Chem Biodivers. 2021 Jul 5. doi: 10.1002/cbdv.202100288. Online ahead of print.
Seven phenolic compounds (ferulic acid, caffeic acid, 4-methoxycinnamic acid, 3,4-dimethoxycinnamic acid, 3-hydroxy-4-methoxybenzaldehyde, 3-methoxy-4-hydroxypropiophenone and 1- O ,2- O -digalloyl-6- O -trans- p -coumaroyl-β-D-glucopyranoside), a flavanonol (7- O -methyl aromadendrin), two lignans (pinoresinol and matairesinol) and six diterpenic acids/alcohol (19-acetoxy-13-hydroxylabda-8(17),14-diene, totarol, 7-oxodehydroabietic acid, dehydroabietic acid, communic acid and isopimaric acid) were isolated from the hydroalcoholic extract of a Brazilian Brown Propolis and characterized by NMR spectral data analysis. The volatile fraction of brown propolis wascharacterized by CG-MS, composed mainly of monoterpenes and sesquiterpenes, being the major α-pinene (18.4%) and β-pinene (10.3%). This propolis chemical profile indicates that Pinus spp., Eucalyptus spp. and Araucaria angustifolia might be its primary plants source. The brown propolis displayed significant activity against Plasmodium falciparum D6 and W2 strains with IC 50 of 5.3 and 9.7 μg/mL, respectively. The volatile fraction was also active with IC 50 of 22.5 and 41.8 μg/mL, respectively. Among the compounds, 1- O ,2- O -digalloyl-6- O -trans- p -coumaroyl-β-D-glucopyranoside showed IC 50 of 3.1 and 1.0 μg/mL against D6 and W2 strains, respectively, while communic acid showed an IC 50 of 4.0 μg/mL against W2 strain. Cytotoxicity was determined on four tumor cell lines (SK-MEL, KB, BT-549, and SK-OV-3) and two normal renal cell lines (LLC-PK1 and VERO). Matairesinol, 7- O -methyl aromadendrin, and isopimaric acid showed an IC 50 range of 1.8 - 0.78 µg/mL, 7.3 - 100 µg/mL, and 17-18 µg/mL, respectively, against the tumor cell lines but they were not cytotoxic against normal cell lines. The crude extract of brown propolis displayed antimicrobial activity against C. neoformans , methicillin-resistant Staphylococcus aureus , and P. aeruginosa at 29.9 μg/mL, 178.9 μg/mL, and 160.7 μg/mL, respectively. The volatile fraction inhibited the growth of C. neoformans at 53.0 μg/mL. The compounds 3-hydroxy-4-methoxybenzaldehyde, 3-methoxy-4-hydroxypropiophenone and 7-oxodehydroabietic acid were active against C. neoformans , and caffeic and communic acids were active against methicillin-resistant Staphylococcus aureus .