Abstract :
[en] Ultrasonic–microwave synergistic extraction was used to extract flavonoids from
sweet potato leaves (SPL) by response surface methodology. The optimal conditions
for flavonoids extraction were 1:40 (g/ml) of solid–liquid ratio, 57°C of extraction
temperature, 76 s of extraction time, and 72% (v/v) ethanol for 2 times, the highest
extraction efficiency was 91.65 ± 3.37%. After purification, the flavonoids purity
reached to 76.10 ± 3.11 (%, DW). The result of high‐performance liquid chromatography
revealed 11 compounds including astragalin (473.8 ± 7.3 mg/g, DW), quercetrin
(86.5 ± 0.7 mg/g, DW), 4,5‐chlorogenic acid (76.4 ± 0.5 mg/g, DW), isoquercitrin
(62.4 ± 0.4 mg/g, DW), tiliroside (18.8 ± 0.3 mg/g, DW), quercetin (12.5 ± 0.2 mg/g,
DW), 3,4,5‐chlorogenic acid (6.5 ± 0.2 mg/g, DW), caffeic acid (6.1 ± 0.2 mg/g, DW),
kaempferol (6.0 ± 0.2 mg/g, DW), myricetrin (5.9 ± 0.1 mg/g, DW), and rhamnetin
(4.3 ± 0.1 mg/g, DW) in sweet potato leaf flavonoids, which possessed good antioxidant
activity compared to soy isoflavones, ginkgo biloba extract, and propolis flavone.
The IC50 value of sweet potato leaf flavonoids was 13.26 ± 0.09 μg/ml in ferric
reducing antioxidant power and 5.41 ± 0.21 in 2, 2′‐azino‐bis(3‐ethylbenzothiazoline‐
6‐sulphonic acid) scavenging capacity, respectively.
Scopus citations®
without self-citations
28