The flavonoids of Megalodonta beckii and isolation of 2′-3-Dihydroxy-4-methoxy-4′-glucosyl chalcone

A new naturally occurring chalcone glycoside, $\text{2′,-}\text{dihydroxy}\text{-4-}\text{methoxy}\text{-4′-O-β-}\text{d}\text{-}\text{glucosyl}$ chalcone, and other chalcones, aurones, flavonols, and anthocyanins are reported from Megalodonta (Bidens) beckii. The plan is an amphibious aquatic with heterophyllous leaves, but the presence of certain flavonoids is correlated with vegetative versus floral tissues rather than vegetative leaf form. The implications of flavonoid chemistry with respect to the relationship of M. beckii to several sections of Bidens are discussed.