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Volume 113, Issue 11
Displaying 1-8 of 8 articles from this issue
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Hiroki TAKAHATA1993 Volume 113 Issue 11 Pages 737-759
Published: November 25, 1993
Released on J-STAGE: May 30, 2008
JOURNAL FREE ACCESSProgress toward highly selective intramolecular heterocyclization and its application to the syntheses of biologically active compounds have been reviewed. The highly selective electrophilic heteroatom nucleophiles cyclization of carbon-carbon π-bonds such as iodoiminothiolactonization, iodolactamization, amidomercuration, iodolactonization, and oxylactonization has been developed. Our recent advances taking advantage of stereoselective heterocyclization of homochiral substrates readily available from optical active amine, the Katsuki-Sharpless oxidation, lipase-mediated transesterification, and α-amino acids have provided an attractive entry into the functionalized heterocycles as chiral building blocks. A promising approach to the chiral synthesis of a number of biologically active compounds such as alkaloids, antibiotics, and pheromones has emerged.View full abstractDownload PDF (1517K) -
Takayuki SHIOIRI1993 Volume 113 Issue 11 Pages 760-780
Published: November 25, 1993
Released on J-STAGE: May 30, 2008
JOURNAL FREE ACCESSRecent studies on the new methods and new reagents in organic synthesis developed by our laboratories have been reviewed. Their application to the synthesis of biologically intriguing natural products has been also described. Dolastatin 10 (1), a potent antitumor peptide of marine origin, has been efficiently synthesized by use of diethyl phosphorocyanidate (DEPC), diphenyl phosphorazidate (DPPA) and (+)-2-hydroxy-3-pinanone ((+)-HyPN). Mugineic acid (27), a typical phytosiderophore from barley, has been synthesized using a phenyl group as a carboxyl synthon. The method is quite efficient to produce mugineic acid on a large scale. Tilivalline (50), isolated from Klebsiella pneumoniae var. oxytoca, has been synthesized by use of DPPA as an +NH2 synthon and DEPC as a coupling reagent. The new Mannich type reaction has been explored to construct the pyrrolo [2.1-c] [1.4] benzodiazepine skeleton. The chiral phase transfer catalyst (65a) based on cinchonine has been utilized for the asymmetric hydroxylation of the α-tetralone derivatives (63). The first synthesis of the chiral ammonium fluoride (71) has been achieved, and its use for the silicon-based asymmetric aldol reaction has been accomplished. Trimethylsilyldiazomethane (TMSCHN2) has been developed as a stable and safe substitute for hazardous diazomethane. As a C1-unit introducing reagent, TMSCHN2 and its lithium salt mostly realize the reactions similar to those carried out with diazomethane. On the other hand, they generally behave as a [C-N-N] azole synthon in an analogous but not as the same way as diazomethane. Using the lithium salt of TMSCHN2, new methods for the preparation of alkynes and pyrroles have been developed.View full abstractDownload PDF (1491K) -
Kouichi MINATO, Shigehiro TAKEGAWA, Naoyuki KOIZUMI, Kunio TSUKAMOTO, ...1993 Volume 113 Issue 11 Pages 781-791
Published: November 25, 1993
Released on J-STAGE: May 30, 2008
JOURNAL FREE ACCESSThe metabolism of levonorgestrel (LNG) in the bile following oral administration of the drug was examined in female rat. 1) Within 48 h after administration of 14C-labelled LNG (LNG-14C), 67-82% of the radioactivity was excreted into the bile. 2) Almost all the metabolites in the bile were conjugated with glucuronic acid or sulfuric acid and only a small amount of the unchanged compound was found. 3) After treatment of these metabolites in the bile with β-glucuronidase and arylsulfatase, more than ten aglycones were detected on TLC. Three main aglycones, M1, M2 and M3, were isolated. They accounted for 68.0, 0.8 and 11.5% of the radioactivity excreted into the bile, respectively. 4) The structures of M1 and M2 were assumed to be 13-ethyl-18, 19-dinor-5α, 17β-pregn-20-yne-3α, 17-diol and 13-ethyl-18, 19-dinor-5β, 17β-pregn-20-yne-3α, 17-diol, respectively, by NMR and LC/MS analyses, and confirmed by direct comparison with respective authentic samples. M3 was assigned to be 13-ethyl-18, 19-dinor-5α, 17β-pregn-20-yne-3α, 16β, 17-triol by NMR, LC/MS and GC/MS analyses and acetonide derivation. 5) Isolation of the glucuronide metabolite, M4, from the bile, was achieved by column chromatography using Amberlite XAD-2 and Sephadex LH-20. Hydrolysis of this compound with β-glucuronidase released M1 and glucuronic acid. After M4 was converted to an acetylated-methyl ester derivative, the definite structural assignment of M4 was established to be M1-3-O-yl glucuronic acid by NMR analysis. The NOE effect and the value of the corresponding coupling constant of the anomeric proton showed that the glucoside moiety was in the beta configuration. These findings suggested that LNG was predominantly converted to 5α-reduced metabolites and that the 5β-metabolite accounted for less than 1% of the total metabolites in female rats. These metabolites were excreted as glucuronides into the bile.View full abstractDownload PDF (1138K) -
Teruhiko HAGIWARA, Kunio OHYAMA, Toshio YAMAKAWA, Hajime WATANABE, Shu ...1993 Volume 113 Issue 11 Pages 792-802
Published: November 25, 1993
Released on J-STAGE: May 30, 2008
JOURNAL FREE ACCESSPerchloric acid-soluble fractions (PASFs 1-3) which were obtained from cyst fluids of two patients [(Nos. 1 (blood group B) and 2 (blood group A))] with ovarian mucinous cystadenoma and one patient (No. 3 (blood group A)) with ovarian dermoid cyst in benign, were identified as glycoproteins by their chemical composition analyses, respectively. Reactivities of PASFs1-3 against blood group anti-sera and lectins suggest that these PASFs did not contain MN blood group substances, Vgu glycoproteins and T-active glycoproteins. PASF 1 was separated into 11 fractions by Sephacryl S-500 gel filtration. From chemical composition, SDS-PAGE and serological property of the main fraction (Fr. 5), other one fraction (Fr. 7) and mild acid hydrolysates of these two fractions, it is possible to presume that PASF 1 consisted of a large number of AB-active and fucose-rich glycoproteins with high molecular weights and some of these glycoproteins bear either NeuNAcα2→6GalNAc (sialyl Tn) group or both sialyl Tn and sialylated T groups.View full abstractDownload PDF (1016K) -
Hiroshi NAGANO, Tsunemasa SUZUKI, Shigeyoshi NAKAMURA, Tetsushi TOMOGU ...1993 Volume 113 Issue 11 Pages 803-809
Published: November 25, 1993
Released on J-STAGE: May 30, 2008
JOURNAL FREE ACCESSWe investigated the cerebral protective effects of human urinary kallidinogenase (SK-827) in rabbits. The following results were obtained : 1) At a dose of 5.0×10-3 to 1.25×10-2 PNA U/kg, SK-827 significantly inhibited the decrease of focal cerebral blood flow and the impairment of electrocorticogram (ECoG) activity in infarcted rabbits. 2) SK-827 at a dose of 2.5×10-3 PNA U/kg inhibited the development of infarction area induced by internal carotid arterial injection of glass beads. 3) SK-827 at a dose of 2.5×10-3 to 5.0×10-3 PNA U/kg inhibited the decrease of cerebral cortical pO2 induced by 5% oxygen inhalation. 4) On subacute phase 7 days after the destruction of internal capsule, SK-827 at a dose of 1.25×10-2 PNA U/kg improved the abnormality of spontaneous ECoG. These findings suggest that SK-827 minimizes the reduction of cerebral function induced by ischemia.View full abstractDownload PDF (875K) -
Masahiko KUBOTA, Kiyoshi ARAI, Akiko YORIMITU, Masako SHIMAOKA, Kyo HO ...1993 Volume 113 Issue 11 Pages 810-817
Published: November 25, 1993
Released on J-STAGE: May 30, 2008
JOURNAL FREE ACCESSThe cultivation of Papaver bracteatum, having thebaine as a major alkaloid, needs permission by the law of the narcotic regulation in Japan. Therefore, the flowergrowing of P. bracteatum as garden plants is prohibited by law. Chemical, morphological and cytological analyses of gardening 18 plants of the section Oxytona of the genus Papaver collected in western Hiroshima prefecture were carried out as a preliminary study. On inquiry, thebaine was identified as an only alkaloid from one of the gardening plants. The amounts of thebaine contained in this sample was 0.68%. Petals of this plant are scarlet with black spots at their bases which are surrounded by bracts. These results indicated that one of the investigated plants was identified to be P. bracteatum.View full abstractDownload PDF (1611K) -
Katsuhiro YAMASAKI, Toru OTAKE, Haruyo MORI, Motoko MORIMOTO, Noboru U ...1993 Volume 113 Issue 11 Pages 818-824
Published: November 25, 1993
Released on J-STAGE: May 30, 2008
JOURNAL FREE ACCESSThe anti-HIV-1 effects of 204 crude drugs of common use in Japan were evaluated in vitro. As a result, 45 samples inhibited HIV-1-induced cytopathogenicity in MT-4 cells. In particular, the hot water extracts of Lithospermum erythrorhizon (root) and Prunella vulgaris (spike) showed the strongest anti-HIV-1 activities. Their IC100 values were both 16μg/ml. In general, the hot water extracts of the crude drug suppressed the replication of HIV-1 growth more strongly than the cold water extracts.View full abstractDownload PDF (705K) -
Hiroshi NAGANO, Tsunemasa SUZUKI, Tetsushi TOMOGURI, Motohide HAYASHI, ...1993 Volume 113 Issue 11 Pages 825-828
Published: November 25, 1993
Released on J-STAGE: May 30, 2008
JOURNAL FREE ACCESSWe investigated the effects of human urinary kallidinogenase (SK-827) on cerebral metabolism in normal and infarcted rabbits. SK-827 did not influence cerebral glucose and oxygen uptake in normal rabbits. In infarcted rabbits, cerebral glucose and oxygen uptake significantly decreased. SK-827 tended to inhibit the decrease of cerebral blood flow, and significantly inhibited the decrease of cerebral glucose and oxygen uptake in infarcted rabbits. Thus, SK-827 improved cerebral glucose metabolism in infarcted rabbits.View full abstractDownload PDF (539K)
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