Calendic acid
Preferred IUPAC name
(8E,10E,12Z)-Octadeca-8,10,12-trienoic acid
Other names
  • α-Calendic acid
  • (8E,10E,12Z)-Octadecatrienoic acid
  • trans-8-trans-10-cis-12-Octadecatrienoic acid
3D model (JSmol)
  • InChI=1S/C18H30O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h6-11H,2-5,12-17H2,1H3,(H,19,20)/b7-6-,9-8+,11-10+ checkY
  • InChI=1/C18H30O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h6-11H,2-5,12-17H2,1H3,(H,19,20)/b7-6-,9-8+,11-10+
Molar mass 278.436 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Calendic acid (sometimes α-calendic acid) is an unsaturated fatty acid, named for the pot marigold (Calendula officinalis), from which it is obtained. It is chemically similar to the conjugated linoleic acids; laboratory work suggests it may have similar in vitro bioactivities.[1]


Calendic acid is an omega-6 fatty acid.[2] though not usually listed with this group. Calendic acid is synthesised in Calendula officinalis from linoleate by an unusual Δ12-oleate desaturase (a FAD 2 variant) that converts the cis-double bond at position 9 to a trans,trans-conjugated double bond system.[3] An all-trans beta isomer has been described.[1]

Calendic acid comes from the pot marigold


Calendic acid is the fatty acid responsible for the reduction in feed intake and improved feed utilization in mice when calendula oil is added to the feedstuff, as demonstrated by the comparative experiments in the examples using corn oil.[4]


  1. ^ a b Yasui Y, Hosokawa M, Kohno H, Tanaka T, Miyashita K (2006). "Growth inhibition and apoptosis induction by all-trans-conjugated linolenic acids on human colon cancer cells". Anticancer Res. 26 (3A): 1855–60. PMID 16827117.
  2. ^ Kinney, Tony. "Metabolism in Plants to Produce Healthier Food Oils" (PDF). Archived from the original (PDF) on 2006-09-29. Retrieved 2007-01-11.
  3. ^ Christie, William W. "Fatty Acids: Polyunsaturated with other than Methylene-Interrupted Double Bonds". Lipid Library. Archived from the original on 2007-01-12. Retrieved 2007-01-11.
  4. ^ US Patent 20050118208: Powder formulation comprising conjugated octadecapolyenic acids