Phenoplasticity of Essential Oils from Two Species of Piper (Piperaceae): Comparing Wild Specimens and Bi-Generational Monoclonal Cultivars

Circadian Analysis in Volatile Organic Compounds from Piper gaudichaudianum Kunth Fruits and Their Potential Role in Attracting Carollia perspicillata Bats

Piper fruits are one of the main dietary sources of Carollia perspicillata, a fruit-eating bat largely responsible for dispersing their seeds. To investigate the mechanism of this plant-animal interaction, ripe and unripe fruits of Piper gaudichaudianum were collected in the morning, afternoon, and night. The volatile organic compounds (VOC) were obtained through dynamic headspace (HS) and hydrodistillation (HD) and were analyzed by gas chromatography with flame ionization detector and GC-MS, resulting in the identification of ninety-five compounds. The principal component analysis of all samples revealed a distinction between the VOC obtained by the two techniques as well as differentiated the degree of ripeness of the fruits. The VOC compositions of fruits collected at night by HS and HD showed differences concerning those gathered in the morning and afternoon. The presence of linalool exclusively in the composition of ripe fruits collected at night and the highest levels of aromadendrene and (E)-nerolidol were also found in these samples, suggesting that these compounds may be responsible for attracting the bats and/or indicating the degree of fruit ripening. The chemical interaction between VOCs and bats appears to be more complex than simply considering the main compounds, encouraging additional tests to investigate the main compounds and their possible synergistic interactions.

Spatio-Temporal Variations of Volatile Metabolites as an Eco-Physiological Response of a Native Species in the Tropical Forest

This study evaluates the essential oil (EO) composition of Piper rivinoides Kunth, a shrub native to the Brazilian tropical rainforest, across different plant parts and developmental phases. The aim was to explore the chemical diversity of EO and its reflection in the plant's ecological interactions and adaptations. Plant organs (roots, stems, branches, and leaves) at different developmental phases were subjected to hydrodistillation followed by chemical analysis using Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Flame Ionization Detector (GC-FID). The results revealed a relevant variation in EO yield and composition among different plant parts and developmental phases. Leaves showed the highest yield and chemical diversity, with α-pinene and β-pinene as major constituents, while roots and stems were characterized by a predominance of arylpropanoids, particularly apiol. The chemical diversity in leaves increased with plant maturity, indicating a dynamic adaptation to environmental interactions. The study underscores the importance of considering the ontogeny of plant parts in understanding the ecological roles and potential applications of P. rivinoides in medicine and agriculture. The findings contribute to the overall knowledge of Piperaceae chemodiversity and ecological adaptations, offering insights into the plant's interaction with its environment and its potential uses based on chemical composition.

Insecticidal activity of essential oils from Piper aduncum against Ctenocephalides felis felis: a promising approach for flea control

Piper aduncum L., a Brazilian medicinal plant, is known for its bioactive properties, including repellent and insecticidal effects. This study investigated the insecticidal potential of essential oils (EOs) from P. aduncum, collected during the dry and rainy seasons, against fleas (Ctenocephalides felis felis Bouché, 1835) in egg and adult stages. The EOs were obtained by hydrodistillation using a modified Clevenger apparatus for 2 h. Qualitative and quantitative analysis were performed via gas chromatography. The findings revealed that dillapiole was the predominant substance in both EOs, accounting for 77.6% (rainy) and 85.5% (dry) of the EOs. These EOs exhibited high efficacy against the parasite C. felis felis, resulting in 100% egg mortality at a concentration of 100 μg/mL and 100% mortality for adult fleas starting from 1,000 μg/mL. Dillapiole standard was also effective but at a relatively high concentration. This finding suggested that EOs from P. aduncum exhibit cytotoxicity against these pests and might hold potential for commercial production, offering practical applications for such bioprospecting. This study uniquely revealed that the EOs from P. aduncum, which is rich in dillapiole, demonstrated pulicidal activity against the parasite C. felis felis, particularly in inhibiting the hatching of the eggs of these parasites.