Recovery of bioactive compounds from roots of Glycyrrhiza glabra by novel techniques of extraction

Licorice is the most popular ingredient used in over 70% of Chinese medicines and has been used by human beings for at least 4000 years (mainly the species Glycyrrhiza glabra L., Leguminosae). Greek sources provide the first use of licorice as a drug in Europe [1]. Many biological activities such as antimutagenic activity, anti-ulcer effects, protective action against hepatotoxicity, antitumor promoting activity, antimicrobial effects etc., were reported. These activities are reported due to two kinds of main constituents, the saponins and flavonoids [2]. The woody parts of the thickening roots are mentioned as a rich source of these substances [3]. The herb yields the licorice products of commerce that are used as an analgesic or antispasmodic agents, an antidotal agent, and as an expectorant. The licorice extracts have generally been recognized as safe and are also used as flavoring and sweetening agents for tobaccos, chewing gums, candies, toothpaste, and beverages [4]. Various novel techniques, including supercritical fluid extraction (SFE) and accelerated solvent extraction (ASE), have been developed for the extraction of neutraceuticals of plants [5]. In this study we extracted the licorice roots by ASE and SFE in order to shorten the extraction time, decrease the solvent consumption, increase the extraction yield, and enhance the quality of extracts. The yields of the several extractions were calculated and the chemical profile of the prepared extracts was compared by TLC and HPLC methods. The results showed that high yield of bioactive compounds was achieved by ASE extraction, although in the case of SFE extraction the oxidation and thermal degradation of these compounds was avoided. However, a polar modifier has to be added to CO 2 to extract the polar flavonoids. Finally, ASE under elevated temperature and high pressure can be supplementary to SFE for the recovery of these compounds. Acknowledgements: The project is co-funded by the 'Lavipharm' Group of Companies in the frames of program 'Intarnational collaboration in the industrial research and activities of growth in pre-competitive stage' References: 1. Fiore, C. et al. (2005)J. Ethnopharmacol 99: 317–324; 2. Li, W. et al. (2000) Phytochemistry 55: 447–456; 3. Hayashi, H. et al. (1996) Plant Science 116: 233–238; 4. Dong, S. et al. (2007) Food & Chemical Toxicology 45: 2470–2478; 5. Wang, L., Weller, C.L. (2006) 17: 300–312.