Evaluation of antioxidants activity of some tree barks grown in Libya (Al Jabal Al Akhdar) Pinus halepensis Mill, Pistacia lentiscus L, Juniperus phoenicea L

The aim of the present study investigated anti-oxidant activity of various methanol-water extracts from tree barks grown in Libya (Al Jabal AL Akhdar) by four anti-oxidant assays FRAP. DPPH. H2O2 and Metal chelating activity. Additionally, these antioxidant activities were compared with BHA, BHT as reference antioxidants. Tree bark has a large, diverse class of compounds, many with antioxidant properties. This study showed FRAP inhibitory activity of the Pinus halepensis bark extracts 56.8%, while Juniperus phoenicea L 57.6%, and Pistacia lentiscus L bark extracts was 69.2% The DPPH radical scavenging in the bark extracts exerted an inhibition of 66.8 %, 62.3% ,74.6% for Pinus halepensis, Juniperus phoenicea and Pistacia lentiscus L respectively. While H2O2 activity shows variation, ranging from 67. 8 to 81. 3%. The Metal chelating activity of the barks extract was 59% in Pinus halepensis and 57% in Juniperus phoenicea L bark extracts furthermore Pistacia lentiscus L was 67.8% in addition the Metal chelating activity of BHT and BHA 92%, 94% respectively. The high antioxidant activity of bark was founded in Pistacia lentiscus L bark extracts.

Synthesis, Characterization, Antimicrobial and Antioxidant Activities of 1,2,4-triazolyl-isoxazole Moieties via Dehydration Reactions of Carbohydrazides

: For the reason of distinct place in the field of medicinal and pharmaceutical chemistry of 1,2,4-triazole derivatives, a new class of fused 1,2,4-triazolyl-isoxazole moieties was prepared from 3-(2,4,6-trimethoxyphenyl)isoxazolo-4,5-bis[carbonyl-(4̍-phenyl) thiosemicarbazide via dehydration reactions of carbohydrazides by using the appropriate chemical reagents. The structures of the compounds were elucidated by both elemental and spectral (IR, NMR and MS) analyses. The in vitro antioxidant activity of the new compounds was determined by free radical scavenging and metal chelating activity. All the synthesized compounds showed good activity according to free radical scavenging and metal chelating activity compared with standards. The new compounds were screened in vitro antibacterial activity against three gram-positive bacteria and three gram-negative bacteria.

Effect of packaging on phenols, flavonoids and antioxidant characteristics of mechanical cabinet dried wild pomegranate (Punica granatum L.) arils

Wild pomegranate (Punica granatum L.) fruit arils with high acid content are processed into dried arils (anardana) which is used as an ingredient in various medicinal formulations and culinary preparations. The various phenols and flavonoids are responsible for the antioxidant activity of anardana which signifies its functional benefits. The advanced packaging techniques like vacuum packaging, can retain higher antioxidant activity characteristics during storage. So, the present studies were carried out to compare the effect of packaging on total phenols, flavonoids, DPPH (2, 2-diphenyl-1-picrylhydrazyl) antioxidant activity, metal chelating activity, FRAP (ferric reducing antioxidant power) and reducing power of anardana prepared in mechanical cabinet drier. Anardana was packed in different packaging materials and stored under ambient and refrigerated temperature conditions. The overall effect of storage during 12 months revealed that there was a significant (p< 0.05) decrease in total phenols (180.95 to 161.76 mg GAE/100 g), flavonoids (40.60 to 32.66 mg QuE/100 g), DPPH antioxidant activity (61.23 to 56.13%), metal chelating activity (22.25 to 19.37%), FRAP (34.60 to 31.73 ?M Fe2+/100 g) and reducing power (0.610 to 0.521) which was observed less in anardana packed in ALPV (aluminium laminated pouches with vacuum) followed by ALP (aluminium laminated pouches) and gunny bags. Due to slower rates of degradation of various antioxidant compounds, the changes after 12 months of storage were lower under refrigerated conditions. The total phenols, flavonoids and DPPH antioxidant activity were reduced from 180.95 to 167.24 and 156.28 mg GAE/100 g, 40.60 to 34.95 and 30.37 mg QuE/100 g and 61.23 to 57.99 and 54.27 % in refrigerated and ambient temperature conditions, respectively.

Functional and Antioxidant Properties of Angelwing Clam (Phplas orientalis) Hydrolysate Produced using Alcalase

In this study, Hydrolysate from angelwing clam (Pholas orientalis) was produced at 0, 1, 2 and 3 hrs and E/S ratio of0.5 and 3%using alcalase where the pH and temperature were kept constant at pH 8.5 and 60°C, respectively. The hydrolysates were analysed for antioxidant and functional properties such as solubility, emulsifying properties and water and oil holding capacity. Degree of hydrolysis (DH), yield, functional and antioxidant properties were influenced by the hydrolysis time and E/S ratio. Higher enzyme concentration (E/S 3%) and longer hydrolysis time increased the DH. Yield was higher at E/S 3% but reduced with hydrolysis time. Longer hydrolysis time produced more soluble hydrolysate and higher metal chelating activity but lower in emulsifying properties and DPPH activity. Higher enzyme concentration resulted in increase only in solubility and metal chelating activity. This study revealed that enzymatic hydrolysis using alcalase should be performed at shorter hydrolysis time using intermediate concentration of enzyme (E/S between 0.5 to 3%) in order to produce angelwing clam hydrolysate with collectively good functional and antioxidant properties.

Functional and Antioxidant Properties of Angelwing Clam (Pholas orientalis) Hydrolysate Produced using Alcalase

In this study, hydrolysate from angelwing clam (Pholas orientalis) was produced at 0, 1, 2 and 3 hrs and E/S ratio of 0.5 and 3% using alcalase where the pH and temperature were kept constant at pH 8.5 and 60°C, respectively. The hydrolysates were analysed for antioxidant and functional properties such as solubility, emulsifying properties and water and oil holding capacity. Degree of hydrolysis (DH), yield, functional and antioxidant properties were influenced by the hydrolysis time and E/S ratio. Higher enzyme concentration (E/S 3%) and longer hydrolysis time increased the DH. Yield was higher at E/S 3% but reduced with hydrolysis time. Longer hydrolysis time produced more soluble hydrolysate and higher metal chelating activity but lower in emulsifying properties and DPPH activity. Higher enzyme concentration resulted in increase only in solubility and metal chelating activity. This study revealed that enzymatic hydrolysis using alcalase should be performed at shorter hydrolysis time using intermediate concentration of enzyme (E/S between 0.5 to 3%) in order to produce angelwing clam hydrolysate with collectively good functional and antioxidant properties.

Statistical Analysis of Metal Chelating Activity of Centella asiatica and Erythroxylum cuneatum Using Response Surface Methodology

The purpose of the study is to evaluate the relationship between the extraction parameters and the metal chelating activity of Centella asiatica (CA) and Erythroxylum cuneatum (EC). The response surface methodology was used to optimize the extraction parameters of methanolic extract of CA and EC with respect to the metal chelating activity. For CA, Run 17 gave optimum chelating activity with IC50 = 0.93 mg/mL at an extraction temperature of 25°C, speed of agitation at 200 rpm, ratio of plant material to solvent at 1 g : 45 mL and extraction time at 1.5 hour. As for EC, Run 13 with 60°C, 200 rpm, 1 g : 35 mL and 1 hour had metal chelating activity at IC50 = 0.3817 mg/mL. Both optimized extracts were further partitioned using a solvent system to evaluate the fraction responsible for the chelating activity of the plants. The hexane fraction of CA showed potential activity with chelating activity at IC50 = 0.090 and the ethyl acetate fraction of EC had IC50 = 0.120 mg/mL. The study showed that the response surface methodology helped to reduce the extraction time, temperature and agitation and subsequently improve the chelating activity of the plants in comparison to the conventional method.