A Simple and Facile Method for the Isolation of Andrographolide from Andrographis Paniculata Nees

Andrographis paniculata is an important medicinal plant in Indian and Chinese systems of medicine used for a number of ailments. Andrographolide (AP), a diterpene lactone, has been reported to be responsible for many of the activities. A number of methods are available for the isolation of AP.  However, they are time consuming and not cost effective. We employed five relatively simpler methods for the isolation of AP. The identities and purity of the compounds isolated by these five methods were established by thin layer chromatography (TLC), high performance liquid chromatography (HPLC), melting point, ultraviolet (UV), infrared (FTIR), mass, and nuclear magnetic resonance (1H NMR) spectra. Treatment of the extracts with activated charcoal proved to be quite effective in removing all coloring matter and resulted in isolation of pure AP. Of the five methods, prior maceration with methanol for 16 h followed by refluxing for 1h yielded 0.6%w/w of AP and was found to be quite satisfactory. This method does not need prior extraction of the powder with toluene nor does it require washing of the concentrated extract with toluene.  In this method only methanol (MeOH) was employed. All the spectral data and melting point of andrographolide isolated by this method confirmed its purity. This method is simple as it involves only three steps and has the potential for commercial scale up.