New sesquiterpene lactones and other constituents from Ammodaucus leucotrichus growing wild in Algeria.

Phytochemical analysis of the aqueous methanol fraction obtained from the seeds of Ammodaucus leucotrichus growing wild in Algeria afforded seven new compounds including a degraded monoterpene (1), five sesquiterpene lactones (2, 5, 7, 8 and 13) and one acylated flavonoid glycoside (15) in addition to nine known compounds (3, 4, 6, 9-12, 14 and 16). The structures of all isolated compounds were established through extensive spectroscopic analysis. Single crystal X-ray diffraction analysis was further carried out for compound (7). Furthermore, complete 1D and 2D-NMR data together with single crystal X-ray diffraction analysis are reported for the known compound (3) for the first time, extending its earlier report of only 1H NMR data. The new compounds were evaluated for their antioxidant activity using DPPH and ABTS radical scavenging assays. Only compound (15) exhibited moderate scavenging activity on both assays. In-silico molecular docking studies were conducted on cyclooxygenase-2 (COX-2; PDB ID: 3LN1) and epidermal growth factor receptor (EGFR; PDB ID: 2J6M) to further assess the bioactivity of compounds (1-13). For COX-2, the highest predicted binding affinities were observed in the order 6 > 2 > 1, whereas for EGFR, the binding affinities followed the order of 4 > 8 > 9,13. These results suggest that selected compounds from A. leucotrichus may represent promising scaffolds for further investigation as anti-inflammatory and antitumor agents.