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Radical-Scavenging Activity (Radical-Scavenge + activity)
Selected AbstractsAnti-Inflammatory, Antiproliferative, and Radical-Scavenging Activities of Tolfenamic Acid and Its Metal ComplexesCHEMISTRY & BIODIVERSITY, Issue 6 2009Dimitra Kovala-Demertzi Abstract Some new complexes of tolfenamic acid (=2-[(2-methyl-3-chlorophenyl)amino]benzoic acid; Htolf) with potentially interesting biological activities are described. The complexes [Mn(tolf)2(H2O)2], [Co(tolf)2(H2O)2], [Ni(tolf2(H2O)2], [Cu(tolf)2(H2O)]2, and [Zn(tolf)2(H2O)] were prepared by the reaction of tolfenamic acid, a potent anti-inflammatory drug, with metal salts. The radical-scavenging activities of the complexes were evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging assay. Their ability to inhibit soybean lipoxygenase, , -glucuronidase, and trypsin-induced proteolysis was studied. Their inhibitory effects on rat paw edema induced by carrageenin was studied and compared with those of tolfenamic acid. The complex [Zn(tolf)2(H2O)] exhibited the strongest in vivo inhibitory effect at 0.1,mm/kg Body Weight (BW; 93.0±0.9%), superior than the inhibition induced by tolfenamic acid at the same molar dose (76.0±0.9%). Tolfenamic acid and its metal complexes have been evaluated for antiproliferative activity in vitro against the cells of three human cancer cell lines, MCF-7 (breast cancer cell line), T24 (bladder cancer cell line), and A-549 (non-small cell lung carcinoma), and a mouse fibroblast L-929 cell line. The complexes [Mn(tolf)2(H2O)2] and [Cu(tolf)2(H2O)]2 have shown selectivity against T24 cell line. The IC50 values of these two complexes against T24 cancer cell lines are in a micromolar range similar or better to that of the antitumor drug cisplatin. [source] Changes in the Radical-Scavenging Activity of Bitter Gourd (Momordica charantia L.) during Freezing and Frozen Storage with or without BlanchingJOURNAL OF FOOD SCIENCE, Issue 7 2008C. Myojin ABSTRACT:, The effects of blanching, freezing, and frozen storage on the retention of radical-scavenging activity (RSA), total phenolics, and ascorbic acid in bitter gourd were investigated. Blanching of sliced bitter gourd resulted in considerable losses of RSA and total phenolics, and most extensively, of ascorbic acid. In the subsequent frozen storage at ,18 °C, RSA and total phenolic content of unblanched and blanched bitter gourd underwent little change for 90 d then gradually declined, but at ,40 °C, they practically remained unchanged throughout the entire storage period. On the contrary, ascorbic acid content of both unblanched and blanched bitter gourd decreased abruptly at the early stage in frozen storage. The results show that blanching of bitter gourd improves the retention of RSA and total phenolics during subsequent frozen storage but markedly aggravated loss of ascorbic acid. Finally, it is to be noted that RSA, total phenolics, and ascorbic acid originally contained in the raw bitter gourd were overall best retained by quick freezing followed by frozen storage at ,40 °C without preceding blanching. [source] Phenolic Constituents from Balanophora laxiflora with DPPH Radical-Scavenging ActivityCHEMISTRY & BIODIVERSITY, Issue 6 2009Gai-Mei She Abstract Balanophora laxifloraHemsl. (Balanophoraceae), a dioeciously parasitic plant, has been used as a tonic and for sobering up from drunk by the local people of Yunnan province, China. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay on the acetone extract of the fresh female plant of B. laxiflora displayed considerable radical-scavenging activity (SC50=16.4,,g/ml). Further purification of the extract led to the isolation of two new phenolic glycosides, balaxiflorins A and B (1 and 2, resp.), together with 17 known phenolic compounds including 3-phenylpropanoids, 3, 17,18, four lignans, 4,7, nine hydrolyzable tannins, 8,16, and gallic acid (19). Their structures were determined by detailed spectroscopic analysis. The free-radical-scavenging activity of the isolated compounds was examined by DPPH assay. [source] Xanthones from the Bark of Garcinia xanthochymus and Their 1,1-Diphenyl-2-picrylhydrazyl Radical-Scavenging Activity,CHINESE JOURNAL OF CHEMISTRY, Issue 1 2009Fangfang ZHONG Abstract Five new xanthones, garcinenone A (1), B (3), C (4), D (7) and E (8), along with 7 known compounds were isolated from the EtOAc-soluble extract of the bark of Garcinia xanthochymus, and their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques. Jacareubin (2), 1,4,6-trihydroxy-5-methoxy-7-(3-methyl-2-butenyl)xanthone (6), subeliptenone B (11) and symphoxanthone (12) were obtained from this plant for the first time. The isolated compounds exhibited potent antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test with IC50 values in the 6.0,23.2 µmol/L. These results suggested that G. xanthochymus could be a promising rich source of natural antioxidant. [source] | ||||||||||