Chemical investigation, antifungal activity and anatomical aspects of Protium puncticulatum J.F Macbr. and Protium tenuifolium (Engl.) Engl.

Abstract

Protium Burm. f. (Burseraceae) is well known in the Brazilian Amazon for its diversity of species, though some of them are difficult to identify based on only morphological characteristics. We investigated the species Protium puncticulatum J.F. Macbr. and Protium tenuifolium (Engl.) Engl. in relation to their chemical constituents and some biological aspects. The phytochemical study of the hexane extract from the trunk of P. puncticulatum led to the identification of a mixture of triterpenes: α, β-amyrin (1 and 2), and lupeol (3); the methanolic extract gave the lignans 7-oxo-parabenzolactone (4) and 7’-hydroxy-9α-methylcubebin (5); this last lignan showed a MIC of 320 μg/mL for Candida albicans and 160 μg/mL for Cryptococcus neoformans and C. gattii. The hexane extract from the branches of P. tenuifolium also provided a mixture of α and β-amyrin (1, 2); the methanolic extract gave dimeric alkylresorcinols named integracin B (6) and integracin A (7). Analyses of anatomical characteristics confirmed the identity of the species Protium tenuifolium (Engl.) Engl. Essential oils obtained via hydrodistillation from the fresh bark of the trunk of P. tenuifolium showed a predominance of the monoterpenes limonene (56.17%), α-phellandrene (16.22%) and ρ-cymene (10.52%). This study is important since it increases knowledge on the volatile and non-volatile chemical constituents of the woody parts of two species of Protium from the Amazon.