Brown algae are well known as a source of biologically active compounds, especially those having antioxidant activities, such as phlorotannins. In this study we examined the antioxidant activities of crude phlorotanni...Brown algae are well known as a source of biologically active compounds, especially those having antioxidant activities, such as phlorotannins. In this study we examined the antioxidant activities of crude phlorotannins extracts（CPEs） obtained from Sargassum hemiphyllum（SH） and fractionated according to the molecular weights. When CPEs were administrated at a dose of 30 mg/kg to Kunming mice pre-treated with carbon tetrachloride（CCl4）, the levels of oxidative stress indicators in the liver, kidney and brain were significantly reduced in vivo. All the components of various molecular weight fractions of CPEs exhibited greater scavenging capacities in clearing hydroxyl free radical and superoxide anion than the positive controls gallic acid, vitamin C and vitamin E. Particularly, the components greater than 30 k D obtained from ethyl acetate phase showed the highest antioxidant capacities. These results indicated that SH is a potential source for extracting phlorotannins, the algal antioxidant compounds.展开更多
Objective:To study physicochemical properties,antioxidant and anti-inflammatory activities of coumarin-carbonodithioate hybrids.Methods:The substituted 4-bromomethyl coumarins were synthesized in first step by the cyc...Objective:To study physicochemical properties,antioxidant and anti-inflammatory activities of coumarin-carbonodithioate hybrids.Methods:The substituted 4-bromomethyl coumarins were synthesized in first step by the cyclization.Then the reaction of substituted coumarins(a-e)with potassium O-ethyl/methyl carbonodithioate(1)by using absolute ethanol as solvent,afforded coumarin-carbonodithioate(1a-1j)derivatives under microwave irradiation and the conventional method.The spectroscopic analysis was used for the characterization of coumarin derivatives.The title(1a-1j)compounds were confirmed by spectroscopic methods.Antioxidant property was evaluated by using DPPH free radical-scavenging ability assay method and anti-inflammatory activity was evaluated by protein denaturation procedure using diclofenac sodium as a standard.Drug-likeness.In-silico toxicity was predicted with LD_(50)value and bioactivity score was also calculated for all the compounds.Results:All coumarin(1a-1j)compounds exhibited promisingin-vitro antioxidant and anti-inflammatory properties in comparison to standard drugs.All tested compounds were used for evaluating their physicochemical properties as set by Lipinski rule.It was observed that the synthesized compounds followed rule of five,indicating more'drug-like'nature.Conclusions:All the screened coumarin-carbonodithioates display promising in vitro antioxidant and antiinflammatory activities.From the physicochemical properties of coumarin derivatives,it is found that none of the compounds violate the Lipinski rule and they fall well in the range of rule of five.It is concluded that the coumarin-carbonodithioate hybrids act with more'drug-like'nature.展开更多
文摘Brown algae are well known as a source of biologically active compounds, especially those having antioxidant activities, such as phlorotannins. In this study we examined the antioxidant activities of crude phlorotannins extracts（CPEs） obtained from Sargassum hemiphyllum（SH） and fractionated according to the molecular weights. When CPEs were administrated at a dose of 30 mg/kg to Kunming mice pre-treated with carbon tetrachloride（CCl4）, the levels of oxidative stress indicators in the liver, kidney and brain were significantly reduced in vivo. All the components of various molecular weight fractions of CPEs exhibited greater scavenging capacities in clearing hydroxyl free radical and superoxide anion than the positive controls gallic acid, vitamin C and vitamin E. Particularly, the components greater than 30 k D obtained from ethyl acetate phase showed the highest antioxidant capacities. These results indicated that SH is a potential source for extracting phlorotannins, the algal antioxidant compounds.
文摘Objective:To study physicochemical properties,antioxidant and anti-inflammatory activities of coumarin-carbonodithioate hybrids.Methods:The substituted 4-bromomethyl coumarins were synthesized in first step by the cyclization.Then the reaction of substituted coumarins(a-e)with potassium O-ethyl/methyl carbonodithioate(1)by using absolute ethanol as solvent,afforded coumarin-carbonodithioate(1a-1j)derivatives under microwave irradiation and the conventional method.The spectroscopic analysis was used for the characterization of coumarin derivatives.The title(1a-1j)compounds were confirmed by spectroscopic methods.Antioxidant property was evaluated by using DPPH free radical-scavenging ability assay method and anti-inflammatory activity was evaluated by protein denaturation procedure using diclofenac sodium as a standard.Drug-likeness.In-silico toxicity was predicted with LD_(50)value and bioactivity score was also calculated for all the compounds.Results:All coumarin(1a-1j)compounds exhibited promisingin-vitro antioxidant and anti-inflammatory properties in comparison to standard drugs.All tested compounds were used for evaluating their physicochemical properties as set by Lipinski rule.It was observed that the synthesized compounds followed rule of five,indicating more'drug-like'nature.Conclusions:All the screened coumarin-carbonodithioates display promising in vitro antioxidant and antiinflammatory activities.From the physicochemical properties of coumarin derivatives,it is found that none of the compounds violate the Lipinski rule and they fall well in the range of rule of five.It is concluded that the coumarin-carbonodithioate hybrids act with more'drug-like'nature.
