Structurally Diverse Quinoline Alkaloids With Antileukaemia Activities From Taraxacum mongolicum

Taraxacum mongolicum, a medicinal and food homologous traditional Chinese medicine, has important research value in clinical practice. Eight new quinoline alkaloids (1–8), including 1N-geranyl quinoline alkaloids (1–3), 3,4-phenylquinoline alkaloids (4–6) and 10-carbonyl-11-pyrrolyl quinoline alkaloids (7–8), and twelve known quinoline alkaloid derivatives (9–20) were isolated from T. mongolicum for the first time. These compounds were elucidated according to analysing NMR, MS, UV and IR spectra and compared with references. Among them, compounds (7, 8, 14 and 16) showed certain antileukaemia activities, which exhibited important cell growth inhibitory activities against HL-60 and K562 cells than adriamycin, which could be potential antileukaemia agents. The plausible biogenetic pathway and preliminary structure–activity relationship of the selected compounds were scientifically summarised and discussed in this work.