4. Conclusion
Once again, CCC proved to be a powerful technique for both the enrichment of minor compounds from lipid extracts and discovery of trace components in lipid matrices. With regard to the latter point, 18 tocochromanols were detected in the pumpkin seed oil (PSO). However, for three compounds it remained unclear if these were hitherto unknown naturally occurring tocochromanols or artefacts formed during the roasting process involved in the processing of the oil. Even without these compounds, the number of tocochromanols detected in the sample surpassed results from any previous study on PSO or other natural oils.
While CCC allowed to enrich γ-T1 from the oil, a full isolation of this minor compound in the oil (~0.4 mg/100 g) in high purity could not be achieved. However, the subsequent column chromatography which was based on a different separation principle allowed to gain 6.8 mg γ-T1 with 96% purity. Admittedly, the expenditure (44 saponifications, 11 CCC runs, ~45 column chromatographic separations) was high, but the isolation of γ-T1 may also be useful in studies of its biological activity. Recently, α-T1 was found to behave differently to both α-T and α-T3 (Irías-Mata et al., 2020). For example, it does not seem to entirely depend on α-tocopherol transfer protein (TTP) function for its secretion into the systemic circulation (Irías-Mata et al., 2020). Similar studies with γ-T1 would ultimately support the understanding of minor tocochromanols.