Banca de QUALIFICAÇÃO: JENIFFER GOMES DA SILVA

INFLUENCE OF SUBSTRATES, SEASONALITY AND CIRCADIAN CYCLE ON THE YIELD AND PHYTOCHEMICAL COMPOSITION OF THE ESSENTIAL OIL OF THE SPECIES Lippia dulcis Trevir ADAPTED TO THE AMAZON CLIMATE

Amazon. Medicinal plants. Secondary metabolites

Plants are the first types of medicine in the world. The species Lippia dulcis Trevir is an example of a plant that possesses many properties that make it stand out in human health care, such as the sesquiterpene Hernandulcina, a natural calorie-free sweetener that can be suitable for the diet of diabetics. In the Amazon, this plant is already known by traditional peoples and used in the form of teas for diabetes control. Thus, the project aims to analyze the effects of seasonality, circadian cycle, and substrates on the cultivation and chemical composition of the essential oil of the species Lippia dulcis Trevir. For this, 114 cuttings of healthy seedlings were made from specimens acquired from Embrapa Amazônia Oriental and implanted in two beds containing different substrate mixtures: S1 containing worm humus, washed and sieved construction sand, and medium-textured expanded vermiculite, and S2 with commercial organic compost Tropstrato HT for vegetables and fertilized soil. After 30 days of planting, data were collected on the phenophases of flowering and fruiting, budding of internodes, length, number, and color of the leaves of the main branch, visual observation, and length of the root system. The steps that will follow will be the harvest that will occur at intervals of 2 hours, at 8:00 am (T1), 10:00 am (T2), 12:00 pm (T3), 2:00 pm (T4), 4:00 pm (T5), and 6:00 pm (T6), totaling six treatments (collection times) and six repetitions, in duplicates. The aerial parts (leaves, flowers, and branches) will be weighed, and after drying, three samples of 20 g per block will be separated, and 300 g per block will be allocated for the extraction of the essential oil. The Oes will be extracted by the hydrodistillation method using a Clevenger apparatus for 8 hours. Chemical analyses will be performed by the Gas Chromatography coupled to a Mass Spectrometry Detector (GC/MS) method to detect the chemotypes present in the essential oil and their quantity. Finally, the collected data will be subjected to statistical analyses in the R software, where Shapiro-Wilk tests, Spearman correlation, Dunn test, and descriptive statistics will be run. This work aims to first gather information about the planting and proper management of this species during this period and understand the dynamics of the chemotypes that constitute the essential oil of this plant according to the seasonality of the region and collection time to determine the best collection conditions to obtain more satisfactory chemical responses and thus contribute to the knowledge for possible projects to establish the species in the West of Pará region and its use in popular medicine and pharmacology.