Ursolic acid, an important bioactive compound, was isolated from ethanol extract of aerial parts of Sambucus australis. In order to develop bioactive ursolic acid derivatives, two semi-synthetic compounds were obtained through modification at C-3. The antibacterial activity of the ursolic acid and its derivatives was investigated. The microdilution method was used for determination of the minimal inhibitory concentration (MIC), against twelve bacterial strains. The influence of ursolic acid and its derivatives on the susceptibility of some bacterial pathogens to the aminoglycosides antibiotics neomycin, amikacin, kanamycin and gentamicin was evaluated. The most representative synergistic effect was observed by 3β-formyloxy-urs-12-en-28-oic acid at the concentration of 64 μg/mL in combination with kanamycin against Escherichia coli (27), a multidrug-resistant clinical isolate from sputum, with reduction of MIC value from 128 μg/mL to 8 μg/mL. Ursolic acid and its derivatives were examined for their radical scavenger activity using the DPPH assay, and showed significant activity.

Larvicidal activities against Aedes aegypti of technical cashew (Anarcadium Occidentale L.) nut shell liquid (CNSL) and its main constituents, cardanol, cardol and their products of hydrogenation were evaluated. In addition, the structure-activity relationship is also discussed.

A atividade larvicida de quatro saponinas monodesmosídicas (1-4) isoladas de Pentaclethra macroloba e de uma saponina bidesmosídica (5) isolada de Cordia piauhiensis foi avaliada sobre larvas de estágio 3 de Aedes aegypti. As larvas foram expostas a várias concentrações (500, 250, 100, 50, 25 e 12,5 mg/mL) das saponinas por um período de 24 h. Os resultados indicam que somente as saponinas 1-3 mostraram alta atividade larvicida, com CL50 variando de 18,6 a 27,9 mg/mL. Estes resultados ressaltam as potencialidades destas saponinas como possíveis agentes larvicidas naturais.

Estudo fitoquímico dos extratos hexânico e metanólico dos frutos de Pterodon polygalaeflorus Benth forneceu três diterpenos furânicos: 6-alfa-acetoxivouacapano, 6-alfa-hidroxivouacapano e vouacapano, sendo este ultimo relatado pela primeira vez como produto natural. Avaliação da atividade sobre larvas de estágio 3 de Aedes aegypti de 6-alfa-acetoxivouacapano, dos extratos hexânico e metanólico dos frutos de P. polygalaeflorus e de seu óleo essencial também é relatada. Apenas o extrato hexânico mostrou boa atividade com CL50 23,99 ± 0,75 µg/mL, podendo ser considerado um potencial agente larvicida. Chemical investigation of the hexane and methanol extracts of the fruits of Pterodon polygalaeflorus (Leguminosae) resulted in the isolation and identification of furanic diterpenes: 6-alpha-acetoxivouacapane, 6-alpha-hidroxyvouacapane and vouacapane, which is related by the first time as a natural product. The structures of these compounds were established by spectroscopic analysis, including 2D NMR experiments. The 6-alpha-acetoxivouacapane, the hexane and methanol extracts, and the essential oil were evaluated on 3rd instar larvae of Aedes aegypti and only the hexane extract showed good larvicidal activity with LC50 23.99 ± 0.75 µg/mL

The essential oils obtained by hydrodistillation from fresh leaves of Vitex agnus-castus and Ocimum campechianum, and from fresh inflorescences of Ocimum carnosum were analysed by GC-FID and GC-MS. The major components of V. agnus-castus essential oil were identified as 1,8-cineole (47.9%), terpinyl α-acetate (11.6%), sabinene (11.2%) and caryophyllene oxide (9.7%), while in the O. campechianum essential oil were eugenol (72.1%), β-elemene (6.8%), (E)-caryophyllene (6.4%) and bicyclogermacrene (5.2%). Linalool (79.0%), α-epi-cadinol (5.4%), terpinen-4-ol (3.2%) and 1,8-cineole (2.8%) were the major constituents in the O. carnosum essential oil. The essential oils were subsequently evaluated for their larvicidal and cytotoxic activities. Larval bioassay against Aedes aegypti of V. agnus-castus, O. campechianum and O. carnosum essential oils showed LC50 values of 97.55 ± 0.35, 81.45 ± 0.35 and 109.49 ± 0.35 μg/mL, respectively. The in vitro cytotoxic activities of the essential oils has been evaluated on breast adenocarcinoma (MCF-7), lung carcinoma (NCI-H292), pro-myelocytic leukemia (HL-60), and cervical adenocarcinoma (HEP-2) human cell lines, and pro-myelocytic leukemia cells lines (HL-60) were found to be the most sensitive to all the essential oils tested than the others. This is the first report on larvicidal and cytotoxic activities of these essential oils.