Colchicinoids from Colchicum crocifolium Boiss.: a case study in dereplication strategies for (-)-Colchicine and related analogues using LC-MS and LC-PDA techniques

As a part of a project designed to investigate Colchicum species in Jordan, the chemical constituents of Colchicum crocifolium Boiss. (Colchicaceae) were investigated using LC‐MS and LC–UV/Vis PDA. A decision tree for working with colchicinods has been developed by incorporating data from LC‐UV/PDA and LC‐MS. This dereplication strategy draws upon the UV/PDA spectra to classify compounds into one of four structural groups and combines this with retention time and mass spectra/molecular weight to identify the compounds. This strategy was applied on a small amount of extract (2 mg) of Colchicum crocifolium to dereplicate 10 known compounds from four different structural groups, namely (−)‐demecolcine, 2‐demethyl‐(−)‐colchicine or3‐demethyl‐(−)‐colchicine, N‐deacetyl‐(−)‐colchicine, (−)‐colchiciline, (−)‐colchicine, β‐lumidemecolcine, 2‐demethyl‐β‐lumicolchicine or 3‐demethyl‐β‐lumicolchicine, N,N‐dimethyl‐N‐deacetyl‐β‐lumicornigerine, (−)‐isoandrocymbine and (−)‐autumnaline. Furthermore, a new compound was identi?ed as N,N‐dimethyl‐N‐deacetyl‐(−)‐cornigerine. Three compounds, which had molecular ions at m/z 325, 340 and 374, could not be dereplicated into any obvious structural classes that have been isolated in our laboratories previously or reported in the literature. Copyright © 2008 John Wiley & Sons, Ltd.