Extract preparation
The fresh leaves of Holoptelea integrifolia were collected,
cleaned, dried and weighed (2 kg) properly. Chopped into
small pieces and percolated in absolute ethanol (Merck) at
room temperature for 15 days. The percolate was filtered
through Whattman filter paper No.1 and the process was
repeated thrice to get the maximum yield. Ethanol
percolate was evaporated under reduced pressure at 40oC
on the rotary evaporator (Eyela, Japan) to obtain ethanol
extract of leaves (20 g, 1% w/w). The portion (15 g) of
ethanol leaves extract were partitioned with equal
quantity of distilled water (500 mL) and ethyl acetate
(500 mL) and after subsequent repeated fractionation with
more solvents with same ratio and vigorously shaking,
organic ethyl acetate and aqueous layers were obtained.
Then partitioned further followed by the addition of