Light-driven CO2 conversion system: construction, optimization and application / 生物工程学报

The use of light energy to drive carbon dioxide (CO2) reduction for production of chemicals is of great significance for relieving environmental pressure and solving energy crisis. Photocapture, photoelectricity conversion and CO2 fixation are the key factors affecting the efficiency of photosynthesis, and thus also affect the efficiency of CO2 utilization. To solve the above problems, this review systematically summarizes the construction, optimization and application of light-driven hybrid system from the perspective of combining biochemistry and metabolic engineering. We introduce the latest research progress of light-driven CO2 reduction for biosynthesis of chemicals from three aspects: enzyme hybrid system, biological hybrid system and application of these hybrid system. In the aspect of enzyme hybrid system, many strategies were adopted such as improving enzyme catalytic activity and enhancing enzyme stability. In the aspect of biological hybrid system, many methods were used including enhancing biological light harvesting capacity, optimizing reducing power supply and improving energy regeneration. In terms of the applications, hybrid systems have been used in the production of one-carbon compounds, biofuels and biofoods. Finally, the future development direction of artificial photosynthetic system is prospected from the aspects of nanomaterials (including organic and inorganic materials) and biocatalysts (including enzymes and microorganisms).

Potencial antioxidante del extracto de hojas de Spondias mombin L. en etanol al 70 % / Antioxidant potential of Spondias mombin L. leaf extract in 70% ethanol / Potencial antioxidante do extrato da folha de Spondias mombin L. em etanol 70%

RESUMEN Introducción: La especie Spondias mombin L. es una planta que crece en Cuba y a la que se le reporta un número considerables de aplicaciones etnofarmacológicas y elevado poder antioxidante. Sin embargo, la mayor parte de estos reportes está orientada al fruto, el cual resalta por su valor nutricional. Objetivo: Evaluar la actividad antioxidante de un extracto de hojas de Spondias mombin L. en etanol al 70 %. Método: La actividad antioxidante fue evaluada por seis métodos diferentes: determinación del índice de oxidación, poder reductor, inhibición de los radicales DPPH y ABTS, capacidad reductora del peróxido de hidrógeno y capacidad de neutralización del radical oxígeno. Se evaluaron concentraciones desde los 1 000 hasta los 62,5 µg/mL preparadas a partir del valor de sólidos totales determinados. Resultados: Para el índice de oxidación, concentraciones de 250 µg/mL resultaron suficientes para decolorar la solución de permanganato en igual período de tiempo que el patrón de quercetina. Sin embargo, los IC50 calculados para el poder reductor, la inhibición del radical DPPH y del ABTS resultaron mayores que el estándar de ácido ascórbico con valores de 362,33; 190,34 y 241,88 µg/mL, respectivamente. Conclusiones: El extracto de hojas de Spondias mombin L. en etanol al 70 % presenta una elevada acción antioxidante en los seis modelos experimentales ensayados, aun cuando en la mayor parte de casos, con valores inferiores al de la sustancia de referencia empleada. Estos resultados conjuntamente con la diversidad estructural de metabolitos presentes en el mismo resaltan su valor como potencial antioxidante natural.

ABSTRACT Introduction: The species Spondias mombin L. is a plant that grows in Cuba, and to which a considerable number of ethnopharmacological applications and high antioxidant power are reported. However, most of these reports are oriented to the fruit, which stands out for its nutritional value. Objective: To evaluate the antioxidant activity of an extract of Spondias mombin L. leaves in 70% ethanol. Method: The antioxidant activity was evaluated by six different methods: determination of the oxidation index, reducing power, inhibition of DPPH and ABTS radicals, hydrogen peroxide reducing capacity and oxygen radical neutralization capacity. Concentrations from 1000 to 62.5 µg/mL were evaluated, prepared from the value of total solids determined. Results: For the oxidation index, concentrations of 250 µg/mL were sufficient to decolorize the permanganate solution in the same period of time as the quercetin standard. However, the IC50 calculated for the reducing power, the inhibition of the DPPH radical and ABTS were higher than the ascorbic acid standard with values of 362.33; 190.34 and 241.88 µg/mL, respectively. Conclusions: The extract of leaves of Spondias mombin L. in 70% ethanol presents a high antioxidant action in the six experimental models tested, even though in most cases, with lower values than the reference substance used. These results, together with the structural diversity of metabolites present in it, highlight its value as a potential natural antioxidant.

RESUMO Introdução: A espécie Spondias mombin L. é uma planta que cresce em Cuba e à qual são relatados um número considerável de aplicações etnofarmacológicas e alto poder antioxidante. No entanto, a maioria desses relatos é voltada para o fruto, que se destaca pelo seu valor nutricional. Objetivo: Avaliar a atividade antioxidante de um extrato de folhas de Spondias mombin L. em etanol 70%. Método: A atividade antioxidante foi avaliada por seis diferentes métodos: determinação do índice de oxidação, poder redutor, inibição dos radicais DPPH e ABTS, capacidade redutora do peróxido de hidrogênio e capacidade de neutralização do radical oxigênio. Foram avaliadas concentrações de 1000 a 62,5 µg/mL, preparadas a partir do valor de sólidos totais determinado. Resultados: Para o índice de oxidação, concentrações de 250 µg/mL foram suficientes para descolorir a solução de permanganato no mesmo período de tempo do padrão de quercetina. No entanto, o IC50 calculado para o poder redutor, a inibição do radical DPPH e ABTS foram superiores ao padrão de ácido ascórbico com valores de 362,33; 190,34 e 241,88 µg/mL, respectivamente. Conclusões: O extrato de folhas de Spondias mombin L. em etanol 70% apresenta alta ação antioxidante nos seis modelos experimentais testados, embora na maioria dos casos com valores inferiores à substância de referência utilizada. Esses resultados, juntamente com a diversidade estrutural de metabólitos presentes nele, destacam seu valor como potencial antioxidante natural.

Induction of secondary metabolites on nanoparticles stress in callus culture of Artemisia annua L / Indução de metabólitos secundários no estresse de nanopartículas em cultura de calos de Artemisia annua L

Nanoparticles are known bio elicitors in plant biotechnology. Different concentrations of ZnO, CuO and CoO nanoparticles were used for the enhanced accumulation of secondary metabolites and antioxidant activities in the callus derived from root, shoot and leaf of Artemisia annua L. Biomass of callus was somehow affected on high concentrations of Nps. Phenolic content was observed maximum (60µg) in shoot callus at 0.1mg/l of CuONps. Total antioxidant activity was observed maximum (33µg) in root callus at 0.1mg/l of ZnOnps. Total reducing power maximum (33µg) was observed in root callus at concentration of 0.05 mg/l of CoONps. Maximum radical scavenging activity was observed in shoot callus at 0.05mg/l of ZnONps. Rutin gallic acid and caffic acid were also determined in most of the samples by HPLC. The study concludes that different Nps have positive effect on the induction of secondary metabolites in A.annua plant.

Nanopartículas são bio-elicitores conhecidos em biotecnologia de plantas. Diferentes concentrações de nanopartículas de ZnO, CuO e CoO foram usadas para o acúmulo aumentado de metabólitos secundários e atividades antioxidantes no calo derivado da raiz, parte aérea e folha de Artemisiaannua L. A biomassa do calo foi de alguma forma afetada em altas concentrações de Nps. O conteúdo fenólico foi observado no máximo (60 µg) no calo da parte aérea a 0,1 mg / l de CuONps. A atividade antioxidante total foi observada no máximo (33µg) no calo radicular a 0,1mg / l de ZnOnps. O poder de redução total máximo (33µg) foi observado no calo radicular na concentração de 0,05 mg / l de CoONps. Atividade máxima de eliminação de radicais foi observada no calo da parte aérea a 0,05mg / l de ZnONps. O ácido rutina-gálico e o ácido caffic também foram determinados na maioria das amostras por HPLC. O estudo conclui que diferentes Nps têm efeito positivo na indução de metabólitos secundários na planta de A.annua.

Inhibition of Fe2+ Induced Lipid Peroxidation in Rats Brain by Extract of Euphorbia heterophylla in vitro

This study is sought to determine the antioxidant activity and protective ability of aqueous and methanol extractible phytochemicals from Euphorbia heterophylla leaves on lipid peroxidation induced in rat brain by pro-oxidant, in vitro. The extracts of the leaves were prepared, and the ability of the extracts is to inhibit 25 µM FeSO4 induced lipid peroxidation in isolated rats’ brain, were determined. Thereafter, total phenol content, reducing power (FRAP), Fe (II) chelating, and DPPH* free radical scavenging ability of the extracts was determined and considered as an index of antioxidant activity. The results revealed that the extracts inhibit malondialdehyde (MDA) production in the basal and pro-oxidant induced lipid peroxidised rats in a dose-dependent manner, [methanol 80.11%, aqueous 70.3%] with the methanol extract (MEE) significantly (P< 0.05) than that of aqueous extract (AEE). The methanol extract (0.74 ± 0.6 mg/g) had higher total phenol contents than the aqueous (0.57 ± 1.2 mg/g); likewise the methanol extract had higher reducing power (0.08 ± 0.2, 0.03 ± 0.1 mg/g), but had no significant difference in Fe (II) chelating ability (EC50= 0.34, 0.36) with DPPH* scavenging ability (EC50=0.075, 0.075). This antioxidant properties and the protective effect of this leaf could be harnessed in the management and prevention of degenerative diseases in association with oxidative stress.

Evaluation of In vitro Antioxidant Potentials of Nymphaea lotus and Nymphaea pubescens Seed Oils

Aim: The study is aimed at assessing the antioxidant potentials of Nymphaea lotusand Nymphaea pubescensseed oils. Study Design:It was designed to extract oil from the seeds and investigate their antioxidant properties to indicate their capabilities to improve oxidative stability. Place and Duration of Study:The research was conducted between August 2016 and January 2017 atDepartment of Biochemistry, Faculty of Basic Medical Sciences, Bayero University, Kano State-Nigeria. Methodology: 2, 2-diphenyl-1-picryhydrazyl (DPPH) radical scavenging and reducing power assays were used to determine free radical scavenging activities and reducing power potential of Nymphaea lotusand Nymphaea pubescensseed oils. Results:From the DPPH radical scavenging assay, It shows that the IC50value of the ascorbic acid (reference standard) was found to be higher (13.23± 0.16?g/ml) compared to Nymphaea lotusseed oil (8.82 ± 0.82?g/ml). The IC50 value of Nymphaea pubescensseed oil was also compared with the standard and was found to be (41.76 ± 0.98?g/ml) higher than ascorbic acid (13.23± 0.16?g/ml). The lower the IC50 value the higher the antioxidant activity of the oil. The order of the effectiveness of reducing capabilities of the oils was found to be N. lotusseed oil > ascorbic acid> N. pubescensseedoil.Gas chromatographic coupled mass spectroscopy analysis of the N. lotusseed oil showed that Dihydrocarveol (0.87%), Eicosane (1.10%), Lupeol (14.75%), Tetracosane (2.14%) and Viridiflorol (13.72%) were the major antioxidants compounds identified whereas Palmitic acid (23.57), Eicosane (7.65%), Oleic acid (37.85%), Tetracosane (3.10%) and Squalene (1.58%) were the major antioxidants detected in N. pubescensseed oil. Compared with standard (ascorbic acid), the results show that N. lotusseed oil possessed highest antioxidant potential. The higher antioxidant potential displayed by Nymphaea lotusseed oil could be attributed to the presence of these compounds that could act synergistically.Conclusion:Therefore, Nymphaea lotus seed oil and Nymphaea pubescensseed oil contains natural antioxidants that can improveoxidative stability.

In-vitro Antioxidant Effect of Thymoquinone

Aim: In recent years, natural products from medicinal plants have received considerable attention. Thymoquinone, the major compound from Nigella sativa L. Is the most used due to its several pharmacological properties. This study was undertaken to evaluate the antioxidant effect of thymoquinone which is very useful in controlling free radicals noxious species causing the induction and / or amplification of a number of pathologies. Study Design: Spectrophotometric methods. Place and Duration of Study: Biochemistry Department, Applied Biochemistry Laboratory, Nature and Life Sciences Faculty, Ferhat Abbas Setif 1 University, Setif, Algeria, between December 2016 and September 2017. Methodology: In vitro antioxidant study was characterized by using free radicals scavenging methods with reducing power, lipid peroxidation and ß-carotene bleaching assays. All tests were realized by spectrophotometric methods. Results: Our study showed that thymoquinone is a potent antioxidant. It is less effective as a scavenger of both DPPH and ABTS radicals with IC50 of 125.65 ± 0.76 and 332.5 ± 14.39 µg/ml, respectively; While it is a strong scavenger of hydroxyl radical with IC50 of 26.3 ± 0.59 µg/ml and very strong hydrogen peroxide scavenger with IC50 of 11.0 ± 0.57 µg/ml. As superoxide anion scavenger it has inhibition ability less than 50%. In lipid peroxidation, TQ had a very efficient activity it inhibits peroxidation of β- carotene by 73.58 ± 0.50%. Thus, in lipid peroxidation assay, TQ had also a significant activity with percent inhibition of 79.5 ± 2.12%. Conclusion: Our results revealed that thymoquinone possesses a low antioxidant activity against DPPH, ABTS and superoxide anion radicals. Thus, it has a very low reducing power capacity, whereas it is a strong hydrogen peroxide, hydroxyl scavenger and lipid peroxidation inhibitor.

Study on Antioxidant Activity of Different Concentrations of Alcohol Extracts from Paeonia Rockii Pollen / 中国中医药信息杂志

Objective To evaluate the antioxidant activity of different concentrations of alcohol extracts from Paeonia Rockii pollen.Methods The antioxidant activity of different concentrations of alcohol extracts from Paeonia Rockii pollen was evaluated by cupric reducing power method, DPPH radical scavenging activity method and ABTS radical scavenging activity method.Results The amounts of antioxidant activity of gallic acid of anhydrous ethanol extract, 75％ alcohol extract, 50％ alcohol extract, 25％ alcohol extract, and water extract from Paeonia Rockii pollen were 26.00, 28.33, 28.90, 14.98, and 9.24 mg/g, respectively. The sequence of the ability of scavenging DPPH free radical and ABTS radical was Vc > 50％ alcohol extract > 75％ alcohol extract > anhydrous ethanol extract > 25％ alcohol extract > water extract.Conclusion The different concentrations of alcohol extracts from Paeonia Rockii pollen has relatively strong antioxidant activity, especially for 50％ alcohol extract and 75％ alcohol extract.

Induction of secondary metabolites on nanoparticles stress in callus culture of Artemisia annua L

Abstract Nanoparticles are known bio elicitors in plant biotechnology. Different concentrations of ZnO, CuO and CoO nanoparticles were used for the enhanced accumulation of secondary metabolites and antioxidant activities in the callus derived from root, shoot and leaf of Artemisia annua L. Biomass of callus was somehow affected on high concentrations of Nps. Phenolic content was observed maximum (60µg) in shoot callus at 0.1mg/l of CuONps. Total antioxidant activity was observed maximum (33µg) in root callus at 0.1mg/l of ZnOnps. Total reducing power maximum (33µg) was observed in root callus at concentration of 0.05 mg/l of CoONps. Maximum radical scavenging activity was observed in shoot callus at 0.05mg/l of ZnONps. Rutin gallic acid and caffic acid were also determined in most of the samples by HPLC. The study concludes that different Nps have positive effect on the induction of secondary metabolites in A.annua plant.

Resumo Nanopartículas são bio-elicitores conhecidos em biotecnologia de plantas. Diferentes concentrações de nanopartículas de ZnO, CuO e CoO foram usadas para o acúmulo aumentado de metabólitos secundários e atividades antioxidantes no calo derivado da raiz, parte aérea e folha de Artemisiaannua L. A biomassa do calo foi de alguma forma afetada em altas concentrações de Nps. O conteúdo fenólico foi observado no máximo (60 µg) no calo da parte aérea a 0,1 mg / l de CuONps. A atividade antioxidante total foi observada no máximo (33µg) no calo radicular a 0,1mg / l de ZnOnps. O poder de redução total máximo (33µg) foi observado no calo radicular na concentração de 0,05 mg / l de CoONps. Atividade máxima de eliminação de radicais foi observada no calo da parte aérea a 0,05mg / l de ZnONps. O ácido rutina-gálico e o ácido caffic também foram determinados na maioria das amostras por HPLC. O estudo conclui que diferentes Nps têm efeito positivo na indução de metabólitos secundários na planta de A.annua.

Chemical analysis, antimicrobial and anti-oxidative properties of Daucus gracilis essential oil and its mechanism of action

Objective: To evaluate the essential oils (EO) composition, antimicrobial and antioxidant power of a local plant, Daucus gracilis (D. gracilis). Methods: The aerial parts of D. gracilis were subjected to hydro distillation by a Clevenger apparatus type to obtain the EO which had been analyzed by gas chromatography and gas chromatography coupled with mass spectrometry, and screened for antimicrobial activity against five bacteria and three fungi by agar diffusion method. The mechanism of action of the EO was determined on the susceptible strains by both of time kill assay and lysis experience. The minimal inhibitory concentrations were determined by agar macro-dilution and micro-dilution methods. Anti-oxidative properties of the EO were also studied by free diphenyl-2-picrylhydrazyl radical scavenging and reducing power techniques. Results: The EO yielded 0.68 (v/w). The chemical analysis presented two dominant constituents which were the elemicin (35.3%) and the geranyl acetate (26.8%). D. gracilis EO inhibited the growth of Bacillus cereus and Proteus mirabilis significantly with minimal inhibitory concentrations of 17.15 μg/mL by the agar dilution method and 57.05 μg/mL and 114.1 μg/mL, respectively by liquid micro-dilution. A remarkable decrease in a survival rate as well as in the absorbance in 260 nm was recorded, which suggested that the cytoplasm membrane was one of the targets of the EO. The EO showed, also, important anti-oxidative effects with an IC

Essential oils from Elaeoselinum asclepium: Chemical composition, antimicrobial and antioxidant properties

Objective To evaluate the chemical composition of the essential oil isolated from Elaeoselinum asclepium (L.) Bertol. (E. asclepium), and test the efficiency of the essential oil as an antimicrobial and antioxidant agent. Methods Essential oil was obtained from the aerial parts of E. asclepium by hydro distillation and analyzed by gas chromatography and gas chromatography coupled with mass spectrometry. We study for the first time the chemical composition of the essential oil of E. asclepium, followed by the in vitro antimicrobial activities, which were evaluated by agar diffusion method against six Gram-positive bacteria, five Gram-negative bacteria, and two fungi. In addition, The antioxidant activities were also investigated using assays of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and ferric-reducing capacity. Results The analyzed essential oil of the aerial parts of E. asclepium was rich in α-pinene (43.9%), other compounds detected in appreciable amounts were sabinene (27.9%) and β-pinene (16.0%). The essential oil yields 1.2%, the IC

Evaluation of Total Phenolic Content and Antioxidant Activity of Three Leaf Extracts of Ziziphus spina-christi (Sedr) Grown in Jordan.

Aims: The primary aims of this study were to evaluate the total phenolic content and In vitro antioxidant activity of three different leaves extracts (methanolic, ethanolic and aqueous) of Ziziphus spins-christi grown in Jordan. Methods: Total phenolic content of the methanolic, ethanolic and aqueous extracts of the leaves of Ziziphus spins-christi was determined spectrometrically according to the Folin-Ciocalteu procedure. The antioxidant activities of the leaves extracts of this plant at different concentrations were determined by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging activity and reducing power methods. All the analyzes was made with the use of UV-Visible spectrophotometer, and ascorbic acid was used as a standard antioxidant. Place and Duration of Study: Department of Biological Science, Al-Bayt University, Al Mafraq, Jordan. Department of Nutrition and Food Technology, University of Jordan, Amman, Jordan, from April 2015 to December 2015. Results: The total phenolic content was ranged between 11.8 to 52.5 mg/g expressed in terms of Gallic acid equivalent (mg of GAE/g extract). In vitro antioxidant activity of the plant extracts revealed that all the extracts showed good antioxidant power with IC50 values of 21.4, 24.2 and 54.3 μg/mL for methanolic, aqueous and ethanolic extracts, respectively. The reducing power of the extracts was found to be concentration dependent. The results of this study revealed that, the methanolic extract of leaves showed the highest phenolic concentration and largest antioxidant activity. Conclusion: From this study it may be concluded that Z. spina-christi leaves could have potential source of antioxidants for pharmaceutical drug preparations.

Chemical analysis, antimicrobial and anti-oxidative properties of Daucus gracilis essential oil and its mechanism of action

Objective: To evaluate the essential oils (EO) composition, antimicrobial and antioxi-dant power of a local plant, Daucus gracilis (D. gracilis). Methods: The aerial parts of D. gracilis were subjected to hydro distillation by a Cle-venger apparatus type to obtain the EO which had been analyzed by gas chromatography and gas chromatography coupled with mass spectrometry, and screened for antimicrobial activity against five bacteria and three fungi by agar diffusion method. The mechanism of action of the EO was determined on the susceptible strains by both of time kill assay and lysis experience. The minimal inhibitory concentrations were determined by agar macro-dilution and micro-dilution methods. Anti-oxidative properties of the EO were also studied by free diphenyl-2-picrylhydrazyl radical scavenging and reducing power techniques. Results: The EO yielded 0.68 (v/w). The chemical analysis presented two dominant constituents which were the elemicin (35.3%) and the geranyl acetate (26.8%). D. gracilis EO inhibited the growth of Bacillus cereus and Proteus mirabilis significantly with minimal inhibitory concentrations of 17.15 mg/mL by the agar dilution method and 57.05 mg/mL and 114.1 mg/mL, respectively by liquid micro-dilution. A remarkable decrease in a survival rate as well as in the absorbance in 260 nm was recorded, which suggested that the cytoplasm membrane was one of the targets of the EO. The EO showed, also, important anti-oxidative effects with an IC50 of 0.002 mg/mL and a dose-dependent reducing power. Conclusions: D. gracilis EO showed potent antimicrobial and anti-oxidative activities and had acted on the cytoplasm membrane. These activities could be exploited in the food industry for food preservation.

Essential oils from Elaeoselinum asclepium：Chemical composition, antimicrobial and antioxidant properties

Objective: To evaluate the chemical composition of the essential oil isolated from Elaeoselinum asclepium (L.) Bertol. (E. asclepium), and test the efficiency of the essential oil as an antimicrobial and antioxidant agent. Methods: Essential oil was obtained from the aerial parts of E. asclepium by hydro distillation and analyzed by gas chromatography and gas chromatography coupled with mass spectrometry. We study for the first time the chemical composition of the essential oil of E. asclepium, followed by the in vitro antimicrobial activities, which were eval-uated by agar diffusion method against six Gram-positive bacteria, five Gram-negative bacteria, and two fungi. In addition, The antioxidant activities were also investigated using assays of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and ferric-reducing capacity. Results: The analyzed essential oil of the aerial parts of E. asclepium was rich in a-pinene (43.9%), other compounds detected in appreciable amounts were sabinene (27.9%) and b-pinene (16.0%). The essential oil yields 1.2%, the IC50 values of essential oil in 1,1-diphenyl-2-picrylhydrazyl assay in the reducing power assay were 48.26 mg/mL and at 1 mg/mL, respectively. The absorbance value of essential oil at 700 nm was 0.956. The antimicrobial effect was higher on Candida albicans ATCC 1024 strain with the inhibition zone 14.5 mm than bacteria and molds. Conclusions: The essential oil of E. asclepium has antimicrobial and antioxidant ac-tivities. These species may be used as an important source of natural antimicrobial and antioxidant agents.

Antioxidant activities of purified glycoprotein extracted from Codium decorticatum.

Marine algae are known to produce an extensive variety of bioactive metabolites and several novel drugs have been derived for the pharmaceutical industries. However glycoproteins from the algae have not been adequately explored for their potential as a source of bioactive substances. The objectives of this study were to investigate the antioxidant activity effect of glycoprotein (GLP). In the experiment of the radical elimination ability by means of 1,1-diphenyl-2-picryhydrazyl (DPPH) expressed anti-oxidative effect depending on the concentration considering GLP. Hydroxyl (OH) radical, superoxide radical (O2) and nitric oxide radial (NO) scavenging also showed that antioxidant abilities in the dose depended concentration. These results express that GLP eliminates reactive oxygen species (ROS), protect cell membrane, and can act as antioxidants. Therefore, it is thought that GLP can be used to new material of food supplements related to antioxidants.

Phytochemical constituents and antioxidant activities of some plants commonly used in Indian traditional diet.

Dietary antioxidants are known to play a key role in combating the cellular oxidative stress imposed by the free radicals as well as in inhibiting the undesirable changes in nutritional quality of food. The present investigation was designed to evaluate the in vitro antioxidant properties and the major phytoconstituents of some plants regularly used in Indian traditional diet. Methanolic extracts of Costus igneus, Foeniculum vulgare, Leucas aspera, Muntingia calabura, Physalis minima and Sauropus androgynus were prepared by maceration. Antioxidant activities were assessed using phosphomolybdenum method and ferric reducing power assays. Total antioxidant activities of methanolic extracts ranged between 4.89 μg/ml to 46.0 μg/ml ascorbic acid equivalents for the tested extracts. F. vulgare methanolic extract possessed maximum antioxidant activity. This investigation revealed the potential antioxidant activity of the tested extracts and therefore, their use in the regular diet will be helpful in combating free radical associated health effects. Also, antioxidant rich formulations can be prepared using these plant materials.

Antioxidant, antimicrobial activities of flavonoids glycoside from Leucaena leucocephala leaves.

The study aimed to identify the chemical constituents of Leucaeana leucocephala leaves and evaluate the antioxidant and antimicrobial activities of the extract and compounds. An acylated flavanol glycoside, quercetin - 3-O-(2''-trans-p-coumaryl)-α-rhamnopyranosyl-(1'''→6'')-β-glucopyranoside (1) in addition to quercetin-3-O-α- rhamnopyranosyl-(1'''→2'')-β–glucopyranoside (2), quercetin-7-O-α–rhamnopyranosyl-(1'''→2'')-β-glucopyrano side(3), quercetin-3-O-α- rhamnopyranoside(4), quercetin-3-O-β–glucopyranoside (5), isovitexin( 6), vitexin (7) and quercetin (8) were isolated for the first time from the Leucaeana leucocephala. The antioxidant activity of the extract and the isolated compounds 1, 3 & 4 were evaluated by Reducing Power, FRAP, DPPH, Metal chelating and ABTS assays. Compound (3) recorded the highest antioxidant activity in comparison with the extract and other compounds. The extract and compound 1, 2, 3 and 5 were studied for their antimicrobial activity. Both the extract and compound 1 have significant activity against gm-ve bacteria, moderate to gm +ve and Candida and inactive towards fungi. The structures of compounds were elucidated on the basis of spectral analysis. L. leucocephala possess good antioxidant, antibacterial properties and could serve as free radical inhibitors or scavengers, acting possibly as primary antioxidants and have to be investigated for antiinflammatory and anticancer activities.

Actividad antioxidante de extractos de diferente polaridad de Ageratum conyzoides L / Antioxidant activity of different polarity extracts from Ageratum conyzoides L

The present study aimed to investigate the antioxidant activity of extracts of different polarity of the species Ageratum conyzoides L., evaluating by different spectrophotometric methods: ABTS•+, DPPH•, FRAP and ORAC. Extracts of A. conyzoides L., showed good antioxidant activity in the methodologies evaluated. The extract was the most active of ethyl acetate (ACExtA) which showed the best evaluated values techniques with higher power as determined by the assay values of TEAC ORAC = 494048.95 +/- 29695.80 uMol Trolox/100g sample. Measurements of antioxidant activity by different techniques offer advantages in terms of predicting the in vitro antioxidant capacity of this plant, it is also recommended to explore the structural characteristics of the compounds present in the ethyl acetate extract of the plant with to explore the potential benefits and possible mechanisms of action of new antioxidants...

El presente trabajo tuvo como objetivo investigar la actividad antioxidante de extractos de diferente polaridad de la especie Ageratum conyzoides L., mediante la evaluación por diferentes métodos espectrofotométricos: ABTS•+, DPPH•, FRAP y ORAC. Los extractos de A. conyzoides L., presentaron una buena actividad antioxidante en las metodologías evaluadas. El extracto más activo fue el de acetato de etilo (ACExtA), que presentó los mejores valores por las técnicas evaluadas con la mayor potencia determinada por el ensayo ORAC con valores de TEAC = 494048,95 +/- 29695,80 uMol Trolox/100g muestra. Las mediciones de la actividad antioxidante por diferentes técnicas, ofrecen ventajas en términos de la predicción de la capacidad antioxidante in vitro de esta planta, además se recomienda explorar las características estructurales de los compuestos presentes en el extracto de acetato de etilo de esta planta con el fin de investigar los beneficios potenciales y los mecanismos de acción de posibles nuevos antioxidantes...

Antioxidant activities and total phenol content of Inula viscosa extracts selected from three regions of Morocco

Objective: To investigate antioxidant activity, total phenolic and flavonoid content of ethanol (E) and ethyl acetate (A) extracts of Inula viscosa aerial parts selected from three regions of Morocco (Imouzzer, Sefrou and Taounate). Methods: Antioxidants properties were measured by three different test systems of assay namely free radical scavenging activities against 2,2-diphenyl-1-picrylhydrazyl, total antioxidant capacity and iron-reducing capacity. Total phenolic content was measured by Folin- Ciocalteu reagent. Results: All the extracts showed significant antioxidant activities and contained important levels of phenols. The ethanol extract (0.3 mg/mL) from Sefrou showed the greatest antioxidant capacity in the three systems of assay, which was probably due to its high content of polyphenols (274.39±6.94) mg gallic acid equivalent/g dry extract. Total flavonoid content was found equal for all extracts. Conclusions: Our results of antioxidant assays were justified and partially supported the popular usage of the tested plants. The high antioxidant activity found in the plant from Sefrou and its great biomass in this region suggested that Inula viscosa is a good source of natural antioxidants compounds which might have benefits for health.

Optimization of ultrasonic-assisted extraction techniques of isoflavones from Pueraria lobata(Wild) Ohwi in Dabie mountain by response surface methodology and reducing power measurement / 中国药学杂志

OBJECTIVE: To optimize the ultrasonic-assisted extraction process of isoflavones from Pueraria lobata (Wild.) Ohwi using response surface methodology and measure the reducing power. METHODS: On the basis of single factor experiments, a four factors and five levels Box-Behnken experiment was designed. Then the reducing power of isoflavones was measured. RESULTS: The optimum conditions for the ultrasonic-assisted extraction process of isoflavone from Pueraria lobata (Wild.) Ohwi at ultrasonic power of 300 W were as follows: ethanol concentration 75%, liquid-solid ratio 35 mL · g-1, extraction time 35 min, and treatment temperature 50℃. Under the optimum conditions, the yield of polysaccharide from Pueraria lobata (Wild.) Ohwi was 24.18%, and the relative error between experimental value and predicted value was only 3.02%; the EC50 of the reducing power of isoflavones reached 0.135 mg · mL-1. CONCLUSION: The response surface methodology is suitable for regression analysis and optimization of the ultrasonicassisted extraction of polysaccharide from Pueraria lobata (Wild.) Ohwi.

Investigation of Antioxidant Potential of Methanolic Extract of Swertia chirata Buch. Ham.

Aim: To evaluate the in vitro antioxidant potential and total phenolic contents of the methanolic extract of Swertia chirata. Place and Duration: Department of Botany, Dr. H. S. Gour University (HSGVV), Sagar, between February 2010 to July 2010. Methodology: The plant material (aerial part) was subjected to defatting with petroleum ether then successively extracted with methanol. Total phenolic contents of methanolic extract was determined using the Folin-Ciocalteau reagent method while in vitro antioxidant potential was evaluated by using DPPH, hydroxyl radical, nitric oxide radical scavenging as well as ferric reducing power assays. Results: The total phenolic content in 1 mg of methanolic extract of S. chirata was equivalent to 4.5 μg Catechol. The IC50 value of the DPPH method, hydroxyl radical and nitric oxide radical scavenging activity was 222.74±0.19, 307.93±0.10 and 870.55±0.20 μg/ml respectively. When these IC50 value compared with that of standard drug Butylated hydroxy anisole (BHA) the result obtained was as follows: FRSA-SCM>BHA (p=0.000246); HRSA-SCM<BHA (p=0.000507); NORA-SCM<BHA (p=2.22614). These results showed that the S. chirata methanolic extract exhibited significant free radical DPPH scavenging activity and Hydroxyl radical scavenging activity while it exhibited nonsignificant Nitric oxide radical scavenging activity. In ferric reducing power various concentrations (100, 250 and 500 μg/ml) of methanolic extract of S. chirata showed absorbance 0.013±0.31, 0.156±0.12 and 0.298±0.14. Phytochemical screening showed the presence of phenolic compounds such as flavonoids and tannins which may be responsible for the activity. Conclusion: Methanolic extract of Swertia chirata showed significant antioxidant activity which suggest the extract may act as a natural antioxidant agent offering effective protection from free radicals.