Elucidation of a new oleanane glycoside from Barringtonia asiatica

Piscicidal Activity of B. Asiatica at 250µL/mL020406080100120012345Time (hr) Percent Viability1-Butanol FractionWater Fraction Figure 2 Isolation of Ranuncoside VIII. Five seeds (400 g) of B. asiatica, together with the 70% ethanol storage solution (1L) and water (1L) were mixed until homogenized in a Waring blender. The pulp and extraneous plant material were removed by centrifugation, and the supernatant liquid was passed through cheesecloth. The solution was then acidified to pH 2 with trifluoroacetic acid and partitioned three times with equal volumes of 1-butanol. The 1-butanol was removed from the combined fractions, and the resulting residue was exhaustively triturated with hexane. The remaining solid material (5 g) was separated by preparative HPLC (47% isocratic gradient). The sample was introduced onto the column in a 30% isopropanol/water mixture to avoid solubility problems. Seven fractions were obtained, corresponding to seven major chromatographic peaks. The brine shrimp assay revealed that most of the activity was in fraction 7, and this peak was further purified through multiple preparative HPLC runs to yield ranuncoside VIII (20 mg).