3. Results and discussion
A preliminary GC–MS screening of aqueous extracts from Q.resinosa, Q. grisea, Q. laeta and Q. obtusata species showed signif-icant presence of lupeol only in aqueous extracts from Q. obtusataspecies (Fig. 1). This finding was further confirmed with a com-mercial standard, who displayed a retention time of 38.376 minand major ions (m/z) from the trimethylsilylated compound of 498,393 and 369 (Fig. 2). Quantitative analysis revealed that aque-ous extracts of Quercus as prepared by population (1%) contains90.92 g/mL of lupeol. It is documented that this oak species isused for medicinal and food purposes by the Mixtecos, an ethnicgroup that inhabit Southern Mexico (Luna-José et al., 2003). Asthe active compounds in most cases are unknown, assessment ofpharmacological effects of crude extracts, natural products screen-ing and discovery of new biologically active compounds, are thematter of scientific research and new products development bypharmaceutical companies. While the use of oak as forest prod-uct is widely acknowledged, its nutraceutical significance has beenunrecognized, so it is intended to add value to this source via thedevelopment of nutraceutical products.