Liquid Chromatography-Mass Spectroscopy and Liquid Chromatography-Ultraviolet/Visible Photodiode Array Analysis of Selected Colchicum Species

Most natural products drug discovery programs rely on a traditional bioactivity-guided fractionation approach. Although this approach succeeds in isolating most of the well-known drugs of natural origin, it is tedious, costly, time-consuming, and may end up in isolating previously known compounds (Ghisalberti, 1993; Kingston, 1996). In the fi eld of natural products, interest has been growing in the last twenty years in developing fast and effi cient strategies to enable the discrimination between previously isolated known compounds and new compounds at the level of the crude extract. This strategy which is termed dereplication is very important for the effi cient use of human and fi nancial resources. By adopting a suitable dereplication method, tedious and time-consuming isolation of previously known compounds can be avoided, and hence efforts are focused on the targeted isolation of compounds showing novel or uncommon spectroscopic features (Hostettmann et al., 2001; Wolfender et al., 2003). In a pioneering work, Corley and Durley (1994) developed strategies to search through scientifi c and technical network fi les using molecular weight, carbon count, structure fragments, and taxonomy for rapid identifi cation of known compounds. Hyphenated techniques, which can be defi ned as the coupling of high performance liquid chromatography (HPLC) separation technologies with on-line spectroscopic/spectrometric detection technologies, are the most commonly used techniques in dereplication strategies. Of these, liquid chromatography-mass spectroscopy (LC-MS) has a wide range of applications in the development of dereplication tools for the tentative identifi cation of plant and microbial secondary metabolites (Ackermann et al., 1996; Alali and El-Alali, 2005; Liquid Chromatography-Mass Spectroscopy and Liquid Chromatography-Ultraviolet/Visible Photodiode Array Analysis of Selected Colchicum Species Ahmad A. Gharaibeh*, Ala’a Al-Serini, Rana M. Qasaymeh, Amani S. Ma’aya’h, Khaled Tawaha, Tamam El-Elimat, and Feras Q. Alali*