Chemical Composition and In Vitro Antioxidant Activity of (Lamiaceae) Essential Oils and Extracts.

(Lamiaceae) is an endemic shrub from the Chicamocha River Canyon in Santander (Colombia). Its essential oil (EO) was distilled from the aerial parts of the plant via steam distillation and microwave-assisted hydrodistillation and analyzed using GC/MS and GC/FID. Hydroethanolic extracts were isolated from dry plants before distillation and from the residual plant material after distillation. The extracts were characterized via UHPLC-ESI-Orbitrap-HRMS. The essential oil was rich in oxygenated sesquiterpenes (60-69%) and presented τ-cadinol (44-48%) and 1,10-di--cubenol (21-24%) as its major components. The in vitro antioxidant activity of the EOs, measured via an ABTS assay, was 32-49 μmol Trolox g and that measured using the ORAC assay was 1520-1610 μmol Trolox g. Ursolic acid (28.9-39.8 mg g) and luteolin-7--glucuronide (1.16-25.3 mg g) were the major extract constituents. The antioxidant activity of the extract, obtained from undistilled plant material, was higher (82 ± 4 μmol Trolox g, ABTS; 1300 ± 14 μmol Trolox g, ORAC) than that of the extracts obtained from the residual plant material (51-73 μmol Trolox g, ABTS; 752-1205 μmol Trolox g, ORAC). EO and extract had higher ORAC antioxidant capacity than the reference substances butyl hydroxy toluene (98 μmol Trolox g) and α-tocopherol (450 μmol Trolox g). . EOs and extracts have the potential to be used as natural antioxidants for cosmetics and pharmaceutical products.