δ-Tocomonoenol: A new vitamin E from kiwi (Actinidia chinensis) fruits

A new vitamin E, δ-tocomonoenol, has been isolated from Actinidia chinensis (kiwi) fruits. The new structure, 2,8-dimethyl-2-(4,8,12-trimethyltridec-11-enyl)chroman-6-ol, has been elucidated on the basis of EIMS, 1D, and 2D NMR spectral data. GC–MS analysis of peels and pulps of kiwi showed that the new compound, together with δ-tocopherol, is mainly present in the fruit peel, whilst α-tocopherol is present in a similar amount in both matrices. The compound was tested for its radical-scavenging and antioxidant capabilities, by measuring its ability to scavenge DPPH (2,2′-diphenyl-1-picrylhydrazyl radical) and anion superoxide radical, and inhibit the formation of methyl linoleate conjugated diene hydroperoxides and TBARS (thiobarbituric acid reactive species).     

Dietary Marine-Derived Tocopherol has a Higher Biological Availability in Mice Relative to Alpha-Tocopherol

The biologic availability of two kinds of tocomonoenols, marine-derived tocopherol (MDT) and α-tocomonoenol, was investigated in ICR mice. Vitamin E-deficient ICR mice were fed MDT and α-tocomonoenol together with α-tocopherol, β-tocopherol, γ-tocopherol, and δ-tocopherol, and storage in liver, spleen, lung, and brain was quantified using reverse-phase high-performance liquid chromatography. The vitamin E relative biologic availability (VE-RBA) in liver was 100 for α-tocopherol, 26 ± 3 for β-tocopherol, 4 ± 2 for γ-tocopherol, not detected for δ-tocopherol, 49 ± 6 for MDT, and 30 ± 7 for α-tocomonoenol. The VE-RBA in brain was 100 for α-tocopherol, 5 ± 2 for β-tocopherol, not detected for γ-tocopherol and δ-tocopherol, 8 ± 1 for MDT, and 4 ± 1 for α-tocomonoenol. Tocopherols and tocomonoenols did not accumulate in the spleen or lung. MDT and α-tocomonoenol had high VE-RBA values. The VE-RBA value for MDT was much higher than that for β-tocopherol.