Maria Teresa Freitas Bara

Purification and characterization of an exo-β-1,3-glucanase produced by Trichoderma asperellum

Trichoderma asperellum produces at least two extracellular beta-1,3-glucanases upon induction with cell walls from Rhizoctonia solani. A beta-1,3-glucanase was purified by gel filtration and ion exchange chromatography. A typical procedure provided 35.7-fold purification with 9.5% yield. The molecular mass of the purified exo-beta-1,3-glucanases was 83.1 kDa as estimated using a 12% (w/v) SDS-electrophoresis slab gel. The enzyme was only active toward glucans containing beta-1,3-linkages and hydrolyzed laminarin in an exo-like fashion to form glucose. The K(m) and V(max) values for exo-beta-1,3-glucanase, using laminarin as substrate, were 0.087 mg ml(-1) and 0.246 U min(-1), respectively. The pH optimum for the enzyme was pH 5.1 and maximum activity was obtained at 55 degrees C. Hg(2+) strongly inhibited the purified enzyme.

Estudo farmacognóstico das folhas de Pimenta pseudocaryophyllus (Gomes) L.R. Landrum - Myrtaceae

The goal of this research was to obtain quality control parameters for the identification of the plant drug of Pimenta pseudocaryophyllus (Gomes) L. R. Landrum that occurs in Brazilian savannah. So, two samples were collected, one in Minas Gerais state - Brazil, and the other one in Brasilia city - DF - Brazil, and the vouchers were deposited in the UFG Herbarium code number UFG-27159 and Ezechias Paulo Heringer Herbarium code number 21745-0, respectively. Part of the botanical material in both samples was prepared for microscopic analysis. The other one was air-dried, crushed to powder and used for phytochemical screening. The study has shown that P. pseudocaryophyllus leaves are hypostomatic, there are abundant unicellular trichomes in abaxial surface, there are secretory cavities with oily content and epidermal cells have thick wall. Tannins, phenolic compounds and flavonoids were detected in the phytochemical screening. The tannins had been quantified by different methods involving colorimetric and protein precipitation reactions, getting different results. This fact calls the attention for the necessity of specifying the method used together with the minimum tannins limit established. The results configure as important parameters for the quality control of the plant material and denote that the species in study take an important potential as herbal medicine that it deserves to be investigated in pharmacologic and toxicologic studies.

Ação do óleo essencial de Syzygium aromaticum (L.) Merr. & L.M.Perry sobre as hifas de alguns fungos fitopatogênicos

Action of Syzygium aromaticum (L.) Merr. & L.M.Perry essential oil on the hyphae of some phytopathogenic fungi. Currently, the use of alternative methods to control diseases and pests in agriculture has been a recognized and necessary practice to minimize damages to the environment and public health. This study aimed to investigate the action of clove (Syzygium aromaticum (L.) Merr. & L.M.Perry) essential oil on the in vitro mycelial growth of the phytopathogenic fungi Rhizoctonia solani, Fusarium solani, Fusarium oxysporum and Macrophomina phaseolina. Analysis by gas chromatography-mass spectrometry allowed the identification of eugenol (83.6%), eugenyl acetate (11.6%) and caryophyllene (4.2%). Microscopic evaluation of mycelia showed several morphological changes such as presence of vacuoles, cell content disorganization, decreased cell wall clearness, intense fragmentation and lower turgescence of hyphae. Clove essential oil showed fungicidal activity at 0.15% on the growth of R. solani, F. oxysporum and F. solani, but not for M. phaseolina. These results indicate favorable perspectives for future use of clove essential oil to control these phytopathogens in agriculture.

Triterpenes involved in the anti-inflammatory effect of ethanolic extract of Pterodon emarginatus Vogel stem bark

Bioassay-guided fractionation of the ethanolic extract of Pterodon emarginatus Vogel stem bark (EtEx) resulted in the isolation and characterization of lupeol and betulin. Their structures were elucidated by spectroscopic methods including IR, 1H-NMR, 13C-NMR and comparison with literature values. This study showed the anti-inflammatory activity of EtEx, the hexane (HexL) and dichloromethane (DichL) layers, and lupeol and betulin. The extract, HexL, DichL, lupeol and betulin were able to inhibit acetic acid-induced writhing. In the formalin test, EtEx decreased licking time only in the second phase characterizing anti-inflammatory activity. In the oil-induced ear oedema test, EtEx, lupeol and betulin decrease edema formation. In conclusion, EtEx has antinociceptive effects arising from anti-inflammatory activity; this activity could be due to the presence of lupeol and betulin.

Production of laccase by Pynoporus sanguineus using 2,5 - Xylidine and ethanol

Enzyme application in biotechnological and environmental processes has had increasing interest due to its efficiency, selectivity and mainly for being environmentally healthful, but these applications require a great volume of enzymes. In this work the effect of different concentrations of ethanol and 2,5-xylidine on growth and production of laccase by Pycnoporus sanguineus was investigated. In a medium containing 200 mg.L-1 of 2,5-xylidine or 50 g.L-1 of ethanol, the maximum activity of laccase was 2019 U.L-1 and 1035 U.L-1, respectively. No direct correlation between biomass and activity of laccase was observed for any of the inducers used during the tests. Ethanol concentrations, larger than or equal to 20 g.L-1, inhibited the radial growth of P. sanguineus. This study showed that ethanol, which has less toxicity and cost than the majority of the studied inducers, presents promising perspectives for laccase production by P. sanguineus.

Microencapsulation of Essential Oil from Fruits of Pterodon emarginatus Using Gum Arabic and Maltodextrin as Wall Materials: Composition and Stability

The present investigation reports the microencapsulation of the essential oil from the fruits of Pterodon emarginatus by spray drying using gum arabic and maltodextrin. X-ray diffraction studies established that the essential oil was entrapped within the microcapsules rather than being adsorbed onto the surface. The morphology of the microcapsules was analyzed by scanning electron microscopy (SEM). The particle size (Sauter [3,2]) and particle size distribution of microcapsules were also determined. The microcapsules were evaluated for the content and stability of both volatiles and the major component, β-caryophyllene, for 45 days. A 1:3:3.6 blend of essential oil: gum arabic: maltodextrin offered the best protection, with 98.63% of the essential oil being retained and the same proportion of β-caryophyllene being entrapped. The obtained results showed that the microcapsules might have potential applications in the protection of essential oil from fruits of P. emarginatus and contribute to the development of an herbal medicine.

Spray drying of Eugenia dysenterica extract: effects of in-process parameters on product quality

A 23 full factorial design was used to assess the impact of spraying air flow rate (30-50 L/min), drying air inlet temperature (90-150 oC) and extract feed rate (4-6 g/min) on the quality of Eugenia dysenterica DC., Myrtaceae, spray-dried extracts. Response surface methodology (RSM) was applied to analyze the significance of the effects of process factors on product quality and to obtain fitted equations to predict dry powder properties. Powder yields were satisfactory, ranging from 34.64 to 63.92%. The dried products showed moisture contents and water activities below 5% and 0.5, respectively. The recuperation ratios of total polyphenols, tannins and flavonoids ranged from 88.66 to 99.07%, 70.38 to 81.87% and 74.51 to 98.68%, respectively. Additionally, in some conditions the parameters related to dry product’s flowability and compressibility varied over a range acceptable for pharmaceutical purposes. RSM proved that studied factors significantly affected most of the quality indicators at different levels. The spray drying technology is an attractive and promising alternative for the development of intermediate phytopharmaceutical products of E. dysenterica.

Estudo da atividade antibacteriana de plantas medicinais, aromáticas e corantes naturais

Medicinal plants, natural colour and spices were examined in vitro for antibacterial effects on the growth of Escherichia coli (EPEC) serotype O:125, Salmonella thyphimurium, Staphylococcus aureus, Listeria monocytogenes ATCC 7644 and Yersinia enterocolitica ATCC 9610. The most effective medicinal plant was Lippia sidoides at concentration of 3 percent (w/v), that added to Trypticase Soya Broth completely inhibited the growth of S. thyphimurium, S. aureus, L. monocytogenes and Y. enterocolitica. Among the spices, the cloves (Sysygium aromaticum) extract had the strongest inhibitory activity on the growth of E. coli, S. thyphimurium e Y. enterocolitica demonstred through the agar difussion technique. Sage (Salvia officinalis) and rosemary (Rosmarinus officinalis) extracts inhibited the growth of L. monocytogenes and S. aureus. The nutmeg (Myristica fragrans) extract also prevented the development of L. monocytogenes.

Chemical Constituents of Essential Oil fromLippia sidoidesCham. (Verbenaceae) Leaves Cultivated in Hidrolândia, Goiás, Brazil

Several studies involving the family Verbenaceae, occurring in the Brazilian Cerrado, have emphasized the popular use of many aromatic species. We highlight the use of Lippia sidoides Cham., known as “alecrim pimenta,” native to northeastern Brazil and northern Minas Gerais. Leaves of this species were collected in antropized Brazilian Cerrado area, in Hidrolândia, Goiás, and their essential oils were extracted by hydrodistillation in a Clevenger-type apparatus and thereafter analyzed GC/MS. Among the compounds identified in this study were the most abundant oxygenated monoterpenes, followed by sesquiterpenes hydrocarbons. The oxygenated monoterpene 1,8-cineole was the major constituent followed by isoborneol and bornyl acetate. The chemical composition of essential oil described in this paper differs from that described in the literature for L. sidoides found in its native environment, where the major constituents are thymol and carvacrol.

Composição química, atividade antimicrobiana do óleo essencial e ocorrência de esteróides nas folhas de Pterodon emarginatus Vogel, Fabaceae

Pterodon emarginatus Vogel, Fabaceae, conhecida popularmente como sucupira-branca, e uma especie arborea que possui interesse como planta medicinal e fonte de madeira. Varios estudos com o oleo e extratos dos seus frutos demonstraram atividades cercaricida, antimicrobiana e antiinflamatoria. Tendo em vista a importância de P. emarginatus como planta medicinal o presente trabalho analisou a composicao quimica, a atividade antifungica e antibacteriana do oleo essencial de suas folhas, isolou e identificou compostos do extrato etanolico bruto das folhas. A analise do oleo essencial das folhas permitiu a identificacao de 9 hidrocarbonetos sesquiterpenicos, sendo os majoritarios o γ-muuroleno (48,79%) e o biciclogermacreno (22,66%). O oleo essencial apresentou atividade frente a bacterias Gram-positivas, sendo inativo sobre isolados clinicos de Candida. O estudo fitoquimico do extrato etanolico das folhas permitiu o isolamento da mistura dos esteroides estigmasterol e β-sitosterol. Todos os resultados obtidos contribuem para a ampliacao de informacoes sobre essa planta amplamente utilizada pela populacao.