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171.
Cong‐Mei Cao Yi‐Bing Wu Rui‐Xia Guo Mei Dong Françoise Sauriol Chang‐Hong Huo Qing‐Wen Shi Teiko Yamada Hiromasa Kiyota Yu‐Cheng Gu Bin Cong 《Helvetica chimica acta》2013,96(3):375-378
Torreyanoxane, a novel 3,4‐secoglutinane triterpenoid, was isolated from the pulp of Torreya nucifera. The structure was determined on the basis of spectroscopic methods. 相似文献
172.
Amidation of exo/endo mixture of β-nitro bicyclic acids by dehydration with DCC, gives only the corresponding exo-amides. 相似文献
173.
Molydbenum and tungsten-catalyzed oxidations of alcohols with dilute hydrogen peroxide under phase-transfer conditions have been focused in recent years 1–3. In a previous paper, we have reported that tricetylpyridinium-12-molybdophosphate(CMP), [π - C5H5N+(CH2 15CH3]3 (PMO12O40)3-, prepared from 12-molybdophosphoric acid (MPA) and cetylpyridinium chloride (CPC), catalyzed the oxidation of secondary alcohols to carbonyl compounds with tert-butylhydroperoxide(t-BuOOH)4. When hydrogen peroxide in place of t-BuOOH was employed as the oxidant for the above oxidation, however, alcohols were oxidized with difficulty to give carbonyl compounds in poor yields. In continuation of this study, we wish to report here the selective oxidation of secondary hydroxy group of alcohols and diols and diols with H2O2 under the influence to tricetylpyridinium-12 tungstophosphate (CWP), [π-C5H5N+ (CH2) 15 CH3]3(PW12O40)3-, derived from 12-tungstophosporic acid (WPA) and CPC. 相似文献
174.
Daisuke Saeki Takeshi Yamada Yasuko In Tetsuya Kajimoto Reiko Tanaka Yota Iizuka Takahisa Nakane Akihito Takano Kazuo Masuda 《Tetrahedron》2013,69(5):1583-1589
Novel 5 lupane-type of triterpenois, i.e., 3β-acetoxy-18α,19α-epoxylupan-21β-ol (1), 18α,19α-epoxy-21β-hydroxylupan-3-one (2), lup-18-ene-3,21-dione (3), lupa-18,21-dien-3β-yl acetate (4), and (17S)-17,18-seco-lup-19(21)-ene-3,18,22-trione (5), named officinatrione, as well as 16 known compounds from the roots of Taraxacum officinale collected in Takatsuki city, Osaka, Japan. Of the above compounds, 5 was the first lupane-type triterpene, of which the D-ring was open to form a nine-membered ring. Compounds 2 and 5 exhibited moderate cytotoxic activities against L1210 cell line (IC50 10.5 and 10.1 μM). 相似文献
175.
Taro Amagata Makoto Tanaka Takeshi Yamada Yi-Pei Chen Katsuhiko Minoura Atsushi Numata 《Tetrahedron letters》2013
A continuous investigation of secondary metabolites produced by the sponge-derived fungus, Gymnascella dankaliensis, has yielded a new polyketide tyrosine derivative, dankastatin C (3) and the known steroid, demethylincisterol A3 (4), which was originally found from a Homaxinella marine sponge. The stereostructure of the new compound has been determined based on the analysis of 1D and 2D NMR data. Dankastatin C (3) showed potent cell growth inhibitory activity against the murine P388 cell line. 相似文献
176.
Yuichiro Haramoto Taito Yamada Masato Nanasawa Masahiro Funahashi Junichi Hanna Seiji Ujiie 《Liquid crystals》2013,40(8):1109-1111
New conductive thermotropic liquid crystalline materials having a piperazine ring in the central core: 1-[4-(9-decenyloxy)phenyl]-4-alkylpiperazines (6) were synthesized. The mesomorphic behaviours of these compounds and their conductivity in the liquid crystal phase were measured. The principal features of these compounds are to exhibit a smectic B phase around room temperature (for example 6: Cr 50 SmB 81 I, °C) and to exhibit a large dark current (6d: 430 μA cm?2, applied voltage 20 V, at 70°C) in the smectic B phase. 相似文献
177.
Eric M. Yezdimer Tomohiro Umemoto Hiroshi Yamada Satoshi Makino Ikuo Tooyama 《Applied biochemistry and biotechnology》2013,170(5):1138-1150
The potential utility of an imaging agent for the detection of hepatic copper was investigated in a Wilson’s disease animal model. Solid-phase peptide synthesis was used to construct an imaging agent which consisted of a copper-binding moiety, taken from the prion protein, and a gamma ray-emitting indium radiolabel. Long–Evans Cinnamon (LEC) rats were used for the Wilson’s disease animal model. Our evaluation methodology consisted of administering the indium-labeled agent to both LEC and genetically healthy Long–Evans (LE) cohorts via a tail vein injection and following the pharmacokinetics with single-photon emission computed tomography (SPECT) over the course of an hour. The animals were then sacrificed and their livers necropsied. An additional control agent, lacking the copper-binding moiety, was used to gauge whether any change in the hepatic uptake might be caused by other physiological differences between the two animal models. LEC rats injected with the indium-labeled agent had roughly double the amount of hepatic radioactivity as compared to the healthy control animals. The control agent, without the copper-binding moiety, displayed a hepatic signal similar to that of the control LE animals. Additional intraperitoneal spiking with CuSO4 in C57BL/6 mice also found that the pharmacokinetics of the indium-labeled, prion-based imaging agent is profoundly altered by exposure to in vivo pools of extracellular copper. The described SPECT application with this compound represented a significant improvement over a previous MRI application using the same base peptide sequence. 相似文献
178.
Abstract Methyl (methyl α-D-(9a), α-(9b), β-D-(10a), and β-L-(10b) idopyranosid)uronates were synthesized from myo-inositol. Baeyer-Villiger oxidation of the optically resolved inosose derivatives (3a and 3b) proceeded regioselectively to afford 4a and 4b in high yields, respectively. Ring-opening of the 7-membered hemiacetal-lactones (4a and 4b) with acid and subsequent deprotection gave the title compounds. 相似文献
179.
Dr. Bernd M. Schmidt Berit Topolinski Dr. Mihoko Yamada Dr. Shuhei Higashibayashi Prof. Dr. Mitsuhiko Shionoya Prof. Dr. Hidehiro Sakurai Prof. Dr. Dieter Lentz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(41):13872-13880
The syntheses and properties of corannulenes carrying electron‐withdrawing groups (F, CF3, C6F5) are reported. Direct fluorination of corannulene (C20H10) was carried out with xenon difluoride, and the crystal structure of the product was confirmed by the X‐ray analysis. Novel trifluoromethylated corannulenes, including the versatile 4,9‐dibromo‐1,2‐bis(trifluoromethyl)corannulene, were obtained by various established ring‐closing reactions. Besides the use of hexafluorobutyne for the construction of fluoranthenes by Diels–Alder reaction as precursor molecules to form 1,2‐disubstituted corannulenes, bis(pentafluorophenyl)acetylene was employed as dienophile. The molecular structure and crystal packing of a trifluoromethylated corannulene was determined by single‐crystal X‐ray analysis and compared with those known brominated and trifluoromethylated corannulenes. The general electron‐acceptor properties of corannulenes bearing substituents introduced in particular positions by liquid‐phase synthesis are discussed together with published computational results. 相似文献
180.
Takeshi Yamada Yuki MizutaniYoshihide Umebayashi Naoko InnoMaiko Kawashima Takashi KikuchiReiko Tanaka 《Tetrahedron letters》2014
Tandyukisin (1), a novel decalin derivative with an enolic β-ketoaldehyde, has been isolated from a strain of Trichoderma harzianum OUPS-111D-4 originally derived from the marine sponge Halichondria okadai, and its structure has been elucidated on the basis of spectroscopic analyses using 1D and 2D NMR techniques. In addition, the absolute configuration for 1 was established by the application of CD spectrum to the tribenzoate derivative. This compounds exhibited moderate cytotoxicity against human cancer cell lines. 相似文献