José Milton Alves

Chemical composition, antioxidant and antibacterial activities of essential oils from leaves and flowers of Eugenia klotzschiana Berg (Myrtaceae)

Many essential oils (EOs) of different plant species possess interesting antimicrobial effects on buccal bacteria and antioxidant properties. Eugenia klotzschiana Berg (pêra-do-cerrado, in Portuguese) is a species of Myrtaceae with restricted distribution in the Cerrado. The essential oils were extracted through the hydrodistillation technique using a modified Clevenger apparatus (2 hours) and chemically characterized by GC-MS. The major compounds were α-copaene (10.6 %) found in oil from leaves in natura, β-bisabolene (17.4 %) in the essential oil from dry leaves and α-(E)-bergamotene (29.9 %) in oil from flowers. The antioxidant activity of essential oils showed similarities in both methods under analysis (DPPH and ABTS˙+) and the results suggested moderate to high antioxidant activity. The antibacterial activity was evaluated by determining minimum inhibitory concentrations (MICs), using the microdilution method. MIC values below 400 µg/mL were obtained against Streptococcus salivarius (200 µg/mL), S. mutans (50 µg/mL), S. mitis (200 µg/mL) and Prevotella nigrescens (50 µg/mL). This is the first report of the chemical composition and antibacterial and antioxidant activities of the essential oils of E. klotzschiana. These results suggest that E. klotzschiana, a Brazilian plant, provide initial evidence of a new and alternative source of substances with medicinal interest.

Chemical Composition and Biological Activities of the Essential Oils from the Fresh Leaves of Citrus limonia Osbeck and Citrus latifolia Tanaka (Rutaceae)

This study aimed at determining, for the first time, the chemical composition of the essential oils from fresh leaves of Citrus limonia and Citrus latifolia and evaluating its in vitro antibacterial, trypanocidal, leishmanicidal and cytotoxic effects. The essential oils from fresh leaves of C. latifolia and C. limonia were extracted by hydro distillation and analyzed by GC-MS. The oil yield was 0.8% for C. latifolia and 0.5% for C. limonia, whereas 17 and 18 chemical components were identified for C. latifolia and for C. limonia, respectively. Major components were limonene (46.3 %), nerol (10.0 %) and 1,8-cineole (13.4 %). In vitro antibacterial activity was evaluated against the bacteria Streptococcus mitis, Streptococcus mutans, Streptococcus sanguinis, Streptococcus sobrinus and Bacteroides fragilis by the broth dilution method. Protozoa of the Trypanosomatidae family cause neglected tropical diseases, such as trypanosomiasis, whose treatment has depended on few available drugs. Therefore, the essential oils from fresh leaves of C. limonia and C. latifolia were also evaluated against the Y strain of Trypanosoma cruzi trypomastigotes, resulting in IC50 = 88.2 μg/mL and 51.7 μg/mL, respectively. Regarding the evaluation of the cytotoxic activity against fibroblasts LLCMK2 line, the essential oil from C. limonia (CC50 = 422.9 μg/mL) and C. latifolia (CC50 = 502.9 μg/mL) showed moderate cytotoxicity. The leishmanicidal activity of the essential oils from fresh leaves of C. limonia and C. latifolia were evaluated against promastigote forms of Leishmania amazonensis, resulting in IC50 = 2.63 μg/mL and 2.03 μg/mL, respectively. Thus, the essential oils from fresh leaves of Citrus limonia and Citrus latifolia had moderate antibacterial and trypanocidal activities and significant leishmanicidal activity.

ÓLEO ESSENCIAL DAS FLORES DE Eugenia klotzschiana (MYRTACEAE): SUA COMPOSIÇÃO QUÍMICA E ATIVIDADES TRIPANOCIDA E CITOTÓXICA IN VITRO

A Doenca de Chagas e causada pelo Trypanosoma cruzi e os medicamentos mais utilizados em seu tratamento sao o nifurtimox e benzonidazol, que causam varios efeitos colaterais. O uso de produtos naturais no tratamento de doencas aumentou nos ultimos anos e as plantas tornaram-se uma alternativa promissora para o desenvolvimento de novos medicamentos. Portanto, este estudo teve como objetivo determinar a composicao quimica do oleo essencial das flores in natura de Eugenia klotzchiana e avaliar pela primeira vez seus potenciais tripanocida e citotoxico in vitro . O oleo essencial das flores in natura foi obtido por hidrodestilacao em aparato Clevenger e sua composicao quimica foi determinada por CG-EM. Os principais compostos encontrados no oleo essencial das flores foram: ?-cariofileno (21,1 %), biciclogermacreno (10,2 %) e espatulenol (20,9 %). Os resultados mostraram que o oleo essencial apresentou promissora atividade tripanocida contra formas tripomastigotas de Trypanosoma cruzi (IC 50 = 20,2 ?g/mL) e moderada citotoxicidade sobre fibroblastos na faixa de concentracao analisada (CC 50 = 250,5 ?g/mL). Em suma, o oleo essencial das flores in natura de Eugenia klotzchiana pode ser considerado uma excelente fonte de compostos bioativos para o desenvolvimento de novos medicamentos antiparasitarios. Palavras-chave: Eugenia klotzchiana , Myrtaceae, oleo essencial, flores, Trypanosoma cruzi , cytotoxic analysis.

In vitro antiparasitic activity and chemical composition of the essential oil from Protium ovatum leaves (Burceraceae)

Leishmaniasis and trypanosomiasis are globally widespread parasitic diseases which have been responsible for high mortality rates. Since drugs available for their treatment are highly hepatotoxic, nephrotoxic and cardiotoxic, adherence to therapy has been affected. Thus, the search for new, more effective and safer drugs for the treatment of these diseases is necessary. Natural products have stood out as an alternative to searching for new bioactive molecules with therapeutic potential. In this study, the chemical composition and antiparasitic activity of the essential oil from Protium ovatum leaves against trypomastigote forms of Trypanosoma cruzi and the promastigote forms of Leishmania amazonensis were evaluated. The essential oil was promising against trypomastigote forms of T. cruzi (IC50= 28.55 μg.mL-1) and L. amazonensis promastigotes (IC50 = 2.28 μg.mL-1). Eighteen chemical constituents were identified by Gas Chromatography coupled to Mass Spectrometry (GC-MS) in the essential oil, whose major constituents were spathulenol (17.6 %), caryophyllene oxide (16.4 %), β-caryophyllene (14.0 %) and myrcene (8.4 %). In addition, the essential oil from P. ovatum leaves had moderate cytotoxicity against LLCMK2 adherent epithelial cell at the concentration range under analysis (CC50 = 150.9 μg.mL-1). It should be highlighted that this is the first report of the chemical composition and anti-Trypanosoma cruzi and anti-Leishmania amazonensis activities of the essential oil from Protium ovatum leaves.

Liming and Phosphating in Dalbergia nigra (Vell.) Allemão ex Benth. Seedlings

This study aimed to verify the effect of phosphorus and liming doses on the morphological and nutritional characteristics of D. nigra seedlings. The experiment was conducted using a completely randomized 4x4 factorial design. The treatments consisted of 4 levels of liming and 4 phosphorus doses. Morphological characteristics and nutritional analyses of plants were measured. There were no significant interactions between liming x P. Morphological characteristics presented differences for liming and phosphorus when analyzed separately. The best productive performances were found between an increase in base saturation between 48.07% and 54.76%. Morphological characteristics showed a linear behavior for P. Both the application of liming and P promoted positive effects on D. nigra growth.

Essential oils from Piper aduncum inflorescences and leaves: chemical composition and antifungal activity against Sclerotinia sclerotiorum

Even though essential oils from Piper aduncum (Piperaceae) have different biological activities, little is known about their application to agricultural areas. White mold is a plant disease caused by the phytopathogen Sclerotinia sclerotiorum, which needs to be controlled by alternative measures. This study aimed at evaluating the effect of essential oils from P. aduncum leaves (PL-EO) and inflorescences (PI-EO) on the mycelial growth of S. sclerotiorum. Essential oils from P. aduncum were obtained by hydrodistillation by a Clevenger-type apparatus while their chemical composition was analyzed by GC-MS and GC-FID. Piperitone (23.4 %), myristicin (12.4 %), terpinen-4-ol (12.3 %), β-caryophyllene (7.2 %), α-humulene (6.9 %), germacrene-D (6.9 %) and dillapiol (6.3 %) were the main constituents found in oils from P. aduncum. The in vitro antifungal activity showed that PI-EO dose above 30 µL inhibited mycelial growth in 100 %, whereas PL-EO at 50 µL inhibited it in 98.74 %. This is the first report of the chemical composition of PI-EO and results suggest that the essential oils under evaluation have high potential to control the phytopathogenic fungus S. sclerotiorum.

Composição Química do Óleo Essencial de Cardiopetalum calophyllum Schltdl. (Annonaceae) e suas Atividades Antioxidante, Antibacteriana e Antifúngica

The Annonaceae family consists of ~135 genera with diverse species and a large number of chemical compounds arising from the secondary metabolism. However, the chemical composition of the essential oil of several species of the family such as Cardiopetalum calophyllum has not been completely determined. The leaves of Cardiopetalum calophyllum (Annonaceae) were collected during different months of the year, between 5:00 and 8:00 h in the morning, to determine the chemical composition of essential oils. In this study, the essential oils extracted from the leaves of C. calophyllum , collected in typical areas of the Cerrado of Goias, were characterized. The essential oil was extracted by hydrodistillation for 4 h using a Clevenger apparatus. The chemical analysis was carried out by gas chromatography–mass spectrometry (GC-MS), and the constituents were identified by comparing the spectra and retention index obtained with those available in the literature. The chemical analyses showed high concentrations of sesquiterpene hydrocarbons. The antioxidant, antibacterial and antifungal activities of the essential oil of C. calophyllum are described for the first time in this work .