Separation of phenylpropanoids and evaluation of their antioxidant activity.

Phenylpropanoids are a group of natural products with a wide range of biological and pharmacological importance. They have been isolated from a large number of plants by utilizing a diverse range of chromatographic techniques. We describe here the utilization of normal, reverse phase, and high pressure liquid column chromatographic techniques for the purification of phenylpropanoids from the crude plant extracts. Most important of them is the recycling reverse phase HPLC effectively utilized to purify the highly oxygenated phenylpropanoids glycosides from the butanolic and water extracts. The antioxidant activity of the different phenylpropanoids is also reported on the basis of DPPH, superoxide anion scavenging and Fe(2+)-chelating assays, along with electron spin resonance (ESR) method.