antioxidant

A total of five compounds eicosanyl-trans-p-coumarate (1), stigmasterol(2), β-sitosterol (3), β-amyrin(4), 6-hydroxy stigmasta-4,22-dien-3-one (5) were isolated from the methanolic extract of the stem bark of Ipomoea pescaprae(L.) R.Br.(Family:Convolvulaceae). The petroleum ether, carbon tetrachloride; chloroform and aqueous soluble Kupchan fractions of crude methanol extract were studied for antioxidant, antimicrobial and cytotoxic activities. Among the different fractions tested for antioxidant activity, the aqueous soluble partitionate was the most potent with IC50 value of 7.50μg/ml as compared to tertbutyl-1-hydroxytoluene (IC50=20.96μg/ml). Antimicrobial screening of the different extractives was conducted by the disc diffusion method and the crude methanol extract as well as aqueous soluble fractions exhibited moderate antimicrobial activity with zone of inhibition ranging from 10-12 mm. In brine shrimp lethality bioassay, the aqueous soluble materials demonstrated the highest toxicity with LC50 of 1.01μg/ml. Compounds eicosanyl-trans-p-coumarate, stigmasterol, β-sitosterol, 6-hydroxy stigmasta-4,22-dien-3-one are the first report of isolation of compounds from Ipomoea pescaprae. Key words: Ipomoea pescaprae, chemical constituents, antioxidant, antimicrobial, cytotoxicity.

In recent times, interest has focused on phytochemicals as new sources of natural antioxidants. Therefore, the methanolic crude extracts of Acorus calamus, Lantana camara, Plumbago zeylanica and clitoria ternatea, were screened for total phenols, flavonoids, and free radical scavenging activity. Free radical scavenging activity was evaluated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH). Significant differences in DPPH scavenging activity were found between the species investigated, ranging from 26.36 ± 1.00% to 91.14 ± 1.02%. The highest radical scavenging activity was observed in Acorus calamus (91.14 ±1.02% inhibition). The total phenol content of the investigated species ranged from 23.43±0.18 to 57.33± 2.21 mg GAE/g extract, while flavonoid content ranged from 5.76±2.12 to 20.17 ± 2.72 mg QE/g extract. A weak linear correlation between total phenolic or flavonoid content and antioxidant activity was found (correlation coefficient, R2 =0.2319 and R2 = 0.2605, respectively). Key Words: Acorus calamus, Lantana camara, Plumbago zeylanica and Clitoria ternatea, phenolic content, flavonoid content, antioxidant

This study was performed to evaluate the presence of Phytochemical, antimicrobial and antioxidant activity of Eria pseudoclavicaulis Blatt. (Orchidaceae) leaf extracts. Preliminary phytochemical analysis revealed that the ethyl acetate extract shown the maximum phytochemical constituents followed by ethanol and water. Different extracts of Eria pseudoclavicaulis were tested for antimicrobial activity of this, ethyl acetate extract shown the maximum antibacterial activity against five microorganisms. The water extract possess strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (IC50 318 μg/ml), This research findings suggest that Eria pseudoclavicaulis exhibits potential antimicrobial and antioxidant properties. Key words: phytochemical analysis, antimicrobial, antioxidant, Eria pseudoclavicaulis  

Mixture of three compounds lupeol acetate (1), alpha amyrin acetate(2) and beta amyrin acetate(3) were isolated from the methanolic extract of the stem bark of Artocarpus lackoocha Roxb.(Family: Moraceae).The crude methanol extract as well as its petroleum ether, carbon tetrachloride; chloroform and aqueous soluble Kupchan fractions were studied for antioxidant, antimicrobial and cytotoxic activities. Among the different fractions tested for antioxidant activity, the aqueous soluble partitionate was the most potent with IC50 value of 3.47μg/ml as compared to tertbutyl-1-hydroxytoluene (IC50=27.54μg/ml). Antimicrobial screening of the different extractives was conducted by the disc diffusion method and the crude methanol extract as well as aqueous soluble fractions exhibited moderate antimicrobial activity with zone of inhibition ranging from 7-12 mm. In brine shrimp lethality bioassay, the aqueous soluble materials demonstrated the highest toxicity with LC50 of 1.6μg/ml. β-amyrin acetate is the first report of isolation of compounds from Artocarpus lackoocha.

A series of 4-[2-(4-chlorobenzyl)-4-oxoquinazoline-3(4H)-yl)benzoyl] derivatives  were synthesized. The synthesized compounds were characterized by IR, NMR and Mass spectral data. The synthesized compounds were screened for their antioxidant activity by DPPH (1-1-diphenyl 2-picryl hydrazyl) radical-scavenging method and Ferric reducing antioxidant power (FRAP) assay. The synthesized 2,3-disubstituted-3H-Quinazolin-4-one derivatives exhibited moderate to good Anti oxidant activity. Among those Compounds C-GY,C-GU,C-TP, and C-TY were found to be the most potent compound with Promising Anti-Oxidant activity.

  Toxic oxygen radicals play a role in the pathogenesis of ischemia/reperfusion (I/R) injury in the kidney. The present study was designed to investigate the effects of Pongamia pinnata (PP) leaves, a plant rich in flavonoids in I/R induced renal failure in rats. Antioxidant activity of the hydro-alcoholic extract of Pongamia pinnata was determined by DPPH free radical, and Hydroxyl radical scavenging assay. The protective effect of Pongamia pinnata leaves against the damage inflicted by reactive oxygen species (ROS) during renal I/R was investigated in Wistar albino rats using histopathological and biochemical parameters. Animals were subjected to occlusion of both the renal pedicles for 45min followed by 24h of reperfusion. Pongamia pinnata hydro-alcoholic leaf extract (100 mg/kg, 200 mg/kg and 400 mg/kg, p.o.) was administered 8 weeks prior to ischemia. At the end of the reperfusion period, rats were sacrificed. Malondialdehyde (MDA), reduced glutathione (GSH) levels, catalase (CAT), and superoxide dismutase (SOD) activities were determined in renal tissue. Serum creatinine, Serum Cystatin C, serum oxaloacetate transaminase (SGOT), serum pyruvate transaminase (SGPT), blood urea nitrogen (BUN) and Lactate dehydrogenase (LDH) concentrations were measured for the evaluation of renal function. Ischemic control animals demonstrated severe deterioration of renal function, renal morphology and a significant renal oxidative stress. Pretreatment of animals with Pongamia pinnata hydro-alcoholic leaf extract markedly attenuated renal dysfunction, morphological alterations, reduced elevated malondialdehyde levels and restored the depleted renal antioxidant enzymes. The findings imply that ROS play a causal role in I/R induced renal injury and Pongamia pinnata leaves exert renoprotective effects probably by the radical scavenging and antioxidant activities. Key words: Pongamia pinnata, hydro-alcoholic leaf extract, antioxidant, renal ischemia

  A novel series of 2-substituted 4,5-diphenyl imidazoles were synthesized and investigated for their antioxidant activity and membrane stabilization activity. 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical assay was carried out to evaluate the antioxidant potential of the extract. The antioxidant activity of the synthesized compounds increased in a concentration dependent manner. In DPPH radical scavenging assay the IC50 value of the compounds ranged from 40 to 200µg/ml. The membrane stabilization activity of the compounds was evaluated using human red blood cells (HRBC) membrane stabilization method. The concentration of 88.88 to 444.44µg/ml showed a dose dependent inhibition of haemolysis of erythrocytes induced by hypotonic solution. Key words: DPPH, antioxidant, membrane stabilization