'''Acetylenic fatty acid''' is the general name for a [[fatty acid]] with an unbranched chain of [[carbon]] atoms and a single [[triple bond]].  These fatty acids are rare, but do occurin nature. Known instances include:

==16 carbons==
* 16:1 triple-3 (3-hexadecynoic acid). A metabolite of 2-octadecynoic acid.<ref name=carb2014/>

==18 carbons==

* 18:1 triple-2 (2-octadecynoic acid). Synthetic. Claimed to be a promising antimalarial drug.<ref name=carb2014>Néstor M. Carballeira, Angela Gono Bwaly, Maurice Ayamba Itoe, Adriano D. Andricopulo, María Lorena Cordero-Maldonado, Marcel Kaiser, Maria M. Mota, Alexander D. Crawford, Rafael V. C. Guido, and Deniz Tasdemir (2014): "2-Octadecynoic acid as a dual life stage inhibitor of Plasmodium infections and plasmodial FAS-II enzymes" ''Bioorganic & Medicinal Chemistry Letters'', volume 24, issue 17, pages 4151-4157{{|10.1016/j.bmcl.2014.07.050}}</ref>
* 18:1 triple-4 (4-octadecynoic acid). Had its unusual crystal structure determined.<ref name=frmo1979>Froede Mo (1979): "4-Octadecynoic acid, a largely regular structure in space group <math>P\overline{1}</math>". ''Acta Crystallographica Section B'',  volume B35, pages 2135-2140.{{doi|10.1107/S0567740879008608}}/ref>
* 18:1 trple-6 (6-octadecynoic acid), or [[Tariric acid]]. Occurs in the herb ''Marrubium vulgare''<ref name=ohte2013>Anna Ohtera, Yusaku Miyamae, Naomi Nakai, Atsushi Kawachi, Kiyokazu Kawada, Junkyu Han, Hiroko Isoda, Mohamed Neffati, Toru Akita, Kazuhiro Maejima, Seiji Masuda, Taiho Kambe, Naoki Mori, Kazuhiro Irie, and Masaya Nagao (2013): "Identification of 6-octadecynoic acid from a methanol extract of ''Marrubium vulgare'' L. as a peroxisome proliferator-activated receptor γ agonist". ''Biochemical and Biophysical Research Communications'', volume 440, issue 2, pages 204-209. {{doi|10.1016/j.bbrc.2013.09.003}}</ref>
* 18:1 triple-9 (9-octadecynoic acid) occurs in ''Schoepflia californica''.<ref name=berry1991>David E. Berry, James A. Chan, Laurie MacKenzie, and Sidney M. Hecht (1991): "9-Octadecynoic acid: a novel DNA binding agent". ''Chemical Research in Toxicology'', volume 4, issue 2, pages 195–198 {{doi|10.1021/tx00020a011}}</ref>