Maize pollen lipids

Abstract

The chloroform extractives of four wild selections of Zea mays pollen were separated quantitatively into chemical classes and the components of each class were identified. Alkanes, alkenes, fatty acids, triterpene esters and triglycerides were found as the main constituents of the lipid extracts. The two hydrocarbon classes were found in a ratio close to 1:1; pentacosane, heptacosane and nonacosane were dominating in the alkanes, whilst alkenes showed major homologues two carbon atoms longer. Free fatty acids, 8–22% of the total, contained predominantly palmitic (16:0), stearic (18:0), oleic (18:1), linoleic (18:2) and lower amounts of palmitoleic (16:1) and linolenic (18:3) acids. Triglycerides and triterpene esters accounted for 17–31 % and 5–34%, respectively. The former class comprised three homologous series, the latter contained tetracyclic and pentacyclic triterpenes esterified with C 16 and C 18 fatty acids. Free triterpenols and linear esters were also found in pollen lipids. These data are discussed in relation to pollen biochemistry and in regard to the natural functions of the lipid classes found.