Chemical Composition and Biological Activities of the Aqueous Fraction of Parkinsonea aculeata L. Growing in Saudi Arabia

Abstract

Polyphenolic constituents and chromatographic fingerprint of the aqueous fraction obtained from the ethanolic extract of the aerial parts of Parkinsonea aculeata L. growing in Saudi Arabia were investigated for the first time using UPLC-ESI/MS/MS in negative mode. Forty compounds were tentatively identified including sixteen C-flavone glycosides, twenty-two O-flavone glycosides, and two polymethoxylated flavonoids. Compounds identification was based on the MS/MS fragmentation and literature comparison. The aqueous fraction fingerprint is rich in C- and O-flavone glycosides, like apigenin-8-C-β-D-glucopyranoside (vitexin), vitexin 2″-O-rhamnoside, luteolin-8-C-glucoside (orientin), luteolin-8-C-β-D-glucopyranoside-7-O-rhamnoside and luteolin-7-O-rutinoside. These compounds were identified for the first time in the aqueous fraction of Saudi P. aculeata L. plant. Additionally, the antioxidant and anticancer activities were investigated. The aqueous fraction showed a strong DPPH scavenging activity with IC50 48.3 ± 1.5 μg/mL compared to ascorbic acid 14.2 ± 0.5 μg/mL. However, this fraction showed a very weak cytotoxic activity against HepG-2 (Hepatocellular carcinoma) and MCF-7 (Breast carcinoma) with IC50 222 ± 1.8 and 304 ± 9.2 µg/ml respectively compared to cisplatin IC50 3.67 ± 8.1 and 5.71 ± 3.8 µg/ml respectively. Keywords: Parkinsonea aculeata, C and O-flavone glycosides, Antioxidant, Anticancer, UPLC-ESI-MS/MS