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Volume 39, Issue 1
Displaying 1-50 of 58 articles from this issue
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Masami TANAKA, Yutaka ASAHI, Seizo MASUDA, Tadatoshi OTA1991 Volume 39 Issue 1 Pages 1-4
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe binding of ibuprofen (IB) to bovine serum albumin (BSA) was predominantly attributed to a hydrophobic interaction based on the thermodynamic parameters obtained by equilibrium dialysis. Little variation in the proton chemical shift of IB was observed when concentrations of the IB were changed (1-10mM), or with the addition of BSA (7.25×10-5M). The spin-lattice relaxation time (T1) of IB was almost concentration-independent, but decreased in the presence of BSA to 36-45% for the phenyl group and its neighborhood, and to 70-97% for the other positions. The spin-spin relaxation rate (1/T2) of IB was also almost concentration-independent, but significantly increased ca. 37 times for the phenyl group and 12-24 times for the alkyl group in the presence of BSA. The ratio of the spin-spin relaxation rate of the free IB to the bound IB ((1/T2)b/(1/T2)f) of the phenyl group was 2-3 times larger than that of the alkyl group as shown by a contour plot (Chart 1). The binding of IB to BSA was considered to involve mainly the phenyl group of IB.View full abstractDownload PDF (596K) -
Juziro NISHIJO, Masako YASUDA, Mayumi NAGAI1991 Volume 39 Issue 1 Pages 5-9
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe interaction of 8-anilinonaphthalene-1-sulfonate (ANS) with α-cyclodextrin was investigated in a 0.1M phosphate buffer at pH 7.4 by fluorescence spectrophotometry. Utilizing the fact that the fluorescence intensity of ANS increases in the presence of α-cyclodextrin, the thermodynamic parameters for inclusion complex formation were determined as folloews; ΔG°=-1.25kcal/mol at 25°C, ΔH°=-3.0kcal/mol, ΔS°=-5.8e.u. The driving force for the inclusion complex formation was cosidered to be the van der Waals-London dispersion force and hydrogen bonding between -SO-3 of ANS and the secondary hydroxyl groups of α-acyclodextrin.Also, from the measurements of proton nuclear magnetic resonance spectra and studies with Corey Pauling Koltun models, the probable structure was determined.View full abstractDownload PDF (766K) -
Toshikazu MATSUOKA, Kikuma ONO, Kazunobu HARANO, Takuzo HISANO1991 Volume 39 Issue 1 Pages 10-17
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn connection with the pericyclic reaction of 3, 5-dimethylpyridine N-oxide with N-substituted maleimides, the structure of a 1, 5-sigmetropy product was determined by the X-ray crystallographic method. In the reaction of 2-alkylpyridine N-oxides with N-substituted maleimides, we have isolated a series of 1 : 3 ene reaction products of a new type.The primary exo cycloadducts readily transform into the endo 1, 5-sigmatropic rearrangement products, which again react with two molecules of N-substituted maleimide to give the 1 : 3 ene reactio products. The observed reaction behavior and plausible reaction pathways are discussed in terms of frontier molecular orbital considerations.View full abstractDownload PDF (1093K) -
Yoshisuke TSUDA, Shinzo HOSOI, Yorii GOTO1991 Volume 39 Issue 1 Pages 18-22
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNaturally occurring diarylnonanoids, malabaricones A, B, C, D, and 1-(2-hydroxy-6-methoxyphenyl)-9-(3, 4-methylenedioxyphenyl)-nonan-1-one were synthesized from a common intermediate, 6-benzyloxyhexyltriphenyl phosphonium bromide, by use of the Witting reaction and crossed aldol reaction as key steps.View full abstractDownload PDF (876K) -
Ichiya NINOMIYA, Toshiko KIGUCHI, Chiyomi HASHIMOTO, Takeaki NAITO1991 Volume 39 Issue 1 Pages 23-30
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTotal syntheses of several ergoline-type alkaloids, (±)-agroclavine (21), (±)-agroclavine I (24), (±)-fumigaclavine B (28), and (±)-lysergene (33), were accomplished via a route involving reductive photoxyclization of the enamide 5 followed by oxidative cleavage of the dihydrofuran ring.View full abstractDownload PDF (1297K) -
Shigeko OZAKI, Toshikazu NAKANISHI, Mari SUGIYAMA, Chie MIYAMOTO, Hide ...1991 Volume 39 Issue 1 Pages 31-35
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFused and spiro carbocyclic compounds were synthesized by electrochemical reductions of bromoalkylcyclo-hexenones using cobalt or nickel complexes as mediators.View full abstractDownload PDF (795K) -
Fumihiko SUMIYA, Naohiro SHIRAI, Yoshiro SATO1991 Volume 39 Issue 1 Pages 36-40
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFluoride ion-induced desilylation of 1-methyl-1-(trimethylsilyl)methyl-2-(2-substituted phenyl)pyrrolidinium (3a), -piperidinium (3b and 3c), and -perhydroazepinium iodides (3d and 3e) gave high yields of eight- (5a), nine- (5b and 5c), and ten-membered cyclic amines (5d, 5e, 6d and 6e), containing conjugated-triene bond systems. These triene products are intermediates in the Sommelt-Hauser rearrangement of cyclic 1-methyl-2-phenylammonium 1-methylides (4), and were isomerized to the corresponding Sommelet-Hauser rearrangement products (7) in the presence of a strong base or an acid (except for 5b). Heating of these trienes in xylene yielded mixtures of the Stevens rearrangement products (8) and ring-opened amines (9). Selective formation of 8 was achieved by ultraviolet irradiation of the trienes (5) in hexane. The reaction mechanisms are discussed.View full abstractDownload PDF (730K) -
Mitsuaki WATANABE, Mutsuhiro DATE, Kenji KAWANISHI, Takako HORI, Sunao ...1991 Volume 39 Issue 1 Pages 41-48
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA facile synthesis of 2-arylbenzo[b]furans via directed lithiation of ortho-tolyl tetramethylphosphorodiamidates as the key step is described. Lithiation of ortho-tolyl tetramethylphosphorodiamidates at -105°C followed by reaction with aromatic esters and then acidic treatment led to 2-arylbenzo[b]furans in modest overall yields. The utility of this strategy has been demonstrated in regioselective and short syntheses of the naturally occurring neolignans carinatin, eupomatenoid-1, and eupomatenoid-13.View full abstractDownload PDF (1239K) -
Takashi YOSHIDA, Zhe-Xiong JIN, Takuo OKUDA1991 Volume 39 Issue 1 Pages 49-54
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new ellagitannin monomers, heterophylliins A (12) and E (13), and three dimers, heterophylliins B (17), C (18) and D (19), were isolated from leaf extract of Corylus heterophylla (Betulaceae), and their structures were elucidated based on spectral and chemical evidence. Seven known tannins, 1, 2, 3, 6-tetra-O-galloyl-β-D-glucose, tellimagrandin II, casuarictin, casuarinin, rugosin C, rugosin F, and degalloylrugosin F, were also isolated.View full abstractDownload PDF (910K) -
Nobutoshi TANAKA, Ryoki ORII, Kazuo OGASA, Hiroshi WADA, Takao MURAKAM ...1991 Volume 39 Issue 1 Pages 55-59
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new trimeric proanthocyanidins were isolated in lactone form (1L, 2L and 3L) and acid form (1A, 2A and 3A) from the fronds of both Arachniodes sporadosora NAKAIKE and A. exilis CHING. Their structures were determined by spectroscopic methods and thiolytic degradation.View full abstractDownload PDF (672K) -
Takashi TANAKA, Akemi MORITA, Gen-ichiro NONAKA, Ta-chen LIN, Itsuo NI ...1991 Volume 39 Issue 1 Pages 60-63
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSContinuing chemical examinatino on tannins of Combretaceous Plants has led to the isolation of four new ellagitannins, calamansanin and calamanins A, B, and C, together with ten structurally known tannins and related compounds, from the leaves of Terminalia calamansanai (BLANCO) ROLFE. On the basis of chemical and spectroscopic evidence, the structures of calamansanin and calamanin A were established as 1, 6-di-O-galloyl-2, 3-O-(S)-hexahydroxydiphenoyl-4-O-(S)-flavogallonyl-α-D-glucose (11) and 1-O-galloyl-2, 3-O-(S)-hexahydroxydiphenoyl-4, 6-O-(S)-valoneoyl-α-D-glucose (14), respectively, while calamanin B and calamanin C were characterized as dimeric and trimeric ellagitannins 15 and 16, respectively, in which the glucose units are linked through valoneoyl group(s).View full abstractDownload PDF (674K) -
Noriyuki NAKAJIMA, Kouichi UOTO, Osamu YONEMITSU, Tadashi HATA1991 Volume 39 Issue 1 Pages 64-74
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSixteen-membered dienone type macrolide aglycons, carbonolide B (1), niddanolide (5), and platenolide W1 (6), were synthesized highly stereoselectively from D-glucose via Yamaguchi's esterification of two fragments, 8 (C1-C10) and 9 (C11-C16), followed by Witting-Horner cyclization. Stereoselective epoxidation of the 16-membered dienones (34, 35) gave epoxy-enone-type macrolide aglycons, carbonolide A (2) and EOP aglycon (7).View full abstractDownload PDF (1737K) -
Tozo FUJII, Masashi OHBA, Takeshi TACHINAMI, Takako OHASHI1991 Volume 39 Issue 1 Pages 75-78
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA full account is given of the first racemic and chiral syntheses of 11-methoxydihydrocorynantheol [(-)-1], a candidate structure for the Neisosperma alkaloid ochromianine. Coupling of (±)-trans-6-ethoxy-3-ethyl-2, 3, 4, 5-tetrahydro-4-pyridineacetic acid ethyl ester [(±)-6] with 2-chloro-1-(6-methoxy-1H-indol-3-yl)ethanone (4) in the presence of KBr produced the lactam ketone (±)-7, which was then converted into the lactam (±)-9 through the oxazolium salt (±)-8. Bischler-Napieralski cyclization of (±)-9 followed by catalytic hydrogenation gave the tetracyclic ester (±)-11. On reduction with LiAlH4, (±)-11 yielded the racemic target (±)-1. A parallel synthetic route starting from (+)-6 and 4 afforded the chiral target (-)-1 via (+)-7, 8, (+)-9, and (-)-11. Identity of synthetic (-)-1 with ochromianine unequivocally established the structure and absolute stereochemistry of this alkaloid.View full abstractDownload PDF (729K) -
Satoshi HIBINO, Eiichi SUGINO, Takeshi KUWADA, Naoki OGURA, Yohko SHIN ...1991 Volume 39 Issue 1 Pages 79-80
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe potent mutagens, 2-amino-9H-pyrido[2, 3-b]indole (AαC) and 2-amino-3-methyl-9H-pyrido[2, 3-b]indole (MeAαC) were synthesized by the thermal electrocyclic reaction of 2-azahexa-1, 3, 5-triene intermediates.View full abstractDownload PDF (487K) -
Brigitte BOUTEAU, Jean-Louis IMBS, Jean-Charles LANCELOT, Mariette BAR ...1991 Volume 39 Issue 1 Pages 81-85
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSStarting from 2-hydrazino-3-(1-pyrrolyl)pyridine 3 a series of 2, 3-dihydro-8-(1-pyrrolyl-1, 2, 4-triazolo[4, 3-a]-pyridines 49-50 and 5, 6-dihydro-4H-pyrido[2, 3-c]pyrrolo[1, 2-e]-1, 2, 5-triazepines 32-42 were synthesized and tested p.o. in rats for salidiuretic and renal vasodilator activity.View full abstractDownload PDF (745K) -
Yuji NOMOTO, Haruki TAKAI, Tadashi HIRATA, Masayuki TERANISHI, Tetsuji ...1991 Volume 39 Issue 1 Pages 86-90
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of 1-(6, 7-dimethoxy-4-quinazolinyl)piperidines carrying various 5-membered heterocycles at the 4-position was synthesized and examined for cardiotonic activity in anesthesized dogs. The (4-oxo-2-thioxo-3-imidazolidinyl)amino derivatives showed the most potent inotropic activity. Marked loss of activity was observed in the 2, 4-dihydro-3-thioxo-3H-1, 2, 4-triazolyl, the 2, 4-dihydro-3-oxo-3H-pyrazolyl and the (2, 3-dihydro-2-thioxo-3H-1, 3, 4-thiadiazol-5-yl)amino derivatives. The synthesis and structure-activity relationships are discussed.View full abstractDownload PDF (729K) -
Atsuyuki ASHIMORI, Taizo ONO, Yoshihisa INOUE, Satoshi MORIMOTO, Masah ...1991 Volume 39 Issue 1 Pages 91-99
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNovel 1, 4-dihydropyridine derivatives bearing 3-[4-(substituted amino)phenylalkyl]ester side chains were prepared and tested for their antihypertensive activity in spontaneously hypertensive rats. Most compounds showed a more potent antihypertensive effect and a longer duration of action than nicardipine. The derivatives with a benzhydrylpiperazinyl and a benzhydrylpiperidinyl group were distinvtive. 2-[4-(4-Benzhydryl-1-piperazinyl)phenyl]ethyl methyl 1, 4-dihydro-2, 6-dimethyl-4-(3-nitrophenyl-3, 5-pyridinedicarboxylate (4e), its 4-(4-cyano-2-pyridyl) analogue (4f), its 3-[4-(4-benzhydryl-1 piperazinyl)phenyl]propyl ester analogue (4h), its 2-[4-(4-benzhydryl-1-piperidinyl)phenyl]ethyl ester analogue (4j), and its 2-[4-(1-benzhydryl-4-piperidinyl)phenyl] ester ethyl analogue (4k) were selected as candidates for further pharmacological investigations.View full abstractDownload PDF (1197K) -
Yoshiko SONODA, Kimiko ICHINOSE, Tomoko YOSHIMURA, Yoshihiro SATO, Tak ...1991 Volume 39 Issue 1 Pages 100-103
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSLanosterol derivatives with a functional group at C-32 have been synthesized from 3β-acetoxylanostan-7α-ol. The key reaction of the synthesis is the hypoiodite reaction of 3β-acetoxylanostan-7α-ol. In vitro antitumor activity testing of the lanosterol derivatives revealed that 3β-hydroxylanost-7-en-32-oic acid has antineoplastic activity.View full abstractDownload PDF (659K) -
Yasushi ARANO, Masashi YABUKI, Alun G. JONES, Akira YOKOYAMA1991 Volume 39 Issue 1 Pages 104-107
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFurther characterization of the two neutral technetium-99m (99mTc) complexes of pentane-2, 4-dione bis-(N-methylthiosemicarbazone) (PETS) was carried out using a new dianionic PETS derivative, 3, 3-dimethyl-pentane-2, 4-dione bis(N-methylthiosemicarbazone) (DM-PETS), and the well characterized 99mTc complex of 2, 2, 9, 9-tetramethyl-4, 7-diaza-1, 10-decanedithiol (DADT) as references. While PETS generated two neutral 99mTc complexes, 99mTc-PETS-L1 and 99mTc-PETS-L2, by both the stannous reduction method and the ligand exchange reaction with six-coordinated 99mTc(V) complex of N, N'-ethylenebis(acetylacetone imine), DM-PETS formed only one neutral 99mTc complex. 99mTc-PETS-L2, the more lipophilic complex of the two 99mTc-PETS, was obtained with a much higher yield than 99mTc-PETS-L1 by the ligand exchange reaction of PETS with the five-coordinated 99mTc(V) complex of glucoheptonate. In addition, while 99mTc-PETS-L2 and 99mTc-DADT remained unchanged in the presence of CN- anions, a breakdown of the original complexes was observed in 99mTc-PETS-L1 and 99mTc-DM-PETS. All four 99mTc complexes exhibited similar brain, heart and pancreas extraction when injected into mice. These cummulative results imply that 99mTc-PETS-L1 and 99mTc-DM-PETS are six-coordinated mononuclear 99mTc(V) complexes and that 99mTc-PETS-L2 is a five-coordinated mononuclear 99mTc(V) complex. These results also suggest that while the chelate ring structure of the 99mTc-dithiosemicarbazone (DTS) chelate played a singificant role in its stability, ionization of the third proton of the PETS molecule and the subsequent resonating structure afforded further stability to the 99mTc-PETS complex. Markedly high lipophilicity of the 99mTc-PETS-L2 may also be explained by assuming that 99mTc-PETS-L2 is the five-coordinated resonating structure.View full abstractDownload PDF (723K) -
Atsuyuki ASHIMORI, Takeshi UCHIDA, Yutaka OHTAKI, Mikio TANAKA, Kazuhi ...1991 Volume 39 Issue 1 Pages 108-111
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSOptically active 2-[4-(4-banzhydryl-1-piperazinyl)phenyl]ethyl methyl 1, 4-dihydro-2, 6-dimethyl-4-(3-nitrophenyl)-3, 5-pyridinedicarboxylate [(S)-(+)-1 and (R)-(-)-1] hydrochlorides were synthesized with high optical purities from (R)-(-)- and (S)-(+)-1, 4-dihydro-5-methoxycarbonyl-2, 6-dimethyl-4-(3-nitrophenyl)-3-pyridinecarboxylic acids [(R)-(-)-6 and (S)-(+)-6], which are availabel from (±)-6 by optical resolution using quinidine and cinchonidine, respectively. From pharmacological investigations of (S)-(+)-1 and (R)-(-)-1 such as the antihypertensive effect on spontaneously hypertensive rats and inhibition of [3H]nimodipine binding to rat cardiac mambrane homogenate, the active form of 1 was defined to be the (4S)-(+)-enantiomer of 1.View full abstractDownload PDF (615K) -
Kazuhiro HIRABAYASHI, Susumu IWATA, Hiroatsu MATSUMOTO, Takeo MORI, Sh ...1991 Volume 39 Issue 1 Pages 112-115
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSChemically modified compounds of glycyrrhizin have been synthesized and evaluated for their inhibitory effect on the replication of human immunodeficiency virus type 1 (HIV-1) and herpes simplex virus type 1 (HSV-1). Among them, the 11-deoxo compound having a heteroannular diene structure at the C and D rings proved as active against HIV-1 as glycyrrhizin in MT-4 and MOLT-4 cells. It completely inhibited HIV-1-induced cytopathogenicity in both cell lines at a concentration of 0.16mM. The compound was also effective against HSV-1 with a 50% inhibitory concentration of 0.5μM.View full abstractDownload PDF (697K) -
Junei KINJO, Kumiko MATSUMOTO, Mutsumi INOUE, Takashi TAKESHITA, Toshi ...1991 Volume 39 Issue 1 Pages 116-119
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFurther study on the chemical constituents of the Abrus species resulted in the isolation of a new sapogenol, abrisapogenol J (1), from the methanolysate of the seeds for Abrus precatorius L., together with sophoradiol (4), its 22-O-acetate (2) and hederagenin methyl ester (5). The structure of 1 has been elucidated to be 3β, 22β-dihydroxy-11-oxoolean-13(18)-ene by the use of hetero unclear multiple bonds correlation (HMBC) spectroscopy. In addition, various compounds, trimethyl tryptophan dipolar ion (3), kaikasaponin III methyl ester (6), abrine (7), abrusin (8) and its 2"-O-apioside (9) were obtained from the methanolic extract.View full abstractDownload PDF (562K) -
Hiroe KIKUZAKI, Junko USUGUCHI, Nobuji NAKATANI1991 Volume 39 Issue 1 Pages 120-122
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo new diarylheptanoids, meso-3, 5-diacetoxy-1, 7-bis(4-hydroxy-3-methoxyphenyl)heptane (3a) and 3, 5-diacetoxy-1-(4-hydroxy-3, 5-dimethoxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)heptane (4a) were isolated from the rhizomes of ginger (Zingiber officinale ROSCOE), together with dehydroxytetrahydrocurcumin (gingerenone A, 1) and hexahydrocurcumin (2). Their structures were elucidated on the basis of chemical and spectroscopic evidence.View full abstractDownload PDF (631K) -
Jun KOKATSU, Shigeji JINGU, Toshio SUWA1991 Volume 39 Issue 1 Pages 123-125
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA gas chromatographic mass spectrometric procedure using selected ion monitoring is described for the quantification of gallopamil in human plasma. Gas chromatographic separation of gallopamil from phenolic metabolite isomers is made possible by treatment with ethyl chloroformate. The detection limit for the quantitation by the present method is 0.09ng/ml of plasma. The method has sufficient sensitivity to permit pharmacokinetic studies with human subjects following the oral administration of gallopamil hydrochloride.View full abstractDownload PDF (492K) -
Guo-Qing ZHANG, Masaaki KAI, Mutsuko NAKANO, Yosuke OHKURA1991 Volume 39 Issue 1 Pages 126-129
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA high-performance liquid chromatographic method involving fluorescence derivatization followed by separation on a reversed-phase polymer (octadecylated polyvinylalcohol copolymer gel) column is described for the determination of opioid peptides in rat brain tissues. The peptides extracted from brain tissues were converted into fluorescent derivatives by reaction with hydroxylamin, cobalt(II) ion and borate. The derivatives were separated on an Asahipak ODP-50 column by gradient elution of acetonitrile in the mobile phase containing borate buffer (pH 9.5). The detection limits (S/N=3) for the peptides were 0.33-1.21pmol per 100μl injected. The method actually permit the determination of leucine enkephalin, methionine enkephalin, methionine enkephalin-Arg-Phe and methionine enkephalin-Arg-Gly-Leu in the tissues. The method is also applied to the characterization of the peptides in the tissues by means of enzymatic degradations with carboxypeptidase A and trypsin.View full abstractDownload PDF (623K) -
Tetsuo SAKAMOTO, Kenichi TOMITA, Mitsuo YANAGI, Tatsuya OZAWA, Masahir ...1991 Volume 39 Issue 1 Pages 130-132
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSCells of Mycobacterium B-142 have been shown to incorporate (2R, 4'R, 8'R)-α-tocopherol selectively from a mixture of C-2 diasteromers. (2R, 4'R, 8'R)-α-Tocopheryl acetate was isolated from the bacterial cells while the (2S, 4'R, 8'R) isomer was extracted from the culture medium. The method has been extended to other tocopherol diastereomers.View full abstractDownload PDF (456K) -
Hirofumi SUZUKI, Kouichi AKIMOTO, Hiroshi NAKAGAWA1991 Volume 39 Issue 1 Pages 133-136
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA simple and rapid method for the determination of sodium valproate in pharmaceutical preparations, without prior separation, has been developed using a valproate-selective electrode. A plastic liquid membrane electrode kit was used for the electrode based on the use of valproate : methyltris(tetradecyl)ammonium ion-pair complex in n-decanol and polyvinyl chloride matrix. The electrode showed a near-Nernstian response in the range of 10-2 to 2×10-4M sodium valproate. Life span of the electrode was at least 1 month. The electrode was also used fot the determination of the pKa of valproic acid. Determination of 90 to 1500μg/ml of sodium valproate in aqueous solution showed an average recovery of 100.0% (mean standard deviation 0.4%) by direct potentiometry. Pharmaceutical excipients and diluents commonly used in drug formations did not interfere with the analysis. The selectivity of the electrode to some inorganic and organic anions was described. This assay was applied to determine sodium valproate in pharmaceutical preparations and the results compared favorably with those obtained by gas chromatography.View full abstractDownload PDF (603K) -
Hiroshi KUMAGAI, Miki MATSUURA, Aki MURAKAMI, Seiyu HIROSE1991 Volume 39 Issue 1 Pages 137-141
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFree ribonuclease (RNase)-inhibitor activities in both ventral and dorsal prostates had their highest peaks in 4-week-old rats and smallest peaks in around 7-week-old animals. Total RNase activity in the ventral prostate decreased overall with age, while that in the dorsal prostate increased. No significant amount of free RNase activity was found in either prostate.Weight, protein content, and free RNase-inhibitor activity in both prostates decreased after castration and increased after administration of testosterone to castrated rats. Total RNase activity in the ventral prostate was increased by castration and decreased by testosterone administration. In the dorsal prostate, total RNase activity had two peaks, 7d after castration and 2d after testosterone administration. A large amount of free RNase activity was found in the ventral prostate 7d after castration and this activity was decreased by testosterone administration. In the dorsal prostate, free RNase activity was not detected after castration and testosterone administration.These results suggest that changes in the level of RNase-inhibitor in both prostates are involved in the regulation of their RNA content through the control of free RNase activity.View full abstractDownload PDF (698K) -
Noriko MOTOHASHI, Harumi NISHIKAWA, Itsuhiko MORI1991 Volume 39 Issue 1 Pages 142-145
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe inhibitory effects of sulfur compounds, namely cysteine and α-mercaptopropionylglycine (α-MPG) (thiol type), and N-methyl-3-mercaptoimidazole (MMI), 6-propylthiouracil (PTU) and ergothioneine (ESH) (thione type) on melanin formation reaction by tyrosinase, in the presence of tyrosine as a substrate, were assessed. Tyrosine oxidation was monitored both by radioassay using L-[3, 5-3H]tyrosine, L-[2, 6-3H]tyrosine and L-[carboxyl-14C]tyrosine as substrates, and by spectrometry to quantitate the dopachrome formed from L-tyrosine. The rated compounds, ranked as to inhibitory effect in descending order are : cysteine ≃α-MPG>MMI>PTU>ESH. Cysteine and α-MPG, both noncyclic thiol compounds, formed a 3, 4-dihydroxyphenylalanine (dopa) conjugate to inhibit melanin formation when added at low concentrations. At high concentrations, they inctivated the enzyme by interacting with tyrosinase. In MMI, PTU and ESH of heterocyclic thione structure, dopa conjugate formation was more inhibitory than tyrosinase inactivation on melanin formation.View full abstractDownload PDF (661K) -
Ryuzo SAKAKIBARA, Kayo HASHIDA, Nobuaki TOMINAGA, Kazuya SAKAI, Masats ...1991 Volume 39 Issue 1 Pages 146-149
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA putative mouse oocyte maturation inhibitory protein was purified from a urine preparation from pregnant women by Sephadex G-100 gel filtration and reverse-phase chromatography on the basis of inhibitory activity of polar body formation of denuded mouse oocytes in culture. Amino terminal sequence analyses showed that residues 5 to 15 of this protein were identical to residues 1 to 11 of human nonsecretory ribonuclease. Furthermore, residues 1 to 4 of this protein were identical to residues -4 to -1, corresponding to part of a signal peptide region of eosinophil-derived neurotoxin, whose mature sequence is identical to nonsecretory ribonuclease. These results indicate that the protein purified as a putative mouse oocyte maturation inhibitory protein from the urine of pregnant women may be a product of an peculiar processing of a nonsecretory ribonuclease precursor.View full abstractDownload PDF (671K) -
Eriko UCHIDA, Haruki UEMURA, Toshiki TANAKA, Satoshi NISHIKAWA, Seiich ...1991 Volume 39 Issue 1 Pages 150-153
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn order to understand the role of Cys53 and Cys165 of human growth hormone (hGH) in receptor-binding and biological activity, artificial mutant variants of hGH were prepared in Escherichia coli by in vitro mutagenesis. Variants of hGH were constructed by replacement of Cys165 with Ala ([Ala165]hGH) or Ser ([Ser165]hGH), by replacement of Cys53 with Ala ([Ala53]hGH), by replacement of Cys53 and Cys165 with Ala ([Ala53, Ala165]hGH), or by replacement of Cys53 with Ala and Cys165 with Ser ([Ala53, Ser165]hGH). All of the variants constructed as well as reduced hGH exhibited less biological activity than that of intact hGH, and the decreases in biological activity were almost equal, as measured by a sensitive biological assay for growth hormone : adipose conversion assay using 3T3-F422A cells. These variants also showed less receptor-binding activity than that of intact hGH.These results suggest that it is possible neither the residue Cys53 nor Cys165 is directly involved in the receptor binding, and that the disulfide bridge between Cys53 and Cys165 in hGH may not always be crucial for the biological activity, though necessary to express full hGH activity.View full abstractDownload PDF (684K) -
Koichi TAKAHASHI, Satoko TAMAGAWA, Toyoshi KATAGI, Hironori YOSITOMI, ...1991 Volume 39 Issue 1 Pages 154-158
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe in vitro percutaneous transport of sodium diclofenac from various oil vehicles was examined using rat abdominal skin as a model skin membrane. The overall transport of diclofenac through the skin from the oleaginous vehicles was very poor because of a poor solubility of sodium diclofenac in nonpolar oils. To increase the solubility and the permeability of sodium diclofenac, ethanol and n-octanol were added to each oil (designated as the formulated vehicles). The addition of ethanol and n-octanol to the nonpolar vehicles resulted in an extreme increase in drug solubility in each vehicle, with a remarkable increase in the permeation of diclofenac. The effects of oil components in the formulated vehicle on the permeation of diclofenac across the skin were in the following order : squalane≥squalene>liquid paraffin>middle chain triglyceride>olive oil>castor oil.In order to clarify the reason for the differences in permeation of diclofenac from these formulated vehicles, the release of diclofenac and n-octanol from these vehicles in vitro was studied. The release rates of n-octanol from the formulated vehicles were in the following order : liquid paraffin>squalene≥squalane>middle chain triglyceride≥olive oil>castor oil. On the other hand, a linear correlation was observed between the initial release rate of diclofenac from the formulated vehicle and the in vitro permeation of diclofenac through the rat skin. Thus, the oil component in the formulated vehicle effects the release of the drug and the enhancer from the vehicle to the skin. The transport rate of diclofenac from the formulated vehicle of squalane at the steady state proportionally increased with an increase of drug concentration, and the lag times were not influenced by a change of the drug concentration in the formulated vehicles. Therefore, it may be suggested that the intrinsic permeation of diclofenac through the skin is not influenced by the concentration of sodium diclofenac in the vehicle. From these results, it is considered that the important factors in increasing the skin permeation of a drug from an oil vehicle are to select oils which have a low affinity for the drug and enhancer, and to increase the drug concentration in the oil.View full abstractDownload PDF (716K) -
Fumio URUSHIZAKI, Hiroshi MIZUMACHI1991 Volume 39 Issue 1 Pages 159-163
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe control of adhesion properties such as pressure sensitive adhesion and tack (initial pressure sensitive adhesion) is important in external applications of plasters or poultices, including transdermal drug delivery systems, hospital tapes, first aid tapes and others. Excessive tack and pressure sensitive adhesion may cause skin irritation and other maladies. These problems must be overcome when developing external applied preparations.In our previous paper, tacks expressed as rolling friction coefficients of polyvinyl alcohol (PVA) hydrogels were determined by the rolling cylinder method, and viscoelasticities were determined by dynamic viscoelastic methods.The correlation between tacks and viscoelasticities, such as storage modulus and loss tangent, was found to be high using the statistical method of multi-regression analysis.In the present study, the experimental results from tack and viscoelastic data of PVA hydrogels were compared with theoretical values by curve fitting.Theoretical curves were calculated by computer simulation methods according to our equations, based on a four elements mechanical model (two Maxwell elements in parallel connection), failure criteria and viscoelastic data of PVA hydrogels.Tack for external applied preparations formed as plasters and poultices could be predicted by these results. The prediction methods proposed in this paper are essential for establishing the ideal tack of plasters and poultices in the stage of pre-formulation.View full abstractDownload PDF (728K) -
Yoshinobu FUKUMORI, Hideki ICHIKAWA, Yumiko YAMAOKA, Eiichi AKAHO, Yos ...1991 Volume 39 Issue 1 Pages 164-169
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSEthyl cellulose (EC) microcapsules with fine calcium carbonate cores (32-44μm) and drug layers were prepared. The effect of additives on the particle size distribution, the variation in drug content with particle size and the dissolution properties of the products were evaluated.Among eight additives used, cholesterol (CH) most restrained the release of phenacetin, a model drug, which resulted in a saving of coating material and time. For sustained release of phenacetin, only 6.25% or less coating material relative to core material was sufficient. In addition, CH remarkably reduced particle agglomeration. The mean particle size of a product 25% coated with EC : CH=2 : 1 mixture was 58μm. However, the drug content and the phenacetin release were strongly dependent on the particle size of the product. This was the result of retardation of particle recycling in the Wurster chamber due to its adhesion to the well by electrostatic charge. Stearyltrimethyl-ammonium chloride, a cationic surfactant, reduced the particle adhesion when it was added to EC-CH (2 : 1) in a 1% amount on a dry basis. As a result, the particle size distribution became sharper, and there was higher homogeneity of the physical properties. This effect was not observed with polysorbate 80, a nonionic surfactant.View full abstractDownload PDF (1051K) -
Kiyoto EDO, Kunihito SAITO, Yoshinobu MATSUDA, Yuriko AKIYAMA-MURAI, M ...1991 Volume 39 Issue 1 Pages 170-176
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNeocarzinostatin (NCS), an antitumor protein antibiotic, is composed of apo-neocarzinostatin (apo-NCS) and neocarzinostatin-chromophore (NCS-chr), the principle of the biological activities of NCS. Apo-NCS having two tryptophan (Trp) residues at positions (39 and 83) was chemically modified by N-bromosuccinimide in a study on the correlation of the binding site(s) of NCS-chr. Selective oxidation of Trp residues was observed when NCS was titrated with N-bromosuccinimide. In contrast, non-selective oxidation of the two Trps on apo-NCS was observed and both Trp (39 and 83) of apo-NCS were titrated with N-bromosuccinimide. After selective oxidization, the remaining Trp residue of NCS was assigned as Trp (83). These results clearly indicate that the Trp (83) residue of apo-NCS changed from the "reactive type" to the "non-reactive type" after the binding of NCS-chr with apo-NCS. The fluorescence emission intensity of apo-NCS generated from the Trp (39) residue was quenched by NCS-chr. These data suggest that NCS-chr directly interacts with the Trp (39) residue and that a β-sheeted loop containing the Trp (83) residue of apo-NCS changes the high-order structure upon binding with NCS-chr.View full abstractDownload PDF (1060K) -
Mitsuo NAKAO, Yukiko GOTO, Akira HIRATSUKA, Tadashi WATABE1991 Volume 39 Issue 1 Pages 177-180
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSReductive metabolism of the hair dye constituent, nitro-p-phenylenediamine (2-nitro-1, 4-diaminobenzene, NPDA), and its acetylated metabolite, NPDA N4-acetate, was investigated with rat liver subcellular fractions, microsomes and cytosol. Under anaerobic conditions, these compounds were reduced to their corresponding amines by these fractions. The microsomal nitro-reducing activity was retarded completely by air and strongly by carbon monoxide. Reduced nicotinamide adenine dinucleotide phosphate (NADPH) functioned more effectively than reduced nicotinamide adenine dinucleotide (NADH) as an electron donor in the microsomal reduction of the nitro compounds, and flavin mononucleotide (FMN) gave rise to a marked enhancement in the microsomal activity, especially when added to an anaerobic incubation mixture containing both NADH and NADPH. The cytosolic nitro-reducing activity was attributed to xanthine oxidase, aldehyde oxidase and other unknown enzyme(s), based on the results of cofactor requirements and inhibition experiments.View full abstractDownload PDF (682K) -
Yueh-Hsiung KUO, Kae-Shyang SHIH1991 Volume 39 Issue 1 Pages 181-183
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSLow-temperature photooxygenation (-70°C) of furfurylamine derivatives followed by treatment with triphenylphosphine provided 3-hydroxypyridines in high yield.View full abstractDownload PDF (569K) -
Satoshi TSUBOI, Miho TAKEDA, Yoshio OKADA, Yoko NAGAMATSU, Junichiro Y ...1991 Volume 39 Issue 1 Pages 184-186
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSH-Ser-Pro-Val-Thr-Leu-Asp-Leu-Arg-Tyr-OH and H-Thr-Asn-Val-Val-OH, which correspond to the sequences 41-49 and 60-63 of eglin c, respectively, were synthesized by a conventional solution approach using the newly developed 6-chloro-2-pyridyl ester method. The inhibitory activities of the above two peptides against human leukocyte elastase, cathepsin G, porcine pancreatic elastase and α-chymotrypsin were examined in comparison with those of the corresponding methyl esters.View full abstractDownload PDF (608K) -
Tokujiro KITAGAWA, Megumi KAWAGUCHI, Misuzu IKIUCHI1991 Volume 39 Issue 1 Pages 187-189
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS1, 1'-Oxalyldiimidazole (ODI, 3) is a useful reagent for the degradation of 3-aryl-2-hydroxyiminopropionic acids (2) into the corresponding arylacetonitriles (1) under essentially neutral conditions.View full abstractDownload PDF (485K) -
Shunji NARUTO, Atsusuke TERADA1991 Volume 39 Issue 1 Pages 190-191
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe title compound showed potent anti-inflammatory and analgesic activities. For the determination of pharmacological activity differences between the optical isomers, we resolved the title compound via diastereomeric separation of the (-)-phenylethyl amide derivatives and followed by amide bond cleavege with N2O4. The absolute configurations of the enantiomers were determined by comparison of the optical rotatory dispersion and circular dichroism spectra with those of known optically active 2-phenylpropionic acids.View full abstractDownload PDF (418K) -
Tatsuhiko KASHIMA, Mariko TANOGUCHI, Masao ARIMOTO, Hideo YAMAGUCHI1991 Volume 39 Issue 1 Pages 192-194
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS(±)-Desoxypodophyllotoxin (2), a chief component of the seeds of Hernandia ovigera L., and (±)-β-peltatin-A methyl ether (3), an analogous phenyltetralin lignan, which have 2, 3-trans, 3, 4-cis configuration were synthesized according to the method developed for the synthesis of hernandin (1). The syntheses were pursued using the corresponding 4-phenyl-1, 2-dihydronaphthalene lactones (9 and 10) followed by cleavage of the lactone moiety to give the unsaturated hydroxy acids (11 and 12). Subsequent hydrogenation and ring closure by means of p-toluenesulfonic acid afforded both 2, 3-trans, 3, 4-cis and 2, 3-cis, 3, 4-cis ligans (2 and 13 or 3 and 14), which were isolated by preparative thin layer chromatography.View full abstractDownload PDF (536K) -
Magoichi SAKO, Seiji OHARA, Kosaku HIROTA, Yoshifumi MAKI1991 Volume 39 Issue 1 Pages 195-198
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAromatic hydrocarbons, i.e., benzene, naphthalene (4), phenanthrene (6), toluene (19), p-xylene (14), mesitylene (18), and durene (21), were oxygenated by a member of a novel class of heterocyclic N-oxides, 1, 3, 6, 8-tetrabutyl-pyrimido[5, 4-g]pteridine-2, 4, 5, 7(1H, 3H, 6H, 8H)-tetrone 10-oxide (1), under certain thermal conditions to give the corresponding products oxygenated in either the benzene ring or the methyl group, presumably via a single-electron transfer process.View full abstractDownload PDF (620K) -
Yuichi KIKUCHI, Yukinori MIYAICHI, Yumi YAMAGUCHI, Haruhisa KIZU, Tsuy ...1991 Volume 39 Issue 1 Pages 199-201
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom Scutellaria alpina L., two new flavones (I and II) were isolated, together with eighteen known flavonoids. The structures of I and II were shown to be 5, 2', 6'-trihydroxy-6, 7, 8-trimethoxyflavone and 5, 5", 6, 6", 7, 7"-hexahydroxy-8, 8"-biflavone(8, 8"-bibaicalein) on the basis of the chemical and spectral data. Compound I has already been synthesized.View full abstractDownload PDF (603K) -
Kaoru FUJI, Shang-Zhen ZHENG, Manabu NODE, Xiao-Jiang HAO1991 Volume 39 Issue 1 Pages 202-203
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA total synthesis of naturally occurring (+)-9, 10-secoabieta-8, 11, 13-trien-18, 10-olide (1) has been achieved from a chiral building block, (R)-2-methyl-2-(2-E-nitrovinyl)-5-pentanolide (3).View full abstractDownload PDF (470K) -
Yoichi YAMADA, Yukihiro SHOYAMA, Itsuo NISHIOKA, Hiroshi KOHDA, Akira ...1991 Volume 39 Issue 1 Pages 204-206
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWhen the axillary buds of Gentiana scabra BUNGE var. buergeri MAXIM. were cultured on Murashige-Skoog (MS)medium supplemented with a combination of gibberellin A3 (GA) and 6-benzylaminopurine (BAP) (1mg/l each) at 25°C under 16h light conditions for 60d, the direct multiple shoot formation (18.5 shoots per axillary bud) occurred. The MS medium containing Ga-BAP (2.5mg/l each) mostly stimulated the multiple shoot formation having approximately 71 shoots per tissue in the second subculture of the regenerated shoot. The hormone free MS medium stimulated root formation. These clonally propagated plants were transplanted to vermiculite. Quantitative analysis of gentiopicroside contained in the root of plantlets was carried out by high performance liquid chromatography using p-anisic acid as an internal standard. Obviously, the variation of the clonally propagated plants was smaller than that of the cultivated plants bred by morphological selection. From this system, 4.7×108 clonally propagated plants can be theoretically obtained from an axillary bud in a year.View full abstractDownload PDF (965K) -
Tenji KONISHI, Kiyoshi IWAGOE, Akira SUGIMOTO, Shiu KIYOSAWA, Yasuhiro ...1991 Volume 39 Issue 1 Pages 207-209
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new kinds of phenylethylchromone derivatives, called AH17 AH20 and AH23, were isolated from acetone and pyridine extracts of agalwood (Jinko) from Kalimantan. The structures of AH17 and AH23 were characterized as 5α, 6β, 7β-trihydroxy-8α-methoxy-2-(2-phenylethyl-5, 6, 7, 8-tetrahydrochromone and 5α, 6β, 7β, 8α-tetrahydroxy-2-[2-(2-hydroxyphenyl)ethyl]5, 6, 7, 8-tetrahydrochromone, respectively. AH20 was found to be a trimer formed by the ether-linkage made of 2-(2-phenylethyl)chromone and 2mol of agarotetrol at C5, 8' and C6, 5'.View full abstractDownload PDF (513K) -
Katsumi IIDA, Osamu HIDOH, Junichi FUKAMI, Masahiro KAJIWARA1991 Volume 39 Issue 1 Pages 210-213
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSCarbon-13 nuclear magnetic resonance spectroscopy has been used to observe the transformations of [1-13C]-D-glucose to [1, 1'-13C2]-D-trehalose, and [3-13C]-L-alanine to [2-13C]-L-glutamic acid in the living body of Gryllodes sigillatus. [3-13C]-D-Alanine was not metabolized.The metabolic rate of [1-13C]-D-glucose was found to be altered by prior injection of boric acid.View full abstractDownload PDF (495K) -
Teruaki SAKURAI, Iwao SUZUKI, Akira KINOSHITA, Shozo OIKAWA, Akiyoshi ...1991 Volume 39 Issue 1 Pages 214-217
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe effect of intraperitoneally (i.p.) administered SSG, a β-1, 3-glucan obtained from the culture filtrate of the fungus Sclerotinia sclerotiorum IFO 9395, on the functions of alveolar macrophages (AM) in CDF1 mice was examined. SSG administered i.p. increased the number of AM and enhanced several functions of murine AM (lysosomal enzyme activity, phagocytic activity, candidacidal activity, H2O2 production and interleukin 1 (IL-1) production) at a dose of 250μg/mouse on days 1 and 8, especially on day 8. Furthermore, SSG(250μg/mouse)administered i.p. for 10 consecutive days significantly inhibited the experimental pulmonary metastasis of Lewis Lung Carcinoma (3LL) on BDF1 mice.View full abstractDownload PDF (670K) -
Yoshihiko INAMORI, Masafumi OGAWA, Kazuki NISHIGUCHI, Satoko KOYAMA, H ...1991 Volume 39 Issue 1 Pages 218-220
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS3, 4'-Dihydroxy-α, β-diethylstilbene (I), like diethylstilbestrol (II), showed phytogrowth-inhibitory and antimicrobial activities. First, compound I showed strong growth-inhibitory activity against the roots of two kinds of plants. The inhibitory activity of I was almost equal to that of sodium 2, 4-dichlorophenoxyacetate used as a positive control. The phytogrowth-inhibitory activity of I was much higher than that of II. Next, unlike II, I had broad antifungal spectrum against pathogenic fungi. Compound I showed antifungal activity against six kinds of Fusarium oxysporum sp. This compound also had antibacterial activity against pathogenic and plant-pathogenic bacteria. These antibacterial activities of I were as high as those of II, the isomer of I. It should be emphasized that by shifting one of the phenolic hydroxyl groups of II to meta-position, phytogrowth-inhibitory activity was largely increased, while antimicrobial activity was unchanged.View full abstractDownload PDF (496K) -
Noriko MOTOHASHI, Harumi NISHIKAWA, Itsuhiko MORI1991 Volume 39 Issue 1 Pages 221-223
Published: January 25, 1991
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSeveral kinds of α-mercaptopropionylglycine (α-MPG)-2, 4-dihydroxyphenylalanine (dopa) coujugates produced through a mushroom tyrosinase reaction from tyrosine as a substrate in the presence of α-MPG were separated by high-performance liquid chromatography. The two main peaks were analyzed by coloring reactions, ultraviolet spectrometry and proton magnetic resonance determination. 5-S-α-MPG-dopa conjugate and 6-S-α-MPG-dopa conjugate were formed in a ratio of nearly 1 to 1. These conjugates shortened the lag time in tyrosine hydroxylation by tyrosinase and reduced the inhibition of tyrosine hydroxylation by α-MPG.View full abstractDownload PDF (489K)