Figure 1.

HPLC chromatogram of the leaves of P. betle . Reverse phase separation was performed using a C₁₈ Waters column (3.9 X 150 mm). The mobile phase consisted of trifluoroacetic acid (TFA) in water at pH 2.6 (solvent A) and acetonitrile (solvent B). The flow rate was kept at 1 ml/min and the gradient programme consisted of: 7% to 40% B for 20 min, 40% to 100% B for 6 min and 100% to 7% B for 9 min. The eluted peaks were monitored at 260 nm. 200 μl of sample was injected into the HPLC. 1: catechin; 2: morin; 3: quercetin.