Chemical constituents and antibacterial activity of Bromelia laciniosa (Bromeliaceae): Identification and structural characterization

Bromelia laciniosa Mart. ex Schult. & Schult.f. is a Bromeliaceae plant species from the Brazilian Caatinga, popularly used for the treatment of childhood colic, diarrhea, fever, jaundice, dandruff and hepatitis. The objective of this work was to evaluate the chemical composition and antimicrobial activity of the species B. laciniosa. In this study, we evaluated the antimicrobial activity of ethanolic extract from the leaves of B. laciniosa by microdilution MIC method, and provided a comprehensive panel of B. laciniosa’s metabolite composition through mass spectrometry (MS) coupled to gas chromatography (GC–MS) and liquid chromatography (LC-MS). B. laciniosa ethanolic extract inhibited Staphylococcus aureus growth at the lowest concentration tested. The GC–MS analysis revealed 45 non-polar metabolites, including campesterol, palmitic acid, oleic acid and α-tocopherol. Isolation and structural elucidation by NMR experiments supported the identification of cirsilineol (1), and the mixture of steroids β-sitosterol (2) and stigmasterol (3). The LC-MS metabolite profiling was assisted by Global Natural Product Social Molecular Networking (GNPS) and led to the putative annotation of 22 metabolites, consisting of phenylpropanoids, C- and O-glycosyl-flavonoids and fatty acids. In total, 39 chemical constituents are being described for the first time in B. laciniosa. The results show the diversity of secondary metabolites in the species B. laciniosa as well as antibacterial activity against S. aureus.