ABSTRACT
Myrcia tomentosa (Aubl.) DC., Myrtaceae, found in Central Brazilian Cerrado and popularly known as "goiaba-brava", belongs to the Myrcia genus, which has several species with medicinal properties such as: hypoglycemic, diuretic, hypotensive, antidiarrheal, antimicrobial and antitumor. The present study aimed to analyzed the environmental influence on concentrations of phenolic metabolites in M. tomentosa leaves. Compounds assayed in the leaves were: total phenols, tannins by protein precipitation, hydrolysable tannins and total flavonoids and mineral nutrients, while soil fertility was also analyzed, all over during one year. The results were submitted to Pearson Correlation Analysis and stepwise Multiple Regression Analysis to investigate the relationship between phenolics and environment data. Analysis of variance and Cluster Analysis allowed indicated a high variability in samples from different sites. The results obtained suggests that content of phenolics from M. tomentosa leaves are influenced by environmental factors, particularly some foliar nutrients (N1, Ca1 and Mn1), soil nutrients (Ca s and Ks) and Rainfall.
ABSTRACT
Species in the Myrtaceae family are used in folk medicine to treat gastrointestinal disorders, infectious diseases and hemorrhagic conditions and are known for their essential oil contents. Gas chromatography coupled with mass spectrometry (GC-MS) was used to characterize the chemical composition of essential oils of the leaves, stem bark and flowers of Myrcia tomentosa (Aubl.) DC., as well as to assess the chemical variability in the constituents of the essential oils of the leaf. Soil and foliar analyses were also performed to determine the mineral compositions. Principal component analysis (PCA) was used to examine the interrelationships between the obtained data. The most abundant component in the essential oils of the flowers was (2E,6E)-methyl farnesoate, whereas hexadecanoic acid was the most abundant essential oil component in the stem bark. The leaf essential oils showed seasonal variation in their chemical composition, with bicyclogermacrene and (2E,6E)-methyl farnesoate as the major chemical components. Forty-four constituents were identified, and only nine compounds were found in all of the samples. Sesquiterpenes were mainly produced in the flowers and leaves. The PCA showed a positive correlation between the oxygenated sesquiterpenes and the foliar nutrients Cu and P. Significant statistical correlations were verified between the climatic data, foliar nutrients and essential oil compositions.