Salacia oblonga (Wall.) belonging to the family Celastraceae is an important medicinal plant available in India and Sri Lanka. It possesses an array of pharmacological and therapeutic properties. In the present study ...Salacia oblonga (Wall.) belonging to the family Celastraceae is an important medicinal plant available in India and Sri Lanka. It possesses an array of pharmacological and therapeutic properties. In the present study phenolic compounds of S. oblonga methanolic extracts were estimated by high performance liquid chromatography (HPLC) indicating the presence of catechin, quercetin, synapic acid and syringic acid. The study involved evaluation of S. oblonga extracts for cytotoxic and cytoprotective effects on human lymphocytes. Aerial extracts have significant protective activity against hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) induced cytotoxic activity in comparison to the root extracts. The results relate the cytoprotective effect of S. oblonga due to the presence of poly phenols and other phytochemicals, as they have significant ability to remove free radicals or reactive species and might induce the expression of antioxidant enzymes inside the cells.展开更多
hoton emission properties of polyphenylphenol (PPP) synthesized in the pres-ence of a newly-found enzymatic catalyst are reported. The photoluminescence peakexcited by the light at 350 nm is at about 370-420 nm. The a...hoton emission properties of polyphenylphenol (PPP) synthesized in the pres-ence of a newly-found enzymatic catalyst are reported. The photoluminescence peakexcited by the light at 350 nm is at about 370-420 nm. The absorption band edgesand photon emitting peaks of the polymer were found dependent on the conjugatedlengths of the polymer. In the transient luminescence measurement the lifetime ofPL decay was determined to be 2. 0 ns which is supposed as the evidence of polaronexcitation recombination.展开更多
The oxidative polycondensation reaction conditions of 4-[（4-hydroxybenzylidene） amino] phenol （4-HBAP） were studied with H2O2, air oxygen and NaOCl in an aqueous alkaline medium between 50 and 90℃. The structures...The oxidative polycondensation reaction conditions of 4-[（4-hydroxybenzylidene） amino] phenol （4-HBAP） were studied with H2O2, air oxygen and NaOCl in an aqueous alkaline medium between 50 and 90℃. The structures of the obtained monomer and polymer were confirmed by FT-IR, UV-Vis, 1H- and 13C-NMR and elemental analysis. The characterization was made by TG-DTA, size exclusion chromatography （SEC） and solubility tests. At the optimum reaction conditions, the yield of poly[4-（4-hydroxybenzylidene amino） phenol] （P-4-HBAP） was found to be 48.3% （for H2O2 oxidant）, 80.5% （for air O2 oxidant） and 86.4% （for NaOCl oxidant）. According to the SEC analysis, the number-average molecular weight （Mn）, weight-average molecular weight （Mw） and polydispersity index （PDI） values of P-4-HBAP was found to be 8950, 10970 g tool^-1 and 1.225, respectively, using H202; and l l610, 15190 g tool^-1 and 1.308 respectively, using air 02 and 7900, 9610 g mol^-1 and 1.216, respectively, using NaOC1. According to TG-DTA analyses, P-4-HBAP was more stable than 4-HBAP against thermal decomposition. The weight loss of P-4-HBAP was found to be 49.27% at 1000℃. The highest occupied molecular orbital （HOMO） and the lowest unoccupied molecular orbital （LUMO） values calculated from electrochemical measurement. Electrochemical energy gaps （Eg＇） of 4-HBAP and P-4-HBAP were found to be -5.46, -5.28; -2.26, -2.67; 3.20 and 2.61 eV, respectively. According to UV-Vis measurements, optical band gap （Eg） of 4-HBAP and P-4-HBAP were found to be 3.34 and 3.01 eV, respectively. Also, antimicrobial activities of 4-HBAP and P-4-HBAP were examined against selected some bacteria. The electrical conductivity of the polymer was measured after doping with iodine.展开更多
文摘Salacia oblonga (Wall.) belonging to the family Celastraceae is an important medicinal plant available in India and Sri Lanka. It possesses an array of pharmacological and therapeutic properties. In the present study phenolic compounds of S. oblonga methanolic extracts were estimated by high performance liquid chromatography (HPLC) indicating the presence of catechin, quercetin, synapic acid and syringic acid. The study involved evaluation of S. oblonga extracts for cytotoxic and cytoprotective effects on human lymphocytes. Aerial extracts have significant protective activity against hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) induced cytotoxic activity in comparison to the root extracts. The results relate the cytoprotective effect of S. oblonga due to the presence of poly phenols and other phytochemicals, as they have significant ability to remove free radicals or reactive species and might induce the expression of antioxidant enzymes inside the cells.
文摘hoton emission properties of polyphenylphenol (PPP) synthesized in the pres-ence of a newly-found enzymatic catalyst are reported. The photoluminescence peakexcited by the light at 350 nm is at about 370-420 nm. The absorption band edgesand photon emitting peaks of the polymer were found dependent on the conjugatedlengths of the polymer. In the transient luminescence measurement the lifetime ofPL decay was determined to be 2. 0 ns which is supposed as the evidence of polaronexcitation recombination.
基金This work was financially supported by the TUBITAK Grants Commission for a research grant(No.TBAG-2451(104T062)).
文摘The oxidative polycondensation reaction conditions of 4-[（4-hydroxybenzylidene） amino] phenol （4-HBAP） were studied with H2O2, air oxygen and NaOCl in an aqueous alkaline medium between 50 and 90℃. The structures of the obtained monomer and polymer were confirmed by FT-IR, UV-Vis, 1H- and 13C-NMR and elemental analysis. The characterization was made by TG-DTA, size exclusion chromatography （SEC） and solubility tests. At the optimum reaction conditions, the yield of poly[4-（4-hydroxybenzylidene amino） phenol] （P-4-HBAP） was found to be 48.3% （for H2O2 oxidant）, 80.5% （for air O2 oxidant） and 86.4% （for NaOCl oxidant）. According to the SEC analysis, the number-average molecular weight （Mn）, weight-average molecular weight （Mw） and polydispersity index （PDI） values of P-4-HBAP was found to be 8950, 10970 g tool^-1 and 1.225, respectively, using H202; and l l610, 15190 g tool^-1 and 1.308 respectively, using air 02 and 7900, 9610 g mol^-1 and 1.216, respectively, using NaOC1. According to TG-DTA analyses, P-4-HBAP was more stable than 4-HBAP against thermal decomposition. The weight loss of P-4-HBAP was found to be 49.27% at 1000℃. The highest occupied molecular orbital （HOMO） and the lowest unoccupied molecular orbital （LUMO） values calculated from electrochemical measurement. Electrochemical energy gaps （Eg＇） of 4-HBAP and P-4-HBAP were found to be -5.46, -5.28; -2.26, -2.67; 3.20 and 2.61 eV, respectively. According to UV-Vis measurements, optical band gap （Eg） of 4-HBAP and P-4-HBAP were found to be 3.34 and 3.01 eV, respectively. Also, antimicrobial activities of 4-HBAP and P-4-HBAP were examined against selected some bacteria. The electrical conductivity of the polymer was measured after doping with iodine.
