Terezinha de Jesus Faria

Antifungal activity of essential oil isolated from Ocimum gratissimum L. (eugenol chemotype) against phytopathogenic fungi

An investigation of antifungal activity of the essential oil obtained by steam-distillation (1.1% w/w) of the aerial parts of Ocimum gratissimum and of an ethanolic extract from the steam-distillation residue was carried out using the agar diffusion method. The results revealed that the essential oil inhibited the growth of all fungi tested, including the phytopathogens, Botryosphaeria rhodina, Rhizoctonia sp. and two strains of Alternaria sp., while the extract from the residue was inactive. The essential oil was subjected to TLC bioautography used to detect fungitoxic constituents. The compound that showed antifungal activity was isolated and identified as eugenol. GC/MS analysis showed that eugenol was the main constituent of the essential oil studied. The antifungal activity of eugenol was evaluated against a species of Alternaria isolated from tomato (A1) and Penicillium chrysogenum. The minimal inhibitory concentrations of eugenol were 0.16 and 0.31 mg/disc for Alternaria sp. (A1) and P. chrysogenum, respectively.

Efficacy of topical formulations containing Pimenta pseudocaryophyllus extract against UVB-induced oxidative stress and inflammation in hairless mice.

Plants rich in antioxidant substances may be a promising strategy for preventing UV-induced oxidative and inflammatory damage of the skin. Pimenta pseudocaryophyllus is native to Brazil and presents flavonoids and other polyphenolic compounds in high concentration. Thus, the present study evaluated the possible effects of topical formulations containing P. pseudocaryophyllus ethanolic extract (PPE) at inhibiting UV-B irradiation-induced oxidative stress and inflammation. PPE was administered on the dorsal skin of hairless mice using two formulations: F1 (non-ionic emulsion with high lipid content) and F2 (anionic emulsion with low lipid content) before and after UV-B irradiation. The following parameters were evaluated in skin samples: edema, myeloperoxidase activity, cytokines levels, matrix metalloprotease-9 (MMP-9) secretion/activity, reduced glutathione (GSH), superoxide anion and lipid peroxidation levels, and mRNA expression for glutathione reductase and gp91phox. The UV-B irradiation increased all parameters, except for IL-10 levels and glutathione reductase mRNA expression, which were not altered, and GSH levels, which were reduced by exposure to UV-B light. Treatments with F1 and F2 containing PPE inhibited UV-B-induced edema formation (89% and 86%), myeloperoxidase activity (85% and 81%), IL-1β production (62% and 82%), MMP-9 activity (71% and 74%), GSH depletion (73% and 85%), superoxide anion (83% and 66%) and TBARS (100% and 100%) levels, increased glutathione reductase (2.54 and 2.55-fold) and reduced gp91phox (67% and 100%) mRNA expression, respectively. F2 containing PPE also increased IL-10 levels. Therefore, this study demonstrates the effectiveness of topical formulations containing PPE in inhibiting UV-B irradiation-induced inflammation and oxidative stress of the skin.

Potenciação alelopática de extratos vegetais na germinação e no crescimento inicial de picão-preto e alface

O picao-preto (Bidens pilosa L.) e uma planta daninha muito agressiva, que esta presente em quase todo Brasil. O principal metodo de controle e o quimico, porem apresenta elevado impacto ambiental, risco de intoxicacao humana e possibilidade de causar fitotoxicidade as culturas. O objetivo do trabalho foi avaliar o efeito alelopatico de extratos etanolicos de Eucalyptus citriodora Hook. e Pinus elliottii L. na germinacao e no crescimento inicial de picao-preto e alface (Lactuca sativa L.). Foram testadas quatro concentracoes de cada extrato (0,25; 0,50; 1,0 e 2,0 %) alem do controle (0,0 %) agua destilada com Tween 20 a 0,08 %. O delineamento experimental foi o inteiramente casualizado, com quatro repeticoes em condicoes de laboratorio. O extrato de P. elliottii nao causou efeito alelopatico sobre o picao-preto e o alface. O extrato de E. citriodora reduziu significativamente o indice de velocidade de germinacao (IVG) do picao-preto em todas as concentracoes testadas quando comparadas com o controle (0,0%), porem para a alface o IVG foi significativo apenas na concentracao de 2,0 %. Para o comprimento da raiz nao foi possivel observar diferenca significativa entre os tratamentos para os dois extratos testados tanto para o alface como para o picao preto.

Diterpenos, triterpenos e esteróides das flores de Wedelia paludosa

Phytochemical investigation of the flowers of Wedelia paludosa afforded two diterpenes, ent-kaur-16-en-19-oic acid and ent-kaur-9(11),16-dien-19-oic acid, three acylated triterpenes, 3b-O-hexa-decanoylolean-12-en-28-oic acid, 3b-O-pentadecanoylolean-12-en-28-oic acid and 3b-O-tetradecanoylolean-12-en-28-oic acid, and three steroids, stigmasterol, 3b-O-b-D-glycopyranosyl sitosterol and 3b-O-b-D-glycopyrano-sylstigmasterol. The substances were identified by their spectral data.

Antimicrobial activity of essential oils from Pimenta pseudocaryophyllus and Tynanthus micranthus

The present study describes the chemical composition and antimicrobial activity of essential oils obtained by hydrodistillation from the leaves of Pimenta pseudocaryophyllus (1.0% w/w) and Tynanthus micranthus (1.1% w/w). GC and GC/MS analysis demonstrated that eugenol was the only component in the T. micranthus essential oil (99.9%) and the major component in the P. pseudocaryophyllus essential oil (92.59%), which also presented methyleugenol, terpinen-4-ol, o-cymene and (E)-caryophyllene, among others. Both the oils presented antimicrobial activity against bacteria, yeast and filamentous fungi tested.The Bioautography test revealed that eugenol was the bioactive component in both the oils against Cladosporium herbarum. This is the first report about the T. micranthus essential oil, and the antifungal activity of P. pseudocaryophyllus. The results confirmed the potential of eugenol-rich essential oils not only as a source of flavor compounds, but also of use as antimicrobial agent in agriculture and in pharmaceutical and food products.

Antimicrobial activity and chemical investigation of Brazilian Drosera

The antimicrobial activity of three different extracts (hexanic, ethyl acetate, methanol) obtained from Brazilian Drosera species (D. communis, D. montana var. montana, D. brevifolia, D. villosa var. graomogolensis, D. villosa var. villosa, Drosera sp. 1, and Drosera sp. 2 ) were tested against Staphylococcus aureus (ATCC 25923), Enterococcus faecium (ATCC23212), Pseudomonas aeruginosa (ATCC27853), Escherichia coli (ATCC11229), Salmonella choleraesuis (ATCC10708), Klebsiella pneumoniae (ATCC13883), and Candida albicans (a human isolate). Better antimicrobial activity was observed with D. communis and D. montana var. montana ethyl acetate extracts. Phytochemical analyses from D. communis, D. montana var. montana and D. brevifolia yielded 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin); long chain aliphatic hydrocarbons were isolated from D. communis and from D. villosa var. villosa, a mixture of long chain aliphatic alcohols and carboxylic acids, was isolated from D. communis and 3b-O-acetylaleuritolic acid from D. villosa var. villosa.

Eudesmanolide Lactones from Wedelia paludosa

Abstract Two new eudesmanolide lactones (1 and 2) were isolated from the flowers of Wedelia paludosa. The structures of these sesquiterpenoids were elucidated from spectral data.

Alcalóides de flores e folhas de Erythrina speciosa Andrews

In vitro bioassays with leave extracts of Erythrina speciosa showed promising activity against Trypanosoma cruzi. From the flowers of E. speciosa two alkaloids were isolated: erysotrine and erythartine. The leaves furnished one alkaloid, nororientaline. The structures were determined on the basis of spectroscopic evidence. This is the first report about the investigation of alkaloids in flowers and leaves of this species, as well the first report of nororientaline occurrence in this plant.