Antioxidant activity of several essential oils from different rosmarinus officinalis cultivars grown in Sanremo (Italy)

The evaluation of the essential oil (EO) profile of several cultivars of Rosmarinus officinalis, usually not used for food, and the assessment of their antioxidant activity as potential sources of natural antioxidants were studied in this work. Five different cultivars of Rosmarinus officinalis: R. officinalis ‘Alba’; R. officinalis ‘Blue Rain’; R. officinalis ‘Corsican Blue’; R. officinalis ‘Israeli’; R. officinalis ‘Majorca Pink’ and one hybrid of rosemary, Rosmarinus x lavandulaceus Noë, cultivated at CREA Sanremo (Italy), were hydrodistilled separately and the obtained EOs were analysed by GC-MS. Monoterpenes predominated in all the EO profiles but oxygenated monoterpenes were the most abundant constituents in R. officinalis ‘Blue Rain’, R. officinalis ‘Corsican Blue’, R. officinalis ‘Israeli’ and R. officinalis ‘Majorca Pink’. R. x lavandulaceus Noë and R. officinalis ‘Alba’ showed percentages of monoterpene hydrocarbons and oxygenated monoterpenes very similar. -pinene, camphene, 1,8-cineole, camphor, borneol, verbenone, isobornyl acetate and - caryophyllene were the main constituents present in all the plant cultivars, even though in different percentages. Myrcene predominate in R. officinalis ‘Alba’ (30.3 %), 1,8 cineol in R. officinalis ‘Blue Rain’ and R. officinalis ‘Israeli’ (21.9% and 26.4%, respectively), while camphor was the main constituent in R. officinalis ‘Majorca Pink’ (42.5%) and in R. x lavandulaceus (24.2%). R. officinalis ‘Corsican Blue’ showed similar amount of the three main components, verbenone, camphor and isobornyl acetate (18.5% >18.2% >15.4%, respectively). All the EOs were also tested for their antioxidant activity using the ferric reducing antioxidant power (FRAP) method and the stable radical DPPH. R. x lavandulaceus Noë showed the highest antioxidant activity, two folds more than that observed in R. officinalis ‘Israeli’

Ecophysiological and phytochemical responses of Salvia sinaloensis Fern. to drought stress

Abstract Salvia sinaloensis Fern. (sage) is a medicinal plant containing plant secondary metabolites (PSMs) with antioxidant properties. The current study investigated the effects of drought stress on S. sinaloensis morphological and ecophysiological traits, and active constituent production. Sage plants were cultivated in controlled conditions for 34 days and exposed to full irrigation as control, half irrigation, or no irrigation. Changes in growth index (G.I.), dry biomass, leaf water potential (LWP), physiological parameters, active compounds, volatilome (BVOCs) and essential oils (EOs) were determined. Not irrigated plants showed a decrease in total chlorophyll content (~ − 14.7%) and growth (G.I., ~ − 59.4%) from day 18, and dry biomass at day 21 (− 56%), when the complete leaf withering occurred (LWP, − 1.10 MPa). Moderate drought stressed plants showed similar trends for chlorophyll content and growth but kept a constant LWP (− 0.35 MPa) and dry biomass throughout the experiment, as control plants. Carotenoids were not affected by water regimes. The photosynthetic apparatus tolerated mild to severe water deficits, without a complete stomatal closure. Plants under both stress conditions increased the percentage of phenols and flavonoids and showed altered BVOC and EO chemical profiles. Interestingly Camphor, the main EO oxygenated monoterpene, increased in moderate stressed plants while the sesquiterpene hydrocarbon Germacrene D decreased. The same trend was seen in the headspace under stress severity. The data evidenced a possible role of the active molecules in the response of S. sinaloensis plants to drought stress. Taking together, these findings point at S. sinaloensis as a potential drought adaptive species, which could be used in breeding strategies to obtain sages with high quality PSMs,saving irrigation water