Flavonoids from Mimosa tenuiflora Green Propolis: Chemotaxonomy, Antioxidant, Anti‐Inflammation, Anti‐Bacteria, Mosquito Larvicidal Activity, and In Silico Approach

Abstract

AbstractPhytochemical study of green propolis alcohol extract of Brazilian Caatinga Mimosa tenuiflora (Willd.) Poir resulted in the separation of six flavonoids, including quercetin 3‐methyl ether (1) and 3,3′‐O‐dimethylquercetin (2), and four flavanones eriodictyol 5‐O‐methyl ether (3), 5,4′‐dihydroxy‐6,7‐dimethoxyflavanone (4), licoflavanone (5), and macarangaflavanone B (6). All these metabolites were first isolated from green propolis and the genus Mimosa. Metabolites 3–4 also established chemotaxonomic significance since they had never been observed in the bean family Fabaceae. Flavones 1–2 showed strong antioxidative activity against DPPH (1,1‐diphenyl‐2‐picryl hydrazyl) radicals with IC50 values of 12.40 and 16.23 μg/mL, respectively. All six isolates showed anti‐inflammatory effects against NO (nitric oxide) production in LPS (lipopolysaccharide)‐stimulated Raw 264.7 cells, in which the activity of flavone 1 was better than the standard dexamethasone (IC50 13.35 μg/mL). Flavonoids 1–3 also strongly controlled the growth of the Gram‐positive bacteria Bacillus subtilis ATCC 6051, and Staphylococcus aureus ATCC 29213 with MIC values of 32–64 μg/mL. Six isolated flavonoids exhibited strong or moderate mosquito larvicidal activity against Aedes aegypti and Ae. albopictus fourth instar larvae with the 24 h LC50 values of 29.62–55.89 μg/mL. By in silico approach, compound 1 was a non‐toxic agent with an LD50 value of 5000 mg/kg.