**1. Introduction**

*Glycyrrhiza* species (Leguminosae), commonly known as licorice, are perennial plants that grow up to 1.5 m high and are distributed in drylands from Western Europe to Russia, and are particularly abundant in China and Mongolia. Licorice mainly consists of dried roots and stolons of *G. uralensis* Fisch and *G. glabra* Linne. Therefore, two species are listed in pharma‐ copoeia worldwide. Licorice is one of the most important crude drugs prescribed with other

© 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

herb medicines in traditional Chinese medicine (TCM) for the treatment and prophylaxis of sore throats (as an antitussive), coughs and bronchial catarrh (as an expectorant), inflammation, allergic reactions, rheumatism and arthritis, liver disease, tuberculosis and adrenocorticoid insufficiency [1–5]. Nearly 500 components have been identified in licorice. Among them, glycyrrhizin is controlled at a concentration of more than 2.0% as a standardization marker component because the phamacological properties of licorice might be depend upon glycyr‐ rhizin, and furthermore a flavonoid liquiritin has a quantitative limitation in Japanese pharmacopoeia [1]. Glycyrrhizin is a protein‐kinase inhibitor with anti‐ulcer and anti‐viral activities [6]. In Japan and China, nowadays, glycyrrhizin is used for the treatment of hepatitis [4, 7–9]. It has been reported that glycyrrhizin has interferon‐inducing activity and anti‐HIV‐ 1 activity [10–12]. Moreover, glycyrrhizin is well known as a natural sweetener and used in food additives and cosmetics [13]. On the other hand, flavonoids have also various pharma‐ cological activities such as anti‐hepatotoxic, anti‐inflammatory, anti‐ulcer, anti‐allergenic and anti‐viral as well as cardioprotective activities [2]. **Figure 1** indicates major components in licorice.

**Figure 1.** Major components in licorice.

In order to control the quality of licorice, we investigated and succeeded the preparation of monoclonal antibody (MAb) against glycyrrhizin and set up an enzyme‐linked immunosorb‐ ent assay (ELISA) as quick, simple and reproducible assay system [14]. Furthermore, a new staining system, eastern blotting was developed [15] and immunoaffinity isolation of glycyr‐ rhizin resulting in glycyrrhizin‐knockout extract, which can be used to survey the real activity of glycyrrhizin in licorice [16, 17]. Regarding flavonoid, anti‐liquiritin MAb [18] and eastern blotting [19] was developed. Since the above knowledge of components in licorice have been accumulated and also Tanaka et al. have been investigating about proteins [20–22] and mitochondria [23] related to fertilization using reproducing assay system, we have started to survey *in vitro* fertilization (IVF) active components in licorice.
