LC-MS/MS analysis and antioxidant activity of crude extracts from Cistus incanus L.

Cistus incanus L, also known as rockrose, is used to treat various health disorders. The objective of the present work is to identify major constituents of the methanol and n-butanol extracts of C. incanus using LC-MS/MS analysis. Antioxidant activity was also evaluated using the DPPH. radical, ABTS+. and FRAP assays. The methanol extract was subjected to column chromatography, affording β-sitosterol glucoside, reported here for the first time from C. incanus. A total of 26 targeted chemicals were identified in the n-butanol extract, in which catechin appeared as the predominant flavonoid (36.9 mg/g extract); on the other hand, 3-O-Methylquercetin (59.4 mg/g extract) was the major flavonoid in the methanol extract. Antioxidant activity of the n-butanol extract exhibited superior radical scavenging activity on DPPH. radical (IC50 =31.1 ± 1.5 μg/mL), for the ABTS+ radical (IC50 =51.2 ± 2.0 μg/mL), and (IC50 =31.1 ± 1.2 μg/mL) for the FRAP assay.