2.3 Instrument
UV-Vis Spectrophotometer X-ma 1200 Human
Corp., macerator, vacuum rotary evaporator,
analytical scales, and analytic glassware.
2.4 Preparation and Extraction
Angsana leaves, both old and young, were taken at
random and then sorted and washed until clean, then
chopped and dried respectively. The dry leaves were
then milled. The preparation of the extract was
carried out by maceration by dissolving 200 g of
simplicia with 1000 mL of 96% ethanol solvent. The
result of maceration was then concentrated using
Rotary Vaccum Evaporator until a viscous extract
was obtained.
2.5 Qualitative Test
2 ml of Angsana leaves extract were taken and put
into a tube. 0.5 ml of concentrated HCl and 0.02 mg
of Magnesium were then added and mixed. The
presence of flavonoids is characterized by the
occurrence of discoloration. The reduction with
concentrated Mg and HCl produced red, yellow or
orange colors (Robinson, 1995).
2.6 Quantitative Test
2.6.1 Quercetin Standard Curve
Quercetin was weighed for as much as 50 mg and
inserted into a 50 mL measuring flask, then
dissolved with 96% ethanol. Then, it was diluted
through 20 consecutive concentrations; 40; 60; 80;
and 100 ppm. 5 ml were added in 15 ml of 96%
ethanol, 1 ml of 10% aluminum chloride, 1 ml of 1
M sodium acetate, and 28 ml of aquadest. Then, the
mixture was incubated at room temperature for 30
minutes. The blank sample production was done
without the addition of aluminum chloride. The next
stage was the measurement standard curve level
using visible spectrophotometry with a wavelength
of 439 nm (Chang et al., 2002). Then, a calibration
curve was made by connecting the absorption value
and the concentration.
2.6.2 Determination of Flavonoid Levels
Samples of 100 mg were weighed and inserted in a
100 mL measuring flask and then dissolved with
96% ethanol. Samples of 5.0 mL were each added
with 15 ml of 96% ethanol, 1 ml AlCl3, 1 ml of 1 M
sodium acetate, and 28 ml of aquadest. Then, they
were incubated at room temperature for 30 minutes.
The next stage was sample rate measurement using
visible spectrophotometry with a wavelength of 439
nm.
2.6.3 Accuracy and Precision
A sample of 50 mg was weighed and inserted in a 50
mL measuring flask and then dissolved with 96%
ethanol. A standard of 1000 ppm was made by
weighing 50 mg quercetin dissolved in 50 ml
ethanol 96%. 1 ml sample 1000 ppm was extracted
using pipette and inserted into 100 ml measuring
flask. 6 ml of 1000 ppm quercetin solution was
added until the water surface reached the limit
indicator. The flask was then shaken until the
solution was perfectly mixed. 5 ml of each sample
was extracted using pipette and added with 15 ml of
96% ethanol, 1 ml of aluminum chloride, 1 ml of 1
M sodium acetate and 28 ml of aquadest. Then, it
was incubated at room temperature for 30 minutes.
The next step was to measure the sample content
using visible spectrophotometry with a wavelength
of 439 nm (Chang et al., 2002). The procedure was
replicated 6 times (Riyanto, 2014).
3 RESULTS AND DISCUSSION
Flavonoid compounds can be separated from various
other compounds by maceration using 96% ethanol
solvent for analysis. The maceration results were
then concentrated using a vacuum rotary evaporator,
so as to produce a sample in the form of thick
extracts. Then, the extract was evaporated again
through aeration to produce dry extract. The
separated flavonoids were determined using visible
spectrophotometry. The standard comparison used
was quercetin, where quercetin is a type of flavonoid
compound that is most widely distributed in nature.
The results of determination indicate that the
sample used in this study was Angsana with
Pterocarpus indicus Willd species. Extraction
resulted in 200 g of Angsana leaf sample, which was
produced through 96% ethanol solvent with as much
as 1000 mL by maceration method, resulting in a
thick extract of each 2.4 g for old Angsana leaves
and 12.4 g for young Angsana leaves. Qualitative
test results showed positive results with change of
color from dark green to yellowish green.
Flavonoids are compounds containing two aromatic
rings with more than one hydroxyl group. Reduction
with concentrated Mg and HCl produces red, yellow,
or orange colors (Robinson, 1995).