Plants from the genus Mercurialis have a long history of use as herbal remedies in traditional Spanish medicine. The growing interest in the conservation of knowledge related to biodiversity has encouraged us to review the bioactive phytochemicals from the four most widespread Mercurialis species in the Iberian Peninsula (M. annua L., M. ambigua L., M. perennis L., and M. tomentosa L.). First, the medicinal uses of these four species throughout Spain were compiled, and then a bibliographical search on their chemical composition was conducted in an attempt to justify their reported traditional uses. We found that most of the medicinal uses of Mercurialis spp. are supported by scientific evidence. This includes its antidiabetic and antihypertensive properties attributable to the flavonoid rutin and narcissin, respectively; its benefits in the treatment of skin dark spots, attributable to mequinol; and its anti-inflammatory activity, attributable to scopoletin, kaempferol, squalene, and cycloartenol. This review contributes to the validation of the medicinal uses of Mercurialis spp. in Spain and provides some new avenues for further investigations on the biological activity of this interesting medicinal plant.

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.