Piper species are producers of essential oils with high yield and promising chemical composition for both perfumery and the pharmaceutical industry. They present bioactivity against pathogens and against insect pests, whether agricultural or medical, such as Aedes aegypti, for example, a vector of arboviruses with a high incidence in tropical and subtropical regions. In this study, an investigation was carried out to elucidate the chemical composition of essential oils from the leaves and inflorescences of Piper aduncum collected in the state of Goiás, Brazil. Evaluating the interference of the drying process on yield, chemical composition and larvicide potential against Ae. aegypti. Leaves and inflorescences of P. aduncum were collected in the rural area of the municipality of Iporá-GO. Fresh and dried samples were processed separately and subjected to hydrodistillation for two hours. The oil obtained was qualitatively evaluated by gas-coupled chromatography and mass spectrometry. Greater yield was observed in samples submitted to the drying process. Oils obtained from fresh samples had a higher percentage of monoterpene hydrocarbons. Variation was observed between the major components of samples of fresh leaves and inflorescences, with eupatoriochrome being the major component in dried samples. Larvicidal activity against Ae. aegypti was considered promising (LC50<100µg/mL) in all samples. The results obtained showed a chemical composition different from that generally presented by P. aduncum. This reinforces the idea of intraspecific variability of essential oils and the need for chemical evaluation between samples even if they belong to the same species.

The aim of this study was to perform from the morpho-anatomical study, physicochemical characterization, chemical composition, seasonal variability and larvicidal activity of the volatile oils of Campomanesia pubescens (DC.) O. Berg leaves. The botanical material was collected in Hidrolândia, Goiás. Morpho-anatomical characterization and phytochemical screening were performed by conventional methods. Leaf powders were submitted to hydrodistillation in the Clevenger apparatus and the identification of the chemical components of the volatile oils obtained was done by GC-MS. The larvicidal activity was carried out with third-stage larvae of the Aedes aegypti. The leaf blade, the main vein, and the young stem have a uni-stratified epidermis covered by a cuticle. The mesophyll and cortical parenchyma of the main vein and young stem have secretory cavities and idioblasts with crystals. The main rib contains a bicolateral bundle in an open arch. The young stem has a discontinuous band of sclerenchyma external to the phloem cells. Most volatile oil compounds are spathulenol, caryophyllene oxide, α-macrocarpene, and z-caryophylleneIn phytochemical analysis, tannins, digitalis, flavonoids, and total phenols were detected. The content of volatile compounds was 7.36%, that of total ash was 1.77%, and that of mucilage was 3.52 ml. The volatile oil at the concentration used was inactive against Ae aegypti larvae. The present study contributes to the taxonomic knowledge of the species and provides parameters for quality control of the plant raw material. This work represents the first description of the chemical compounds and seasonal variability of volatile oils from C. pubescens leaves collected in Goiás state.

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Psidium guineense Swartz is a bush used in urinary tract diseases, diarrhea, and dysentery. The present study aims to perform the anatomical study of the leaves and evaluation of the chemical composition of the volatile oils from Psidium guineense Swartz leaves and fruits. The botanical material was collected in Hidrolândia, Goiás. Anatomical characterization and phytochemical screening of the leaves were performed by conventional methods. Leaf and fruit (green fruits, immature fruits, and ripe fruits) powders were submitted to hydrodistillation in the Clevenger apparatus and the identification of the chemical components of the volatile oils obtained was done by GC-MS. The leaf blade is hypoestomatic with paracytic and anisocytic stomata. Secretory cavities are observed in the central vein, mesophyll, petiole, and young stem. The powder moisture content was 7.4%. The total ash content of the leaf powder was 6.3% and the acid-insoluble ash content was 0.8%. The presence of tannins, flavonoids, and saponins in the leaves were identified. Leaves volatile oil’s majority compounds were 2Z,6E-farnesol (23.1-25.4%), α-copaene (17.7-20.3%), muurola-4,10(1.4) dien-1-β-ol (5.8-6.7%), epi-α-cadinol (5.5- 6.3%), and δ-Cadinene (5.0- 5.9%). Fruits volatile oil’s majority compounds were 2Z,6E-farnesol (31.9-41.4%), α-copaene (13.3-26.6%), δ-cadinene (5.4-9.8%), γ-himachalene (3.8-6.1%), and cubenol (2.6-6.1%). This is the first report on anatomical study of the leaves, and chemical composition of volatile oils from leaves and fruits of P. guineense collected in Hidrolândia, Goiás.

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