Perfil Químico Obtido por CG-EM e Atividade Biológica da Fração Hexânica das Folhas de Dois Espécimes de Mouriri Guianensis Aubl.

Resumo

Mouriri guianensis Aubl. (Melastomataceae) is an endemic Brazilian species traditionally used for ulcer
treatment, but no phytochemical or biological data have been previously reported. This study aimed
to evaluate the chemical composition and the in vitro cytotoxic and anticholinesterase activities of the
hexane fractions obtained from ethanolic leaf extracts of M. guianensis collected in two municipalities of
Piauí, Brazil. Phytochemical characterization was performed by gas chromatography–mass spectrometry
(GC-MS), leading to the identification of 35 compounds, mainly isoprenoids, fatty acids, and sterols,
with sitosterol as the major constituent and (E)-phytol among the most abundant compounds. Biological
assays were carried out against human tumor cell lines (HCT-116, NCI-H460 and MDA-MB-231)
and non-tumoral murine fibroblasts (L929), and by Ellman’s method for acetylcholinesterase (AChE)
inhibition. The ethanolic extracts showed potent AChE inhibition (IC50 ≈ 1.0 mg/mL), whereas the hexane
fractions exhibited weak activity (IC50 > 25 mg/mL). Cytotoxicity was low, with inhibition below 50%
at 50 µg/mL. Although the pharmacological relevance is limited, this is the first report on the chemical
profile and bioactivity of M. guianensis, expanding the phytochemical knowledge of Melastomataceae
and underscoring the chemotaxonomic importance of the species.