Journal of Pharmacy Research Vol.5 Issue 3.March 2012 Guizelle Aparecida de Alcântara et al. / Journal of Pharmacy Research 2012,5(3),1306-1309 1306-1309 Research Article ISSN: 0974-6943 Available online through http://jprsolutions.info * Corresponding author. Guizelle Aparecida de Alcântara 1 Laboratório de Pesquisa de Produtos Naturais, Faculdade de Farmácia, Praça Universitária, 1166 – Leste Universitário, CEP 74605-220, Universidade Federal de Goiás, Goiânia, GO, I NTRODUCTI ON Seasonal variation in the content of phenolic compounds in barks of Myrcia rostrata DC. by influence of environmental factors Guizelle Aparecida de Alcântara 1* ; Leonardo Luiz Borges 1 ; José Realino de Paula 1 . 1 Laboratório de Pesquisa e Produtos Naturais (LPPN) - Faculdade de Farmácia - Universidade Federal de Goiás - UFG - 74.605-220 - Goiânia-GO. Received on:10-12-2011; Revised on: 15-01-2012; Accepted on:12-02-2012 ABSTRACT Myrcia rostrata DC., Myrtaceae, known as “folha-miúda” is found in the Brazilian Cerrado. The genus Myrcia DC, has a wide spectrum of pharmaco- logical activities. This study aims to evaluate the influence of environmental factors on levels of phenolic compounds in barks of M. rostrata DC. collected in the Brazilian city Hidrolândia/Goiás. The plant material collected was dried in an oven with circulating air at a temperature of 40 ºC. The pulverized material was used to quantification of total phenols, tannins by protein precipitation, hydrolyzable tannins and flavonoids and to chemical analysis of barks and soil in each collection period of the species. The data were statistically analyzed, and the results suggest that metabolite concentrations in the barks of this plant are influenced by environmental factors, in particular the nutrients of the barks, Cu,Na and N, minerals of the soil Fe, Cu and Ca, besides hydrogen potential. Key words: Myrtaceae. Folha Miúda. Phenolic Compounds. Environmental Factors Myrcia rostrata DC., Myrtaceae, known as “folha-miúda” is found in the Brazilian Cerrado. The genus Myrcia, is one of the genera of American Myrtaceae, with over 300 species distributed from Mexico to southern Brazil. Therefore, it has a wide spectrum of pharmacological activities, such as hypoglycemic properties, diuretic, antihypertensive, an antagonist of bradykinin, [1] antidiarrhoeal, [2] , antimicrobial, [3] and antitumor, [4] and the hepatoprotective activity. [5] However, are few studies of popular use and phytochemicals of M. rostrata. Phenolic compounds, as well as other sec- ondary metabolites (responsible for the pharmacological effects of plants), represent a chemical interface between plants and the environment, and their synthesis is often affected by environmental factors. [6] . This study aims to evaluate the influence of environmental factors on levels of phenolic compounds in barks of M. rostrata DC. collected in the Brazilian city Hidrolândia/Goiás. MATERIAL AND METHODS Plant material and processing of samples The species M. rostrata DC was identified by Dr. José Realino de Paula in Lageado Farm located in Hidrolândia in the state of Goiás, Brazil (786m, 16 ° 53 ’59.4 “South and 49 ° 13' 29.4” West). Samples of barks were collected from one specimen adult in four months for one year (april 2010, august 2010, december 2010 and april 2011). Voucher specimen was deposited in the Herbarium of the Universidade Federal de Goiás (UFG), Goiás State, Brazil code number 45519. The plant material collected was dried in an oven with circulating air at a temperature of 40 ºC. After drying, the material was processed in a steel- bladed grinder with a number 100 screen (150 μm), and the powder ob- tained for each sample was packed in plastic bags properly identified and stored in a cool place and protected from the light. The pulverized material was used to quantification of total phenols, tannins by protein precipita- tion, hydrolyzable tannins and flavonoids and to chemical analysis of barks and soil in each collection period of the species. Colorimetric assays Total phenolics assay: Phenolic compounds were assayed in four collec- tions, was used methodology proposed by Hagerman and Butler with ad- aptations. [7] The FeCl3 was used to produce complexes with phenols in the possible solutions analyzed in triplicate, which were read at 510 nm spec- trophotometer. The standard curve (concentration x absorbance) was con- structed with tannic acid in the following dilutions: 0.10, 0.15,0.20, 0.25 and 0.30 mg / mL. Tannins by Protein precipitation assay: The tannins that precipitate in the presence of proteins were also quantified by the methodology of Hagerman and Butler [8] uses BSA solution (1.0 mg/mL) in 0.2 M acetate buffer (pH 4.9). The extract solutions were precipitated with BSA and after centrifuga- tion, the precipitate was dissolved in Sodium Lauryl Sulfate (SLS, 1% w / v) / Triethanolamine (TRI, 5% v / v) / isopropanol (ISOP, 20% v / v) and the tannins were complexed with FeCl3. The coloured complex was read at 510 nm. All solutions were analysed in triplicate. The standard curve was con- structed with tannic acid the same dilutions of the total phenolic assay. Hydrolysable tannins assay: For the determination of hydrolysable tannins in barks was used the modified method of potassium iodate. [9] This tech- nique involves the ability of hydrolysable tannins form colored complexes with aqueous solution of KIO3 2.5% which were read at 550 nm spectro- photometer. The extract is prepared to quantify with acetone: water (7:3 v / v) and is concentrated and lyophilized. The standard curve was con- structed with tannic acid in the following dilutions: 0.30, 0.40,0.50, 0.60 and 0.70 mg / mL. All solutions were analysed in triplicate. Total flavonoids assay: For the quantification of total flavonoids, extracts were prepared with methanol:acetic acid 0.02 M (99:1 v/v) and the mixture was incubated in a water bath under reflux at 90-100 °C for 40 min before being filtered. All samples were prepared in triplicate. The resulting filtrate