Fig. 1. Chemical structures of tocopherols and the order of conversions between forms. Basic structure of all tocopherols is the same, the differences are in the number and location of the methyl groups on the benzene ring.
Fig. 2. Tocopherol concentrations are determined by HPLC.(a) Chromatogram shows -tocopherol and -tocopherol and their respective retention times of 4.185 and 4.880. The concentrations are then associated with (b) a molecular maker genotype to determine if the genotype is associated with the phenotype.
Fig. 3. Chromosome regions affecting tocopherol levels in two populations. Three regions are shared between populations, several are significant in only one of the populations.