Dynamic changes in amino acids, catechins, caffeine and
gallic acid in green tea during withering.
Total phenol contents (TPC) are reported in mg/g of DW as
gallic acid equivalents by reference to standard curve (y = 2.327, [r.sup.2] = 0.9849) and total flavonoid contents (TFC) as rutin equivalent in mg/g by reference to standard curve (y = 8.250x, [r.sup.2] = 0.998).
In order to optimize the CPE of
gallic acid, bergenin, quercitrin, and embelin from the herbal sample, a series of experiments including the type of surfactant, surfactant concentration, ultrasonic extracting time, ultrasonic extraction power, solid-liquid rate, ionic strength, pH of sample solution, bath temperature, and time under different conditions were studied.
The HPLC elution profile recorded at 280 nm showed 5 phenolic acids:
gallic acid, epicatechin, coumaric acid, apigenin, and naringenin (Figure 1(a)) with concentrations of 1111.41 [micro]g/mL, 198.52 [micro]g/mL, 147.73 [micro]g/mL, 7.89 [micro]g/mL, and 6.13 [micro]g/mL, respectively (Table 2), while the HPLC elution profile of flavonoids (Figure 1(b); Table 2) recorded at 360 nm identified 3 compounds: rutin, quercetin, and kaempferol, with concentrations of 50.74 [micro]g/mL, 6.78 [micro]g/mL, and 14.42 [micro]g/mL.
The results of present study indicated that the interactions between thrombin and phenolic acids were weak except for
gallic acids. On the other hand, in docking results, phenolic acids could only interact with residues other than activity centre due to lack of space matching.
Twelve gallotannins, monomers and oligomers of
gallic acid with a hexoside moiety, were characterized in the analyzed extracts.
The groups were normal control (NC, water), radiation control (RC, water+EBR),
gallic acid control (GC, 100 mg/kg b.wt of
gallic acid),
gallic acid pretreatment (GR, 100 mg/kg b.wt of gallic acid+EBR), DMSO control (DC, 10% DMSO), DMSO pretreatment (DR, 10% DMSO+EBR), lutein control (LC, optimized dose-250 mg/kg b.wt), and lutein pretreatment (LR, 250 mg/kg b.wt of lutein+EBR).
The negative control (DPPH + ethanol p.a.] and the positive control (DPPH +
gallic acid) were made in various concentrations.
Total phenolics of quince (Cydonia oblonga Miller) leaves extracts were determined with Folin-Ciocalteu reagent according to the method of Slinkard & Singleton (1977), with some modifications by using
gallic acid as standard (S.
The standard calibration was prepared by using the
gallic acid (Sigma-Aldrich Co.
An active ingredient in the serum, called Diglucosyl
Gallic Acid (DGA), stops the spread of melanin throughout the skin.
