Allan dos Santos Polidoro

Nicotiana alata (hawkmoth-pollinated) and N. forgetiana (hummingbird-pollinated) are two closely related species that were considered reproductively isolated due to their divergent pollination systems. However, the discovery of a natural hybrid zone challenges this view. Floral volatile profiles of these species and their natural hybrids were characterized to identify possible mechanisms and consequences of unexpected gene flow. Organ-specific (corolla, pollen) and diel (day, night) volatile emissions were analyzed using HS-SPME-GC-MS. Corolla scents were dominated by oxygenated monoterpenoids, while pollen blends were rich in microbial-associated compounds, such as acetoin. Hybrid scent profiles more closely match their floral phenotype than their genomic ancestry, with intermediate hybrids emitting blends distinct from those of both parental species. The discovery of a natural hybrid zone, combined with phenotype-specific scent emissions, challenges the view of strict pollinator isolation. Floral scent presents a complex, modular trait that may facilitate hybridization in this system.

Nicotiana alata (hawkmoth-pollinated) and N. forgetiana (hummingbird-pollinated) are two closely related species that were considered reproductively isolated due to their divergent pollination systems. However, the discovery of a natural hybrid zone challenges this view. Floral volatile profiles of these species and their natural hybrids were characterized to identify possible mechanisms and consequences of unexpected gene flow. Organ-specific (corolla, pollen) and diel (day, night) volatile emissions were analyzed using HS-SPME-GC-MS. Corolla scents were dominated by oxygenated monoterpenoids, while pollen blends were rich in microbial-associated compounds, such as acetoin. Hybrid scent profiles more closely match their floral phenotype than their genomic ancestry, with intermediate hybrids emitting blends distinct from those of both parental species. The discovery of a natural hybrid zone, combined with phenotype-specific scent emissions, challenges the view of strict pollinator isolation. Floral scent presents a complex, modular trait that may facilitate hybridization in this system.

Introduction: Piper amalago has a distribution from Mexico to Brazil; their aerial parts have been used in folk medicine to treat diuretic and kidney diseases.Objective: The purpose of this study was to obtain a deeper understanding of the chemical composition of essential oils (EOs) extracted from both the leaves and stems of P. amalago, compare them, and evaluate their antilithiasic activity and acute toxicity.Methodology: Extraction was performed by hydrodistillation, whereas chemical characterisation by two‐dimensional gas chromatography coupled with rapid‐scanning quadrupole mass spectrometry (GC×GC/qMS). The antilithiasic activity was evaluated by the effect of the EOs on calcium oxalate crystallisation in vitro. The turbidity index and the number of crystals formed were determined and used as an estimative of the activity. In the acute toxicity assay, the effects of a single oral dose of the EOs in Wistar rats were determined. General behaviour, adverse effects, and mortality were determined.Results: A total of 322 compounds were identified in the EOs. The sesquiterpenes displayed the highest contribution in leaves EOs among which included bicyclogermacrene and δ‐cadinene. Sesquiterpenes and oxygenated sesquiterpenes displayed the highest contribution in EOs from stems, among which included bicyclogermacrene and α‐cadinol. The EOs demonstrated an excellent action on the crystals growth inhibition, and the oral dose tested did not induce significant changes in the parameters for acute toxicity.Conclusion: The oils have a high chemical complexity, and there are differences between their compositions, which could explain the observed differences in antilithiasic activity. The findings support the use of this plant in folk medicine to treat kidney diseases.

The present study investigated the essential oil obtained from Campomanesia guazumifolia (Cambess.) O. Berg, an aromatic plant used in Brazilian folk medicine. The chemical composition was performed by GC×GC/qMS. The antioxidant and antimicrobial activities were evaluated by DPPH and BCB and, MIC assays, respectively. Sixty-eight compounds were identified in the oil, where the major compounds were bicyclogermacrene (15%), globulol (5%) and spathulenol (5%). Sesquiterpene hydrocarbons (29 compounds) and oxygenated sesquiterpenes (20 compounds) were the most representative classes of terpenes. DPPH (IC₅₀ value 26.1 ± 0.5 μg/mL) and BCB (68.3 ± 1.5%) values indicated a significant antioxidant activity. The essential oil strongly inhibited Staphylococcus aureus (MIC 15 ± 0.1 μg/mL), Escherichia coli (MIC 25 ± 0.2 μg/mL) and Candida albicans (MIC 5 ± 0.1 μg/mL). The results give a deeper understanding of the chemical composition and report for the first time the antioxidant and antimicrobial potential of the C. guazumifolia essential oil.