Singlet oxygen(^(1)O_(2)) is a strong oxidant which plays important roles in photodynamic therapy(PDT). The exploitation of photosensitizers with high ^(1)O_(2) production is crucial to improve PDT efficiency. In this...Singlet oxygen(^(1)O_(2)) is a strong oxidant which plays important roles in photodynamic therapy(PDT). The exploitation of photosensitizers with high ^(1)O_(2) production is crucial to improve PDT efficiency. In this study, a radical labeled quartet photosensitizer Cy-DENT is reported with high singlet oxygen quantum yield(Φ_(Δ)=32.3%) due to a radical enhanced inter-system crossing(ISC) process. After the introduction of 2,2,6,6-tetramethylpiperidinyloxy(TEMPO) radical, quartet state ^(4)[R,T] of CyDENT could be formed to give an over 20-fold enhancement of singlet oxygen quantum yield compared to Cy-DEN(without TEMPO radical) under irradiation of near infrared(NIR) light. In addition, the ^(1)O_(2 )production is well controlled by varying the electron-donating ability of the terminal substituent group. Cy-DENT possesses good cell permeability and is localized in mitochondria. Under the irradiation of 700 nm light, Cy-DENT can produce high levels of ROS to destroy the mitochondria membrane potential and induce cell apoptosis. Through the encapsulation of PEG-SS-PCL micelle, Cy-DENT can be effectively delivered to tumors and suppresses the tumor growth after PDT treatment.展开更多
An effective transition-metal-free catalytic system is developed for aerobic oxidations of alcohols. Using catalytic amount of bromide-bromate coupling, H2SO4, and NaNO2, together with 2,2,6,6-tetramethylpiperidine N-...An effective transition-metal-free catalytic system is developed for aerobic oxidations of alcohols. Using catalytic amount of bromide-bromate coupling, H2SO4, and NaNO2, together with 2,2,6,6-tetramethylpiperidine N-oxyl radical （TEMPO） in the presence of air, various alcohols could be converted into the corresponding aldehydes or ketones in good to excellent isolated yields under mild conditions.展开更多
基金supported by the National Natural Science Foundation of China(21421005,21576037,U1608222)。
文摘Singlet oxygen(^(1)O_(2)) is a strong oxidant which plays important roles in photodynamic therapy(PDT). The exploitation of photosensitizers with high ^(1)O_(2) production is crucial to improve PDT efficiency. In this study, a radical labeled quartet photosensitizer Cy-DENT is reported with high singlet oxygen quantum yield(Φ_(Δ)=32.3%) due to a radical enhanced inter-system crossing(ISC) process. After the introduction of 2,2,6,6-tetramethylpiperidinyloxy(TEMPO) radical, quartet state ^(4)[R,T] of CyDENT could be formed to give an over 20-fold enhancement of singlet oxygen quantum yield compared to Cy-DEN(without TEMPO radical) under irradiation of near infrared(NIR) light. In addition, the ^(1)O_(2 )production is well controlled by varying the electron-donating ability of the terminal substituent group. Cy-DENT possesses good cell permeability and is localized in mitochondria. Under the irradiation of 700 nm light, Cy-DENT can produce high levels of ROS to destroy the mitochondria membrane potential and induce cell apoptosis. Through the encapsulation of PEG-SS-PCL micelle, Cy-DENT can be effectively delivered to tumors and suppresses the tumor growth after PDT treatment.
基金grants from National Natural Science Foundation of China，Program for Changjiang Scholars and Innovative Research Team in University
文摘An effective transition-metal-free catalytic system is developed for aerobic oxidations of alcohols. Using catalytic amount of bromide-bromate coupling, H2SO4, and NaNO2, together with 2,2,6,6-tetramethylpiperidine N-oxyl radical （TEMPO） in the presence of air, various alcohols could be converted into the corresponding aldehydes or ketones in good to excellent isolated yields under mild conditions.
