Douglas-fir bark. III: Sterol and wax esters of the n-hexane wax

Sterol and wax esters were isolated as chemically intact compounds from the n-hexane-soluble fraction of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] bark in a continuing effort to elucidate the properties of this wax. The sterol esters were composed of sitosterol and campesterol esterified to any or all of the fatty acids, n-tridecanoic acid, n-hexadecanoic acid, n-heptadecanoic acid, cis-9-octadecenoic acid, n-nonadecanoic acid, n-eicosanoic acid, n-docosanoic acid, and n-tetracosanoic acid. The wax esters were composed of 1-docosanol and 1-tetracosanol, also esterified to the above-named acids. The fact that any or all of the fatty acids can be esterified to each of the sterols and alcohols, producing a great mixture of different sterol and wax esters, may partly account for the softness and low melting point of Douglas-fir n-hexane wax.