CHEMICAL CONSTITUENTS, ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF Pavonia glazioviana Gurke (Malvaceae)

Abstract

Species from Pavonia genus (Malvaceae) are traditionally used as antioxidant, n‑anti‑inflammatory and antimicrobial remedies. Previous studies have revealed their diversity of specialized metabolites widely used in the development of new medicines. This is the first study on Pavonia glazioviana Gurke, a Brazilian species known as “Malva‑da‑Chapada”. The research led to identify fifteen compounds: 132‑(S)‑hydroxy‑pheophytin a; and 132(S)‑hydroxy‑173‑ethoxyphaeophorbide, n‑decanol, cycloart‑23Z‑ene‑3β,25‑diol, cycloart‑24S‑25‑ene‑3β,24‑diol, sitosterol‑3‑O‑β‑D‑glucopyranoside, stigmasterol‑3‑O‑β‑D‑glucopyr anoside, quercetin, acacetin, kaempferol, tiliroside, 5‑hydroxy‑3,7,8,4’‑tetramethoxyflavone, 5,7‑dihydroxy‑3,8,4’‑trimethoxyflavone, 5,7‑dihydroxy‑4’‑methoxyflavone, 5,7,4’‑trihydroxy‑3,8‑dimethoxyflavone and 5,7,4’‑trihydroxy‑3‑methoxyflavone. The major flavonoids were tested for their antimicrobial activity, and the compound 5,7‑dihydroxy‑3,8,4’‑trimethoxyflavone showed strong activity against Escherichia coli (MIC = 512 μg mL‑1), Pseudomonas aeruginosa (MIC = 512 μg mL‑1), Candida albicans (MIC = 512 μg mL‑1), Candida tropicalis (MIC = 512 μg mL‑1), Candida parapsilosis (MIC = 512 μg mL‑1), Aspergillus flavus (MIC = 512 μg mL‑1) and A. fumigantus (MIC = 512 μg mL‑1). The total phenolic content, flavonoid content, and radical scavenging potential were determined showing its great production of phenolics and flavonoids, along with interesting radical scavenging potential (DPPH EC50 = 6.36 ± 0.029 mg mL‑1). Our findings contributed to characterize P. glazioviana as a source of methoxylated flavonoids with antimicrobial potential.