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Volume 50, Issue 3
Displaying 1-29 of 29 articles from this issue
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Regular Articles
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Long Zhu Piao, Hyang Rae Park, Yun Kyung Park, Seung Ki Lee, Jeong Hil ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 309-311
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSCurrently, aloesin is used in the cosmetic industry as a whitening agent because it inhibits tyrosinase activity. Aloesin is a C-glycosylated chromone compound isolated from aloe, and it is difficult to synthesize because of C-glycosyl moiety in the molecule. The purpose of this study is to search for a new chromone compound which is easy to synthesize and which posesses stronger tyrosinase inhibitory activity than aloesin. Fourteen chromone derivatives were synthesized and screened for their mushroom-tyrosinase inhibitory activity. 5-Methyl-7-methoxy-2-(2′-benzyl-3′-oxobutyl)chromone (15) showed the strongest activity among tested compounds. Its activity was not only stronger than aloesin, but also stronger than arbutin and kojic acid. The kinetic analysis revealed a competitive inhibition of 15 with tyrosinase for the L-tyrosine binding site.View full abstractDownload PDF (56K) -
Ahmed Ahmed Omran, Keisuke Kitamura, Shigehiko Takegami, Tatsuya Kitad ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 312-315
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSThe affinity of the psychotropic benzodiazepine drugs diazepam (DZ) and flurazepam (FZ) to phosphatidylserine (PS) was examined since PS is abundantly contained in brain membranes. The effect of PS content on the partition coefficients (Kps) of these drugs between phosphatidylcholine (PC)–PS bilayer membranes of small unilamellar vesicles (SUV) and water was measured using second derivative spectrophotometry. The second derivative spectra of DZ and FZ measured in the solutions containing various amounts of PC–PS SUV clearly showed derivative isosbestic points and a distinct derivative intensity change depending on the amount of the SUV added. The derivative intensity differences (ΔD) of the drugs before and after addition of the SUV suspension were measured at a specific wavelength. Using the ΔD values, the Kp values were calculated and obtained with relative standard deviation of below 10%. The Kp values of both drugs increased according to the PS content in the PS–PC bilayer membranes of the SUV proving that both have higher affinity to the PC–PS bilayer membranes than to PC membranes. The effect was much larger for FZ, i.e., the Kp value of FZ at 30 mol% PS content increased to about five times the value for the PC SUV. This can be explained by the fact that at the experimental pH of 7.4, 80% of FZ molecules are in a cationic form (pKa=8.1), so that these molecules are highly accessible to the negatively charged PS molecules. The results support the rapid and high distribution of DZ and FZ in the central nervous system after their administration.View full abstractDownload PDF (68K) -
Jean Binet, Didier Thomas, Abdellah Benmbarek, Daniel de Fornel, Patri ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 316-329
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSWe have designed more potent inhibitors from the previously reported LF 05-0038, a 6-isoquinolinol based inhibitor of 2,3-oxidosqualene cyclase (IC50: 1.1 μM). Replacement of the 3-OH group by various 3-substituted amino groups, and modification of the alkyl chain borne by the endocyclic nitrogen led to inhibitors with IC50 in the range of 0.15 to 1 μM. In a second step, opening of the bicyclic ring system afforded the corresponding aminoalkylpiperidines which were slightly more potent. Finally, introduction of suitable aromatic containing moieties on the piperidine nitrogen yielded very potent inhibitors such as 20x (IC50=18 nM) easy to synthesize and achiral. The recent availability of the crystal structure of squalene-hopene cyclase allowed us to construct a three-dimensional (3D) model of the related 2,3-oxidosqualene cyclase (OSC) which was tentatively used to describe the possible mode of binding of our compounds and which can be useful for designing new inhibitors.View full abstractDownload PDF (220K) -
Haruhiro Fujimoto, Masato Nozawa, Emi Okuyama, Masami IshibashiArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 330-336
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSFive novel chromones (1,4-benzopyran-4-ones), among which three are tetracyclic and one contains a sulfonyl group, have been isolated from an Ascomycete, Chaetomium quadrangulatum, as monoamine oxidase inhibitory features, and named chaetoquadrins A (1)—E (5).View full abstractDownload PDF (106K) -
Eriko Ueda, Yutaka Yoshikawa, Yoshio Ishino, Hiromu Sakurai, Yoshitane ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 337-340
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSFollowing the finding of in vitro insulinominetic activities of new prepared Zn(II) complexes with amide ligands (2-picolinamide (pa-a) and 6-methyl-2-picolinmethylamide (6mpa-ma)) in isolated rat adipocytes treated with epinephrine in terms of inhibition of free fatty acid release, their blood glucose normalizing effects were observed on daily intraperitoneal injections for 14 d in a type 2 diabetes mellitus model animal, KK-Ay mice. The blood glucose levels of KK-Ay mice were maintained in a normal range during the administration of both complexes. After the administration of each complex for 14 d, the improvement of glucose metabolism was confirmed as judged by the glucose tolerance test.View full abstractDownload PDF (65K) -
Satoru Watano, Takumi Okamoto, Masamitsu Tsuhari, Ichiro Koizumi, Yosh ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 341-345
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSA novel multi-functional vertical high shear kneader has been developed. Wet kneading of pharmaceutical powders was conducted under various blade components and operating conditions. Compression properties of wet kneaded mass was analyzed and dispersion of binder liquid (water) among the mass was investigated by assaying tracer aqueous pigment. Pellets were produced through a dome type extrusion granulator with continuous extrusion pressure measurement device and a fluidized bed drier, and then the physical properties were measured. Quantitative relationship between the pellet's physical properties and the binder dispersion condition as well as the compression properties could be obtained. It was found that the newly developed kneader was very effective to uniformly disperse binder as well as impart high shear stress to the wet mass without generating obvious adhesion onto the vessel wall. It was also pointed out that the extrusion pressure could determine the physical strength of pellet. This method proposes a new methodology for continuous monitoring of kneading condition as well as predicting pellet's physical properties.View full abstractDownload PDF (103K) -
Taisuke Itaya, Takehiko Iida, Yasuko Gomyo, Itaru Natsutani, Masashi O ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 346-353
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSBased on the mechanism postulated for the formation of the cyclic carbonates 3 in the reactions of glycols 1 with oxalyl chloride in the presence of triethylamine, we present here three efficient syntheses of the cyclic oxalates 2 of various glycols 1 by controlling the formation of 3: replacement of the base by pyridine markedly diminishes yields of 3 in all reactions, realizing dramatic reversals of the product ratios in the reactions with the (R*,R*)-compounds 1g—i, q, r and pinacol (1k); although considerable amounts of the oxalate polymers are formed in the reactions with some (R*,S*)-glycols, this drawback can be removed by the use of 2,4,6-collidine instead of pyridine; 1,1′-oxalyldiimidazole is useful for the synthesis of two selected cyclic oxalates 2e, f. The cyclic oxalates 2 other than trisubstituted and tetrasubstituted ones were found to be very reactive: kinetic studies on the hydrolysis of 1,4-dioxane-2,3-dione (2a) as well as its mono- and some selected 5, 6-disubstituted derivatives 2 have revealed that they undergo hydrolysis 260—1500 times more rapidly than diethyl oxalate (12) in acetate buffer–acetonitrile (pH 5.69) at 25 °C. Although the cyclic oxalate 2l from cis-1, 2-cyclopentanediol (1l) was 1.5 times more reactive than 2a, it has been shown with other substrates that increasing number of the alkyl substituents decreases the rate of hydrolysis. On the contrary, the phenyl group was found to have somewhat accelerative effect.View full abstractDownload PDF (107K) -
Yukihiro Kodera, Makoto Ichikawa, Jiro Yoshida, Naoki Kashimoto, Naoto ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 354-363
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSThe pharmacokinetic behavior of allixin (3-hydroxy-5-methoxy-6-methyl-2-penthyl-4H-pyran-4-one) was investigated in an experimental animal, mice. Allixin was administered using an inclusion compound because the solubility of allixin in aqueous solution is very low. The allixin content in serum and in the organs of administered animals was analyzed by liquid chromatography (LC)-MS. Most of the administered allixin disappeared within 2 h, and the bioavailability of allixin was estimated to be 31% by obtained area under the blood concentration–time curve (AUC). The metabolites of allixin were studied using the metabolic enzyme fraction of liver and liver homogenate. Several new peaks corresponding to allixin metabolites were observed in the HPLC chromatoprofile. The chemical structure of the metabolites was investigated using LC-MS and NMR. Three of them were identified as allixin metabolites having a hydroxylated pentyl group.View full abstractDownload PDF (114K) -
Hsiencheng Shih, Howard Brinkerhoff Cottam, Dennis Anthony CarsonArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 364-367
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSA facile synthesis of 9-substituted 9-deazapurines as potential inhibitors of purine nucleoside phosphorylase has been achieved by the direct Friedel–Crafts aroylation or arylmethylation of 9-deazapurines using trifluoromethanesulfonic acid as catalyst. The aroylated 9-deazapurines could be transformed into the corresponding 9-arylmethyl derivatives by the Wolff–Kishner reaction. A novel synthesis of 9-deazahypoxanthine was also developed by treatment of 4-hydroxy-5-phenylazo-6-methylpyrimidin-2-thione with triethyl orthoformate in trifluoroacetic acid (TFA) to yield 8-oxo-7H-2-phenylpyrimido[5,4-c]pyridazin-6-thione followed by Raney nickel reduction.View full abstractDownload PDF (59K) -
Yoshiyasu Fukuyama, Hiroyuki Minami, Asami Matsuo, Kanako Kitamura, Mi ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 368-371
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSNew five seven-membered vibsane-type diterpenes named 5-epi-vibsanin C, 5-epi-vibsanin H, 5-epi-vibsanin K, 18-O-methyl-5-epi-vibsanin K and 5-epi-vibsanin E have been isolated from the leaves of Viburnum awabuki (Caplifoliaceae). Their structures have been elucidated by analyses of spectroscopic data and comparison of their spectral data with those of the previously known seven-membered vibsane-type diterpenes. The occurrence of these seven-membered vibsane-type diterpenes with a cis relationship on the C-5 and C-10 positions in nature have been predicted by conformational analysis of vibsanin B, an eleven-membered vibsane-type diterpene. Vibsanin C, 5-epi-vibsanin C and 5-epi-vibsanin H exhibited moderate cytotoxic activities on KB cells.View full abstractDownload PDF (60K) -
Kazuhiro Watanabe, Takashi Hirasawa, Kunio HiroiArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 372-379
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSNew chiral sulfoxide-1,3-oxazoline ligands have been developed as chiral ligands for Lewis acid-catalyzed asymmetric Diels–Alder reactions. The use of chiral sulfinyl 1,3-oxazoline ligands in copper(II)-catalyzed asymmetric Diels–Alder reactions provided an endo cycloadduct as a major product with moderate enantioselectivity. A rationale is proposed for the mechanism of the asymmetric induction.View full abstractDownload PDF (110K) -
Atsushi Kawada, Kayo Yasuda, Hitoshi Abe, Takashi HarayamaArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 380-383
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSRare earth metal trifluoromethanesulfonates [rare earth metal triflate, RE(OTf)3] were found to be efficient catalyst for benzyl-etherification. In the presence of a catalytic amount of RE(OTf)3, condensation of benzyl alcohols and aliphatic alcohols proceeded smoothly to afford the benzyl ethers. The condensation between benzyl alcohols and thiols also proceeded, and thio ethers were obtained in good yield. In these reactions, RE(OTf)3 could be recovered easily after the reactions were completed and could be reused without loss of activity.View full abstractDownload PDF (62K) -
Yukiko Takenaka, Takao Tanahashi, Hiromi Taguchi, Naotaka Nagakura, To ...Article type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 384-389
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSPhytochemical study of the leaves of Jasminum nudiflorum has led to the isolation of nine new secoiridoid glucosides, jasnudiflosides F—L (1—7), nudifloside D (8) and isooleoacteoside (9). The structures of these compounds were elucidated on the basis of chemical and spectroscopic evidence.View full abstractDownload PDF (71K) -
Hideaki Otsuka, Akie TamakiArticle type: Regular Article
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 390-394
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSFrom the leaves of Alangium paltanifolium var. platanifolium, collected in Fukuoka Prefecture, twelve further megastigmane glycosides were isolated. Seven of them, named platanionosides D—J (1—7), were found to be new compounds. Their structures were elucidated from spectroscopic evidence and their absolute structures were determined from β-D-glucosylation-induced shift trends of 13C-NMR and by application of a modified Mosher's method.View full abstractDownload PDF (78K)
Notes
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María-Angeles Honrubia, Jordi Rodrigo, María-Isabel Cada ...Article type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 395-398
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSCyproheptadine is one of the compounds exhibiting the highest activity at 5-HT2B receptors. In a previous work we analysed the relevance of the amino group in diphenylmethylenepiperidines (DPMP), which are open cyproheptadine analogues. Only compounds containing N–H or N-methyl motifs, showed significant 5-HT2B activity. Surprisingly, the corresponding quaternary ammonium salt demonstrated a total lack of activity. Therefore, the question arises whether protonation favours the interaction of these compounds with 5-HT2B receptors. Consequently, we studied the protonation influence (by varying the pH of the medium) on the antagonism of serotonin by some cyproheptadine analogues in rat stomach fundus. The main results were: 1) N-protonation increases the activity of DPMPs. 2) Alkaline pH facilitates the occurrence of a non-surmountable antagonism. 3) The contrast between the activity of protonated DPMPs and the lack of activity of the corresponding quaternary ammonium cation, suggests either that the latter is prevented from acting by steric hindrance, or that the mechanism by which protonation may increase the activity depends not only on the charge of the proton, but also on its ability to form hydrogen bonds.View full abstractDownload PDF (59K) -
Hui Xu, Xing Zhang, Xuan Tian, Min Lu, Yan-guang WangArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 399-402
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSTwelve new 4β-halogenated benzoylamino compounds (7.1—7.12) of podophyllotoxin have been synthesized, and their structures were confirmed by IR, 1H-NMR, MS spectra as well as CHN elemental analysis. These compounds showed delayed insecticidal activity against 5th instar larvae of Pieris rapae LINNAEUS in vivo, when tested by a leaf-dipping method at a concentration of 250 ppm. By preliminary qualitative structure–activity relationship analysis, we found the following results: 1) Compounds 7.2, 7.5—7.9 were more potent than the nature parent product in the mortality after 15 d against P. rapae in vivo. Especially compounds 7.5 and 7.6 bearing meta- and para-chlorobenzene substituents respectively, were the most potent of these compounds; 2) Substitution on the benzene ring moiety of 4β-benzoylamino podophyllotoxin (PPT) with Cl, Br, I at the para or at the meta position yielded compounds which were as potent or more potent than those containing the corresponding substituting group at the ortho position. 3) Substitution on the benzene ring moiety of 4β-benzoylamino podophyllotoxin with I either at the ortho, meta or para position yielded less potent compounds (7.10—7.12) when compared with PPT.View full abstractDownload PDF (58K) -
Hidenori Ueda, Norito Kaneda, Kazuko Kawanishi, Sergio Mello Alves, Ma ...Article type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 403-404
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSFrom the 80% EtOH extract of the bark of Ceiba pentandra (L.) GAERTNER, a new isoflavone glycoside was isolated along with known isoflavones, vavain and vavain glucoside. The structure was elucidated by spectroscopic analysis as 5-hydroxy-7,4′,5′-trimethoxyisoflavone 3′-O-α-L-arabinofuranosyl(1→6)-β-D-glucopyranoside.View full abstractDownload PDF (46K) -
Yukihiro Kodera, Masanori Ayabe, Kozue Ogasawara, Susumu Yoshida, Nori ...Article type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 405-407
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSExtremely high accumulation of allixin, a phytoalexin derived from garlic, was observed in necrotic tissue areas after long-term storage. The allixin produced recrystallized on the surface of the garlic clove. The amount of allixin produced in raw garlic with necrotic tissue areas was 1400 ng/mg wet garlic, which exceeds the minimum exhibitory concentration of allixin. After approximately 2 years of storage, amount of allixin accumulated reached slightly less than 1% of the dry weight of garlic cloves.View full abstractDownload PDF (77K) -
Junya Fujimori, Etsuo Yonemochi, Eihei Fukuoka, Katsuhide TeradaArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 408-412
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSIn order to develop the polymer materials having temperature-sensitive and high biological safety, Eudragit RS-PO and polyethylene glycol 400 (PEG 400) blend polymers (EPG) were prepared. The EPGs that have the glass transition temperature (Tg) at around the body temperature were prepared by the addition of 5—13% PEG 400 to Eudragit RS. As glassy polymers are not in thermodynamic equilibrium below their Tg, the effects of isothermal aging on the Tgs of Eudragit RS and EPG containing 10% PEG 400 (10% EPG) were also studied at various aging temperatures. The Tg values of Eudragit RS increased with the aging time and after 30 d of aging, they apparently reached constant values which markedly differed depending on the aging temperatures. On the other hand, the Tg values of 10% EPG were almost independent of the aging temperature and reached around 33 °C at 30 d after aging. The ability as thermo-sensitive polymer of EPG was evaluated by the dissolution test of the acetaminophen (AAP) matrix tablets prepared with EPG. The AAP release rate from the EPG matrix tablets slightly changed below the Tg of tablets, and then, it markedly increased above the Tg. Considering high biological safety of Eudragit RS and PEG 400, EPG might be available to develop the novel thermo-sensitive drug delivery systems.View full abstractDownload PDF (65K) -
Nikolas Fokialakis, Prokopios Magiatis, Ioanna Chinou, Sofia Mitaku, F ...Article type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 413-414
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSTwo alkaloids, megistoquinone I (1) and megistoquinone II (2), were isolated from the bark of Sarcomelicope megistophylla. Their structures have been elucidated on the basis of MS and NMR data. Both belong to quinoline alkaloid series and should be considered as oxidation products of a furo[2,3-b]quinoline precursor. The two alkaloids showed antibacterial properties with minimum inhibitory concentration (MIC) ranging from 2.35 to 5.25 mg/ml for 1 and 0.73 to 1.23 mg/ml for 2.View full abstractDownload PDF (45K) -
Do Kyu Pyun, Bong Jin Kim, Hee Jung Jung, Jae Hak Kim, Jin Soo Lee, Wo ...Article type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 415-418
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSA new series of 1β-methylcarbapenems 1a—d bearing 5-methyl-4-mercaptopyrrolidinone rings has been prepared and evaluated for in vitro antibacterial activity and pharmacokinetic parameters. Most compounds showed excellent antibacterial activity and high stability to dehydropeptidase-1. We have synthesized optically active 5-methyl-4-hydroxypyrrolidinones from enantiomerically pure aziridine esters.View full abstractDownload PDF (65K) -
Tenji Konishi, Takao Konoshima, Yasuo Shimada, Shiu KiyosawaArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 419-422
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSSix new chromones, 6-methoxy-2-[2-(3-methoxy-4-hydroxyphenyl)ethyl]chromone (2), 6,8-dihydroxy-2-(2-phenylethyl)chromone (3), 6-hydroxy-2-[2-(4-hydroxyphenyl)ethyl]chromone (4), 6-hydroxy-2-[2-(2-hydroxyphenyl)ethyl]chromone (5), 7-hydroxy-2-(2-phenylethyl)chromone (6), and 6-hydroxy-7-methoxy-2-(2-phenylethyl)chromone (7) were isolated from the ether extract of agarwood in addition to a known compound, 2-(2-phenylethyl)chromone or flidersiachromone (1). Their structures were determined by spectroscopic methods including UV, IR, and NMR spectral data and comparisons with the calculated values using the hydroxyl and methoxyl substituent increments of the chromone ring.View full abstractDownload PDF (51K) -
Takashi Hashihayata, Hiroki Sakoh, Yasuhiro Goto, Koji Yamada, Hajime ...Article type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 423-425
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSA (2R,4S)-trans-disubstituted pyrrolidine ring system was constructed by employing iodine-mediated oxidative cyclization of (1R)-N-[1-(4-bromophenyl)-3-butenyl]acetamide 3 as a key step. The resulting diastereomeric mixture of (2R)-2-aryl-4-acetoxypyrrolidine 4 was stereoselectively converted to the side-chain of a novel ultra-broad-spectrum carbapenem 1, via (2R,4R)-2-aryl-4-hydroxypyrrolidine 7.View full abstractDownload PDF (56K) -
Masao Shimizu, Akihiro Oishi, Yoichi Taguchi, Yasuo Gama, Isao ShibuyaArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 426-428
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSThe reaction of N-aryl-substituted ketenimines with N,N-disubstituted cyanamides or (MeS)2C=N–CN under high pressure afforded 4-(N,N-disubstituted amino) or 4-(MeS)2C=N-substituted quinazoline derivatives, respectively. These products were formed by [4+2] cycloaddition between the aza-diene moieties of the N-aryl-substituted ketenimines and cyano groups. A 4-(unsubstituted amino)quinazoline derivative was synthesized by hydrolysis of the latter product.View full abstractDownload PDF (52K) -
Hisashi Matsuda, Norihisa Nishida, Masayuki YoshikawaArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 429-431
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSFollowing the characterization of myrciacitrins I and II and myrciaphenones A and B, three new flavanone glucosides, myrciacitrins III, IV, and V, were isolated from the leaves of Brazilian Myrcia multiflora. The structures of new myrciacitrins were elucidated on the basis of physicochemical and chemical evidence. Myrciacitrins were found to show potent inhibitory activity on aldose reductase.View full abstractDownload PDF (72K) -
Kazuaki Ito, Takafumi Tamura, Kazuhito Watanabe, Yoshihiro OhbaArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 432-434
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSChiral calixarene analogs incorporating cystine peptide into their macrocyclic ring were easily prepared by the cyclization reactions of bis(chloromethyl)phenol-formaldehyde oligomers with cystine peptides in moderate yields. Circular dichroism (CD) spectra indicated the existence of the transmission of the chirality from peptide unit to phenol-formaldehyde oligomer moiety.View full abstractDownload PDF (55K) -
Shigeki Hoshimoto, Hirofumi Matsunaga, Masako Wada, Takehisa KuniedaArticle type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 435-438
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSThe intramolecular ruthenium(II)-catalyzed radical addition of the trichloroacetyl pendant group to the 2-oxazolone skeleton is greatly enhanced in the presence of catalytic Lewis acids including rare earth metal triflates, thus providing a convenient route to a highly potential chiral synthon for vic-amino alcohols.View full abstractDownload PDF (63K) -
Satomi Furukawa, Naomichi Takagi, Tsuyoshi Ikeda, Masateru Ono, Alaa M ...Article type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 439-440
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSTwo new long-chain alkanoic acid esters of lupeol were isolated together with known triterpenoids, α-amyrin, β-amyrin, cycloartenol, lanosta-7,24-diene-3β-ol and lupeol from Alecrim-propolis collected in Brazil. The structures were characterized by spectroscopic means.View full abstractDownload PDF (41K) -
Yasumasa Iwai, Kumiko Kita, Yoko Matsushita, Aiko Yamauchi, Masaru Kih ...Article type: Note
Subject area: [not specified]
2002 Volume 50 Issue 3 Pages 441-443
Published: 2002
Released on J-STAGE: June 30, 2002
JOURNAL FREE ACCESSThe new coupling reaction of phenacylamines with silylstannane and lithium diisopropylamide (LDA) is reported. The treatment of a phenacylamine iodide 1 with (trimethylsilyl)tributylstannane (Me3SiSnBu3) and cesium fluoride (CsF) gave a dimerization product 2 having no iodine atom. Reaction of 1 with LDA afforded a dimerization product 3 with an iodine atom. The products 2 and 3 were separated to the meso and racemic isomers, respectively.View full abstractDownload PDF (49K)
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