To investigate the phytochemical constituents of aboveground parts of Croton tiglium L. （family Euphorbiaceae）, its ingredients were isolated by repeated chromatography on silica gel, Sephadex LH-20, ODS and prepara...To investigate the phytochemical constituents of aboveground parts of Croton tiglium L. （family Euphorbiaceae）, its ingredients were isolated by repeated chromatography on silica gel, Sephadex LH-20, ODS and preparative HPLC. Their structures were identified based on 1D, 2D NMR and mass spectral analysis. A total of 10 phorbol esters were obtained. Among them, compound 1 （12-O-（2-methyl）butyryl-4ct-deoxyphorbol-β-isobutyrate） and compound 10 （20-formyl-4a-deoxyphorbol- β-acetate） were two new compounds, and the other eight were known compounds.展开更多
The deoiled Jatropha curcas meal by hexane extraction was detoxified phorbol esters by two different methods. These two methods were alkali in methanol and only ethanol washing. After both treatments, the PEs （phorbo...The deoiled Jatropha curcas meal by hexane extraction was detoxified phorbol esters by two different methods. These two methods were alkali in methanol and only ethanol washing. After both treatments, the PEs （phorbol esters） was decreased by 100%. The crude protein in detoxified meal of alkali in methanol washing was less amount than only ethanol washing. The result showed that treatment by only ethanol washing was a promising way to detoxify deoiled Jatropha curcas meal for animal feeds in industrial scale.展开更多
Dopamine （DA） exposure at a dose of 100 pmol/L for 24 hours causes oxidative stress in SH-SY5Y cells with induction of neuronal differentiation by retinoic acid （RA,10 pmol/L,72 hours） followed by phorbol ester 12...Dopamine （DA） exposure at a dose of 100 pmol/L for 24 hours causes oxidative stress in SH-SY5Y cells with induction of neuronal differentiation by retinoic acid （RA,10 pmol/L,72 hours） followed by phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate （TPA,80 nmol/L,72 hours）. However,it remains unclear whether the alteration of phenotype observed in response to oxidative stress is associated with protein regulation in this cellular model for Parkinson＇s disease. The present study detected protein regulation affected by oxidative stress at a proteomic level：selection of differentially altered proteins using two dimensional difference in-gel electrophoresis and identification of these proteins using matrix assisted laser desorption/ionization time-of-flight mass spectrometry. The results demonstrated significant alterations in expression of six proteins in SH-SY5Y cells following the differentiation and fourteen proteins in the differentiated cells following the exposure,exemplified by an increase of tubulin alpha1 in the former but a decrease of tubulin alpha-ubiquitous chain in the latter. These results suggest that two potentially specific but relevant patterns of proteomic change may be produced in SH-SY5Y cells with the induction of differentiation by RA followed by TPA,and in the differentiated cells after DA exposure.展开更多
To investigate the correlation between the activity of kinases in the growth factor signal transduction pathway and the development of resistance of breast cancer to tamoxifen, reporter gene regulated by the regulat...To investigate the correlation between the activity of kinases in the growth factor signal transduction pathway and the development of resistance of breast cancer to tamoxifen, reporter gene regulated by the regulating fragment of CCD1 was transfected into the MCF 7 cells, and the influence of tamoxifen on the reporter gene expression was examined under different conditions of TPA treatment. Our results showed that the reporter gene expression was inhibited by tamoxifen and promoted by TPA. Furthermore, tamoxifen exerts an agonist effect on the reporter gene expression when the cells was treated by TPA previously for 12 h. It is concluded that TPA could induce estrogen like effect of tamoxifen on estrogen receptor positive breast cancer cells and it may be one of the mechanisms responsible for the development of tamoxifen resistance.展开更多
Protein kinase C with a molecular weight of 82 kD has been purified to electrophoresis homogenous from rat brain through a series of chromatography cohmns including DE-52, Sepharose G-200 and phenyl-Sepharose. The enz...Protein kinase C with a molecular weight of 82 kD has been purified to electrophoresis homogenous from rat brain through a series of chromatography cohmns including DE-52, Sepharose G-200 and phenyl-Sepharose. The enzyme possessed autophosphorylation activity. Yuanhuacin A inhibited the ~3H-phorbol-12, 13-dibutyrate (~3H-PdBu) binding of PKC with an IC_(50) value of 1.48±0.287×10^(-8) mol/L when the concentration of ~3H-PdBu was 1.5×10^(-9) mol/L (K_i=1.2×10^(-8) mol/L). Yuanhuacin A inhibited the PdBu-stimulated PKC activity in the catalysis of the phosphorylation of Histone Ⅲ-S with an IC_(50) of 2.82±0.37×10^(-9) mol/L (PdBu=10^(-6) mol/L), while it had no effect on the basal and Ca^(2+)-stimulated PKC activity in the same assay system. This result suggests that Yuanhuacin A is a selective antagonist of the phorbol ester receptor in protein kinase C.展开更多
Cardiomyocytes isolated from neonatal rats were treated with phorboll 2-myristatel 3-acetate (PMA ) ranging from 10(-11)to 10-7 mol/L for 20 min, causing cytosol protein kinase A (PKA) activity to decrease while parti...Cardiomyocytes isolated from neonatal rats were treated with phorboll 2-myristatel 3-acetate (PMA ) ranging from 10(-11)to 10-7 mol/L for 20 min, causing cytosol protein kinase A (PKA) activity to decrease while particulate PKA activity increase in a concentration-dependent manner. The change of PKA activity induced by PMA was abolished completely by pretreatment of polymyxin B or depletion of protein kinase C (PKC). Type II PKA activity in particulate fraction was enhanced remarkably, while that of type I PKA was not altered when the cells were treated with 100 nmol/L PMA. The results suggested that subcellular distribution and activity of PKA in cardiomyocytes may be regulated by PKC.展开更多
In this study,37 derivatives of phorbol esters were synthesized and their anti-HIV-1 activities evaluated,building upon our previous synthesis of 51 phorbol derivatives.12-Para-electron-acceptor-trans-cinnamoyl-13-dec...In this study,37 derivatives of phorbol esters were synthesized and their anti-HIV-1 activities evaluated,building upon our previous synthesis of 51 phorbol derivatives.12-Para-electron-acceptor-trans-cinnamoyl-13-decanoyl phorbol derivatives stood out,demonstrating remarkable anti-HIV-1 activities and inhibitory effects on syncytia formation.These derivatives exhibited a higher safety index compared with the positive control drug.Among them,12-(trans-4-fluorocinnamoyl)-13-decanoyl phorbol,designated as compound 3c,exhibited the most potent anti-HIV-1 activity(EC_(50)2.9 nmol·L^(−1),CC50/EC_(50)11117.24)and significantly inhibited the formation of syncytium(EC_(50)7.0 nmol·L^(−1),CC50/EC_(50)4891.43).Moreover,compound 3c is hypothesized to act both as an HIV-1 entry inhibitor and as an HIV-1 reverse transcriptase inhibitor.Isothermal titration calorimetry and molecular docking studies indicated that compound 3c may also function as a natural activator of protein kinase C(PKC).Therefore,compound 3c emerges as a potential candidate for developing new anti-HIV drugs.展开更多
基金National Natural Science Foundation of China(Grant No.81172943)
文摘To investigate the phytochemical constituents of aboveground parts of Croton tiglium L. （family Euphorbiaceae）, its ingredients were isolated by repeated chromatography on silica gel, Sephadex LH-20, ODS and preparative HPLC. Their structures were identified based on 1D, 2D NMR and mass spectral analysis. A total of 10 phorbol esters were obtained. Among them, compound 1 （12-O-（2-methyl）butyryl-4ct-deoxyphorbol-β-isobutyrate） and compound 10 （20-formyl-4a-deoxyphorbol- β-acetate） were two new compounds, and the other eight were known compounds.
文摘The deoiled Jatropha curcas meal by hexane extraction was detoxified phorbol esters by two different methods. These two methods were alkali in methanol and only ethanol washing. After both treatments, the PEs （phorbol esters） was decreased by 100%. The crude protein in detoxified meal of alkali in methanol washing was less amount than only ethanol washing. The result showed that treatment by only ethanol washing was a promising way to detoxify deoiled Jatropha curcas meal for animal feeds in industrial scale.
基金the Science and Technology Development Program of Jilin Province, No. 200505200the Distinguished Professor Foundation of Jilin University, No. 450011011204
文摘Dopamine （DA） exposure at a dose of 100 pmol/L for 24 hours causes oxidative stress in SH-SY5Y cells with induction of neuronal differentiation by retinoic acid （RA,10 pmol/L,72 hours） followed by phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate （TPA,80 nmol/L,72 hours）. However,it remains unclear whether the alteration of phenotype observed in response to oxidative stress is associated with protein regulation in this cellular model for Parkinson＇s disease. The present study detected protein regulation affected by oxidative stress at a proteomic level：selection of differentially altered proteins using two dimensional difference in-gel electrophoresis and identification of these proteins using matrix assisted laser desorption/ionization time-of-flight mass spectrometry. The results demonstrated significant alterations in expression of six proteins in SH-SY5Y cells following the differentiation and fourteen proteins in the differentiated cells following the exposure,exemplified by an increase of tubulin alpha1 in the former but a decrease of tubulin alpha-ubiquitous chain in the latter. These results suggest that two potentially specific but relevant patterns of proteomic change may be produced in SH-SY5Y cells with the induction of differentiation by RA followed by TPA,and in the differentiated cells after DA exposure.
基金This project was supported by a grant of the National Nat-ural Sciences Foundation of China (No.39770 72 4)
文摘To investigate the correlation between the activity of kinases in the growth factor signal transduction pathway and the development of resistance of breast cancer to tamoxifen, reporter gene regulated by the regulating fragment of CCD1 was transfected into the MCF 7 cells, and the influence of tamoxifen on the reporter gene expression was examined under different conditions of TPA treatment. Our results showed that the reporter gene expression was inhibited by tamoxifen and promoted by TPA. Furthermore, tamoxifen exerts an agonist effect on the reporter gene expression when the cells was treated by TPA previously for 12 h. It is concluded that TPA could induce estrogen like effect of tamoxifen on estrogen receptor positive breast cancer cells and it may be one of the mechanisms responsible for the development of tamoxifen resistance.
文摘Protein kinase C with a molecular weight of 82 kD has been purified to electrophoresis homogenous from rat brain through a series of chromatography cohmns including DE-52, Sepharose G-200 and phenyl-Sepharose. The enzyme possessed autophosphorylation activity. Yuanhuacin A inhibited the ~3H-phorbol-12, 13-dibutyrate (~3H-PdBu) binding of PKC with an IC_(50) value of 1.48±0.287×10^(-8) mol/L when the concentration of ~3H-PdBu was 1.5×10^(-9) mol/L (K_i=1.2×10^(-8) mol/L). Yuanhuacin A inhibited the PdBu-stimulated PKC activity in the catalysis of the phosphorylation of Histone Ⅲ-S with an IC_(50) of 2.82±0.37×10^(-9) mol/L (PdBu=10^(-6) mol/L), while it had no effect on the basal and Ca^(2+)-stimulated PKC activity in the same assay system. This result suggests that Yuanhuacin A is a selective antagonist of the phorbol ester receptor in protein kinase C.
文摘Cardiomyocytes isolated from neonatal rats were treated with phorboll 2-myristatel 3-acetate (PMA ) ranging from 10(-11)to 10-7 mol/L for 20 min, causing cytosol protein kinase A (PKA) activity to decrease while particulate PKA activity increase in a concentration-dependent manner. The change of PKA activity induced by PMA was abolished completely by pretreatment of polymyxin B or depletion of protein kinase C (PKC). Type II PKA activity in particulate fraction was enhanced remarkably, while that of type I PKA was not altered when the cells were treated with 100 nmol/L PMA. The results suggested that subcellular distribution and activity of PKA in cardiomyocytes may be regulated by PKC.
基金supported by the National Natural Science Foundation of China(Nos.81202882,82060670)Suzhou Science and Technology Planning Project in Jiangsu Province of China(No.SNG2021022)+1 种基金the Priority Academic Program Development of the Jiangsu Higher Education Institutes,China(PAPD)and the Project of Innovative Research Team of Yunnan Province(No.202005AE160005).
文摘In this study,37 derivatives of phorbol esters were synthesized and their anti-HIV-1 activities evaluated,building upon our previous synthesis of 51 phorbol derivatives.12-Para-electron-acceptor-trans-cinnamoyl-13-decanoyl phorbol derivatives stood out,demonstrating remarkable anti-HIV-1 activities and inhibitory effects on syncytia formation.These derivatives exhibited a higher safety index compared with the positive control drug.Among them,12-(trans-4-fluorocinnamoyl)-13-decanoyl phorbol,designated as compound 3c,exhibited the most potent anti-HIV-1 activity(EC_(50)2.9 nmol·L^(−1),CC50/EC_(50)11117.24)and significantly inhibited the formation of syncytium(EC_(50)7.0 nmol·L^(−1),CC50/EC_(50)4891.43).Moreover,compound 3c is hypothesized to act both as an HIV-1 entry inhibitor and as an HIV-1 reverse transcriptase inhibitor.Isothermal titration calorimetry and molecular docking studies indicated that compound 3c may also function as a natural activator of protein kinase C(PKC).Therefore,compound 3c emerges as a potential candidate for developing new anti-HIV drugs.
