A new type of Brazilian propolis: Prenylated benzophenones in propolis from Amazon and effects against cariogenic bacteria

Ethanol extracts of four propolis samples (E1–E4) from Manaus (Brazilian Amazon) were analysed by HPLC/DAD/ESI–MS/MS and GC/EIMS. The major constituents of E2 and E4 were analysed by NMR (1H and 13C) and ESI/MS/MS. The main constituents of E2 and E4 are polyprenylated benzophenones: 7-epi-nemorosone, 7-epi-clusianone (major E4 constituents), xanthochymol and gambogenone (major E2 constituents), making up a chemical profile so far unreported for Brazilian propolis. Aristhophenone, methyl insigninone, 18-ethyloxy-17-hydroxy-17,18-dihydroscrobiculatone B, and derivatives of dimethyl weddellianone A and B, propolones, and a scrobiculatone derivative, were detected as minor constituents. Triterpenoids (β-amyrins, β-amyrenone, lupeol and lupenone) were ubiquitous and predominant in E1 and E3. The extracts E2 and E4 were highly active against the cariogenic bacteria Streptococcus mitis, Streptococcus mutans and Streptococcus salivarius. E2 was more active than E4, probably due to a higher content of 2-epi-nemorosone, while the latter was richer in di-hydroxylated compounds.