Chemical and Biochemical Characterization of Essential Oils and Their Corresponding Hydrolats from Six Species of the Family.

Many plants belonging to the family are rich in essential oils (EOs) which are intensively used for aromatherapy, food and beverage flavoring, alternative medicine, cosmetics, and perfumery. Aerial parts of L., All., L., , L., and var. L. were subjected to hydrodistillation, and both resulting fractions were analyzed. The purpose of this study was to determine the chemical composition, antioxidant activity, and total phenolic content of six essential oils and their corresponding hydrolats (HDs) through GC-MS and spectrophotometric analyses. Overall, 161 compounds were identified, some found exclusively in essential oils and others in hydrolats, making them individual products with specific end purposes. The total phenolic content was the highest for the L. EOs (3022 ± mg GAE L), because of its high phenolic oxygenated monoterpenes content (thymol and carvacrol) and the smallest for the L. EOs (258.31 ± 44.29 mg GAE L), while hydrolats varied from 183.85 ± 0.22 mg GAE L for L. HD and 7.73 mg GAE L for All. HD. Significant antioxidant effects determined through DPPH and ABTS assays were also observed in samples with higher hydrophilic compounds. The highest antioxidant activity was determined for L. EO and its corresponding HD. Although EOs are the principal traded economic product, HDs represent a valuable by-product that could still present intense antiseptic activities, similar to their corresponding EOs (thyme and oregano), or have multiple aromatherapy, cosmetics, and household applications (lavender and lavandin).