Sulcatone A, a naturally occurring biflavonoid isolated from Ouratea sulcata. Extracts of the leaves of this plant, used with and with other plant's extracts, are used in many African countries to treat some infections such as upper tract respiratory infections, dysenteria, diarrhoea and toothache. Positive antimicrobial activity has been shown in-vitro against Staphylococcus aureus and Bacillus subtilis. Escherichia coli showed to be resistant in the same study.
Leaflets of Cycas circinalis and C. revoluta contain biflavonoids such as (2S, 2′′S)-2,3,2′′,3′′-tetrahydro-4′,4′′′-di-O-methylamentoflavone (tetrahydroisoginkgetin).