Macroalgae in a littoral zone are inevitably exposed to UV-B irradiance. We analyzed the effects of UV-B on isoenzyme patterns and activities of superoxide dismutase （SOD）, peroxidase （POX）, catalase （CAT）, and ...Macroalgae in a littoral zone are inevitably exposed to UV-B irradiance. We analyzed the effects of UV-B on isoenzyme patterns and activities of superoxide dismutase （SOD）, peroxidase （POX）, catalase （CAT）, and ascorbate peroxidase （APX） of red algae Grateloupia filicina （Lamour.） C. Agardh. The activities of SOD, CAT, and APX changed in response to UV-B in a time- and dose-dependent manner. POX activity increased significantly under all three UV-B treatments. The enzymatic assay showed three distinct bands of SODI （Mn-SOD）, SODII （Fe-SOD）, and SODIII （CuZn-SOD） under a low （Luv） and medium （Muv） dose of UV-B irradiation, while SODI and SODIII activities decreased significantly when exposed to a high dose of UV-B irradiation （Huv）. The activity of POX isoenzymes increased significantly after exposure to UV-B, which is consistent with the total activity. In addition, a clear decrease in activity of CATIV was detected in response to all the three doses of UV treatments. Some bands ofAPX isoenzyme were also clearly influenced by UV-B irradiation. Correspondingly, the daily growth rate declined under all the three exposure doses, and was especially significant under Muv and Huv treatments. These data suggest that, although the protection mechanisms of antioxidant defense system are partly inducible by UV-B to prevent the damage, G.filicina has incomplete tolerance to higher UV-B irradiation stress.展开更多
This research presents complete phenolic compounds and biological activity of Tamarix pauciovulata J. Gay, an endemic Saharan species. The antioxidant assays revealed that crude extract showed strong DPPH scavenging a...This research presents complete phenolic compounds and biological activity of Tamarix pauciovulata J. Gay, an endemic Saharan species. The antioxidant assays revealed that crude extract showed strong DPPH scavenging activity （IC50 = 49.357 μg/mL） but in reducing power and hydrogen peroxide scavenging activity, butanolic and ethyl acetate fractions have a potent ferrous ion-chelating ability in particularly the butanolic fraction （63.18% reduced power at 50 μg/mL） and a powerful scavenging activity on hydrogen peroxide in particularly ethyl acetate fraction （IC50 = 0.205 μg/mL）. The phenolic compounds of Tamarix pauciovulata leaves were analyzed by HPLC-UV. The major phenolic of leaf extracts are syringic acid （1.07 g/100g）, quercetin （34.1 mg/100g）, kaempferol （5.77 mg/100g）, isorhamnetin （5 mg/100g）. Others phenols were identified such as isoquercetin, catechin, epicatechin and its derivatives. Results indicated that the leaves extracts from Tamarix pauciovulata have great capacities to prevent diseases caused by the overproduction of radicals and can become important source of dietary compounds with health protective potential.展开更多
基金Supported by the National Natural Science Foundation of China(No.31300326)the Natural Science Foundation of Shandong Province(Nos.ZR2010DQ007,ZR2011CM006)
文摘Macroalgae in a littoral zone are inevitably exposed to UV-B irradiance. We analyzed the effects of UV-B on isoenzyme patterns and activities of superoxide dismutase （SOD）, peroxidase （POX）, catalase （CAT）, and ascorbate peroxidase （APX） of red algae Grateloupia filicina （Lamour.） C. Agardh. The activities of SOD, CAT, and APX changed in response to UV-B in a time- and dose-dependent manner. POX activity increased significantly under all three UV-B treatments. The enzymatic assay showed three distinct bands of SODI （Mn-SOD）, SODII （Fe-SOD）, and SODIII （CuZn-SOD） under a low （Luv） and medium （Muv） dose of UV-B irradiation, while SODI and SODIII activities decreased significantly when exposed to a high dose of UV-B irradiation （Huv）. The activity of POX isoenzymes increased significantly after exposure to UV-B, which is consistent with the total activity. In addition, a clear decrease in activity of CATIV was detected in response to all the three doses of UV treatments. Some bands ofAPX isoenzyme were also clearly influenced by UV-B irradiation. Correspondingly, the daily growth rate declined under all the three exposure doses, and was especially significant under Muv and Huv treatments. These data suggest that, although the protection mechanisms of antioxidant defense system are partly inducible by UV-B to prevent the damage, G.filicina has incomplete tolerance to higher UV-B irradiation stress.
文摘This research presents complete phenolic compounds and biological activity of Tamarix pauciovulata J. Gay, an endemic Saharan species. The antioxidant assays revealed that crude extract showed strong DPPH scavenging activity （IC50 = 49.357 μg/mL） but in reducing power and hydrogen peroxide scavenging activity, butanolic and ethyl acetate fractions have a potent ferrous ion-chelating ability in particularly the butanolic fraction （63.18% reduced power at 50 μg/mL） and a powerful scavenging activity on hydrogen peroxide in particularly ethyl acetate fraction （IC50 = 0.205 μg/mL）. The phenolic compounds of Tamarix pauciovulata leaves were analyzed by HPLC-UV. The major phenolic of leaf extracts are syringic acid （1.07 g/100g）, quercetin （34.1 mg/100g）, kaempferol （5.77 mg/100g）, isorhamnetin （5 mg/100g）. Others phenols were identified such as isoquercetin, catechin, epicatechin and its derivatives. Results indicated that the leaves extracts from Tamarix pauciovulata have great capacities to prevent diseases caused by the overproduction of radicals and can become important source of dietary compounds with health protective potential.
