Scavenging effects of tea catechins and their derivatives on 1,1-diphenyl-2-picrylhydrazyl radical

Chá verde brasileiro (Camellia sinensis var assamica): efeitos do tempo de infusão, acondicionamento da erva e forma de preparo sobre a eficiência de extração dos bioativos e sobre a estabilidade da bebida

“…A atividade antioxidante foi determinada pelo ensaio do DPPH (radicais 2,2-difenil-1-picrilhidrazil), que avalia a eficiência do sequestro dos radicais livres, sendo um método largamente utilizado para determinação de atividade antioxidante de vinhos, sucos de frutas e chás (CHAN; LIM; CHEW, 2007;NANJO et al, 1996;ZAPOROZHETS et al, 2004). O DPPH (0,024 g) foi dissolvido em 100 mL de metanol.…”

New Enzymatic Method for the Determination of Total Phenolic Content in Tea and Wine

“…The results were compared with those obtained by applying the Folin and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging methods (26).…”

Antioxidative Activity of 3-O-Octanoyl-(+)-Catechin, a Newly Synthesized Catechin, in Vitro

“…In fact, the radical scavenging activity of 3-O-octanoyl-(+)-catechin, which was esterified at the 3-OH of (+)-catechin with caprylic acid, was slightly weaker than (+)-catechin. Nanjo et al 11) have also reported that the acetylation of the 3-OH of (-)-chatechin slightly reduces the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radical.…”

“…On this point, the findings of Lemańska et al 14) that the Trolox equivalent antioxidant capacity values for 3-hydroxyflavone, 5-hydroxyflavone, 3′,4′-didihydroxyflavone, and 5,7-dihydroxyflavone increased with in- creasing pH are suggestive. Further, Nanjo et al 11) have reported that the radical scavenging ability of (+)-catechin increases with increasing pH value.…”