Antiviral activity of the aqueous extract of twelve monthly-collections of propolis from Barra do Corda

Viral infections constitute one of the major health problems. Since ancient times, propolis has been used due to its bactericidal, antiviral, and antifungal activity. In a previous study, we detected several substances in the ethanolic extract of propolis from Scaptotrigona aff. postica collected in Barra do Corda, showing an intense antiviral action against different viruses. The objective of this study was to characterize the compounds present in aqueous extracts of twelve-monthly collected samples of propolis from Scaptotrigona postica and its respective antiviral effects against the measles virus. Twelve aqueous extracts were analysed using reverse-phase chromatography, coupled with mass spectrometry, to identify 37 elements, being 14 benzophenones, 8 flavonoids, 4 pyrrolizidine alkaloids, caffeoyl-4-O-glucoside, 5-caffeoylquinic acid-1-O-arabinoside, 2-O-galloyl galactaric acid, 1-O- galloylglycerol, homovanillic acid, 5,6-dihydroxyferulic acid, 5- hydroxy ferulic acid, quinic acid, pomolic acid and 11-keto-β-boswellic acid. The determination of the antiviral activity was based on cytopathic effect inhibition. The most significant reduction in viral titer against the measles virus was observed with the extracts obtained in January, May, and June. The benzophenone, 6-hydroxy benzophenone-2-O-(2″),3-C-(1″)-1’-desoxy-fructofuranoside (2); 2, 3’,4,5,6-pentahydroxy-4’- methoxy-benzophenone-3-C-glucoside (32), 5,6-dihydroxy ferulic acid (15) and vicenin-2 (17), are detected in months of January, May and June that exhibited the better antiviral activity.