Tulipalin A (α-methylene-γ-butyrolactone) (2-Methylenebutyrolactone) which has some phytotoxicity is a natural compound extracted from Tulipa gesneriana.
Homoeriodictyol chalcone(2',4,4',6'-tetrahydroxy-3-methoxychalcone) is a natural chalcone glucoside used in biochemical experiments and organic synthesis.