Uv 1601 series

The determination of TFC followed the procedure of Chang et al. (2002) (link) with modification. The standard used is quercetin. Ethanolic extract of S. androgynus leaves in methanol solution was piped as much as 0.5 mL. Then, 1.5 mL of methanol, 0.1 mL of AlCl 3 10%, and 0.1 mL of 1 M sodium acetate were added. Finally, distilled water was added up to 5 mL. The solution was incubated for 60 min at room temperature. The absorbance of the solution was measured with a UV-Vis Shimadzu UV-1601 Series (Kyoto, Japan) spectrophotometer at a wavelength of 434 nm. The absorbance obtained is plotted into the linear regression equation. TFC is expressed in mg, which is equivalent to quercetin per g of extract. Each extract was tested for five replication and reported as mean ± SD.

TPC determination followed a procedure Hikmawanti et al. ( 2020) with modification using Folin-Ciocalteu reagent (FCR) and gallic acid as standard. Ethanolic extract of S. androgynus leaves in ethanol solution was piped as much as 300 µL and then added with 1.5 mL of FCR (1:10) and homogenized. After incubated for 3 min, then 1.2 mL of 7.5% Na 2 CO 3 solution was added. Finally, distilled water was added to the mixture to obtain a total volume of 10 mL. The mixture was incubated again for 60 min at room temperature. The absorbance of the solution was measured using a UV-Vis Shimadzu UV-1601 Series (Kyoto, Japan) spectrophotometer with a maximum wavelength of 756.5 nm at room temperature. The maximum wavelength was obtained through optimization using gallic acid (30 µg/mL) in the range of 600-800 nm. The absorbance obtained is plotted into the linear regression equation. TPC is expressed in mg, which is equivalent to gallic acid per g of extract.
Each extract was tested for five replication and reported as mean ± SD.