Lactone n. : One of a series of organic compounds, regarded as anhydrides of certain hydroxy acids. In general, they are colorless liquids, having a weak aromatic odor. They are so called because the typical lactone is derived from lactic acid.

Example:
Does the plant Crape Myrtle contain the substance Sesquiterpene Lactone?A substance is found in several plants

Taxonomy
lactone, CH2, Sesquiterpene lactones, carbons, COOH, esters, molecule, free encyclopedia, propiolactone, Reactions, membered ring, Nomenclature, compound, Gamma-lactones, COOH group, parent compound, product, Reduction.

Defination from the web:
lactone derives from the ring compound called lactide, which is formed from the dehydration of 2-hydroxypropanoic acid (lactic acid) CH3 ... reduction reaction will first break the ester bond of the lactone and then, reduce the carboxylic acid group (-COOH) to the alcohol ...