Quantification of total flavonoids and tannins present in the aqueous extract of leaves of Thea sinensis L. and its antioxidant capacity

Abstract

We studied the quantification of total flavonoids and tannins present in the aqueous extract of leaves of Thea sinensis L. and its antioxidant capacity, he prepared an aqueous extract, which was then lyophilized. Likewise purified and quantified the total flavonoids obtained by the method described by Z. Kostennikova adapted by the department of pharmacognosy and pharmacobotany, at 258 nm., finding percentages expressed to the decoction of green tea for 1.6% and 1.3% infused the same, likewise we have for black tea decoction was of 1.21% and for the same infused was 1.12%, with the average absorbance pattern as quercetin 3.87. Quantification of tannins was performed spectrophotometrically by the Folin adapted in the department of pharmacognosy, Faculty of Pharmacy and Biochemistry, the percentages of total tannins in the extract and infused lyophilized decoction of leaves Thea sinensis L., being for the decoction of green tea for 15.29% and 0.23% of that infused, likewise we have for black tea decoction was 21.68% and for the same was infused of 2.61%, with the average absorbance for tannic acid pattern 0.1063. Subsequently we determined the antioxidant capacity in vitro of total flavonoids from leaves of Thea sinensis L. expressed as a percentage of radical scavenging by the method described by Brand-Williams et al, for each concentration and time (1, 15, 30, 45 minutes) was determined by the percentage of capture of the free radical 2,2- diphenyl-1 -picrylhydrazyl (DPPH *). Where it was found that the higher the concentration, and time, the greater this percentage.