Protein extraction was performed as follows: 10 g of fresh leaves were frozen in liquid nitrogen and ground to a fine powder in a pre-cooled mortar and pestle, and next lyophilized. The lyophilized powder was then homogenised, and 0.3 g were treated with 3 mL of a water:ACN mixture (7:3, v/v) containing a 5% (v/v) Celluclast 1.5L enzyme at pH 5.0, sonicated at 55 C for 15 min using an ultrasound power of 0.5 W/mL, and centrifuged at 10,000g for 10 min. An aliquot of the supernatant was taken and used for Bradford’s assay, and the rest of solution was stored at 20 C until their use