12-Methyltridecanoic acid

In a few cases, 3-hydroxy fatty acids that contain additional functional groups were characterized. Thus (i )-3-hydroxydodec-(5Z)-enoic add [A5-12 l(3-OH)] was identified in ester linkage in lipid A of the chloridazon-de-grading bacterium P. immobile (105). Unsaturated 3-hydroxy fatty adds are also present in R. trifolii (81) and R. meliloti (82). In an extract of L. pneumophila, 2,3-dihydroxy-12-methyltridecanoic acid [12-Me-13 0(2,3-diOH)] and 2,3-dihydroxytetradecanoic acid [ 14 0(2,3-diOH)] were identified in amide-linkage (138). It remains, however, to be established, whether these 2,3-dihydroxylated fatty acids are lipid A constituents. Small amounts of 2-methyl-3-hydroxy-fatty adds have been detected in B. pertussis (139). 

Lanolin has been used for many years as a vehicle for pharmacologically active substances in ophthalmic ointments and topical formulations.55-60 In addition to being a vehicle for penicillin and other antimicrobial substances, lanolin contains lipids such as 10-methyldodecanoic acid and 12-methyltridecanoic acid, which have antimicrobial activity.61,62... 

OH n-Tridecanoic acid OH n-Tetradecanoic acid OH 10-Methyltridecanoic acid OH 11 -Methyltridecanoic acid OH 12-Methyltridecanoic acid OH 10-Methyltetradecanoic acid OH 11,11,13-Trimethyltetradecanoic acid OH Cyclopropylnonanoic acid OH Cyclobutylnonanoic acid OH Cyclopentylnonanoic acid OH Cyclohexylnonanoic acid... 

Methyltridecanoic acid, M-OOl 17 12-Methyltridecanoic acid, M-OOl 18 2-Methyl-3-tridecanol, M-OOl 19... 

Methyltridecanoic acid Amide, in M-OOl 18 Tetradecanal Oxime, in T-00029 Tetradecanoic acid Amide, in T-00034... 

Chromic acid oxidation of lipopeptin A destroyed threo- -hydvoxy glutamic acid and serine, but not threonine. Therefore the lactone ring involved the hydroxyl group of threonine, a conclusion supported by comparing the HNMR spectra of lipopeptin A and its open-ring derivative. Hence structure (47) was proposed for lipopeptin A. In lipopeptin B, the fatty acid was identified as 12-methyltridecanoic acid 114). 

The seven amino acids mentioned above linked together with 12-methyltridecanoic acid gave the formula C50H77N9O17, smaller than the formula determined by SIMS mass spectrometry for neopeptin A (m/z 1194(M + l), m/z 1216 (M + Na) ). The difference, C3H4N2O2, showed the presence of an eighth amino acid with a basic group, in agreement with the basic pKa found for neopeptins. 

Tridecan-2-one 11-Methyltridecanoic acide 3-Methylbutanoic acid Desmosterol... 

Ethyl 2-cyano-3-hexyl-3-methyltridecanoate refluxed 6 hrs. in aq.-alc. KOH, the resulting crude acid mixed with Gu-powder, heated slowly with stirring whereupon decarboxylation occurs at 150-160°, and heated a short period at 180° when the vigorous COg-evolution has ceased >3-hexyl-3-methyltridecane-nitrile. Y 86%. F. e. s. N. Rabjohn, L.V. Phillips, and R. J. DeFeo, J. Org. Chem. 24, 1964 (1959). 

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