Influência do habitat na produção de metabólitos secundários: análise comparativa do perfil cromatográfico de três espécies endêmicas da caatinga por GC-MS.

Abstract

Caatinga is a biome with species found only in Brazil and is currently suffering from environmental degradation. The search for information about the natural wealth of the biome and sustainable reforestation projects is becoming increasingly necessary. The main objective of this study is to analyze, using GC-MS, whether there is quantitative or qualitative variability in secondary metabolites of species present in the Açú National Forest Reserve (FLONA) and in the Brazildry, a reforestation experiment area of Caatinga biome. The identification of the major chemical constituents was performed based on the analysis of their mass spectra, comparing them with data from the NIST spectral library and literature. Besides, it was confirmed by calculating and comparing its Kovats Retention Index (RI) with reference values. For the comparative quantitative analysis, the relative peak area of each identified compound was used. Differences in mean areas between habitats were submitted to Student's t-test with Bonferroni correction. The comparative analysis revealed distinct adaptive responses among species. Cenostigma bracteosum and Libidibia ferrea responded to the Brazildry environment with a significant quantitative increase in the intensity of their metabolites (p < 0.0125 and p < 0.0071, respectively), including squalene, γ-sitosterol, tocopherols, and neophytadiene. In contrast, Cochlospermum vitifolium exhibited mainly a qualitative response, altering the composition of its phytochemical profile, in addition to also presenting significant quantitative variations (p < 0.0071).