Natural Products Chemistry and Biotechnology

The objective of this study was the valorization of the essential oils from Spanish Artemisia absinthium domesticated plants from Teruel and Sierra Nevada (Spain). These populations were experimentally cultivated in the field and under controlled conditions. The insect antifeedant properties of their essential oils collected yearly from two locations were tested against Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi. Additionally we studied their phytotoxic, antifungal and antiparasitic effects. The oils from cultivated A. absinthium were characterized by the presence of cis-epoxyocimene, chrysanthenol, and chrysanthenyl acetate. The variations observed in oil composition were mostly quantitative but also qualitative. (Z)-2,6-Dimethyl-5,7-octadien-2,3-diol has been isolated and identified by NMR. Among the oil samples, these rich in cis-epoxyocimene and sesquiterpenes were the most active ones against S. littoralis. (Z)-2,6-Dimethyl-5,7-octadien-2,3-diol showed moderate activity against S. littoralis. The strongest antifeedant effects were found for commercial A. absinthium oil samples rich in thujones and sabinyl acetate. F. oxysporum and F. solani were affected by oils from cultivated A. absinthium and commercial oil samples. Oils from cultivated A. absinthium showed antiparasitic effects against Leishmania infantum and Trypanosoma cruzi with better results than the commercial

The objective of this study was the valorization of Spanish Artemisia absinthium populations from Teruel (Aragón) and Sierra Nevada (Granada). These populations were experimentally cultivated in the field and under controlled conditions. Three major components were isolated from a two year-old population obtained from the Teruel population cultivated in Ejea-Zaragoza in 2003, and identified by NMR experiments as the sequiterpene lactone hydroxypelenolide (I) and the flavones artemetin (II) and casticin (III). The I–III content of the plant extracts was analyzed by HPLC-DAD. The insect antifeedant properties of plant extracts from different years and crops were tested against Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi. Additionally we studied their antioxidant, phytotoxic and antiparasitic effects.

The objective of the work was to optimize the extraction of Persea indica L. bioactive compounds by means of supercritical fluid extraction (SFE) and analyze their insecticidal effects. P. indica L. is one of the dominant species of the Canarian laurel forest, a relict of the Tertiary flora. Different extraction conditions (pressure, plant material particle size, temperature, CO2 flow) and the influence of entrainer were tested and the evolution of the extracted compounds was screened by HPLC–MS. A comparison with conventional techniques such as hydrodistillation (HD) or organic solvent extraction (OSE) was also presented. Particularly, four CO2 densities ranging from 628.61 kg/m3 to 839.81 kg/m3 were studied in the range of 10.0–20.0 MPa and 40–50 °C. The extracts contained insecticidal ryanodanes of great interest, previously described as insecticidal components of P. indica. The insecticidal antifeedant activity of selected extracts was inspected. A model based on mass transfer equations, the Sovová model, was successfully applied to correlate the experimental data.

The objective of this study was the characterization of nematicidal activity and valorization of hydrolate obtained as a byproduct of the semi industrial vapor-pressure essential oil extraction of a domesticated Artemisia absinthium population (Teruel, Spain), in comparison with a population (Sierra Nevada, Spain) undergoing the domestication process. Hydrolates from three crops of these two populations showed strong in vitro nematicidal effects against the root knot nematode Meloidogyne javanica and similar chemical profiles. The hydrolate of the A. absinthium population from Teruel strongly suppressed nematode egg hatching (>95%) after 5 days of incubation. In vivo tests on tomato seedlings showed a significant reduction in the of root penetration rate of M. javanica J2 treated with a hydrolate sublethal concentration (33%). In pot experiments, the hydrolate of A. absinthium tested on tomato plants significantly affected the nematode population, the infection frequency and the reproduction rate. The extraction of the organic fraction of the hydrolate gave a nematicidal extract and an inactive aqueous residue. The chemical profile of the active organic extract showed the presence of (5Z)-2,6-dimethylocta-5,7-diene-2,3-diol, previously described in the hydrodistilled essential oil of this A. absinthium population, among other compounds. This study demonstrates that the organic fraction of the A. absinthium hydrolate is a potential root-nematode control agent. Therefore, the hydrolate byproduct of the semi industrial vapor-pressure essential oil extraction could be a source of new nematicidal products.

In this study we evaluated the effect of a pressure gradient (1–2 atm) in the extraction and composition of the essential oil (EO) of Piper hispidinervum by steam distillation. We also evaluated the insect antifeedant effects (Spodoptera littoralis, Leptinotarsa decemlineata, Myzus persicae and Rhopalosiphum padi) and nematicidal activity (Meloidogyne javanica) of the oils, their major components and their synergistic interactions. Safrole was the major component (78–81%) followed by terpinolene (5–9%). The EOs tested were effective insect antifeedants. Safrole, explained most of the insect antifeedant action of P. hispidinervum EOs. When safrole and terpinolene were tested in binary combinations, low ratios of safrole improved the antifeedant effects of terpinolene. P. hispidinervum EOs caused higher mortality of M. javanica juveniles than their major components. In binary combinations, low ratios of terpinolene increased the nematicidal effects of safrole. The EO treatment strongly suppressed nematode egg hatching and juvenile infectivity. P. hispidinervum EOs affected the germination of S. lycopersicum and L. sativa mostly at 24 h of treatment, being L. sativa the most sensitive. Safrole moderately affected germination and root growth of L. sativa, S. lycopersicum and L. perenne. Terpinolene only affected S. lycopersicum root growth.

The objective of this study was the characterization and valorization of the essential oil from a domesticated Artemisia absinthium population (Teruel, Spain), and its comparison with another one (Sierra Nevada, Spain) undergoing the domestication process. These populations are being experimentally cultivated in the same field since 2008. We studied their biomass and essential oil production (Clevenger hydrodistillation, HD and semi-industrial vapor-pressure, VP). The domesticated population showed lower chemical variation and higher biomass and essential oil yields, allowing for the registration of a new plant variety. The observed variations in oil composition (HD, VP) between the two populations were mostly quantitative. The oils were characterized by the presence of cis-epoxyocimene, (-)-. cis-chrysanthenol, chrysanthenyl acetate, linalool and trans-caryophyllene. The insect antifeedant (. Leptinotarsa decemlineata, Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi) and antifungal (. Fusarium spp. and Botrytis cinerea) effects of their oils were also tested. All VP extracts showed strong antifungal effects and the active antifungal compounds have been identified.