Isolation of andrographolide from A. paniculata leaves: The final extract of A. paniculata (Burm. f.) Nees was subjected to vacuum column chromatography on silica gel 60F254 and eluted with a mixture of solvents consisting of chloroform and methanol (9:1) as the mobile phase. The clear solution was collected and then allowed to stand for 24 h at 4°C to yield an andrographolide sediment. The sediment was recrystalized by washing with cold methanol and then with cold n-hexane, respectively