Fresh leaves (0.5 g) were homogenized with potassium
phosphate buffer (100 mM, pH 7.0) containing 0.5% Triton X-
100 and 1% polyvinyl pyrrolidone (PVP) using chilled mortar and
pestle. The homogenate was centrifuged at 15,000 g for 20 min
at 48 8C. The supernatant obtained was used for the enzymes assay