Polyphenols Content, Antioxidant and Antimicrobial Activity of Ethanol Extracts from the Aerial Part of Rock Rose （Hefianthemum nummularium） Species

This study aimed to evaluate polyphenols content, antioxidant and antimicrobial activities of ethanol extract from rock rose （Helianthemum nummularium （L.） Mill.）. Plant material has been harvested in July from Romanian Carpathian Mountains. The ethanolic extract （70%, v/v） was prepared from the aerial part of rock rose species. High performance thin layer chromatography （HPTLC） analysis of ethanol extract and subsequently hydrolysed sample indicated that quercetin glycosides were the major polyphenolic compounds, and kaempferol derivates, chlorogenic and gallic phenylcarboxylic acids are also being present in the polar extracts. Chemiluminescence assay in luminol/H：O2 system indicated very high antioxidant activity of the ethanolic type of extract （ICs0 = 1.27 ~tg/mL）, while microbiological studies （cylinder method in plates） indicated certain antimicrobial activity （measuring from 12.5 mm to 21.5 mm of the diameter of the inhibition zone） of the propylene glycol （20%, v/v） standardized extract （5 mg gallic acid equivalents/mL sample） against several standard bacterial strains, Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 8739, Salmonella typhimurium ATCC 14028 and Salmonella enterritidis ATCC 13076, respectively. Therefore, based on the augmented antioxidant effect of the rock rose polar extracts, there can be found numerous applications in the pharmaceutical industry, but also in non-pharmaceutical fields, for example in cosmetic and hygiene products areas, due to certain antimicrobial properties.

Optimization of ionic liquid-based microwave-assisted extraction of polyphenolic content from Peperomia pellucida (L) kunth using response surface methodology

Objective: To optimize the ionic liquid based microwave-assisted extraction (IL-MAE) of polyphenolic content from Peperomia pellucida (L) Kunth. Methods: The IL-MAE factors as experimental design parameters, including microwave power, extraction time, ionic liquid concentration, and liquid–solid ratio had been involved. Response surface methodology and Box–Behnken design were used to obtain predictive model (multivariate quadratic regression equation) and optimization of the extraction process. The response surface was analyzed by using the yields of total polyphenolic content as response value. Results: Based on the obtained results the optimum extraction condition, including microwave power of 30% Watts, extraction time of 18.5 min, the ionic liquid concen-tration of 0.79 mol/L, and the liquid–solid ratio of 10.72 mL/g 1-Buthyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) as a solvent was selected. The regression model was obtained to predicts the yields from Peperomia pellucida:Y = 30.250 – 1.356X1 + 2.655X2 + 2.252X3 – 0.565X4 + 0.990 X1X3 – 8.172 X1X4 – 3.439 X3X4 – 4.178 X12 – 3.210 X32 – 6.786 X42 – 7.290 X12X3 + 5.575 X1X32 – 4.843 X32X4 with R2 = 0.82519. Scale-up confirmation test was obtained the maximum yields of total polyphenolics content with the amount of 31.1725μg GAE/g. Conclusions: The IL-MAE method produced a higher extraction polyphenolic and performed rapidly, easily and efficiently.

Determination of Total Polyphenols in Different Extraction Fractions of Pholidota chinensis Lindl.and Their Antioxidant Activity

[Objectives]This study was conducted to study the total polyphenol content and antioxidant capacity of different extraction fractions of Pholidota chinensis.[Methods]Different polar fractions of P.chinensis were obtained by ultrasonic extraction method,and determined for polyphenol contents by UV spectrophotometry,and their antioxidant activity was evaluated by DPPH free radical scavenging and ferric ion reducing antioxidant power(FRAP).SPSS analysis software was used to analyze the correlation between total polyphenol contents and antioxidant activity of different extracts.[Results]The contents of total polyphenols in different polar fractions ranged from 1.52 to 6.41 mg/g,and the order from low to high was:water<petroleum ether<ethyl acetate<95%ethanol.The reduction capacity of the total antioxidant capacity method ranged from 12.54 to 22.45μmol/L,and the order was 95%ethanol>ethyl acetate>petroleum ether>water.The DPPH median inhibition concentration ranged from 0.35 to 2.65 mg/ml,and the order was water>petroleum ether>ethyl acetate>95%ethanol.The total polyphenol content of P.chinensis was best in the 95%ethanol extraction fraction,which showed the strongest total antioxidant capacity,so the total polyphenol content of the 95%ethanol fraction was positively correlated with its antioxidant capacity,while the DPPH free radical-scavenging capacity was better in the water fraction,indicating that the free radical-scavenging capacity of the water fraction was better.[Conclusions]This study provides a theoretical basis for the further study of the chemical components of P.chinensis and the development and utilization of natural antioxidants.

Comparison of Antioxidant and Antimicrobial Activities of Methanolic Extracts of the Artemisia sp.Recovered by Different Extraction Techniques

The polyphenol content,antioxidant and antimicrobial activities of the extracts obtained by classical, ultrasonic and Soxhlet extractions from dry aerial parts of two Artemisia species(Artemisia vulgaris and Artemisia campestris)were compared.Ultrasound positively affected the yield of extractive substance and the kinetics of extraction,but the extract obtained by the classical extraction showed the highest antioxidant activities and contained higher total contents of phenolic compounds and flavonoids than the extracts obtained by two other extraction techniques.Both flavonoid aglycones(apigenin,quercetin,quercetin 3,3′-dimethyl ether)and flavonoid glycosides(rutin,hyperoside and kaempferol 3-rhamnoside)were identified by thin layer chromatograph(TLC)analysis in the extracts from both species.A.campestris extracts were richer in quercetin than A.vulgaris and its antimicrobial activity was also better than A.vulgaris.Extracts obtained from both species were found to be more effective on the tested yeasts than bacteria.The kinetics of the total extractive substances,such as phenolic,flavonoids and quercetin extraction,was successfully described by the model of unsteady-state diffusion.

Bongardia chrysogonum(L.)Spach:a valuable source for nutraceutical and pharmacological industries

Background:Bongardia chrysogonum(L.)Spach,also known as“Uruf-el-Deek”,has been used by rural communities for the treatment of various diseases and disorders,owing to its wide array of secondary metabolite compositions.Methods:The current study was conducted to determine the total polyphenolic content of Bongardia chrysogonum(L.)Spach as well as its potential free radical scavenging and metal-chelating antioxidant capacities.Its leaves,stems,and tubers were separately extracted using ethanol,water,and chloroform;their antioxidant activities were analyzed using in vitro models,including DPPH,ABTS,FRAP,and CUPRAC assays.The total polyphenolic content of the extracts was spectrophotometrically measured.Results:The richest polyphenolic content of the extracts was yielded by tuber chloroform and leaf ethanol extraction(215.09±0.53 mg/g extract as gallic acid equivalent and 240.74±1.12 mg/g extract as quercetin equivalent,respectively).Almost all of the tested extracts exhibited remarkable antioxidant activities,with the highest antioxidant capacity observed in the leaf extracts.On the other hand,the tuber ethanol extract demonstrated the weakest DPPH radical scavenging activity(%inhibition=49.75±0.38,P<0.01),while the tuber chloroform extract showed the weakest ABTS radical scavenging activity(%inhibition=62.61±0.06,P<0.05).These were closely followed by the tuber water extract(%inhibition=63.28±0.65,P<0.01).In terms of their FRAP and CUPRAC assays,the leaf ethanol extract was determined as the best one,with absorbance values of 3.64±0.01 and 2.22±0.01(P<0.01),respectively.Conclusion:Bongardia chrysogonum(L.)Spach possesses rich polyphenolic content and strong antioxidant activities.Thus,it could be a valuable source for the pharmaceutical industry in the prevention and treatment of diseases associated with oxidative stress.

Antioxidant and antibacterial activities of the ethyl acetate extracts of endophytic fungi isolated from Ageratum conyzoides L.

Accumulating evidence has demonstrated that endophytic fungi metabolites possess important biological activities.Ageratum conyzoides L.(Asteraceae)is an invasive aromatic herb with immense therapeutic importance.In the present study,we aimed to isolate and identify endophytic fungi in the roots,stems,leaves and flowers of Ageratum conyzoides L.and evaluate its antioxidant activity(DPPH,ABTS^(+) and FRAP assays),the contents of flavonoids and phenolic and antibacterial activity of their ethyl acetate extracts.Accordingly,a total of 25 endophytic fungi were isolated from Ageratum conyzoides L.and classified into 14 genera based on the Internal transcribed spacer sequence,among which Fusarium sp.(20%)were found to be the dominant groups.All fungal extracts exhibited antioxidant activity,and the extracts of fungi WZ07 exhibited antioxidant activities as well as higher flavonoids and phenolic content in all tests.Moreover,the extracts of fungi WL01 had good antibacterial activity against both Gram-positive and Gram-negative bacteria.We,for the first time,reported the antioxidant and antibacterial activity of endophytic fungi from Ageratum conyzoides L.,which may help lay the foundation for developing other medicinal components.