Flower pigment composition of Crocus species and cultivars used for a chemotaxonomic investigation

Abstract

A survey of floral anthocyanins and other flavonoids by analytical high-performance liquid chromatography (HPLC) was performed among 70 species and subspecies, 43 cultivars and six artificial hybrids of Crocus and the results were compared with taxonomical delimitations established by Mathew (The Crocus. B.T. Batsford Ltd, London, 1982). Nine anthocyanins were detected. The Crocus species and cultivars were placed into seven chemotypes according to their contents of 3,7- di - O -, 3,5- di - O -glucosides or 3- O -rutinosides of delphinidin and petunidin and to the presence of 3,7- di - O -malonyl-glucosides of petunidin and malvidin and delphinidin 3- O -glucoside-5- O -malonylglucoside. These malonated anthocyanins have only been found in Crocus and may be characteristic for this genus. The same 18 flavonoids were detected in every taxon. However, quantitative differences were noted and four chemotypes of Crocus were defined by their major contents of flavonoids. Six of the flavonoids appear to be unique for Crocus. The anthocyanin/flavonoid patterns of some of the taxa provide a valuable supplement to the taxonomy based on morphological and cytological patterns. Most chemotypes were represented in several series but the chemical data were useful in distinguishing different species. For all series except Series h the chemical data were very similar for all subspecies or accessions within a species, and chemotypes within a series were more similar than between series. However for six species, the analyses suggest that they should be further investigated using other methods, to evaluate their relations to other series.