RP-UHPLC-ESI-QTOF-MS analyses and evaluation of the antioxidant, antimicrobial, anti-diabetic and anti-Alzheimer activities of Desf.

The polyphenolic compounds of the -butanol fraction of Desf. (BFLTe) were characterised by RP-UHPLC-ESI-QTOF-MS analyses with the main presence of 6,8-di--glucosyl naringenin (11.7%), vicenin 2-isomer 2 (8.18%), luteolin-7,3'-di-βglucoside (7.18%), isovitexin (5.98%), luteolin-7--β-D-glucoside (5.713%), myricitrin (4.41%), luteolin-4'--β-glucoside (4.04%), chlorogenic acid (28.68%), 3-(2,6-dihydroxyphenyl)-4-hydroxy-6-methyl-3-2-benzofuran-1-one (8.17%) and -coumaric acid (4.0%.). The antioxidant capacity was evaluated using three complementary methods (DPPH, ABTS and Reducing power). Additionally, the antimicrobial activity was tested against eight bacterial strains and the fungi whereas the antidiabetic activity was performed against -amylase. The anti-Alzheimer activity was tested by inhibiting the butyrylcholinesterase (BChE). The BFLTe showed, for the first-time, a good antioxidant potential in DPPH (IC:68.83 ± 2.74 µg/mL), ABTS (IC:48.73 ± 1.07 µg/mL) and Reducing power assays (A:99.98 ± 1.18 µg/mL) and a moderate antimicrobial activity with 250 and 500 µg/mL MICs values. Moreover, the fraction exhibited an excellent inhibition of the BChE (IC:33.00 ± 0.85 µg/mL) and -amylase (IC:1093.13 ± 12.93 µg/mL).