Medicinal Herb Extraction Strategy - A Solvent Selection and Extraction Method Study

Abstract Medicinal herbs have a long history of use in improving human health and curing diseases. Herbal materials are naturally an excellent medicine library because they provide unlimited components with complex chemical structures and a wide range of bioactivities. Herbal materials have thus attracted wide interest of researchers in the identification of the active components and verification of their efficacy. Herb preparation and extraction is the first step and in fact one of the most important steps in the chemical identification process. This step makes the down stream processes possible, including bioactive component identification, isolation and characterization. In this research, using a model herb material, Echinacea, we studied chemical extractability of different solvents with various polarities. Several extraction methods were used and their extraction efficiencies were compared. The extraction methods used in this research were soxhlet extraction (SE), sonication assisted extraction (SAE), and accelerated solvent extraction (ASE). Chemical profile and yield of each extract and the throughput capability of different extraction methods were systematically compared and discussed. Based on the results, a recommendation was made for a consolidated herb extraction-fractionation process.