|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
|the offspring of a zebra and a donkey.|
lactone lac·tone (lāk'tōn')
An anhydride formed by the removal of a water molecule from the hydroxyl and carboxyl radicals of hydroxy acids.
|lactone (lāk'tōn') Pronunciation Key
Any of various organic esters derived from organic acids by removal of water. Lactones are formed when the carboxyl (COOH) group of the acid reacts with a hydroxyl (OH) group in the same acid, releasing water and causing the carbon atom to join to the hydroxyl's remaining oxygen atom, forming a ring. Vitamin C, the antibiotic erythromycin, and many commercially important substances are lactones.