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991.
Yui Fujii Makoto Yoritate Kana Makino Kazunobu Igawa Daiki Takeda Daiki Doiuchi Katsuhiko Tomooka Tatsuya Uchida Go Hirai 《Molecules (Basel, Switzerland)》2022,27(1)
Seven mono- and dihydroxycholesterols were prepared by direct C–H oxidation of the cholestane skeleton with a recently developed Ru(Bpga) catalyst (Ru(Bpga) = [RuCl (bpga) (PPh3)] Cl; bpga = 2-(bis(pyridin-2-ylmethyl)amino)-N-(2,6-dimethylphenyl)acetamide)). Due to the high selectivity of the Ru(Bpga) complex for tertiary C–H, the reaction afforded a mixture of 25-, 20-, 17-, and 14-oxygenated cholesterols that could be easily separated by high-performance liquid chromatography. These results suggest that late-stage C–H oxidation could be a viable strategy for preparing candidate metabolites of biologically important molecules. 相似文献
992.
The structure of nephritogenoside 总被引:1,自引:0,他引:1
Nephritogenoside is a minor component of the basement membrane of normal animals (including humans). It is a glycopeptide with the ability to induce chronic progressive glomerulonephritis (end stage kidney) when administered as a single footpad injection, and contains a novel carbohydrate-peptide linkage. The total chemical structure was investigated. It was revealed that nephritogenoside is a simple glycopeptide composed of three glucose residues [alpha-Glc-(1----6)-beta-Glc-(1----6)-Glc] and twenty-one amino acids [1Asn-Pro-Leu-Phe-5Gly-Ile-Ala-Gly-Glu-10Asp-Gly-Pro -Thr-Gly-15Pro-Ser-Gly-Ile-Val-20Gly-21Gln], and that the glucose residues are linked alpha-N-glycosidically to the N-terminal amino acid. 相似文献
993.
Glochiflavanosides A-D: flavanol glucosides from the leaves of Glochidion zeylanicum (Gaertn) A. Juss. 总被引:1,自引:0,他引:1
From the leaves of Glochidion zeylanicum collected in Okinawa, four flavanol glucosides, named as glochiflavanosides A-D were isolated along with known flavone C-glucosides, vitexin and isoorientin. Their structures were elucidated by spectroscopic analyses. 相似文献
994.
Yuening Luo Siqi Zhou Reiko Takeda Kazuma Okazaki Marie Sekita Kazuichi Sakamoto 《Molecules (Basel, Switzerland)》2022,27(6)
Parkinson’s disease (PD) is the second most common progressive neurodegenerative disease, after Alzheimer’s disease. In our previous study, we found that amber—a fossilized plant resin—can protect cells from apoptosis by decreasing the generation of reactive oxygen species (ROS). In this study, we focused on the effect of amber on 6-hydroxydopamine-induced cell apoptosis in the human neuroblastoma cell line SHSY5Y (one model for PD). Initially, we determined the protective effect of amber on the PD model. We found that amber extract has a protective effect against 6-hydroxydopamine-induced cell apoptosis. The decrease in ROS, cleaved caspase-3, pERK, and extracellular signal-regulated kinase (ERK) protein levels confirmed that amber extract decreases apoptosis via the ROS-mediated ERK signaling pathway. Furthermore, we determined the effects of amber extract on autophagy. The results showed that amber extract increased the levels of LC3II and Beclin-1, suggesting that amber extract can protect neuronal cells against 6-hydroxydopamine-induced cell apoptosis by promoting autophagy. 相似文献
995.
996.
S Wakida A Chiba T Matsuda K Fukushi H Nakanishi X Wu H Nagai S Kurosawa S Takeda 《Electrophoresis》2001,22(16):3505-3508
To evaluate organic pollution in water, we did preliminarily studies on high-throughput characterization of organic pollution in water using microchip-based capillary electrophoresis (CE) with laseer-induced fluorescence (LIF) detection. The applied voltage was investigated to control the gated valve injection and CE separation for conventional cross type microchips using a self-made personal computer (PC)-based controller as the voltage supply. We obtained high-throughput data for the reproducible separation of fluorescein isothiocyanate (FITC)-labeled river-water samples using a zwitter-ion based buffer solution to avoid adsorption of the labeled sample onto the channel of a microchip made from quartz glass. We used real samples from the Hino River that flows into Lake Biwa, from ten sampling points and obtained several reproducible peaks in different separation patterns for each sample within 2 min. We successfully demonstrated high-throughput characterization of dissolved organic carbon (DOC) in environmental water using the microchip. 相似文献
997.
998.
999.
Toshiki Nagamachi Dr. Youhei Takeda Kazuhisa Nakayama Prof. Dr. Satoshi Minakata 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(38):12035-12045
Highly selective and versatile methods for the synthesis of aza[60]fulleroids and aziridino[60]fullerenes from C60 have been developed. The reactions utilized N,N‐dihalosulfonamides as an N1 source. The photophysical, electrochemical, and thermal properties of the iminofullerenes were investigated by means of UV/Vis spectroscopy, cyclic voltammetry, and thermogravimetry, respectively. Furthermore, photovoltaic cells based on the synthesized iminofullerenes were fabricated. The power conversion efficiencies (PCEs) of the devices showed moderate values ranging from 1.33 to 2.35 %. 相似文献
1000.