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Mestrado em cooperação com a Universidade de Salamanca As plantas foram usadas pelos nossos ancestrais, não só como alimento, mas também como uma solução terapêutica. Tendo em conta os seus benefícios para a saúde e, de acordo com a Organização Mundial de Saúde (OMS), a sua utilização como ingrediente na industria farmacêutica e alimentar, aumentou significativamente, ao longo do tempo. Os compostos bioativos são um grupo importante presente nas plantas, atuando na prevenção de doenças humanas associadas ao stresse oxidativo. O objetivo deste estudo foi caracterizar a composição fenólica e avaliar a bioatividade de várias amostras de Lavandula pedunculata (Mill.) Cav, cujas sementes são provenientes de diversas populações naturais de diferentes regiões de Portugal, e comparar os seus extratos aquosos e hidroetanólicos. A partir da análise HPLC-DAD-ESI/MSn foram identificados treze compostos, sendo o ácido salvianólico B, o ácido rosmarínico e luteolina-7-O-glucurónido, os principais compostos presentes. O extrato aquoso de L. pedunculata revelou maior potencial antioxidante, que pode estar relacionado com a sua maior concentração em compostos fenólicos; no entanto, o extrato hidroetanólico demostrou maior potencial anti-inflamatório e capacidade anti-proliferativa. Assim, este estudo destaca os efeitos bioativos desta espécie e abre possibilidades para o seu uso em formulações alimentares e farmacêuticas. No entanto, existem potenciais diferenças nestas propriedades de acordo com a origem geográfica do material vegetal, visto que as amostras do Alentejo apresentaram, em geral, melhores resultados para todas as bioatividades, comparativamente com as amostras de Trás-os-Montes. Plants were used by our ancestors, not only as food, but also as a therapeutic solution. Taking into account their health benefits and, according to the World Health Organization (WHO), their use as an ingredient in the pharmaceutical and food industries has increased significantly, over time. Bioactive compounds are an important group present in plants, acting in the prevention of human diseases associated with oxidative stress. The aim of this study was to characterize the phenolic composition and evaluate the bioactivity of several samples of Lavandula pedunculata (Mill.) Cav, whose seeds were provided from various natural populations of different regions of Portugal, and compare aqueous and hydroethanolic extracts. From the HPLC-DAD-ESI/MSn analysis thirteen compounds were identified, being salvianolic acid B, rosmarinic acid and luteolin-7-O-glucuronide, the main compounds present. L. pedunculata aqueous extract revealed a higher antioxidant potential, which could be related to its higher concentration in phenolic compounds; however, the hydroethanolic extract showed a higher anti-inflammatory potential and anti-proliferative capacity. Thus, this study highlights the bioactive effects of this species and opens possibilities for uses in food and pharmaceutical formulations. However, there are potential differences in such properties according to geographical origin of plant material, as in general, the samples from Alentejo presented higher results in all the bioactivities, compared with Trás-os-Montes samples. Este trabalho foi financiado pelo programa FEDER-Interreg España-Portugal através do projeto 0377_Iberphenol_6_E.

Mestrado em Engenharia Agronómica - Proteção de Plantas - Instituto Superior de Agronomia The Portuguese flora is very rich in aromatic and medicinal plants, among which are Lavandula stoechas subsp. luisieri and L. pedunculata. The present study was aimed to evaluate the potential antimicrobial activity of five plant extracts and essential oils (EO) obtained from these species, with respect to human and plant pathogens. The EO were extracted from dried material by hydrodistillation and the extracts by a solvent system of increasing polarity. To evaluate the activity of samples against human pathogens the microdilution method was used and determined the values of minimum inhibitory concentration (MIC) at different concentrations: 7.5, 15.5, 31, 62.5, 125, 250 and 500 μg/mL. Results were considered positives for MIC values < 100 μg/mL. Lavandula species showed different antimicrobial properties, attributed to differences in the chemical composition of the respective EO and extracts. For phytopathogenic bacteria a similar procedure was followed. Regarding the fungi, the activity of EO and extracts was evaluated by the disc diffusion method on solid medium inoculated with spore suspensions or mycelial discs at sample concentration of 1 mg/mL and 2 mg/mL, respectively. None of the plant pathogens was inhibited. This study tends to confirm the use of EO and plant extracts to control different types of microbial pathogens

Relatório Final de Estágio de Iniciação à Investigação Científica / ISA - Centro de Botânica Aplicada à Agricultura In this study we performed a histochemical characterization of glandular trichomes in plantules of Lavandula pedunculata (Miller) Cavanille exposed to three different photoperiodic regimes: 16h light/8h dark (to control), 12h light/12h dark and still 8h light/16h dark. We aim at understanding whether changes in photoperiodic regime can modify the composition of the secretions of the trichomes. To evaluate the differences between the regimes we were carried a battery of fluorescence and histochemical tests. It was found that there are significant changes in the segregations, mainly characterized by reduced production of secretions even quantitatively and qualitatively.

Relatório de Estágio de Iniciação à Investigação Científica /ISA - Centro de Botânica Aplicada à Agricultura The genus Lavandula is known since classic antiquity as aromatic and medicinal. These characteristics are due to compounds synthesized and accumulated in secretory structures. In Portugal, we find several species of the genus including the L. pedunculata species. In this species, it is possible to distinguish between protective and secretory trichomes. With this work we pretend study the ontogeny of the types of trichomes and plantlets along their development, under different photoperiod conditions, 16 hours light/8 hours dark and 12 hours light/12 hours dark, respectively. Cotyledons and leaves from plantlets along different development were collected and used for scanning electron microscopy. The results demonstrated that in the conditions used the rate of germination of this species was low. Also this study showed that there are variations in plant development under different photoperiod in relation to the number of leaves, dimensions, density and types of the trichomes present.