The acidified suspension was partitioned with EtOAc
to remove the nonalkaloids. The acidic solution was then
basified with 5% Na2CO3 to pH 6-7 and extracted with CHCl3
(3 1.0 L) to obtain the A1 alkaloids. The aqueous phase was
further adjusted with 5% Na2CO3 to pH 9-10 and extracted
with CHCl3 (3 1.0 L) again to give A2 alkaloids