Chemical constituents, antioxidant and antimicrobial activities of Pavonia glazioviana Gurke (Malvaceae)

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 glucopyranoside, 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 mL¹), Pseudomonas aeruginosa (MIC = 512 μg mL¹), Candida albicans (MIC = 512 μg mL¹), Candida tropicalis (MIC = 512 μg mL¹), Candida parapsilosis (MIC = 512 μg mL¹), Aspergillus flavus (MIC = 512 μg mL¹) and A. fumigantus (MIC = 512 μg mL¹). 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.

Keywords:
Pavonia glazioviana; methoxylated flavonoids; antioxidant potential; antimicrobial activity.