No abstract

The aim of this study was evaluate the antioxidant capacity of the extracts of the leaves of 31 vegetable species collected at the vicinity of the town of Tamshiyacu, in the department of Loreto, Peru. The percentage of inhibition of free radicals of 2,2-diphenyl-1-picrylhydrazyl (DPPH) was calculated. From the concentration of the best species with high activity, which were three, it was realized the analysis of total concentration of phenolic compounds and alkaloids was analyzed by UV/Vis spectrophotometry. Besides the metanolics extracts were submitted to fractionation in chromatographic column and the fractions with similar molecules, grouped by thin layer chromatography. The final fractions were analyzed by a Gas Chromatograph coupled to mass spectrometry (CG-MS), to identify the molecules present in them and causing this activity. According to the results, the species that showed the best activity at concentrations lower than 5.0 mg/ml were Virola sebifera, Caryocar glabrum and Tapirira guianensis. The concentration of total phenolic compounds was 18580.9, 15180.7 and 11568.7 mg/100g for V. sebifra, C. glabrum and T. guiannensis, and total alkaloids were 36.6, 0.0 and 74.0 mg/100g for these same species. The main secondary metabolites are 3,5-di-tert-butyl-4-hydroxyanisole and normolatedol and caryophyllene, in V. sebifera, diisooctyl dicarboxylate.1,2-benzene and 3, 5-bis (1,1-dimetyl etill-phenol in C. glabrum and diisoctylphthalate, α-panasinseno, and vitamin E in T. guianensis.

In this study were evaluated the antioxidant activity (AAO), allelopathic (ALL) and bioactive substances present in leaves of eight plant species from the Tamshiyacu-Tahuayo Community (Loreto-Peru). The AAO evaluation was performed by the free radical DPPH capture method, using dry and pulverized leaves, macerated in methanol for fifteen days, solutions of 0.01-5.0 mg/mL and 0.1 mM DPPH were prepared, reading was performed in the UV/vis spectrometer at 517 nm, for the ALL was performed by the Petri plates method, using methanolics extracts of fresh leaves with concentrations of 0.1-50.0 mg/mL against the growth of pregerminated seeds of Latuca sativa , the reading was made by measuring the hypocotyl and radicle of the seedling. In the results of species with high AAO were Virola sebifera, Caryocar glabrum and Tapirira guianensis, which present a percentage of inhibition superior to 50% in concentrations of 5.0 mg/mL. The species with high ALL are Xylopia benthami, Malouetia naias and Virola surinamensis, reaching an EC50 for the radicle at concentrations lower than 1.0-50.0 mg/L. The concentration of phenolic compounds for these species varied from 115217,18-321815,14 mg/kg, flavonoids from 1030,79-1441,16 mg/kg and proanthocyanidins from 0.65-1,77 mg / 100g. Total alkaloids range from 0,0-68,2 m/g evaluation, presenting differences between them.