
Naotake OGAWA, Hiroyuki TAGUCHI, Takatoshi SATO1993 Volume 41 Issue 12 Pages 2180-2182
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSMaleic anhydride was copolymerized with divinylbenzene by suspension polymerization, and the spherical beads obtaiend (10-30 μm in diameter) were then hydrolyzed to a carboxylic acid (CA) resin. This CA resin had a low exchange capacity (0.40 meq/g), and was proposed to be useful as a packing material for high-performance liquid chromatography. The retention behavior of various compounds on a column packed with the CA resin was studied using methanol or a mixture of acetonitrile and buffer solution as the mobile phase. The acid-base and hydrophobic interactions, which occur because of the ionongenic and hydrophobic moieties of the CA resin, work effectively for the separation of the solutes. The CA resin column, with the appropriate selection of a mobile phase, is suggested to be useful for the separation of various kinds of solutes such as neutral, acidic and basic compounds.View full abstractDownload PDF (501K) -
Zenei TAIRA, Masaru KIDO, Masami TANAKA, Yutaka ASAHI1993 Volume 41 Issue 12 Pages 2183-2186
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe structures of the photodimers (I) and (II) of menadione (2-methyl-1, 4-naphthoquinone, MNQ) were determined by X-ray analysis. It was confirmed that both dimers are structural isomers of the cis-syn and cis-anti forms, i.e., 5a, 5b-cis-dimethyl (I) and 5a, 11a-cis-dimethyl (II) isomers of 5a, 5b, 11a, 11b-tetrahydro-β, β'-cis-binaphthylene-5, 6, 11, 12-tetrone. The dimer (II), which was twisted around the cyclobutane ring, was more deformed than the dimer (I). MM2 calculation indicated that such twisting decreases the steric energy of the dimer (II) more than that of the dimer (I).View full abstractDownload PDF (614K) -
Katsuhiro SAITO, Masatoshi KOZAKI, Kensuke TAKAHASHI1993 Volume 41 Issue 12 Pages 2187-2189
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSReaction of 7-ethoxycarbonyl-1, 3, 5-cycloheptatrine with palladium(II) acetate afforded 2- and 4-formylbenzoic acid ethyl ester and diethyl maleate via aromatization, and a mixture of position isomers of the cycloheptatriene through hydrogen-shift. The reaction with 7-cyano-1, 3, 5-cycloheptatriene was also investigated. The reactions are considered to proceed through palladium complexes of the cycloheptatrienes and their norcaradiene isomers.View full abstractDownload PDF (486K) -
Yukiko DOI, Hideyuki SHIGEMORI, Masami ISHIBASHI, Fumio MIZOBE, Akira ...1993 Volume 41 Issue 12 Pages 2190-2191
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new pentacyclic sesterpenes, 12-O-desacetylfuroscalarol (1) and 12-O-desacetylscalarin (2), which enhance nerve growth factor synthesis, have been isolated from the Okinawan marine sponge Hyrtios sp. and their structures elucidated on the basis of spectroscopic data.View full abstractDownload PDF (462K) -
Yasuo KIKUGAWA, Masahiro SHIMADA, Miyako KATO, Takeshi SAKAMOTO1993 Volume 41 Issue 12 Pages 2192-2194
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTreatment of N-alkoxy-N-chloroarylacetamides with triethylamine in ethanol results in removal of a chlorine atom and introduction of an ethoxy group at the C-2 position of arylacetamides in moderate yields.View full abstractDownload PDF (423K) -
Seiko MITSUI, Kiyotaka MARUMO, Sumie ANDO-INOUE, Hideo KATO, Yosiro SA ...1993 Volume 41 Issue 12 Pages 2195-2196
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSLithiation of the Si-methyl groups of N-methyl-N-[(trimethylsilyl)methyl]benzylamine (1) occurred in preference to ortho-lithiation of the benzyl group with butyllithium in ether. In a similar reaction with benzyl (trimethylsilyl)methyl ether (7), lithiation of the benzylic position competed with that of the Si-methyl groups.View full abstractDownload PDF (467K) -
Masaharu TAKEYAMA, Hirofumi MATSUO, Kazuo MORI1993 Volume 41 Issue 12 Pages 2197-2199
Published: December 15, 1993
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA sensitive and specific double-antibody enzyme immunoassay (EIA) for a gastrin-like immunoreactive substance (G-IS) in human plasma was developed. For competitive reactions, the gastrin antibody was incubated with gastrin standard (or sample) and β-D-galactosidase labeled synthetic C-terminal gastrin I fragment (residue 2-17). Free and antibody-bound enzyme hapten were separated using an anti-rabbit IgG coated immunoplate. Activity of the enzyme on the plate was fluorometrically determined. The present immunoassay allows detection of 1 to 20 fmol/ml (2.1 to 42 pg/ml) of gastrin. The levels of G-IS determined in human plasma were 7.8±1.6 pg/ml before lunch and 26.4±8.4 pg/ml after lunch.View full abstractDownload PDF (551K)
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