A rapid method for isolation of andrographolide from andrographis paniculata nees (kalmegh)

A simple and rapid method for isolation of andrographolide from the leaves of Andrographis paniculata is reported. This involves extraction of the leaf powder by cold maceration in a 1:1 mixture of dichloromethane and methanol and isolation of andrographolide directly from the resulting extract by recrystallisation. The identity of the compound was confirmed through IR, UV, mass and melting point, and co-chromatography with a reference standard on TLC. The purity of the compound was confirmed by TLC, UV absorption spectrum, HPLC and differential scanning calorimetry, the latter of which gave the melting point of andrographolide as 235.3°C.