Fresh leaves (45 g) and homogenised rhizomes (125 g) were separately hydrodistiled for 4 h in an all-glass apparatus similar
to that described in the British Pharmacopoeia, using pentane as the collecting solvent
The solvent was carefully removed using a
gentle stream of nitrogen gas, yielding yellow aromatic oils in each
case. The oil yields (w/w) were 0.03% (leaves) and 0.02% (rhizomes),
all on a fresh weight-basis.