Tocotrienol-Dominated Profiles in Ilex Genus (Aquifoliaceae) Seeds and Their Relationship to Plant Phylogeny

Most research on tocochromanols suggests that tocotrienols (T3) are rarely found in nature, especially in dicotyledonous species. The present study investigates species from the Ilex (holly) genus, the sole surviving genus in the Aquifoliaceae family. The study tested 29 species or hybrids from botanical gardens across Eurasia and the US. A direct ultrasound-assisted extraction in ethanol (UAEE) protocol was validated and used to extract tocochromanols. Tocochromanol recovery from seeds via UAEE ranged between 96–100%, compared to saponification. α-T3 and γ-T3 accounted for an average of 91% of all tocochromanols determined in Ilex species. The highest tocochromanol content was found in I. crenata and I. serrata (8.11 and 6.66 mg 100 g−1 dry weight, respectively). A total of 19 of 29 species in the Aquifoliaceae family were dominated by α-T3. Differences between plant type (shrub/tree) and seasonality (deciduous/evergreen) were not statistically significant, and appear to be mainly influenced by other factors. Linear discriminant analysis identified I. crenata, I. asprella, I. × meserveae, I. vomitoria, and I. geniculata (all shrubby) as divergent.