Abstract

Flavonoids are major active constituents in mulberry (Morus alba L.) leaves and possess various pharmacological activities. In the present study, the extraction technology and preparative separation of total flavonoids (TFs) in mulberry leaves extracts by macroporous resins were studied systematically, and the column packed with selected resin was used to perform dynamic adsorption and desorption tests to optimize the separation process. The research results indicated that the maximal yield of TFs was achieved when mulberry leaves were extracted under the optimized conditions of a pH of 8, a solid-liquid ratio of 1:40, a temperature of 90^oC and a time of 4 h. H103 resin is the most appropriate for the separation of TFs from other components in mulberry leaves extracts, which adsorption behavior can be described with Langmuir and Freundlich isotherms and two-step adsorption kinetics model. The optimum parameters for TFs separation by H103 were achieved, after one run treatment. The recovery and purity of TFs in the final product were 90.57 and 76.33%, respectively. In conclusion, the preparative separation of TFs in mulberry leaves can be easily and effectively done by H103 resin.

Key words: Optimization, isolation, flavonoids, Morus alba (L.), mulberry leaves, macroporous resin.