Chemical Profile, Chemometric Analysis, Acetylcholinesterase Inhibitory and Antioxidant Activity of Diverse Boldo Species Employed in The Amazon Region.

The term 'boldo' is popularly used in the Amazon region to refer to different plant species. This study aimed to identify the chemical profile, evaluate the antioxidant potential and acetylcholinesterase inhibitory activity of leaf infusions of fresh samples of Plectranthus barbatus, Plectranthus ornatus, Gymnanthemum amygdalinum, and Peumus boldus commercially acquired at different retail venues in Manaus and Itacoatiara (AM), Brazil. The compounds tentatively identified included the alkaloids N-methyllaurotetanine, N-methylcoclaurine, isoboldine, and norisoboldine in P. boldus leaves; the flavonoid glycosides luteolin 7-O-glucoside and quercetin 3-O-glucoside, along with diterpenoid coleon H, in P. ornatus; the flavonoid glycoside isorhamnetin 3-O-glucoside and rosmarinic acid in P. barbatus; and the flavonoid glycoside apigenin 7-O-glucoside, toguether with 3-O-caffeoylquinic acid, in G. amygdalinum. The antioxidant activity was assessed using the DPPH assay, with P. boldus exhibiting the highest activity among the samples at 1073.33 μM ET. The remaining extracts showed moderate anti-acetylcholinesterase activity. In the in silico prediction assay, luteolin 7-O-glucoside showed the strongest acetylcholinesterase inhibitory activity, with a binding energy of -10.4 kcal.mol-1. This study enhances the understanding of the chemical and biological knowledge of P. barbatus, P. ornatus, G. amygdalinum, and P. boldus.