Extraction of rotenone from Derris elliptica and Derris malaccensis by pressurized liquid extraction compared with maceration

The extraction of active compounds from plants is one of the most critical steps in the commercial development of natural products for medicinal, herbicidal or pesticidal use. The focus of this study was to compare conventional maceration and pressurized liquid extraction (PLE) techniques for the efficient extraction of rotenone from the stem and root of Derris elliptica Benth and Derris malaccensis Prain. The effects of experimental variables, such as solvent, temperature and pressure, on PLE efficiency have been studied. Chloroform was determined to be a good extraction solvent (rotenone content 40.6%, w/w) compared to commonly used solvent, 95% ethanol (rotenone content 15.0%, w/w). The optimal conditions for PLE were 50 degrees C and 2000 psi. PLE showed higher extraction efficiency (rotenone content 46.1%, w/w) as compared with conventional maceration method (rotenone content 40.6%, w/w). The order of rotenone content found in crude extract obtained by optimized method from the highest to the lowest was root (46.1%, w/w) and stem (9.4%, w/w) of D. elliptica and stem of D. malaccensis (5.2%, w/w), respectively. Moreover, the results from this study indicated that PLE was considerably less time and solvent consuming (30 min, 3 ml/g of dried sample) than the conventional maceration techniques (72 h, 10 ml/g of dried sample).