Cones of Coniferous Taxa as a Potential Source of Bioactive Polyphenols

Abstract

Background: Coniferous cones are a by-product of forestry and wood logging, used for many possible purposes, e.g., the extraction of polyphenols. Objective: The aim of the present article was the comparison of the antioxidant polyphenol content of the differently matured cones of 17 selected conifers, either common in Hungary or yet uninvestigated. Methods: Total polyphenol content, ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl assays were used to determine the antioxidant contents. A scoring system was implemented using the three assay results to evaluate and compare the overall antioxidant power of the samples. Result and Conclusion: Highest antioxidant contents were found in green cones, followed by mature and opened cones. Taxa with the highest scores were Tsuga canadensis, Cryptomeria japonica, Chamaecyparis lawsoniana, Thuja orientalis, Metasequoia glyptostroboides and Picea abies. For the samples with the highest overall antioxidant power the high-performance liquid chromatographic/ tandem mass spectrometric polyphenol profiling was carried out (green cones of T. canadensis and P. abies) and 83 compounds have been tentatively identified and described. Results contribute to the future bioactivity testing and evaluation of the cone extracts of T. canadensis and P. abies.