What is "butenolide"

n. (context organic compound English) The cyclic lactone derived from ''4-hydroxybut-2-enoic acid'' (one of the isomers of furanone); any of its derivatives

Butenolides are a class of lactones with a four- carbon heterocyclic ring structure. They are sometimes considered oxidized derivatives of furan. The simplest butenolide is 2-furanone, which is a common component of larger natural products and is sometimes referred to as simply "butenolide". A common biochemically important butenolide is ascorbic acid (vitamin C). Butenolide derivatives known as karrikins are produced by some plants on exposure to high temperatures due to brush fires. In particular, 3-methyl-2H-furo[2,3-c]pyran-2-one was found to trigger seed germination in plants whose reproduction is fire-dependent.