11 -Cyclohexylundecanoic acid

Cyclohexanecarboxylic acid moieties were previously observed in 11 -cyclohexylundecanoic acid (126) and 13-cyclohexyltridecanoic acid (127) isolated from a thermophilic bacterium Bacillus acidcaldarius and Curtobacterium pusillum [207-209], asukamycin [191,210] and ketomycin (128) [211]. 

Some saturated FAs have a ring system connected to the chain, such as 11-cyclohexylundecanoic acid, 13-cyclohexyltridecanoic acid, and cycloheptaneunde-canoic acid (Figure 3). 

Fatty acids with a cyclohexane ring at the end of the hydrocarbon chain, such as 11-cyclohexylundecanoic (3-27) and 13-cyclohexyltridecanoic acids are minor constituents of milk, butter, sheep s tallow and rumen bacteria. The amount of 11-cyclohexylundecanoic acid in cow and goat milk is 1 2 g/kg. It was found that this acid has inhibitory effects on the bacteria Bacillus cereus, Escherichia coli and fungi Fusarium ctdmorum. Cyclic fatty acids are also found in the ordinary oils, where their formation is induced by heating (see Section 3.8.1.5). 

Smidrkal J., Karlova T., FUip V., Zarubova M., Hradkova 1. Antimicrobial properties of 11-cyclohexylundecanoic acid. Czech Journal of Food Sciences, 27 463-469 (2009). 

Cyclohexylundecanoic acid has been isolated from bovine milk and characterized (Schogt and Haverkamp Begemann 1965). Brewington et al. (1974) found glucuronides of 17 milk fatty acids in bovine milk. These were presumably detoxification products formed in the liver and, interestingly, included the odd-chain acids, 9 0-17 0. 

Cyanononane, in M-00074 2-Cyanononanoic acid, C-00028 9-Cyanononanoic acid, C-00029 2-Cyanopelargonic acid, see C-00028 w-Cyanopelargonic acid, see C-00029 l-Cyano-2-propanol, in H-00232 1-Cyanopropene, in B-00040 Cycloartanol, C-00030 Cycloartenol, C-00031 Cycloartenone, in C-00031 1,12-Cyclodocosanedione, C-00032 Cycloeucalanol, in C-00033 Cycloeucalenol, C-00033 Cyclohexaneundecanoic acid, C-00034 Cyclohexylundecanoic acid, see C-00034 9/lJ,19-Cyclolanostan-3/5-ol, see C-00030 9/5,19-Cyclo-24-lanosten-3i5-ol, see C-00031 9/3,19-Cyclolanost-24-cn-3-one, in C-00031 Cyclolaudenol, in M-00022... 

Other saturated and unsaturated cyclic esters are more stable to gas chromatography. Methyl 11-cyclohexylundecanoate, a minor constituent of rumen microrganisms and milk fat, is eluted with 18 2(n-6) on a packed column of PEGA and with 18 0 on one of Apiezon [354]. In addition, retention data have been published for some synthetic and natural (o-alicyclic fatty acids on polar and non-polar phases [215,458]. 

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