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

A new vitamin E, delta-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 delta-tocopherol, is mainly present in the fruit peel, whilst alpha-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 (thiobirbituric acid reactive species). (C) 2008 Elsevier Ltd. All rights reserved.