Optimal process for the extraction and identification of flavonoids from the leaves of Polyalthia longifolia using L16 Orthogonal design of experiment

The study has been carried out to investigate the effects of single factors such as temperature, extraction time, concentration of ethanol, material ratio and no. of extractions on the contents of flavonoids present in the leaves of Polyalthia longifolia. On this basis, an L16 orthogonal design of experiment was used to determine the optimal conditions for the extraction of flavonoids. The amount of flavonoids extracted reached its maxima at 65 ºC for 2 hrs by using 75% ethanol (modifier) with a material ratio of 1:10 and 2 times ofextraction. The TLC performed for the optimal extracts showed the presence of rutin and quercetin related compounds.Keywords: Annonaceae, Flavonoids, Orthogonal experiments, Single-factor experiments, Polyalthia longifolia