All issues
Volume 44, Issue 1
Displaying 1-50 of 50 articles from this issue
- |<
- <
- 1
- >
- >|
-
Kumi ARAKANE, Akemi RYU, Kenji TAKARADA, Takuji MASUNAGA, Kouichi SHIN ...1996 Volume 44 Issue 1 Pages 1-4
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSinglet oxygen generation from laser-excited photosensitive dyes was measured directly using a sensitive near-infrared emission spectrometer to monitor the O2(1Δg)→O2(3Σ-g) transition at 1268 nm. The emission intensity was proportional to both the laser power and the concentration of the dyes. The singlet oxygen producing ability of the dyes was compared with that of eosin YS as a standard in methanol. The relative efficiencies of singlet oxygen generation were determined for rose bengal, erythrosine B, phloxine B and eosin YS as 2.39, 1.73, 1.38, 1.00, respectively, while uranine showed no emission in this spectral region. Using rose bengal, erythrosine B, phloxine B and eosin YS, the efficiency of singlet oxygen generation correlated with the photobleaching reaction rate of azo-dyes by these dyes, suggesting singlet oxygen to be a species responsible for causing the photobleaching of azo-dyes. The halogen substituent effect on the efficiency of singlet oxygen generation from laser-excited photosensitive dyes was also examined systematically.View full abstractDownload PDF (668K) -
Sotoo NAGAI, Keiko OKIMURA, Naohito KAIZAWA, Kazuhiro OHKI, Shoichi KA ...1996 Volume 44 Issue 1 Pages 5-10
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe total synthesis of surfactin B2, a cyclic depsipeptide isolated from Bacillus natto KMD 2311, was achieved to elucidate the absolute configuration of its fatty acid moiety. This is the first chemical confirmation of the absolute configuration of a surfactin homolog. Two possible diastereoisomers of surfactin B2, cyclo[D- and L-3-(Glu-Leu-D-Leu-Val-Asp-D-Leu-Leu-O)-n-tetradecanoyl] (1a and b), were synthesized by a solution method using mainly active ester and azide fragment condensation methods. Cyclization reaction of the partially protected linear depsipeptide containing the C-terminal N-succinimidyl active ester in pyridine by the high dilution method at room temperature for 3d gave the desired cyclic depsipeptide in a high yield of about 70%. The synthetic product 1a, containing the D-isomer of 3-hydroxytetradecanoic acid as a fatty acid moiety, was identical with natural surfactin B2.View full abstractDownload PDF (1001K) -
Motoharu JU-ICHI, Yuko TAKEMURA, Masayoshi OKANO, Narihiko FUKAMIYA, K ...1996 Volume 44 Issue 1 Pages 11-14
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo novel dimeric coumarins, claudimerin-A (1) and -B (3), were isolated from the roots of Citrus hassaku (Rutaceae). The chemical structures were elucidated by spectroscopic studies and/or single-crystal X-ray analysis. The main structural characteristic is a pyranopyran ring connecting two clausarin (2) units.View full abstractDownload PDF (609K) -
Eisuke KAJI, Yumiko OSA, Keiko TAKAHASHI, Shonosuke ZEN1996 Volume 44 Issue 1 Pages 15-20
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA novel α-D-talosaminyl donor, 2-(benzoyloxyimino)-2-deoxy-α-D-lyxo-hexopyranosyl bromide has been synthesized in a total yield of 32% over 6 steps from D-galactose. The utility of the donor was evaluated for the elaboration of α-D-TalNAc-(1→6)-α-D-Gal, α-D-TalNAc-(1→6)-α-D-Glc, and α-D-TalNAc-(1→3)-L-serine derivatives by a simple 3-step sequence, comprising α-selective glycosylation of appropriately protected acceptors of D-galactose, D-glucose, and L-serine, talo-selective hydroboration of the oxyimino function to an amino group, and N-acetylation.View full abstractDownload PDF (900K) -
Masanori SOMEI, Fumio YAMADA, Yoshihisa YAMAZAKI, Akiko SHINKURA1996 Volume 44 Issue 1 Pages 21-28
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe developed a novel synthesis of 2-aminoindan derivatives, having a 2-methyl-1-propenyl group at the 1-position and oxygen functional groups in the benzene ring, in 8 or 9 steps from vanillin.View full abstractDownload PDF (1250K) -
Ermitas ALCALDE, Maria GISBERT, Lluisa PEREZ-GARCIA1996 Volume 44 Issue 1 Pages 29-33
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe first synthesis of some imidazolium(pyridinium) 4-nitrobenzimidazolate betaines with an ethylene interannular spacer has been performed. Their chemical behavior concerning a type of β-elimination reaction has also been studied and contrasted to that of their pyridinium counterparts.View full abstractDownload PDF (711K) -
Takashi TANAKA, Isao KOUNO, Gen-ichiro NONAKA1996 Volume 44 Issue 1 Pages 34-40
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSGeraniin (1), a widely distributed ellagitannin having a dehydrohexahydroxydiphenoyl (DHHDP) ester moiety, was converted into chebulagic acid (2), an ellagitannin having a chebuloyl ester moiety, which was reported to be a potent inhibitor of DNA topoisomerases. This was achieved by addition of the thiol group of glutathione to the six-membered acetal ring form of the DHHDP moiety (1a) with concomitant hydrolytic ring cleavage and subsequent reductive desulfurization with Raney nickel. The concurrent addition of the thiol to the five-membered acetal ring form of the DHHDP group (1b) generated the product 14 and its precursor 13, which are structurally related to naturally occurring ellagitannins isolated from Euphorbiaceous plants. Thus, the rearrangements observed in these reactions may be relevant to the metabolism of DHHDP esters in plants.View full abstractDownload PDF (1221K) -
Masayuki YOSHIKAWA, Youichi FUKUDA, Toshio TANIYAMA, Isao KITAGAWA1996 Volume 44 Issue 1 Pages 41-47
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFollowing the characterization of the iridoid and iridoid glycoside constituents in Chinese Rehmanniae Radix, the dried root of Rehmannia glutinosa LIBOSCH. [Kan-jio in Japanese], we investigated the structures of biologically active ionone glucosides, rehmaionosides A, B, and C, and a monoterpene glucoside, rehmapicroside. Their absolute stereostructures were determined on the basis of chemical and physicochemical evidence, which included the result of application of the exciton chirality method to the allylic benzoyl derivatives.View full abstractDownload PDF (1100K) -
Masanobu TANI, Takahiro ARIYASU, Chika NISHIYAMA, Hiroko HAGIWARA, Tos ...1996 Volume 44 Issue 1 Pages 48-54
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe Friedel-Crafts acylation of ethyl pyrrole-2-carboxylate (3) was studied under several conditions using various Lewis acids and acyl chlorides. The acylation with various acyl chlorides in the presence of aluminum chloride gave exclusively ethyl 4-acylpyrrole-2-carboxylate (5), whereas weaker Lewis acids such as zinc chloride and boron trifluoride etherate gave a mixture of ethyl 4- and 5-acylpyrrole-2-carboxylates.View full abstractDownload PDF (1063K) -
Masanobu TANI, Takahiro ARIYASU, Masanori OHTSUKA, Terumi KOGA, Yumi O ...1996 Volume 44 Issue 1 Pages 55-61
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAs a synthetic application of the previously reported C4-acylation of ethyl pyrrole-2-carboxylate (1), a new strategy for indole synthesis was developed. Ethyl pyrrole-2-carboxylate (1) was allowed to react with succinic anhydride or 3-methoxycarbonylpropionyl chloride to give, in good yield, a C4-succinyl derivative of 1, which was converted into ethyl 7-oxo-4, 5, 6, 7-tetrahydroindole-2-carboxylate (6) as a key intermediate for indole synthesis. Starting from 6, several indoles functionalized on the benzene moiety were synthesized.View full abstractDownload PDF (1180K) -
Fumihiro KONDO, Shojiro MAKI, Katsuhiro KONNO, Hiroaki TAKAYAMA1996 Volume 44 Issue 1 Pages 62-66
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe first synthesis of the title compound 4, a novel analog of 1α-hydroxyvitamin D (α-calcidiol) that might be therapeutically useful, is described. A key feature in the synthesis is the radical deoxygenation of the diol 21, which was prepared according to the previously reported procedure starting from 17. The resulting deoxygenated product 22 with the desired side-chain moiety was finally led to 4 in a conventional manner. Some aspects of the unusual reactivity of 25-OH on radical deoxygenation are also discussed.View full abstractDownload PDF (799K) -
Hideaki MURATAKE, Itsuko ABE, Mitsutaka NATSUME1996 Volume 44 Issue 1 Pages 67-79
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTotal synthesis of duocarmycin SA (1), an extremely potent cytotoxic antibiotic, was achieved in the racemic form at first by effectively utilizing two reactions as key steps, (i) an intramolecular Heck reaction of the benzyl ether 21a, derived from a dihydropyridine 13a and a pyrrole derivative 11, to form tricyclic compounds 25a and 26a, and (ii) a modified Mitsunobu reaction on the diol derivative 40 for the construction of compound 41 having the pivotal pharmacophore of a cyclopropanoindolinone partial structure, which is critical for the high biological activities of 1. Next, optical resolution of an intermediary racemic secondary alcohol 50 was cleanly attained by derivatizing it to (R)-O-methylmandelates 52 and 53, and the resulting chiral alcohols (+)-50 and (-)-50 were respectively transformed into unnatural (-)-1 and natural (+)-1. Finally inversion of the secondary alcohol (+)-50 to the enantiomer (-)-50 was effected by using the Mitsunobu reaction. This constitutes an enantio-convergent total synthesis of natural duocarmycin SA (1) starting from a racemic compound.View full abstractDownload PDF (2196K) -
Hong-Min LIU, Yoshisuke TSUDA1996 Volume 44 Issue 1 Pages 80-87
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSMethyl arabino-hexopyranosid-2-uloses rearranged, in pyridine, into arabino-hexopyranosid-3-uloses through an intramolecular hydride shift. The product further isomerized, through enolization, to the most stable ribo-hexopyranosid-3-uloses, which, on prolonged standing in the same solvent, gradually liberated methanol giving rise to dioxo derivatives. The last change was particularly evident for 3-oxoglycosides carrying a 4-axial hydroxyl group.View full abstractDownload PDF (910K) -
Hong-Min LIU, Yoshisuke TSUDA1996 Volume 44 Issue 1 Pages 88-90
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS4-Oxoglycosides of xylo-configuration (1a, 1b) rearranged in pyridine-d5 to give exclusively 3-oxoglycosides of ribo-configuration through enediol intermediates. On the other hand, 4-oxoglycosides of lyxo- and arabino-configuration (5, 6) gave an epimeric mixture of both isomers. The reason for this difference was discussed on the basis of AM1 calculations.View full abstractDownload PDF (400K) -
Abimael D. RODRIGUEZ, Javier J. SOTO1996 Volume 44 Issue 1 Pages 91-94
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFive new pseudopteranoid diterpenes, pseudopteradiene (2), pseudopteradienoic acid (3), 11-pseudopteranol (4), pseudopteranoic acid (5), and diepoxygorgiacerodiol (7), along with five previously described analogues, have been isolated from Puerto Rican specimens of the gorgonian octocoral Pseudopterogorgia acerosa. Detailed analysis of the spectral data and chemical methods were used to establish their structures and to define the relative stereochemistry.View full abstractDownload PDF (760K) -
Mitsuru OHKUBO, Atsushi KUNO, Kiyotaka KATSUTA, Yoshiko UEDA, Kiyoharu ...1996 Volume 44 Issue 1 Pages 95-102
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of 1, 2, 3, 4-tetrahydroisoquinoline derivatives were synthesized and evaluated for anticonvulsant activity against intracerebro-ventriculas (i.c.v.) N-methyl-D-aspartate (NMDA)-induced seizures in mice. Among these compounds, (+)-1-methyl-1-phenyl-1, 2, 3, 4-tetrahydroisoquinoline hydrochloride ((+)-1a, FR115427) was the most effective anticonvulsant, and also protected CA1 hippocampal neurons from ischemia-induced neuronal degeneration in rats at 32 mg/kg i.p. In addition, (+)-1a showed anti-hypoxic activity in mice at 3.2-32 mg/kg i.p. The absolute configuration at the C-1 position of the isoquinoline ring was determined to be S by a single-crystal X-ray analysis of (+)-1a (+)-di-p-toluoyl-D-tartrate. Structure-activity relationships with regard to the anticonvulsant activity of this series of compounds are discussed, and the three-dimensional structures of (S)-(+)-1a and MK801 are compared.View full abstractDownload PDF (1180K) -
Yuzo MATSUMOTO, Ryuji TSUZUKI, Akira MATSUHISA, Kazuhisa TAKAYAMA, Tor ...1996 Volume 44 Issue 1 Pages 103-114
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSStrong potassium channel-activating effects were found among a series of novel 4-substituted 3, 4-dihydro-2H-1, 4-benzoxazine derivatives. The key step in preparation was the nucleophilic substitution of 3, 4-dihydro-2H-1, 4-benzoxazine (3) with activated halogenopyridines, such as halogenopyridine N-oxides (15a-c) and the borane adduct (15d) of 4-bromopyridine. Structure-activity relationship studies identified 2-(3, 4-dihydro-2, 2-dimethyl-6-nitro-2H-1, 4-benzoxazin-4-yl)pyridine-1-oxide (16a : YM934) as the optimal compound. This compound (16a) showed a more potent oral antihypertensive effect than cromakalim in conscious spontaneously hypertensive rats.View full abstractDownload PDF (1442K) -
Hitoshi KURATA, Koki ISHIBASHI, Shinichi SAITO, Takakazu HAMADA, Hiroy ...1996 Volume 44 Issue 1 Pages 115-121
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of 4-aza-5α-androstane compounds with one or two aromatic moieties in the carbamoyl group at the C-17 position were synthesized and their inhibitory activities for rat and human prostatic testosterone 5α-reductase were tested in vitro. Compounds with one aromatic moiety in the carbamoyl group showed high inhibitory activity for rat 5α-reductase, but little for human prostatic 5α-reductase. On the other hand, compounds with two aromatic moieties had potent inhibitory activities for both rat and human 5α-reductase. The structural requirements for potent inhibition for both enzymes are discussed in relation to the spatial arrangement of the C-17 carbamoyl group.View full abstractDownload PDF (1094K) -
Masaaki KUWAHARA, Yasuhiko KAWANO, Hiroshi SHIMAZU, Yasuko ASHIDA, Aki ...1996 Volume 44 Issue 1 Pages 122-131
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of novel (imidazo[1, 2-b]pyridazin-6-yl)oxyalkylsulfonamides was synthesized and evaluated for the ability to inhibit platelet activating factor (PAF)-induced bronchoconstriction in guinea pigs. The compounds bearing a gem-dialkyl or a cycloalkylidene group at the 2 position of the sulfamoylpropyloxy group in the side chain were found to have potent activity. Among them, 3-(imidazo[1, 2-b]pyridazin-6-yl)oxy-2, 2-dimethylpropanesulfonamide (6) showed excellent anti-asthmatic activity and the longest duration of action. The compounds bearing a methyl group at the 7 or 8 position of the imidazo[1, 2-b]pyridazine ring were found to have enhanced activity. Among them, 3-(7-methylimidazo[1, 2-b]pyridazin-6-yl)oxy-2, 2-dimethylpropanesulfonamide (25) showed the most potent inhibitory effect, and its anti-asthmatic effect in an experimental model of allergic asthma was superior to that of theophylline. The structure-activity relationships in this series of compounds are discussed.View full abstractDownload PDF (1328K) -
Kenji SUZUKI, Toshio TATSUOKA, Takafumi ISHIHARA, Tomochika OHNO, Kazu ...1996 Volume 44 Issue 1 Pages 132-138
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new series of 1-(1, 4-benzoquinon-2-yl)-1, 2, 3, 4-tetrahydronaphthalenes (3, 4) were synthesized for evaluation of their pharmacological activities. These compounds showed significant anti-lipid peroxidation (ALP) activities with rat brain homogenate and some of them possessed a protective effect against hypobaric hypoxia in mice.View full abstractDownload PDF (985K) -
Kenji SUZUKI, Toshio TATSUOKA, Tomiko MURAKAMI, Takafumi ISHIHARA, Kaz ...1996 Volume 44 Issue 1 Pages 139-144
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new series of 2-arylmethyl-1, 4-benzoquinones (2) was synthesized for evaluation of their pharmacological activities. These compounds showed significant inhibition of platelet aggregation induced by arachidonic acid (AA) and some of them possessed a protective effect against endothelial cell injury caused by hydrogen peroxide.View full abstractDownload PDF (942K) -
Toyoshi KATAGI, Hiromi KATAOKA, Yuriko KONISHI, Yuki TAKATA, Sachiyo K ...1996 Volume 44 Issue 1 Pages 145-149
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNovel O-acyloximes having an acetyl group or N-protected amino acid as an O-acyl group were synthesized by reaction with acetyl chloride or by a mixed anhydride method. 4'-Morpholinoacetophenone oxime (oxime-2) was determined to be the (E) isomer by X-ray crystal structure analysis. The anti-inflammatory activities of the test compounds were assessed in terms of the inhibitory effect on increased vascular permeability induced by histamine, and several compounds were assessed together by means of the carrageenan-induced paw edema assay. In general, acetyl oximes and tert-butyloxycarbonylphenylalanyl oximes showed inhibitory action on increased vascular permeability. Particularly important for the appearance of anti-inflammatory activity was direct attachment of the acetyl group to the oxime. Of the two isoforms of cyclooxygenase (COX-1 and COX-2), COX-1 activity was inhibited by oxime-2 and 4'-piperidinoacetophenone oxime (oxime-3) with IC50 values of 50 and 130 μM, respectively, while COX-2 activity was not inhibited. The in vitro inhibitory effect of oxime-2 and oxime-3 on COX-1 activity decreased with O-acylation of the oximes.View full abstractDownload PDF (734K) -
Atsuhiko UEMURA, Yukio TADA, Setsuo TAKEDA, Junji UCHIDA, Jun-ichi YAM ...1996 Volume 44 Issue 1 Pages 150-155
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSVarious O-alkyl derivatives of 2'-deoxy-5-fluorouridine (FUdR) were synthesized and their antitumor activities in mice bearing sarcoma 180 (s.c.-p.o.) were evaluated in terms of the ED50 values (mg/kg/d). Most of these compounds were superior to FUdR in antitumor activity. In particular, the antitumor activity of 3'-O-(p-chloro-benzyl)-FUdR (3e) (ED50 =0.87mg/kg/d) was as much as 100 times that of FUdR (ED50=84mg/kg/d). Further, various 5'-O-aminoacyl derivatives of 3e were synthesized and evaluated in terms of ED50 value and therapeutic index (T.I.). Both the ED50 value (0.41mg/kg/d) and the T.I. (4.18) of 3'-O-(p-chlorobenzyl)-5'-O-glycyl-FUdR hydrochloride (6a) were significantly improved, compared with those of 3e and FUdR. FUdR plasma concentration after a single p.o. dosing of 6a was maintained for as long as 24h.View full abstractDownload PDF (813K) -
Yoshihiro SHIBATA, Keizo SASAKI, Yuichi HASHIMOTO, Shigeo IWASAKI1996 Volume 44 Issue 1 Pages 156-162
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSPhenylphthalimides (2-phenyl-1H-isoindole-1, 3-diones) were prepared and their effects on tumor necrosis factor alpha (TNF-α) production by human leukemia cell line HL-60 stimulated with 12-O-tetradecanoylphorbol-13-acetate (TPA) were examined. An analysis of the structure-activity relationships of the phenylphthalimides indicated that potent enhancing activity on TPA-induced TNF-α production by HL-60 cells requires medium-sized substituent(s) at the ortho position(s) of the phenyl group; 2-(2, 6-diisopropylphenyl)-1H-isoindole-1, 3-dione (PP-33) increased the TNF-α production to more than 600% at the concentration of 1×10-5 M. Introduction of a nitro group at the phthalimide moiety of PP-33 enhanced the activity; 2-(2, 6-diisopropylphenyl)-4-nitro-1H-isoindole-1, 3-dione (4NPP-33) and its 5-nitro isomer (5NPP-33) enhanced the TNF-α production to more than 800% and 700%, respectively, at the concentration of 1×10-5 M. Introduction of fluorines into the phthalimide moiety of PP-33 greatly lowered the concentration of the compound necessary to elicit the TNF-α production-enhancing activity;2-(2, 6-diisopropylphenyl)-4, 5, 6, 7-tetrafluoro-1H-isoindole-1, 3-dione (FPP-33) showed the activity at nanomolar concentration, with the optimum concentration of 1×10-7 M.View full abstractDownload PDF (1115K) -
Noriko MOTOHASHI, Yutaka SAITO1996 Volume 44 Issue 1 Pages 163-166
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSulfasalazine, an anti-inflammatory drug, is metabolized to sulfapyridine and 5-aminosalicylic acid (5-ASA) which is therapeutically active. In the inflammation, active oxygen species have been suggested to play an important role. Among various active oxygen species, hydroxyl radical is known to be the most active radical. To elucidate the reactivity of sulfapyridine, 5-ASA, 4-ASA and 3-ASA with hydroxyl radicals, the rate constants were determined measuring the fluorescence of hydroxybenzoates induced by radiolysis hydroxylation of benzoate. The constant for 5-ASA, strongly fluorescent but insoluble in ether, was measured after ether extraction of hydroxybenzoates under acidic condition. For the other compounds, the rate constants were determined using a method which separates hydroxybenzoates by HPLC after the ether extraction, since the three compounds moved to the ether layer and interfered with the fluorescence of the hydroxybenzoates induced. Four rate constants were obtained in the range of 6.4-7.0×109 M-1 s-1, showing that they similarly scavenge hydroxyl radicals in vitro.View full abstractDownload PDF (602K) -
Akiko KUSANO, Makio SHIBANO, Genjiro KUSANO1996 Volume 44 Issue 1 Pages 167-172
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour new xylosides (1-4) were isolated from the aerial parts of Cimicifuga simplex (Ranunculaceae), and their structures were determined to be 24-epi-7β-hydroxy-24-O-acetylhydroshengmanol-3-O-β-D-xylopyranoside (1), 25-O-methyl-24-O-acetylhydroshengmanol-3-O-β-D-xylopyranoside (2), 25-O-methyl-7β-hydroxy-24-O-acetylhydroshengmanol-3-O-β-D-xylopyranoside (3) and 25-O-methyl-1α-hydroxy-24-O-acetylhydroshengmanol-3-O-β-D-xylopyranoside (4).View full abstractDownload PDF (877K) -
Studies on the Constituents of Polygala japonica HOUTT. III. Structures of Polygalasaponins XX-XXVIIDongming ZHANG, Toshio MIYASE, Masanori KUROYANAGI, Kaoru UMEHARA, Aki ...1996 Volume 44 Issue 1 Pages 173-179
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSEight new oleanane-type saponins, polygalasaponins XX-XXVII, along with a known saponin, hederagenin 3-O-β-D-glucopyranosyl (1→2)-β-D-glucopyranoside, were isolated from the aerial part of Polygala japonica. The structures of these compounds were established on the basis of spectroscopic and chemical evidence.View full abstractDownload PDF (948K) -
Hideaki OKOCHI, Masahiro NAKANO1996 Volume 44 Issue 1 Pages 180-186
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA method of preparing a stable water-in-oil-in-water type multiple emulsion (w/o/w emulsion) as a carrier of peptides was sought by studying rotation rate of homogenizer, mixing ratio of each component and concentrations of surfactants. We used "Lipiodol Ultra-Fluid[○!R] and isoropyl myristate oil mixture (4.5 : 5.5)" for an oil phase of the w/o/w emulsion to minimize the difference in specific gravity between this phase and an aqueous phase and to reduce the viscosity of the former. w/o/w emulsions entrapping vancomycin hydrochloride in their internal aqueous phases were prepared by a modified two-stage emulsification procedure and their particle size, entrapment efficiency, viscosity, separation and drug release property studied.The particle size of the w/o/w emulsion was smaller with an increase in rotation rate at an emulsification stage (96.3±31.8 μm at 1000 rpm and 2.81±1.37 μm at 20000 rpm), but its entrapment efficiency was slightly reduced with rate increase. The best mixing ratio of internal aqueous phase : oil phase : external aqueous phase was 1 : 4 : 5. For surfactants, HCO-40 (5% (w/v)) and Pluronic F-88 (5% (w/v)) were dissolved in the oily and the external aqueous phase, respectively. Drug release from the w/o/w emulsion was extremely slow and sustained, and that property tended to be faster with a decrease in their particle size (0% at 96.3 μm and 2.97±0.41% at 2.81 μm). The stability of w/o/w emulsion of 10 μm diameter was good from observations of optical and scanning electron microphotographs and measurement of w/o/w emulsion diameters. The w/o/w emulsion prepared in this study is viewed as a possible carrier of water-soluble drugs.View full abstractDownload PDF (1679K) -
Toshio YAJIMA, Akemi NOGATA, Miki DEMACHI, Nobuo UMEKI, Shigeru ITAI, ...1996 Volume 44 Issue 1 Pages 187-191
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA method of taste-masking using a spray-congealing technique was developed. Clarithromycin (CAM), a macloride antibiotic with a bitter taste, was selected as the model compound. The fundamental objective was to prevent the preparation from dissolving in the mouth, while ensuring that rapid release of CAM from the preparation could be attained in the gastrointestinal tract, resulting in bioequivalence to the conventional dosage form. Glyceryl monostearate (GM) and aminoalkyl methacrylate copolymer E (AMCE) were selected as ingredients, since GM, a substance with a low melting point, is able to be decomposed by an enzymatic reaction in the intestinal tract where the solubility of AMCE is very low. On the other hand, AMCE was selected because it is freely soluble at low pH levels (e.g. the pH level in the stomach), but insoluble in neutral and high pH levels (e.g. the pH level in the mouth).Spherical particles of the matrix (spherical matrix) and disks of matrix with various ratios were prepared, and the optimum ratios of CAM, GM and AMCE for the following release criterion were determined by experimental design (the simplex method). That is, 100 mg/l of CAM in the spherical matrix should be completely released within 20 min in pH 4.0, and less than 14 mg/l of CAM in spherical matrix should be released at 60 min in pH 6.5.As a result, the optimum formula for the matrix in consistency with the criterion was 3 : 6 : 1 for CAM, GM and AMCE, respectively.View full abstractDownload PDF (837K) -
Masayuki KUZUYA, Masanao ISHIKAWA, Tadashi NOGUCHI, Junji NIWA, Shin-i ...1996 Volume 44 Issue 1 Pages 192-195
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe rapid drug release from a double-compressed tablet containing theophylline with the water-soluble polymer polymethacrylic acid (PMAA) or polyacrylamide (PAAm) used as a wall material can be suppressed by argon plasma irradiation and changed into the slow release due to a decrease in the solubility of water-soluble polymers used as the outer layer. This report is the first to deal with an attempt to control the release of drugs by controlling polymer solubility, and to fabricate a completely soluble controlled release type of drug delivery system (DDS) making use of plasma processing.View full abstractDownload PDF (614K) -
Masahiro FUKAHORI, Keiko KAKINUMA, Masako SEKI, Hiroaki TAKAHASHI, Yas ...1996 Volume 44 Issue 1 Pages 196-200
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe effects of added lower alcohols on the sorption of tocopherol acetate (VEA) to polyethylene film were studied in an aqueous solution with polyoxyethylene cetyl ether used as a solubilizer. The sorption rate of solubilized VEA increased in inverse proportion to the dielectric constant of added lower alcohols. The increasing concentrations of lower alcohols resulted in turbidity of the VEA-surfactant system, i.e., a reduction of the VEA solubilizing ability of the surfactant, followed by transparentization. An increase in ethanol concentration enhanced the sorption rate of solubilized VEA followed by a rate decrease. It also caused greater solubility of VEA in the absence of the surfactant, increasing the polarity of the surfactant micellar interior and causing disintegration of the micelles. Lower alcohols lessen the polarity of the solution in inverse proportion to the dielectric constant of the alcohols. Consequently, the alcohols may be responsible for weakening the hydrophobic binding between hydrophobic VEA and the hydrocarbon chain in the surfactant due to an increased affinity of VEA and the surfactant molecules for the bulk phase. We thus conclude that the sorption of solubilized VEA to polyethylene film is accelerated by thermodynamic labilization of VEA, but an increase in the VEA solubility in an aqueous-alcohol phase contributes to a decrease in the sorption rate.View full abstractDownload PDF (792K) -
Shigeo TAKESHIMA, Takehisa INOUE1996 Volume 44 Issue 1 Pages 201-203
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSErgothioneine (Erg) which possesses an imidazole-2-thione (IT) moiety had a strong quenching effect on indole fluorescence. The Stern-Volmer quenching constants (KSV), which quantified its fluorescence-quenching ability were 1508 (Erg) and 517 (IT) with respect to indole at pH 5.0. Compared with the structure of IT, the KSV values of ethylenethiourea (ET), which lacks a double bond between the 4 and 5 position, imidazole (IM) which lacks a sulfur atom, and mercaptoethylamine (MEA) which exhibits no thione-thiol tautomerizm were 71, 14, and 18, respectively under the same instrumental conditions. According to these results, the fluorescence-quenching effect of Erg was about 20-100 times stronger than related compounds such as ET, IM, and MEA. This physico-chemical property may help clarify the biological role of Erg.View full abstractDownload PDF (508K) -
Ching-nien CHEN, Paul C. WANG, Hua-fu SONG, Yuek C. LIU, Ching-shih CH ...1996 Volume 44 Issue 1 Pages 204-207
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA non-invasive in vivo 13C-NMR experiment is performed to follow the metabolic pathway of ibuprofen in rats. Detection of possible intermediates and the stereoselectivity of ibuprofen chiral inversion process are discussed.View full abstractDownload PDF (595K) -
Reaction Products from Fischer's Methylation of 3-Deoxy-D-glycero-D-galacto-2-nonulosonic Acid (KDN)Toshitsugu KAI, Xue-Long SUN, Makoto TANAKA, Hiroaki TAKAYANAGI, Kimio ...1996 Volume 44 Issue 1 Pages 208-211
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSeveral compounds were isolated from the Fischer's methylation reaction mixture of 3-deoxy-D-glycero-D-galacto-2-nonulosonic acid (KDN) with hydrochloric acid or methanesulfonic acid in methanol. The major product was methyl (methyl 3-deoxy-β-D-glycero-D-galacto-2-nonulopyranosid)onate (2), which we have already reported. New furan derivatives and a 4, 8-anhydro product were also isolated. The structures of these compounds were elucidated by nuclear magnetic resonance spectroscopy and X-ray crystallographic analysis.View full abstractDownload PDF (583K) -
Norikazu NISHINO, Toru ARAI, Yukio UENO, Masataka OHBA1996 Volume 44 Issue 1 Pages 212-214
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe tandem action of serine protease (α-chymotrypsin or subtilisin BPN') and Aspergillus genus aminoacylase on racemic N-acetyl-α-aminoalkanedioic acid α, ω-diester produced L-α-aminoalkanedioic acid ω-ester in good yield and high optical purity. L-α-Aminosuberic acid ω-ester thus obtained was conveniently introduced into an oxytocin analog, [Asu1, 6]oxytocin, by the solid-phase-synthesis and cyclization-cleavage method with oxime resin.View full abstractDownload PDF (559K) -
Shin-ichi YAMADA, Takaji YAMAGUCHI, Kazuyuki AIHARA, Akihiko NAGAI, Ke ...1996 Volume 44 Issue 1 Pages 215-221
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe sodium salts (5) of four stereoisomeric benzimidazolylsulfoxides, (Ss, 9R)-(-)-4, (Rs, 9S)-(+)-4, (Ss, 9S)-(-)-4 and (Rs, 9R)-(+)-4, were prepared from optically pure sulfides, (+)-8 and (-)-8. The sulfoxides (4) were transformed into sulfenamides (6) and symmetric disulfides (9) under acidic conditions, without any change of stererochemical configuration at the α-carbon bearing the sulfinyl group. No significant difference was observed among the four stereoisomers in inhibitory activity towards (H++K+)-ATPase in vitro. However, (Ss, 9R)-(-)-5 showed more long-lasting antisecretion activity in vivo than that of another enantiomer, (Rs, 9S)-(+)-5.View full abstractDownload PDF (1108K) -
Toshiaki KUMAZAWA, Masashi YANASE, Shiro SHIRAKURA, Eiko OHISHI, Koji ...1996 Volume 44 Issue 1 Pages 222-225
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn a previous paper, we reported a novel inhibitor of acyl-CoA : cholesterol acyltransferase (ACAT), 2-bromo-N-(2, 6-diisopropylphenyl)-6, 11-dihydrodibenz[b, e]oxepin-11-carboxamide (1). In this work, we prepared both enantiomers and tested them for ability to inhibit ACAT (liver microsomes from cholesterol-fed rabbits) in vitro and to decrease serum total cholesterol in cholesterol-fed golden hamsters in vivo. The precursor carboxylic acid 4 was optically resolved with cinchonidine. The obtained (-)- and (+)-4 were converted to (-)- and (+)-1 without racemization, respectively. The enantiomer (-)-1 showed potent ACAT inhibitory activity in vitro with an IC50 value of 8 nM and was approximately 10-fold more active than (+)-1. Furthermore, (-)-1 showed strong hypocholesterolemic activity in vivo, whereas (+)-1 was inactive.A molecular modeling study showed that the difference of ACAT inhibitory activity between the enantiomers was derived from the spatial alignment of the bromine.Compound (-)-1 was selected for further evaluation as KW-3033.View full abstractDownload PDF (594K) -
Kenji TAKAHATA, Shukuro IGARASHI1996 Volume 44 Issue 1 Pages 226-228
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS5, 10, 15, 20-Tetrakis(4-sulfophenyl)porphine (TPPS) has a strong fluorescence, while the silver(I) complex [Ag(I)2-TPPS] has very little fluorescence. Also, the Ag(I)2-TPPS complex easily releases the silver ion from the porphine ring in the presence of thiol compounds such as L-cysteine, glutathione and 2-mercaptoethanol. Based on these results, a highly sensitive spectrofluorimetric determination of 10-7 M levels of thiol compounds was developed. Calibration curves were linear in the concentration ranges of 0-5×10-7 M for L-cysteine, 0-5×10-7M for glutathione and 0-2×10-6 M for 2-mercaptoethanol. Detection limits (3σ) were 1×10-10 M for L-cysteine, 5×10-11 M for glutathione and 2×10-10 M for 2-mercaptoethanol. Precisions were 1.89% for L-cysteine (2.5×10-7 M), 3.33% for glutathione (2.5×10-7 M) and 2.33% for 2-mercaptoethanol (1.0×10-6 M).View full abstractDownload PDF (533K) -
Tenji KONISHI, Masuji AZUMA, Rie ITOGA, Shiu KIYOSAWA, Yasuhiro FUJIWA ...1996 Volume 44 Issue 1 Pages 229-231
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom the wood of Excoecaria agallocha LINN., three new labdane-type diterpenes, ent-11α-hydroxy-3-oxo-13-epi-manoyl oxide (4), ent-16-hydroxy-3-oxo-13-epi-manoyl oxide (5) and ent-15-hydroxy-labda-8(17), 13E-diene-3-one (6) were isolated together with three known compounds, ent-3-oxo-13-epi-manoyl oxide (ribenone, 1), ent-3β-hydroxy-13-epi-manoyl oxide (ribenol, 2) and ent-13-epi-manoyl oxide (3), and their structures were determined.View full abstractDownload PDF (606K) -
Munekazu IINUMA, Hideki TOSA, Toshiyuki TANAKA, Soedarsono RISWAN1996 Volume 44 Issue 1 Pages 232-234
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new xanthones were isolated from the bark of Garcinia dioica (Guttiferae) in addition to a known xanthone, 1, 3, 6-trihydroxy-8-geranyl-7-methoxyxanthone (rubraxanthone). The structures of the three xanthones were elucidated to be 1, 3, 6-trihydroxy-8-(7-hydroxy-3, 7-dimethyl-2, 5-octadieyl)-7-methoxyxanthone, 1, 3, 6-trihydroxy-8-(6, 7-epoxy-3, 7-dimethyl-2-octenyl)-7-methoxyxanthone and 1, 3, 7-trihydroxy-2, 4-diisoprenylxanthone by the aid of spectroscopic analysis including the two dimensional NMR technique. The occurrence of xanthone with such a C10 alkyl chain is rare in naturally occurring compounds.View full abstractDownload PDF (587K) -
Takahiro UCHIDA, Akira YAGI, Yuko ODA, Yoichi NAKADA, Shigeru GOTO1996 Volume 44 Issue 1 Pages 235-236
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSBiodegradable poly(lactide-co-glycolide) (PLGA; 50/50) microspheres containing bovine insulin as a model protein were prepared by an oil-in-oil (o/o) emulsion solvent evaporation process. When aluminum tristearate (0.15% (w/v)) was employed as a dispersing agent, the loading efficiency of insulin was almost 100% and the yield was over 80%. The average diameter of the PLGA microspheres always ranged between 100 and 200 μm. Morphology study using a scanning electron micrograph showed smooth, spherical, fairly monodispersed PLGA microspheres containing insulin. In relation to release profile, the very low release rate of insulin was demonstrated (only 1% of insulin released after 7 d release test in pH 7.4 Tris buffer) for the PLGA microspheres. Nevertheless, the degradation of bovine insulin in PLGA microspheres was confirmed by high performance liquid chromatography. This degradation seemed to be caused by an acidic condition caused by poly(lactide-co-glycolide) polymer.View full abstractDownload PDF (567K) -
Xian-Rong QI, Yoshie MAITANI, Tsuneji NAGAI1996 Volume 44 Issue 1 Pages 237-240
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA soybean-derived sterol mixture (SS) was used to stabilize liposomes prepared from dipalmitoylphosphatidylcholine (DPPC). The effect of SS on the stability and rigidity of liposomes entrapping calcein was investigated by measuring retentivity of calcein in liposomes in vitro and in vivo, and by fluorescence anisotropy, respectively. The entrapment efficiency is directly proportional to the total concentration of DPPC and SS. The presence of SS tends to increase the rigidity of the bilayer above its gel-liquid crystalline phase transition temperature of liposomes, and SS tends to fluidize the bilayer below its gel-liquid crystalline phase transition temperature. The relation between the stability of DPPC-liposomes with SS and the rigidity of liposomal membrane was discussed.View full abstractDownload PDF (677K) -
Naomi YAGI, Yuhji TERASHIMA, Harumi KENMOTSU, Hitoshi SEKIKAWA, Masahi ...1996 Volume 44 Issue 1 Pages 241-244
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSolid dispersion systems of probucol-polyvinylpyrrolidone (PVP) K25, K30 and K90 were prepared in various weight ratios by co-evaporation of the drug and PVP ethanolic solution. The observation of solid dispersion systems by powder X-ray diffraction spectra and differential scanning calorimeter indicated that probucol in the systems did not exhibit its crystalline property. The solubility of probucol in water at 25°C was 5 ng/ml at most, and its dissolution was markedly increased in the solid dispersion systems in the JP XII disintegration media No. 1 (pH 1.2) and No. 2 (pH 6.8) at 37°C. Probucol concentrations after the dissolution of the solid dispersion systems showed hypersaturation. The solid dispersion system of 1 : 9 (probucol : PVP K 30 in weight ratio) showed the best dissolution of probucol among the systems prepared in the study.View full abstractDownload PDF (565K) -
Masahiro FUKAHORI, Yasuo TAKATSUJI, Takahiro YAMAKITA, Hiroaki TAKAHAS ...1996 Volume 44 Issue 1 Pages 245-248
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe aggregate formation of p-hydroxybenzoic acid esters (parabens) in aqueous solutions was studied by ultrafiltration and light scattering. The permeability of parabens in aqueous solution passing through an ultrafiltration membrane decreased with an increase in carbon number in the alkyl group from methyl- to butyl-paraben. Dissociation of the phenolic hydroxyl group and the addition of ethanol made possible the free passage of butyl-paraben through the membrane. An increase in the concentration of butyl-paraben was responsible for the steep rise in light scattering intensity plots. Undissociated molecules of parabens in aqueous solution are thus shown to form aggregates by hydrophobic intermolecular force. The membrane permeability of butyl-paraben decreased and increased with concentration and the cutoff molecular weights of the membranes, respectively. Plots of surface tension against concentration of butyl-paraben showed a linear decrease but no inflection point. Paraben molecules possessing long alkyl chains may thus be concluded to form non-micellar type aggregates in aqueous solution, which differ from the clear-cut aggregate formation of conventional surfactants.View full abstractDownload PDF (578K) -
Fu-An CHEN, Hui-Wen CHENG, An-Bang WU, Hsing-Chu HSU, Chau-Yang CHEN1996 Volume 44 Issue 1 Pages 249-251
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe photodegradation of alkannin/shikonin (A/S) was studied as a function of solvent polarity, pH and ionic strength. This process follows an apparent first-order kinetic reaction. The photodegradation rate is inversely proportional to the solvent polarity in the order of chloroform > dichloromethane > 2-propanol > ethanol > methanol. The rate-pH profile reveals that A/S is more stable in an acidic condition : marginally subject to specific acid or base catalysis and is affected by two ionizable groups on the molecule. Ionic strength does not affect the photochemical decomposition rate at pH 5, 9 or 12.View full abstractDownload PDF (502K) -
Akira MIYASHITA, Yumiko SUZUKI, Yoko OKUMURA, Takeo HIGASHINO1996 Volume 44 Issue 1 Pages 252-254
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe treatment of 2-benzyl-1, 2-diphenyl-2-hydroxyethanone (3a, benzylbenzoin) with potassium cyanide in DMF gave deoxybenzoin (4a). The formation of deoxybenzoin (4a) proceeds through retro-benzoin condensation by catalytic action of cyanide ion. Similarly, retro-benzoin condensation applied to several substituted benzoins 3 resulted in the formation of the corresponding ketones 4 in excellent yields.View full abstractDownload PDF (485K) -
Motomi MATSUKAWA, Toshifumi AKIZAWA, Jennifer F. MORRIS, Jr. BUTLER, M ...1996 Volume 44 Issue 1 Pages 255-257
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe found a novel substance, 3β-hydroxy-11, 12-seco-5β, 14β-bufa-20, 22-dienolide-11, 14-olide-12-oic acid (1), which we called marinoic acid, in the skin of the toad, Bufo marinus. The structure was established from NMR and MS data. Like bufadienolides, marinoic acid contained an A/B ring structure in the cis configuration and a D/α-pyrone ring structure, but the structure of the C ring differed considerably from that of bufadienolides. Marinoic acid exhibited biological activity, as demonstrated by inhibition of Na+, K+-ATPase enzymatic activity, and by inhibition of [3H]ouabain binding to the digitalis receptor site on Na+, K+-ATPase, although marinoic acid was a less effective inhibitor than typical bufadienolides. Although marinoic acid cannot be classified as a bufadienolide, its chemical structure and its Na+, K+-ATPase inhibitory activity suggest that it is bufadienolide-related.View full abstractDownload PDF (506K) -
Akito NAGATSU, Yukitaka NAKAMURA, Kouya TAKEMOTO, Shin-ichi NAGAI, Tai ...1996 Volume 44 Issue 1 Pages 258-260
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAn unusual oxidative transformation of α, β-unsaturated γ-lactone of the cardenolide gitoxin (1a) by tetra-n-butylammonium fluoride (TBAF) is reported. The structure of the product (2a) was finally confirmed by an X-ray crystal structure analysis of its genin (2b). The oxidation proceeded also in the presence of CsF, and KF + 18-crown-6.View full abstractDownload PDF (461K) -
Hideaki WAKAMATSU, Yoshiyasu TERAO1996 Volume 44 Issue 1 Pages 261-263
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSOptically active 4- or 5-substituted 2-oxazolidinones were obtained by lipase-catalyzed enantioselective hydrolysis of the 3-acyloxymethyl-2-oxazolidinones and transesterification of the 3-hydroxymethyl-2-oxazolidinones with vinyl propionate in organic solvents.View full abstractDownload PDF (435K) -
Tetsuro SHINADA, Kazuo YOSHIHARA1996 Volume 44 Issue 1 Pages 264-266
Published: January 15, 1996
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSStereoselective functionalization at C-9 of retinal based on the use of the C4+X-unit is described. A sequential linkage of C4+X-units (X=Cl, Br, and I) with ylide 8 (C10) and phosphonate 12 (C5)selectively gave 9-trans-19-nor-9-Cl, Br, and I-retinal derivatives.View full abstractDownload PDF (418K)
- |<
- <
- 1
- >
- >|