The Occurrence of Flavonoids and Related Compounds in Cedrus brevifolia A. Henry ex Elwes & A. Henry Needles. Inhibitory Potencies on Lipoxygenase, Linoleic Acid Lipid Peroxidation and Antioxidant Activity

The phytochemical analysis of the polar extracts of Cedrus brevifolia needles yielded 20 compounds, namely from the methanol extract we isolated three flavonoids (1–3), one hydrolysable tannin (4), eleven phenolic derivatives (5–15) and one apocarotenoid (16), while from the methanol: water (5:1) extract we isolated four flavonoids (17–20). Chemical structures of all isolated compounds were determined by 1D, 2D-NMR (1 Dimension, 2 Dimensions Nuclear Magnetic Resonance) and UV-Vis (Ultraviolet-Visible) spectroscopy. Furthermore, the antioxidant potentials and the anti-inflammatory activities of both crude extracts and isolates were evaluated through DPPH radical scavenging capability, linoleic acid lipid peroxidation inhibition, and soybean LOX inhibition assays. This is the first report on the chemical profile of C. brevifolia needles. Catechin was the main compound derived from the methanol extract. According to our results, 4-O-β-d-glucopyranyl trans-p-coumaric acid and taxifolin were the most active ingredients.