Determination of lignans and phenolic components of Schisandra chinensis (Turcz.) Baill. using HPLC-ESI-ToF-MS and HPLC-online TEAC: Contribution of individual components to overall antioxidant activity and comparison with traditional antioxidant assays

• Leaves, stems, and fruits of Schisandra chinensis were analysed by LC-ESI-ToF-MS.
• Twelve phenolic compounds were identified for the first time in Schisandra leaves.
• Individual antioxidant capacities were determined by HPLC-online TEAC.
• Chlorogenic acids and quercetin glycosides contribute over 80% of the total TEAC.
• Leaves and stems of Schisandra can be considered as functional ingredients.

Schisandra chinensis is a widely-consumed nutraceutical providing advantageous nutritional and bioactive properties. This study aimed at characterizing the chemical composition and antioxidant capacity of S. chinensis fruits as well as the underestimated leaves and stems. A special aim of this study was to characterize the contribution of single constituents (lignans and further phenolic compounds) to the overall antioxidant activity using an HPLC-online TEAC approach. By using LC-DAD/ESI-ToF-MS, twenty-eight lignans and twenty phenolic compounds were identified. Among the 48 characterized components, twelve phenolic compounds were identified for the first time in Schisandra. Gomisin D was the only lignan being able to scavenge ABTS+ radicals, suggesting that not its amount but rather its chemical structure is responsible. Overall, clorogenic acid isomers and quercetin glycosides contribute to over 80% of the total antioxidant activity. This study indicates that leaves and stems of S. chinensis may be used for obtaining bioactive formulations and functional foods.