Seed tocochromanol-based chemotaxonomy of Euroasian grapevine (Vitaceae) species

Tocochromanols (tocopherols and tocotrienols) are powerful lipophilic antioxidants, along with other bioactive functions, found in plants. Tocopherols are more common, and present in all plant parts, while tocotrienols are generally only present in the seeds of some plants. Grapeseed ( Vitis vinifera ) one of few household cooking oils to contain predominantly tocotrienols. Meanwhile, tocochromanol profile in other grapevines ( Vitis and other genera of Vitaceae family) is scarcely investigated. The aim of the study was to investigate tocochromanol profiles in the grapevine family ( Ampelocissus , Ampelopsis , Cissus , Cyphostemma , Leea , and Parthenocissus genus), and validate a simplified ultrasound-assisted ethanolic extraction protocol. Total tocochromanol content ranged 4.9–24.4 mg 100 g -1 dw, all grapevine seeds predominantly contained tocotrienols. The main tocochromanol in Ampelocissus , Ampelopsis and Parthenocissus was generally α-tocotrienol, while γ-tocotrienol was preferentially accumulated in Cyphostemma species’ seeds. Vitis species contained a similar amount of both, and Leea either contained α-tocotrienol, or both. Ultrasound-assisted extraction in ethanol, produced 92–98% tocotrienol and 62–86% tocopherol recovery, respectively, compared to the standard saponification protocol. The simplified ultrasound-assisted ethanolic extraction protocol is suitable for all studied Vitaceae species, facilitating rapid extraction and testing. Principal component analysis and cluster analysis grouped species into two groups: α-tocotrienol or γ-tocotrienol-dominated.