Bioguided fractionation and isolation of esculentoside P from Phytolacca americana L.

Various solvent extracts from different organs of Phytolacca americana L. were tested for their acaricidal activities against female carmine spider mite [Tetranychus cinnabarinus (Boisduval)] adults by slide-dip bioassay. The acetone extracts of roots with mortality rates of 95.72% and 100.00% at 2.5 mg/mL were more active than those of leaves and stems and compared with other solvent extracts from other organs after 48 and 72 h of treatment, respectively. The root acetone extracts were fractionated using a silica gel column; after thin-layer chromatography, the concentrated extracts were separated into 15 groups and further analyzed for their acaricidal activities. The ninth fraction exhibited the highest acaricidal activity. Phytochemical evaluation and liquid chromatography/mass spectrometry analysis revealed that esculentoside P was the dominant active phytolaccasaponin in the said fraction. This biological compound is a promising candidate as an acaricide against T. cinnabarinus.

► Phytolacca americana L. may be a promising biological candidate as acaricide.
► P. americana acetone root extract showed the highest acaricidal activity.
► Oleanane triterpenoid saponins are the most active saponins in the acetone extract.
► Esculentoside P is the dominant active phytolaccasaponin.
► P. americana can be locally grown and obtained at low cost.