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Also known as macrocycles, macrocyclic compound

class=skin-invert-image|thumb|240px|Erythromycin, a [[macrolide antibiotic, is one of many naturally occurring macrocycles.]] Macrocycles are often described as molecules and ions containing a ring of twelve or more atoms. Classical examples include the crown ethers, calixarenes, porphyrins, and cyclodextrins. Macrocycles describe a large, mature area of chemistry.