Chemo-type of essential oil of Ocimum basilicum L.from DR Congo and relative in vitro antioxidant potential to the polarity of crude extracts

Objective:To carry out a phyto-chemical characterization of essential oil from Ocimum basilicum L.(O.basilicum) harvested in DR Congo and to assess the antioxidant potential of crude extracts with respect to the polarity for comparison reason.Methods:The phyto-chemical characterization of essential oil produced by hydrodistillation was performed by coupled gas chromatography-mass spectrometer analysis and the antioxidant potential evaluation by in vitro 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity method.Results:A previously weighed amount of fresh leaves of O.basilicum produced 0.65%of essential oil that led to the identification of a set of 84.44%out of 99.98%as major compounds(> 1.5%).The chemo-type of this essential oil was linalool-methyl chavicol.Chemical components of oil were characterized by oxygenated aromatic hydrocarbons(46.00%) and oxygenated monoterpenes(26.75%).With respect to the amount of components,methyl chavicol also known as estragole(35.72%) constituted the very large quantity afterward linalool(21.25%) and then epi-α-cadinol(8.02%),α-bergamotene(6.56%),eugenol(4.60%),1,8-cineole(4.04%),germacrene D(2.06%),thymol(1.64%),and(E)-citral(1.55%),respectively.Essential oil exhibited antioxidant potential and IC_(50) =(1.180 ± 0.015) mg/mL.Non-polar crude extracts yields were low compared to the one of polar extracts.Only methanol and ethyl acetate had considerably manifested antioxidant potential with IC_(50) values equal to(0.025 ± 0.013) mg/mL and(0.085 ± 0.012) mg/mL,respectively.As concerns to IC50 values,essential oil was less active than methanol and ethyl acetate extracts.The methanol crude extract exhibited the highest activity.Non-polar extracts showed insignificant radical scavenging ability that did not allow assessing IC50 values.These results highlighted the occurrence of antioxidant potential compounds in polar media.Conclusions:Essential oil and crude extracts of O.basilicum growing in DR Congo can be advocated as natural sources of antioxidant potential compounds not only in food but also in pharmaceutical industries.The high antioxidant potential of polar crude extracts highlights antioxidant character of its composition particularly butyl stearate and rosmarinic acid we isolated and identified,respectively in the methanol crude extract.

Purification and Identification of a Novel Protein Isolated from Panax quinquefolium and Evaluation of its In vitro Antioxidant Properties

Objective:A novel protein was first purified from Panax quinquefolius L.(AGNP),and in vitro antioxidant activities of AGNP were first studied in this work.Methods:AGNP was purified by Ion-exchange chromatography and Gel-filtration chromatography.The chemical characterizations of AGNP were tested by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE),high-pressure gel-filtration chromatography,MALDI-TOF-MS and HPLC.In vitro antioxidant effects were tested in simple antioxidant assay including 2,2-diphenylpicrylhydrazyl radical scavenging,superoxide radical(O2^-)scavenging,hydroxyl radical(OH)scavenging,and ferric-reducing ability.Results:The results showed which the content of AGNP measured by Bradford method was 2.42 mg/m L and the subunit molecular weight of AGNP measured by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE)was 15 kD.The AGNP molecular weight was 15,114 Da both of SDS-PAGE and mass spectrum purity.The result of high-pressure gel-filtration chromatography demonstrated that the molecular weight of AGNP was 31,086 Da,which implied that AGNP was a homodimer.The in vitro Antioxidant results indicated that AGNP had obvious effects to remove the free radicals in vitro.Conclusion:In conclusion,AGNP had more powerful antioxidant capacity and it can be used as an effective natural antioxidant to alleviate oxidative stress.

Evaluation of in vitro antioxidant potential of different polarities stem crude extracts by different extraction methods of Adenium obesum

Objective:To select best extraction method for the isolated antioxidant compounds from the stems of Adenium obesum.Methods:Two methods used for the extraction are Soxhlet and maceration methods.Methanol solvent was used for both extraction method.The methanol crude extract was defatted with water and extracted successively with hexane,chloroform,ethyl acetate and butanol solvents.The antioxidant potential for all crude extracts were determined by using 1,1-diphenyl-2-picrylhydrazyl method.Results:The percentage of extraction yield by Soxhlet method is higher compared to maceration method.The antioxidant potential for methanol and its derived fractions by Soxhlet extractor method was highest in ethyl acetate and lowest in hexane crude extracts and found in the order of ethyl acetate>butanol>water>chloroform>methanol>hexane.However,the antioxidant potential for methanol and its derived fractions by maceration method was highest in butanol and lowest in hexane followed in the order of butanol>methanol>chloroform>water>ethyl acetate>hexane.Conclusions:The results showed that isolate antioxidant compounds effected on the extraction method and condition of extraction.

Physicochemical properties,antioxidant and anti-inflammatory activities of coumarin-carbonodithioate hybrids

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.

Antioxidant Activities of Crude Phlorotannins from Sargassum hemiphyllum

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.