scholarly journals Isoxazoles-A Biocompatible Radical Scavenging Agents: Citrus Juice Mediated Environmentally Benign Synthesis and Characterization

2020 ◽  
Vol 32 (12) ◽  
pp. 2997-3001
Author(s):  
K.R. Raghavendra ◽  
M.G. Prabhudeva ◽  
A. Dileep Kumar ◽  
K. Ajay Kumar ◽  
H.P. Jayadevappa

This study demonstrates the efficient eco-friendly synthesis of a series of isoxazole derivatives 5a-h through (3+2) annulation of chalcones 3a-h and hydroxylamine (4) in citrus juice medium. The synthesized compounds were characterized by spectroscopic and CHN analysis, and assessed in vitro for their antioxidant susceptibilities by DPPH and hydroxyl radical scavenging assays. The result shows that compounds 5a, 5b, 5d and 5h have excellent DPPH and hydroxyl radical scavenging activity in both assays and therefore these molecule could serve as potent antioxidant agents.

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4114
Author(s):  
Jozef Fejér ◽  
Ivan Kron ◽  
Daniela Gruľová ◽  
Adriana Eliašová

In the present study, in vitro hydroxyl radical scavenging activities, total phenols and terpene contents in 70% ethanol extracts were evaluated. Samples of crushed (CB) and non-crushed ripe juniper berries (NCB) collected at five localities in North-East Slovakia during the years 2012–2014 were compared. Standard or modified methods for determining phytochemical and antioxidant activity were used together with a novel method for the evaluation of the results after the correction of the measured values per gram of dry matter (DM). Statistically significantly higher DM contents (average values for three years) were found in the CB extracts (ranging from 18.86 to 21.91 mg/mL) in comparison to those for NCB (ranging from 2.59 to 9.90 mg/mL). Depending on the localities and years, the hydroxyl radical scavenging activity ranged from 15.52 to 32.85% for NCB and from 65.59 to 88.12% for CB, respectively. The contents of total phenols ranged from 43.75 to 246.75 mg gallic acid equivalents (GAE)/L (NCB) and from 151.84 to 278.19 mg GAE/L (CB), respectively. However, the higher content of total phenols per gram of DM was found in the NCB extracts (8.49–42.23 mg GAE/g DM) and then in CB (6.87–18.77 GAE/g DM). The results obtained in this study showed a higher efficiency for extraction from juniper berries in 70% ethanol if the pericarp was disrupted in comparison to that achieved with the maceration of intact berries.


2008 ◽  
Vol 63 (7-8) ◽  
pp. 483-491 ◽  
Author(s):  
Mortada M. El-Sayed ◽  
El-Sayed S. Abdel-Hameed ◽  
Wafaa S. Ahmed ◽  
Eman A. El-Wakil

The methanol extract of the leaves of Buddleja asiatica Lour. (Loganiaceae) showed antioxidant activity toward the well known in vitro antioxidant tests such as total antioxidant capacity by the phosphomolybdenum method, free radical scavenging activity by the 1,1- diphenyl-2-picrylhydrazyl scavenging assay (DPPH assay) and hydrogen peroxide scavenging methods. Due to the high scavenging activity of the n-butanol successive fraction toward DPPH and H2O2 (SC50 = 11.99 and 18.54 μg/ml, respectively), this extract was subjected to chromatographic separation and isolation. Four non-phenolic compounds were isolated and identified on the basis of spectroscopic and chemical analyses: 1-O-ß-D-glucopyranosyl- 2-methoxy-3-(2-hydroxy-triaconta-3,12-dienoate)-glycerol (1), 3-O-[α-l-rhamnopyranosyl- (1→4)-ß-d-glucopyranosyl-(1→3)]-[ß-d-glucopyranosyl-(1→2)]-ß-d-fucopyranosyl-olean- 11,13(18)-diene-3ß,23,28-triol (2), 3-O-[α-l-rhamnopyranosyl-(1→4)-ß-d-glucopyranosyl- (1→4)-ß-d-glucopyranosyl-(1→3)]-ß-d-fucopyranosyl-olean-11,13(18)-diene-3ß,23,28-triol (3), and 3-O-[α-l-rhamnopyranosyl-(1→4)-ß-d-glucopyranosyl-(1→3)]-[ß-d-xylopyranosyl- (1→2)]-ß-d-glucuronopyranosyl-acid-olean-11,13(18)-diene-3ß,23,28-triol (4). The four compounds were evaluated as antioxidant agents using the three antioxidant bioassay tests.


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