Editing Lactone (section)

== Occurrence ==
[[File:Glucono-delta-lactone-2D-skeletal.png|right|thumb|110px|[[glucono delta-lactone|<small>D</small>-glucono-δ-lactone]] ([[E number|E575]])]]
Lactone rings occur widely as building blocks in nature, such as in [[ascorbic acid]], [[kavain]], [[nepetalactone]], [[gluconolactone]], [[hormones]] ([[spironolactone]], [[mevalonolactone]]), [[enzymes]] ([[lactonase]]), [[neurotransmitter]]s ([[butyrolactone]], [[avermectin]]s), [[antibiotic]]s ([[macrolide]]s like [[erythromycin]]; [[amphotericin B]]), [[anticancer drugs]] ([[vernolepin]], [[epothilones]]), [[phytoestrogen]]s ([[resorcylic acid]] lactones, [[cardiac glycoside]]s).

5-Membered γ-lactones and 6-membered δ-lactones are prevalent. β-lactones appear in a number of natural products.<ref name=DNThiolSynth>{{cite journal|doi=10.1021/jo00003a047|pages=1176–1185|journal=Journal of Organic Chemistry|year=1991|volume=56|title=A practical and efficient method for the synthesis of β{{nbh}}lactones|first1=Rick&nbsp;L.|last1=Danheiser|first2=James&nbsp;S.|last2=Nowick|orig-date=25 July 1990|number=3}}</ref>  α{{nbh}}Lactones can be detected as transient species in [[mass spectrometry]] experiments.<ref>Detlef Schröder, Norman Goldberg, Waltraud Zummack, [[Helmut Schwarz]], John C. Poutsma and Robert R. Squires (1997), ''Generation of α-acetolactone and the acetoxyl diradical •CH2COO• in the gas phase''. International Journal of Mass Spectrometry and Ion Processes, Volumes 165-166, November issue, Pages 71-82. {{doi|10.1016/S0168-1176(97)00150-X}}</ref> 

Macrocyclic lactones are also important natural products.<ref name="fnf">{{citation | author=Karl-Georg Fahlbusch | contribution=Flavors and Fragrances | title=[[Ullmann's Encyclopedia of Industrial Chemistry]] | edition=7th | publisher=Wiley | year=2007 | pages=74‒78|display-authors=etal}}</ref> Lactones are present in [[oak]] wood, and they contribute to the flavour profile of [[barrel-aged beer]]s.<ref>{{cite web|url=https://beerandbrewing.com/dictionary/h63PzW6oDQ/ |website=Craft Beer and Brewing|title=The Oxford Companion to Beer definition of barrel-aging|first = Garrett|last = Oliver}}</ref>