Glechon spathulata Benth. (Lamiaceae) compostos fenólicos e atividade biológica

Abstract

Glechon spathulata Bentham, belonging to the Lamiaceae family, is known as manjerona-do-campo, has its leaves used popularly as culinary flavoring, diaphoretic, stomachic in dyspepsia, antiseptic and expectorant in catarrhal respiratory diseases, colds, bronchitis and laryngitis, between others. Similarly to G. spathulata a range of plant species of the Brazilian flora representatives are used to combat various diseases of the most popular medicine without prior knowledge of the pharmacology or the inherent toxicity of the prepared plants. Therefore, for greater therapeutic efficacy, it is necessary prior knowledge of the chemical profile and evidence of biological activity of the plant. The objective of this study was to develop a phytochemical characterizationof the crude extract (CE) hydroethanolic 70% from the aerial parts (leaves and stems) of G. spathulata from spectrophotometric methods and ultra performance liquid chromatography coupled to mass detector with electrospray ionization interface (UHPLC-ESI-MS/MS), and evaluate their antimicrobial and antioxidant activities. The CE showed adequate antioxidant activity by the two methods employed, getting to the method of inhibition of DPPH radical IC50 of 48.29 ± 1.21 mg/g for the ORAC method the value of 10.51 ± 0.78 μmol Trolox/g, higher than the standard Trolox tested at the same concentration. The CE showed high levels of total polyphenols (186 ± 4.00 mg GAE/g) and total flavonoid (59.4 ± 0.58 mg QE/g) when compared to the species of the family. Added to this, 13 phenolic compounds divided into five major classes (derived from cinnamic acid, derived from benzoic acid, derivatives of caffeic acid, flavonoids and phenolic terpenes) were identified and quantified by UHPLC-ESI-MS/MS, highlighting the rosmarinic acid, which have a concentration of 34.458% in the CE. The gram-negative bacteria tested in the study were sensitive to G. spathulata CE (Escherichia coli ATCC 35218 - 200 μg/mL; Escherichia coli ATCC 25922 - 800μg/mL; Salmonella spp. ATCC 5217 – 200 μg/mL). The results of this study, together indicate that this plant has antioxidant potential and may be a promising source of natural antioxidants and derivatives with antimicrobial potential.