A composição química de plantas é afetada por estresses abióticos e bióticos. No caso da Mangifera indica foi observado que as suas folhas respondem claramente a ataque do gafanhoto Tropidacris collaris e por dano causado mecanicamente, biossintetizando diversos compostos voláteis associados aos estresses, principalmente fenilpropanóides como miristicina, dilapiol, eugenol e acetato de eugenol. A identificação desses fenilpropanóides em folhas de mangueira como resposta aos estresses abióticos e bióticos é crucial à pesquisa de novos pesticidas naturais, considerando que fenilpropanóides possuem diversas atividades biológicas, principalmente inseticidas.

It is now widely recognized that plant’s chemical composition is affected by both abiotic and biotic stress. This is the case of Mangifera indica leaves which respond very clearly to the damages caused by the grasshopper Tropidacris collaris and to mechanical damage by biosynthesizing several stress-related volatile compounds, mainly phenylpropanoids such as myristicin, dillapiole, eugenol and eugenol acetate. The identification of these phenylpropanoids in mango leaves in response to abiotic and biotic stress factors is a key step in the search for new natural pesticides, since phenylpropanoids have various biological activities, mainly insecticidal.

The essential oils from leaves, stems and fruits of Piper divaricatum were analyzed by GC-MS. The tissues showed high safrole content: leaves (98%), fruits (87%) and stems (83%), with yields of 2.0, 4.8 and 1.7%, respectively. This is a new alternative source of safrole, a compound widely used as a flavoring agent and insecticide. The leaf's oil showed antibacterial activity against gram-negative bacteria while safrole was active against Salmonella Typhimurium and Pseudomonas aeruginosa. In addition, the study of circadian rhythm of the safrole concentration in the essential oils of leaves showed a negligible variation of 92 to 98%.

No presente estudo, 32 extratos hexânicos e etanólicos de Protium bahianum, P. heptaphyllum, Croton sellowii, C. rhamnifolius, C. jacobinensis, C. micans e Muntingia calabura, foram avaliados para atividade antibacteriana, pelo método de difusão em disco. Ensaios de citoxicidade foram realizados com o modelo do microcrustáceo Artemia salina Leach para determinar a concentração letal para 50% dos indivíduos (CL50 µg/mL). A presença de atividade antibacteriana foi observada com os extratos hexânicos das flores de M. calabura contra B. subtilis, e extratos etanólicos das folhas contra S. aureus and B. subtilis na concentração de 1 mg/mL. Dentre os 32 extratos, 19 apresentaram toxicidade baixa ou ausente (CL50 > 250 µg/mL), 6 mostraram toxicidade moderada (CL50 entre 80 µg/mL e 250 µg/mL) e 7 foram muito tóxicos (CL50 < 80 µg/mL).

In the present study, 32 hexane and ethanol extracts of Protium bahianum, P. heptaphyllum, Croton sellowii, C. rhamnifolius, C. jacobinensis, C. micans and Muntingia calabura were screened for antibacterial activity by the disc-diffusion method. Cytotoxicity assays using the brine shrimp Artemia salina Leach as a model were performed to determine lethal doses for 50% of individuals (LC50 µg/mL). Antibacterial activity was found in flowers hexane extracts of M. calabura against B. subtilis, and leaves ethanol extracts against S. aureus and B. subtilis at concentration of 1mg/mL. Among 32 extracts, 19 showed low or no toxicity (LC50 > 250 µg/mL), 6 showed moderate toxicity (LC50 between 80 µg/mL and 250µg/mL), and 7 were highly toxic (LC50 < 80 µg/mL).