LC-MS-Based Screening for Colchicine and Characterization of Major Bitter Constituents in Lily

Lilies (Lilium spp.) are highly valued in China for their edible and medicinal properties; however, bitterness in certain varieties limits consumer acceptance. Although historically attributed to colchicine, the presence of alkaloids in lilies remains a subject of debate. This research screened five lily species for colchicine and its 15 biosynthetic precursors, using Gloriosa superba and Colchicum autumnale as positive controls. While detected in the controls, none were detected in any tissues (bulbs, roots, stems, flowers, and leaves) of the five lilies. A comparative analysis of five lily varieties—Longyahong, Lanzhou, Lilium lancifolium, Longya, and Guiyanghong—revealed that Longyahong exhibited the strongest bitterness, which was localized exclusively in the bulb peels. Based on comparative LC-MS profiling between bitter and non-bitter varieties, three high-abundance compounds were selected for isolation and subsequent sensory evaluation. Two monomeric compounds were isolated and confirmed via chromatographic methods as the primary bitter components. This study provides compelling chemical and biochemical evidence of the presence of colchicine in the examined lilies. By identifying two specific bitter components in Longyahong bulb peels, these findings refute the long-standing misconception regarding colchicine in lilies and provide a chemical foundation for improving the palatability and commercial value of bitter lily varieties.