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Volume 47, Issue 1
Displaying 1-26 of 26 articles from this issue
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E. J. COREY, Wei-Dong Z. LI1999 Volume 47 Issue 1 Pages 1-10
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSLactacystin (1) and the related β-lactone omuralide (2) are remarkably selective and potent irreversible inhibitors of the 20S proteasome, a large polymolecular protein machine which is responsible for the degradation of ubiquitin-labeled proteins. Because of this fact 1 and 2 have emerged as important tools in biochemistry and cell biology. The challenge of synthesis has been accepted by several research groups with the result that 1 and 2 and their analogs can now be synthesized by a variety of synthetic approaches. This review summarizes the synthetic processes which have been developed to date for the production of such compounds. The study of biological activity of analogs of 1 and 2 has clearly defined the structural features which are responsible for the potency of 1 and 2, as described in the closing section of this account. It is concluded that 1 and 2 are nearly optimal for the irreversible inactivation of the 20S proteasome.View full abstractDownload PDF (1042K) -
Yoshinori OKAMOTO, Hideki ANAN, Eiichi NAKAI, Koichiro MORIHIRA, Yasuh ...1999 Volume 47 Issue 1 Pages 11-21
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSBased on the X-ray structure of the complex of Ac-Tyr-Val-Ala-Asp-H (L-709049) and interleukin-1β converting enzyme (ICE), we synthesized compounds which were derived from 2-NapCO-Val-Pro-Asp-CH2OPh (1) to obtain a potent inhibitor in the cell assay. Among these compounds, (3S)-N-methanesulfonyl-3-[[1-[N-(2-naphthoyl)-L-valyl]-L-prolyl]amino]-4-oxobutanamide (27c) showed high potency not only in the enzyme assay but also cell assay with IC50 values of 38 nM and 0.23 μM, respectively. Compound 27c, with a c log P value of 1.76, had more hydrophilic character compared with 1. Compound 27c also dose dependently inhibited LPS-primed ATP-induced IL-1β release in mice. The crystal structure of the complex of compound 27c and ICE revealed that compound 27c had further interactions with ICE in the naphthoyl group at the P4 position and in the methyl group of the methanesulfonamidecarbonyl group at the P1 position, compared with L-709049. To our knowledge, compound 27c is the first example that shows a strong inhibitory activity without the carboxyl group at the P1 position.View full abstractDownload PDF (1665K) -
Takeshi YAMAMOTO, Manabu HORI, Ikuo WATANABE, Hisayoshi TSUTSUI, Shoji ...1999 Volume 47 Issue 1 Pages 22-27
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn the search for a practical synthesis of N-(4-isopropyl-2, 2-dimethyl-3-oxo-3, 4-dihydro-2H-benzo[1, 4]oxazine-6-carbonyl)guanidine methanesulfonate (KB-R9032), a potent Na/H exchange inhibitor, the acylation of methyl 4-hydroxy-3-isopropylaminobenzoate 6a with 2-bromoisobutyryl bromide was carried out in order to prepare an N-acyl derivative, 8a. However, an O-acyl derivative 7a was obtained selectively. Acylations of derivatives of 6a were examined. The results revealed that the O-acylation occurred because of the steric repulsion between the N-isopropyl moiety and the bulky acyl bromide. Then, we investigated the O, N-acyl migration of 7a. We found that the migration was catalyzed by carboxylic acid and that 8a was precipitated from a diisopropyl ether solution in good yield. Treatment of 8a with potassium carbonate and subsequent guanidine gave the synthetic intermediate for KB-R9032 in high yield.View full abstractDownload PDF (775K) -
Tomoo SUZUKI, Mitsuru OKA, Kouji MAEDA, Kenichi FURUSAWA, Hiroshi UESA ...1999 Volume 47 Issue 1 Pages 28-36
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn order to develop drugs effective against Alzheimer's disease, we synthesized a series of aniline derivatives having a characteristic cyclic amine, 1-azabicyclo[3.3.0]octane ring, and evaluated their binding affinity for the central muscarinic cholinergic receptor.Among these compounds which showed high affinity to the M1 receptor, N-[2-(1-Azabicyclo[3.3.0]octan-5-yl)ethyl]-2-nitroaniline (9f fumarate, SK-946) showed the highest affinity. The ability of this compound to improve cognitive function was assessed using the passive avoidance test in scopolamine-induced dementia mice.Some anilines with a 1-azabicyclo[3.3.1]nonane ring were also synthesized by the ring expansion of the 1-azabicyclo[3.3.0]octane ring, and showed a high affinity for the central muscarinic cholinergic receptor.View full abstractDownload PDF (1376K) -
Shinzo HOSOI, Fumiyuki KIUCHI, Norio NAKAMURA, Masaaki IMASHO, Mohamma ...1999 Volume 47 Issue 1 Pages 37-43
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwenty diarylnonanones were synthesized and their nematocidal activity was examined. Among those, the p-hydroxy compound 16 exhibited the strongest activity comparable to the natural diarylnonanoids, malabaricones A and C. Diarylundecanoid 57 also showed appreciable activity.View full abstractDownload PDF (1045K) -
Shuji KITAGAWA, Hui LI1999 Volume 47 Issue 1 Pages 44-47
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSkin penetration of benzoic acid and its 4-alkyl substituents (methyl, ethyl, n-propyl and n-buthyl) through excised guinea pig dorsal skin was examined, and effects of removal of stratum corneum, delipidization and addition of the penetration enhancers, ethanol and l-menthol plus ethanol, were observed. Permeability coefficients, which increased with the increase in their alkyl chain lengths, depended on the ratio of undissociated form of the derivatives. Removal of stratum corneum by tape stripping and delipidization by a chloroform-methanol mixture, whose effects on the permeation were similar, increased the permeability coefficients of the derivatives, especially those of relatively hydrophilic derivatives. Addition of 1% l-menthol plus 15% ethanol increased the permeability coefficient of benzoic acid, but decreased those of ethyl-, n-propyl- and n-butyl-substituents, and differences in the permeability coefficients among these acides almost disappeared. A similar though weaker tendency was observed for the effects of 15% ethanol itself. Analysis of transfer free energy of the methylene group from vehicle to skin revealed taht tape stripping and delipidization induced the reduction of lipophilic barrier property, although it still remained after these treatments. The analysis also showed that the addition of the enhancers made the skin relatively more hydrophilic compared to the vehicle, which induced an increase in permeability coefficient of benzoic acid and decreases in those of its lipophilic substituents.View full abstractDownload PDF (729K) -
Hajime KATAYAMA, Yusuke KAWADA, Kimiyoshi KANEKO, Takamitsu OSHIYAMA, ...1999 Volume 47 Issue 1 Pages 48-53
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new type of synthetic inhibitor of DNA topoisomerase I and II was examined and several of these derivatives exhibited strong dual activity against these enzymes. This series of compounds showed high cytotoxic activities against cancer cells, but only a limited number of compounds showed any noticeable activity in an in vivo test against murine P388. Non-specific toxicity was observed in the in vivo tests.View full abstractDownload PDF (1001K) -
Kaori JONO, Hideki ICHIKAWA, Kazuhiro FUJIOKA, Yoshinobu FUKUMORI, Yas ...1999 Volume 47 Issue 1 Pages 54-63
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSLecithin microcapsules containing gadolinium (Gd) were designed and prepared as a dosage form for intraarterial administration to accumulate Gd in tumors in neutron capture therapy. The microcapsules were composed of 1) a lactose core, 2) a layer of distearylamide of gadopentetic acid (Gd-DTPA-SAm) and polyvinylpyrrolidone (PVP) with or without soybean lecithin (SL) and 3) a membrane containing SL, cholesterol, stearic acid and PVP at three different compositions. A dilution method using the Wurster process was developed for small-scale preparation. In spite of using only 2 g of Gd-DTPA-SAm each, three types of microcapsules wewe obtained with a content of 24.9% as Gd-DTPA-SAm (3.66% as Gd) even at 150% coating level. The swelling type of microcapsules (MC-D1) did not release Gd at all for the entire 120 min of the experiment in a 0.9% saline solution. On the other hand, the rapid-erosion type (MC-D2) and the vesicle-dispersing type (MC-D3) released Gd with a lag time. The percent released depended on the coating level and the SL content in the Gd-fixing layer. A large number of droplet-like particles spouted out, and/or tubular vesicles formed with MC-D2 and MC-D3 in the saline solution. These phenomena implied that the water-insoluble Gd-DTPA-SAm would be entrapped in these particles/vesicles. When MC-D2 and MC-D3 were administered to normal rats via the hepatic artery, a Gd-accumulation as high as 70 and 71% of the injected dose was detected in the whole liver 2 h after administration. In addition, biochemical and histological evaluation of the liver after administration indicated that embolization of the microcapsules actually occurred in the blood vessels, and that necrosis induced by ischemia was not serious. These results suggested that administration of these microcapsules might be multiply repeated in order to accumulate the required amount of Gd in tumors.View full abstractDownload PDF (2337K) -
Tetsuya TAKEYA, Hirotaka EGAWA, Natsu INOUE, Akiko MIYAMOTO, Toichiro ...1999 Volume 47 Issue 1 Pages 64-70
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe reaction of cholesteryl acetate 1 with a FeIII(PA; picolinate)3/H2O2/MeCN system (reagent system A), a simple model system for mono-oxygenases, gave mainly the 7α-hydroxylation product 2a, along with 7-ketonization product 3 and the 5, 6-epoxidation product 4. On the other hand, reaction of 1 using a Fe(PA)3/peracetic acid (AcOOH)/MeCN system (reagent system C) or a FeIII(ClO4)3·9H2O-picolinic acid(PAH)-pyridine(Py)/AcOOH/MeCN system (reagent system F), provided 4 predominantly without formation of 2a. The former reaction may proceed via the dimeric FeIII-FeV manifold complex, (PAH)(PA)2FeIII-O-O-FeV=O(PA)2 (VII) as a hypothetically active species and a nonradical pathway, and the latter may proceed through monomeric iron complexes, [(PAH)(PA)2FeV=O]+ (IX) and [(PAH)(PA)2FeV(OH)(OOH)]+ (X).View full abstractDownload PDF (1004K) -
Haruhiro FUJIMOTO, Megumi SUMINO, Junko NAGANO, Hiroko NATORI, Emi OKU ...1999 Volume 47 Issue 1 Pages 71-76
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree new 2-pyrones (2H-pyran-2-ones) called multiforisins G (3), H (1), and I (4), and a known hexaketide sordarial (2) have been isolated from an Ascomycete Gelasinospora heterospora. Among them, 1, 2, and 3 have been proved to be the immunosuppressive components of the fungus. Compounds 1, 3, and 4 have also been isolated from G.multiforis together with multiforisin A (5), which was formerly isolated from this fungus as its main immunosuppressive feature, and 1-5 have also been isolated from G. longispora. The absolute stereostructure of 2, which was not previously certain, has finally been determined to be (3'R, 4'S). It has been found that the multiforisins 1, 3, and 5 in which one of the two substituents at positions 3 and 5 is a hydroxymethyl group and the other is a formyl or an acetoxymethyl group, show high immunosuppressive activity; the immunosuppressive activity of 3 does not seem to be due to inhibition of interleukin 2 (IL-2) production.View full abstractDownload PDF (949K) -
Akira KAJI, Ryo SAITO, Yukako HATA(nee SHINBO), Noriki KIRIYAMA1999 Volume 47 Issue 1 Pages 77-82
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS3-Alkoxy-6-hydroxy-p-benzoquinones were prepared by the treatment of 3, 6-diacetoxy-p-benzoquinones with a mixture of alcohol and alkali, followed by acidification. The key intermediate acetoxy-alkoxy-p-benzoquinones were formed by the base-catalyzed addition of an alkoxy anion to the conjugated double bonds in the diacetoxy-p-benzoquinone ring, followed by an acetoxy anion elimination. This method was applied for preparing a novel o-quinone derivative of asterriquinone (ARQ) by the addition of 2-haloethanol and intramolecular O-alkylation.View full abstractDownload PDF (844K) -
Synthetic Studies on the Starfish Alkaloid Imbricatine. Construction of an ent-Imbricatine FrameworkMasashi OHBA, Masaaki IMASHO, Tozo FUJII1999 Volume 47 Issue 1 Pages 83-89
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA chiral synthetic route to the amino esters 5 and 6, which contain the fundamental framework of ent-imbricatine (ent-3), has been developed as a prelude to the total synthesis of the starfish alkaloid imbricatine (3). The route started from the sulfur-containing L-phenylalanine derivative 7 and proceeded through key steps such as cyclization fo the amide 8 without racemization, reduction to the 1, 3-cis-tetrahydroisoquinoline 9, and introduction of a chiral α-amino acid moiety into the chloride 18 by the "bis-lactim ether" method.View full abstractDownload PDF (1135K) -
Binghe WANG, Wei WANG, Gian P. CAMENISCH, Jennifer ELMO, Huijuan ZHANG ...1999 Volume 47 Issue 1 Pages 90-95
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSEarlier, we reported the development of a coumarin-based prodrug system that could be used for the preparation of cyclic prodrugs of opioid peptides. These cyclic prodrugs exhibited excellent membrane permeability characteristics. Therefore, it was of interest to determine the effects of this prodrug strategy on the membrane permeabilities of peptidomimetics which also have low membrane permeabilities. For this study, we have chosen two RGD (Arg-Gly-Asp) peptidomimetics, which have the potentials to be developed clinically as orally active antithrombotic agents. However, the clinical development of oral dosage forms of these RGD analogs has been hindered by their low intestinal mucosal permeability. Therefore, we have synthesized the corresponding coumarin-based cyclic prodrugs of these RGD peptidomimetics, which have the two most polar functional groups, a carboxyl and an amino group, masked as an ester and an amide, respectively. These cyclic prodrugs were shown to have higher membrane interaction potentials, as estimated by their partitioning between aqueous buffer and an immobilized artificial membrane, than the corresponding RGD analogs suggesting that they should exhibit good membrane permeation characteristics. Subsequently, in a separate study these cyclic prodrugs were shown to be 5 to 6-fold more able to permeate monolayers of Caco-2 cells, an in vitro cell culture model of the intestinal mucosa barrier, than the corresponding RGD peptidomimetics.View full abstractDownload PDF (1097K) -
Toshihiro FUJIOKA, Kazuhiro FURUMI, Hiroko FUJII, Hikaru OKABE, Kunihi ...1999 Volume 47 Issue 1 Pages 96-100
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe CHCl3 extract of the root of Angelica japonica showed high inhibitory activity against human gastric adenocarcinoma (MK-1) cell growth. From this extract, a new furanocoumarin named japoangelone and four furanocoumarin ethers of falcarindiol, named japoangelols A-D, were isolated together with caffeic acid methyl ester, four polyacetylenic compounds (panaxynol, falcarindiol, 8-O-acetylfalcarindiol, and (9Z)-1, 9-heptadecadiene-4, 6-diyne-3, 8, 11-triol), eight coumarins (osthol, isoimperatorin, scopoletin, byakangelicin, xanthotoxin, bergapten, oxypeucedanin methanolate, and oxypeucedanin hydrate), and two chromones (3'-O-acetylhamaudol, and hamaudol). The structures of the new isolates were determined based on spectral evidence. The ED50 of isolates against MK-1, HeLa, and B16F10 cell lines are reported.View full abstractDownload PDF (811K) -
Zhi-Hong JIANG, Takashi TANAKA, Isao KOUNO1999 Volume 47 Issue 1 Pages 101-103
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSInvestigation of the MeOH extract of the leaves of Rhoiptelea chiliantha DIELS et HAND.-MAZZ. (Rhoipteleaceae) led to the isolation of two new euphane-type triterpene tridesmosides termed rhoiptelesides C and D. Their structures were elucidated on the basis of spectral and chemical evidence.View full abstractDownload PDF (470K) -
Haruo SEKIZAKI, Kunihiko ITOH, Eiko TOYOTA, Kazutaka TANIZAWA1999 Volume 47 Issue 1 Pages 104-110
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFour series of inverse substrates, position isomers of guanidinonaphthyl esters derived from N-(tert-butyloxycarbonyl)amino acid, were prepared as acyl donor components for trypsin-catalyzed peptide synthesis. The kinetic behavior of these synthetic inverse substrates toward spontaneous and tryptic hydrolysis was analyzed. These substrates were found to readily couple with α-amino acid p-nitroanilide to produce peptide. 4-Guanidino-1-naphthyl esters, in which the guanidino group and the carbonyl group are aligned linearly on the shorter axis of the naphthalene ring, were the most efficient substrates for enzymatic peptide synthesis. The method was especially useful for the preparation of peptides containing α, α-dialkyl amino acids. The enzymatic hydrolysis of the resulting products was negligible.View full abstractDownload PDF (969K) -
Chinuyo SUMITA, Mitsutomo TSUHAKO, Yoshinobu BABA1999 Volume 47 Issue 1 Pages 111-113
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA mixture of polymerase chain reaction (PCR) products, 100, 105, 300, 310, 485, and 500 base pair (bp) DNA fragments, was analyzed by capillary electrophoresis equipped with a laser-induced fluorescence detector (CE-LIF) using a stepwise gradient of electric field strength. The optimum condition for the analysis of PCR products was 0.5% methylcellulose and 160 V/cm from 0 to 10 min and 270 V/cm from 10 to 17 min.The length (bp) of DNA could be estimated from the relationship between the relative migration time and bp length. The relative standard deviation (R.S.D.) of DNA size (bp) was less than 3.5% and the difference from the true value was only 2.4bp.View full abstractDownload PDF (495K) -
Nisar ULLAH, Saeed AHMAD, Abdul MALIK1999 Volume 47 Issue 1 Pages 114-115
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA new phenylpropanoid glucoside, daphnenoside, was isolated in addition to coniferin, conferinoside, syringin and syringinoside, from the n-butanol soluble fraction of Daphne oleoides SCHREB (Thymelaeaceae). Structures were characterized on the basis of spectroscopic methods.View full abstractDownload PDF (386K) -
Eiko TOYOTA, Hiromitsu MIYAZAKI, Kunihiko ITOH, Haruo SEKIZAKI, Kazuta ...1999 Volume 47 Issue 1 Pages 116-119
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAmidine-containing Schiff base iron(III) and copper(II) chelates were prepared from α-amino acid, metal ion, and salicylaldehyde. These chelates behaved as specific inhibitors of trypsin, with Ki values in the range 10-5-10-6 M. Selective cleavage of the trypsin backbone resulting from specific binding of the chelate to the trypsin active site was investigated. Cleavage was observed when trypsin was incubated with amidine-containing copper(II) or iron(III) chelate, H2O2, and ascorbate. Examination of the three-dimensional structure of trypsin suggests that cleavage occurred at a peptide bond within the Gly195-Ala204 sequence.View full abstractDownload PDF (780K) -
Takeshi SUZUKI, Kiyoshi IWAOKA, Naoki IMANISHI, Yukinori NAGAKURA, Ken ...1999 Volume 47 Issue 1 Pages 120-122
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn a search for novel 5-hydroxytryptamine 4 (5-HT4) agonists focusing on the linker group of benzamide derivatives, 2-chloro-5-methoxy-4-[5-(2-piperidylmethyl)-1, 2, 4-oxadiazol-3-yl]aniline (2) was prepared and its optical isomers were separated. The S isomer 2(S) showed high affinity for the human 5-HT4 receptor without affinity for the human 5-HT3 receptor, and potent 5-HT4 agonistic activity in longitudinal muscle myenteric plexus (LMMP) preparations of guinea pig ileum. The R isomer 2(R) showed opposite selectivity. As a result of other receptor binding studies, 2(S) (YM-53389) was shown to be a highly selective 5-HT4 agonist.View full abstractDownload PDF (569K) -
Gil-Ja JHON, Sun-Young PARK, So-Yeop HAN, Sangwon LEE, Yangmee KIM, Yo ...1999 Volume 47 Issue 1 Pages 123-127
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe biological activity of deer antler has been considered to originate in the gangliosides, although the structures of gangliosides have not been well elucidated. The quality of deer antler as an Asian folk medicine has often been evaluated by the amount of gangliosides contained in the crude drug. We have completed the structural determination of five gangliosides isolated from deer antler in the present study.Five ganglioside fractions were isolated and purified from deer antler, Cervus nippon, by the Folch-Suzukipartition method, DEAE-Sephadex A-25, and further by silica gel column chromatography. High field proton nuclear magnetic resonance spectroscopy, gas chromatography/mass spectrometry, and fast atom bombardment-mass spectrometry studies characterized the isolated ganglioside fractions. GM3 and GD3 were present in the isolated ganglioside fractions. Samples were hydrolyzed in trifluoroacetic acid for direct compositional analysis and analyzed for sialic acid and neutral sugar without prior derivatization. Separation of the monosaccharides was achieved by HPLC on a Dionex CarboPac column eluted at a high pH. The resolved monosaccharides were identified using standard monosaccharides by pulsed amperometric detection. N-Acetyl GM3 (Neu5Ac), N-glycolyl GM3 (Neu5Gc), and N-acetyl GD3 (Neu5Ac) were present in the antler. The major ceramide moiety was composed of C16 : 0 or C22 : 0 fatty acids along with either C18 sphingosine or C20 eicosasphingosine.View full abstractDownload PDF (800K) -
Takeshi KOIKE, Naoki TAKEUCHI, Seisho TOBINAGA1999 Volume 47 Issue 1 Pages 128-130
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe reactions of magnesium amides 4 derived from sec-aminoacrylates 3 and ethylmagnesium bromide with methyl propiolate (2) afforded α-pyridones. This provides an efficient heterocyclic annelation reaction.View full abstractDownload PDF (563K) -
Chisato MUKAI, Haruhisa YAMASHITA, Syuichi HIRAI, Miyoji HANAOKA, Jerr ...1999 Volume 47 Issue 1 Pages 131-132
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS(±)-Gonioheptolide A (3) was unambiguously synthesized from (±)-goniofupyrone (4) and thereby its structure was revised as (1'R*, 2S*, 3S*, 4S*, 5R*)-3, 4-dihydroxy-2-[(1'-hydroxy-2'-methoxycarbonyl)ethyl]-5-phenyl-tetrahydrofuran. Methanolysis of (±)-goniofupyrone (4) with conc.H2SO4 at room temperature provided (±)-gonioheptolide A (3) in 48% yield. The synthetic (±)-gonioheptolide A and its triacetate were comparable to natural gonioheptolide A and its triacetate, respectively.View full abstractDownload PDF (414K) -
Takashi ITOH, Yuji MATSUYA, Hiromi MAETA, Michiko MIYAZAKI, Kazuhiro N ...1999 Volume 47 Issue 1 Pages 133-135
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSecondary amines were allowed to react with nitric oxide in the presence of oxygen to afford N-nitrosamines in good yields. Detailed investigation revealed that the reaction proceeded by two pathways; the one involves the catalytic behavior of oxygen, and the other consumes a stoichiometrical amount of oxygen. Both pathways afforded the same nitroso adducts.View full abstractDownload PDF (488K) -
Zhe-Bin ZHENG, Sachie NAGAI, Naoko IWANAMI, Dae-Yeon SUH, Ayako KOBAYA ...1999 Volume 47 Issue 1 Pages 136-137
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSStarting with 5-S-glutathionyl-β-alanyl-L-dopa (1) and 5-S-glutathionyl-β-alanyl-dopamine (2), a series of analogues with truncated glutathionyl and β-alanyl-dopa moieties were synthesized, and their inhibitory effects on autophosphorylation and substrate phosphorylation reaction by c-Src and by epidermal growth factor receptor (EGFR) were evaluated. When the glutamyl residue was removed, the inhibitory effects on v-Src autophosphorylation decreased about 4- to 5-fold, and concomitant removal of the glutamyl and β-alanyl residues resulted in a 40- to 60-fold decrease in the inhibition of v-Src autophosphorylation. On the other hand, these modifications had little effect on the inhibitory activity of substrate (RaytideTM) phosphorylation by c-Src. Interestingly, 5-S-cysteinyl dopamine inhibited the Src substrate phosphorylation reaction with comparable potency to that of genistein. Nonpeptide lipophilic derivatives had a similar inhibition on v-Src autophosphorylation but decreased inhibitory effects on substrate phosphorylation when compared to the lead compounds. Most compounds showed little effect on substrate phosphorylation by EGFR.View full abstractDownload PDF (446K) -
Fumihiro NAGASHIMA, Yoko MURAKAMI, Yoshinori ASAKAWA1999 Volume 47 Issue 1 Pages 138-139
Published: January 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA novel skeletal diterpenoid, named hatcherenone, has been isolated from the German liverwort Barbilophozia hatcheri, together with the previously known daucane- and acorane-type sesquiterpenoids, hercynolactone and barbiacoradienone. Their structures were confirmed by NMR techniques.View full abstractDownload PDF (383K)
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