Kinetic studies of the oxidation of benzhydrol and some of its para-substituted derivatives using phase transferred permanganate in organic solvents that are immiscible with water have been carried out. The products o...Kinetic studies of the oxidation of benzhydrol and some of its para-substituted derivatives using phase transferred permanganate in organic solvents that are immiscible with water have been carried out. The products of oxidation were the corresponding benzophenones. Kinetically first order dependence on the concentrations of substrate as well as the oxidant has been observed. The reaction rate was found to decrease with an increase in the dielectric constant of the organic solvent employed. The electronic effects of the substituents were found to be interesting. Both electron withdrawing and electron releasing groups at the para position of benzhydrol increased rate of the oxidation. The effects of different phase transfer catalysts (PTC) were also compared. The activation parameters have been evaluated and a mechanism consistent with the kinetic results has been proposed.展开更多
Autophagy is a cellular self-eating process essential for stress response and maintainingtissue homeostasis by lysosomal degradation of unwanted or damaged proteins and organelles.Here, we show that cells with defecti...Autophagy is a cellular self-eating process essential for stress response and maintainingtissue homeostasis by lysosomal degradation of unwanted or damaged proteins and organelles.Here, we show that cells with defective mitochondria induce autophagy to promotecell survival through activating the AMPK pathway. Loss of mitochondrial complex III proteincytochrome b activates the AMPK signaling and induced autophagy. Inhibiting mitochondria energeticsby mitochondria-targeted agents activates the AMPK signaling and induced autophagy.Genetic inhibition of AMPK inhibits autophagy induction in cells with defective mitochondria,while genetic inhibition of autophagy has no effect on AMPK activation. Mitochondria dysfunctionhas no effect of DNA repair of UV-induced DNA damage. However, mitochondria dysfunctionsensitizes cells to apoptosis induced by UV radiation. Genetic inhibition of autophagy orAMPK sensitized cells to apoptosis in cells with defective mitochondria. Our results demonstratethat AMPK and autophagy senses mitochondria dysfunction and serves as a mechanismfor survival. Our findings may provide new insights into the interplay between mitochondriafunction and autophagy process in maintaining tissue homeostasis, and suggest that this interactionmay play important roles in diseases such as cancer and neurodegeneration.展开更多
文摘Kinetic studies of the oxidation of benzhydrol and some of its para-substituted derivatives using phase transferred permanganate in organic solvents that are immiscible with water have been carried out. The products of oxidation were the corresponding benzophenones. Kinetically first order dependence on the concentrations of substrate as well as the oxidant has been observed. The reaction rate was found to decrease with an increase in the dielectric constant of the organic solvent employed. The electronic effects of the substituents were found to be interesting. Both electron withdrawing and electron releasing groups at the para position of benzhydrol increased rate of the oxidation. The effects of different phase transfer catalysts (PTC) were also compared. The activation parameters have been evaluated and a mechanism consistent with the kinetic results has been proposed.
基金This work was supported by the NIH/NIEHS grant ES024373 and ES016936(YYH)the American Cancer Society(ACS)grant RSG-13-078-01(YYH)+1 种基金the University of Chicago Cancer Research Center(P30 CA014599),the CTSA(UL1 TR000430)the University of Chicago Friends of Dermatology Endowment Fund.
文摘Autophagy is a cellular self-eating process essential for stress response and maintainingtissue homeostasis by lysosomal degradation of unwanted or damaged proteins and organelles.Here, we show that cells with defective mitochondria induce autophagy to promotecell survival through activating the AMPK pathway. Loss of mitochondrial complex III proteincytochrome b activates the AMPK signaling and induced autophagy. Inhibiting mitochondria energeticsby mitochondria-targeted agents activates the AMPK signaling and induced autophagy.Genetic inhibition of AMPK inhibits autophagy induction in cells with defective mitochondria,while genetic inhibition of autophagy has no effect on AMPK activation. Mitochondria dysfunctionhas no effect of DNA repair of UV-induced DNA damage. However, mitochondria dysfunctionsensitizes cells to apoptosis induced by UV radiation. Genetic inhibition of autophagy orAMPK sensitized cells to apoptosis in cells with defective mitochondria. Our results demonstratethat AMPK and autophagy senses mitochondria dysfunction and serves as a mechanismfor survival. Our findings may provide new insights into the interplay between mitochondriafunction and autophagy process in maintaining tissue homeostasis, and suggest that this interactionmay play important roles in diseases such as cancer and neurodegeneration.
