ABSTRACT
A visible-light photocatalytic generation of N-centered hydrazonyl radicals has been accomplished for the first time. This approach allows efficient intramolecular addition of hydrazonyl radical to terminal alkenes, thus providing hydroamination and oxyamination products in good yields. Importantly, the protocol involves deprotonation of an N-H bond and photocatalytic oxidation to an N-centered radical, thus obviating the need to prepare photolabile amine precursors or the stoichiometric use of oxidizing reagents.
Subject(s)
Amines/chemistry , Hydrazones/chemistry , Catalysis , Free Radicals , Photochemical ProcessesABSTRACT
An unprecedented three-component coupling reaction of arynes, α-bromo carbonyl compounds, and DMSO triggered by insertion of arynes into the SâO bond of DMSO has been developed. The reaction can generate a wide range of multisubstituted aryl methyl thioethers in good yields, wherein DMSO serves as both methylthiolation reagent and oxygen source.
ABSTRACT
AIM: To investigate effects of sulforaphane on the BIU87 cell line and underlying mechanisms involving IGFBP-3. METHODS: Both BIU87 and IGFBP-3-silenced BIU87 cells were treated with sulforaphane. Cell proliferation was detected by MTT assay. Cell cycle and apoptosis were determined via flow cytometry. Quantitative polymerase chain reaction and Western blotting were applied to analyze the expression of IGFBP-3 and NF-κB at both mRNA and protein levels. RESULTS: Sulforaphane (80 µM) treatment could inhibit cell proliferation, inducing apoptosis and cell cycle arrest at G2/M phase. All these effects could be antagonized by IGFBP-3 silencing. Furthermore, sulforaphane (80 µM) could down-regulate NF-κB expression while elevating that of IGFBP-3. CONCLUSIONS: Sulforaphane could suppress the proliferation of BIU87 cells via enhancing IGFBP-3 expression, which negatively regulating the NF-κB signaling pathway.
Subject(s)
Cell Proliferation/drug effects , Insulin-Like Growth Factor Binding Protein 3/biosynthesis , Isothiocyanates/pharmacology , Urinary Bladder Neoplasms/drug therapy , Anticarcinogenic Agents/pharmacology , Apoptosis , Cell Line, Tumor , Humans , Insulin-Like Growth Factor Binding Protein 3/genetics , M Phase Cell Cycle Checkpoints/drug effects , NF-kappa B/biosynthesis , NF-kappa B/genetics , RNA Interference , RNA, Messenger/biosynthesis , RNA, Small Interfering , Signal Transduction/drug effects , SulfoxidesABSTRACT
An enantioselective oxa-Michael addition of oximes to ß-CF3-ß-disubstituted nitroalkenes catalyzed by a chiral bifunctional cinchona alkaloid-based thiourea has been developed. A variety of trifluoromethylated oxime ethers possessing a tetrasubstituted carbon stereocenter were obtained in good yields with high enantioselectivities.
Subject(s)
Alkenes/chemistry , Amino Alcohols/chemical synthesis , Nitro Compounds/chemistry , Oximes/chemistry , Amino Alcohols/chemistry , Catalysis , Crystallography, X-Ray , Models, Molecular , Molecular Structure , StereoisomerismABSTRACT
Based on an air pollution modeling system coupling with the non-hydrostatic fifth generation mesoscale meteorological model (MM5) and the regional modeling system for aerosols and deposition (REMSAD), the forecast results of NOx and SO2 in August and September 2002 in Nanjing were assimilated with the optimal interpolation method and the ensemble Kalman filter. The results show that the improvement rates of deviation mean value of NOx and SO2 after assimilated with the optimal interpolation method are 34.20% and 47.53%, and the improvement rates of root mean square errors are 31.95% and 42.04% respectively. It is also demonstrated that the improvement rates of deviation mean value of NOx and SO2 after assimilated with the ensemble Kalman filter with 30 ensemble members are 26.73% and 60.75%, and the improvement rates of root mean square errors are 25.20% and 55.16% respectively. So, the optimal interpolation method and the ensemble Kalman filter both can improve the quality of the initial state from the air pollution numerical prediction model. The comparative experiments on the assimilation performance with the optimal interpolation method and the ensemble Kalman filter with 61 ensemble members were performed, and the experiments demonstrate that the assimilation performance of the ensemble Kalman filter with 61 ensemble members were improved compared with 30 ensemble members, and with the increase of the ensemble members, the improvement to the initial state of NOx and SO2 with the ensemble Kalman filter will be better than the optimal interpolation method.
