2.3. Extraction of M. piperita L. leaves
The chopped, dried leaves of M. piperita (1 kg) were transferred
into a round bottom flask and subjected to hot extraction
by refluxing it with petroleum ether (2 · 2 L) for 2 · 3 h.
The extract was cooled and filtered. Further, the plant material
was refluxed with chloroform, ethyl acetate, and ethanol, finally
with distilled water (2 · 2 L each) for 2 · 3 h, cooled and filtered
after each extraction. Each filtrate was evaporated under
reduced pressure in rotary evaporator to obtain an oily mass
(32.4 g after deep freeze cooling) in case of pet. ether, a viscous
mass (28.7 g) for chloroform, 14.2 g for ethyl acetate, 11.8 g
for ethanol and 16.3 g for water extract