3,7,11,15-Tetramethylhexadecanoic acid, a constituent of butterfat

Absolute Stereochemical Configuration of Phytanyl (Dihydrophytyl) Groups in Lipids of Halobacterium cutirubrum*

“…The present findings have a bearing on the configuration of pristanic and phytanic acids isolated from various natural sources. These two acids have been identified in butterfat (Sonneveld et al, 1962;Hansen and Morrison, 1964;Hansen et al, 1965), human and animal tissues , and marine fish oil (Gupta and Peters, 1966), and phytanic acid has been found in ox plasma (Duncan and Garton, 1963;Lough, 1964), ox and sheep perinephric fat (Hansen, 1965a-c), rumen bacteria (Hansen, 1966), and humans with Refsum's syndrome (Klenk and Kahlke, 1963;Hansen, 1965d). Since phytanic and pristanic acids in the above organisms are probably derived ultimately from the phytol of chlorophyll (Steinberg et al, 1966; 3331 Mize et al, 1966;Patton and Benson, 1966;Hansen, 1966;Hansen et al, 1965Hansen et al, , 1966; Stoffel and Kahlke, 1965), it follows that C-7 and C-ll in the phytanic acid (and C-6 and C-10 of pristanic acid) should have the R configuration, as in natural phytol.…”

“…Although the data in the literature on phytanic and pristanic acids either lack optical rotatory measurements or give rotatory dispersion values, there are a few examples where comparison with the present results is possible. Hansen and Shorland (1953) and Sonneveld et al (1962) reported a value for [a]D of + 10 for phytanic acid in butterfat, and Hansen (1965a) found tab +0.3°for phytanic acid from ox fat, indicating that in these samples, both the S,R,R and R,R,R isomers are present with the latter isomer predominating (cf. Ackman and Hansen, 1967).…”