Francisco María Vázquez Pardo

Chemical composition and antioxidant activity of the essential oil of Thymbra capitata (L.) Cav. in Spain

Abstract We studied the chemical composition of the essential oil of Spanish populations of Thymbra capitata. The production from different parts and their antioxidant capacity were compared both during flowering and during fruiting over three years, from wild and cultivated material. 38 components were identified: highlighting aromatic monoterpenes (carvacrol ≥ 66%; p-cymene, 7.39.2%), monocyclic monoterpenes (y-terpinene, 3.4–11.2%; α-terpinene, 0.3–2.0%), bicyclic monoterpenes (α-thujene, 0.9–2.0%; α-pinene, 0.7–1.4%, camphene, 0.2–0.9%), acyclic monoterpene (myrcene, 1.7–2.4%) and sesquiterpenes as (E)-caryophyllene (1.0–2.0%). A very high lipophilic antioxidant activity was measured with no significant differences between the flowering and fruiting stage.

Seed germination and risks of using the invasive plant Eichhornia crassipes (Mart.) Solms-Laub. (water hyacinth) for composting, ovine feeding and biogas production.

Abstract Water hyacinth (Eichhornia crassipes (Mart.) Solms-Laub.) is an invasive aquatic weed that has one of the highest growth indices of vascular plants, producing large amounts of biomass. Its use for composting, livestock feed and biogas production has been proposed as a management strategy for its control. The work presented here is an assessment of the potential spread of water hyacinth due to the release of seeds from the by-products of some of these manufacturing processes. We tested experimentally if the seeds were destroyed or did not lose germinability when they had passed through the gut of sheep, remained in compost piles or been used in biogas bioreactors. We made optical and electronic microscopic observations, and calculated retrieval and germination percentages of the seeds subjected to these treatments. After having passed through the gut of sheep, the anatomical organization of the seed was completely destroyed, only 30.50 ± 5.83% of the seeds were retrieved and the germinability was null (0 ± 0%). The biogas production and compost-treated seeds both had retrieval percentages of 100 ± 0% and germination values of 1.00 ± 0.57 and 3.50 ± 0.96% respectively, with several anatomical damages. The use for compost or biogas production as a management strategy to control this pest is not completely safe from an environmental perspective and the selected management option should focus on sheep fodder production.

Biosystematic study of the subsection Thymastra (Nyman ex Velen.) R. Morales of the Thymus L. genus (Lamiaceae)

Abstract The interest to revision of the Thymus genus in the southern western Iberian peninsula is important to comprehension of the taxonomy and evolution process in the genus. Biosystematic study of the subsect. Thymastra (Nyman ex Velen.) R. Morales of the Thymus genus revealed the existence of two new subspecies: Thymus camphoratus subsp. congestus subsp. nov. and Thymus capitalletus subsp. anomalus subsp. nov., and a new variety: Thymus camphoratus subsp. camphoratus var. grandiflorus var. nov. Also are typified all the taxa associated to the subsection Thymastra (Nyman ex Velen.) R. Morales.

Study of the essential oil of three species of thyme in their limit of distribution in Spain

Abstract We analyzed the essential oils of three cultivated thymes whose provenance was populations at the limit of their distribution in Spain. In the flowering stage, the Peninsular endemic Th. villosus subsp. lusitanicus has linalool (49.6%) as principal component, an evidence for the chemical polymorphism described for this taxon. For Th. caespititius, high values are obtained for α-terpineol (41.1%), confirming the chemical homogeneity in the Iberian Peninsula. The studied population of the Eurosiberian species Th. pulegioides, which is at its southern limit in the Iberian Peninsula, has as principal components γ-terpinene (31.7%), thymol (25.6%), p-cymene (16.4%), and carvacrol (3.5%), values which do not compare readily with the literature data. The chemical analyses performed for the fruiting stage are new. The only major differences with the flowering stage are found for Th. pulegioides.