Content of phenolic compounds, ascorbic acid, and photosynthetic pigments in Vaccinium macrocarpon Ait. dependent on seasonal plant development stages and age (the example of introduction in Russia)

- Leaves secondary metabolites content varied depending on seasonal development stage.
- Leaves of young plants had high phenolics level without clearly marked seasonality.
- Leaves of older plants had lower phenolics level, especially in flowering stage.
- Changes in total phenolic compounds content was mostly determined by flavonoids.
- Phenolics content in cranberry leaves was higher than in berries (at least 10 times).

American cranberry plants (Vaccinium macrocarpon Ait.) were introduced in Nizhegorodsky region (Russia) in 2008. The main goal was to evaluate influence of seasonal plant development stages and age on secondary metabolites accumulation in two cranberry cultivars. This article presents findings from the investigation of annual and seasonal dynamics of phenolic compounds (total soluble phenolic compounds, flavonoids, catechins, procyanidins, and anthocyanins) and ascorbic acid accumulation in V. macrocarpon leaves and fruits. The analysis of photosynthetic pigments level in leaves was also conducted. Antioxidant activity of leaf and fruit extracts was evaluated. Some chemical parameters of soil from V. macrocarpon growing site were characterized. Young plants featured high secondary metabolites content without clearly marked seasonality. Plants of reproductive age accumulated less phenolic compounds and demonstrated minimum of their concentration in leaf tissues during flowering. Content of leaf photosynthetic pigments during fruiting tended to decrease with plant age. There was no regularity in ascorbic acid accumulation. We suggest that seasonal plant development stages and age have a considerable effect on secondary metabolites content in tissues of introduced plants. The obtained results provide new insight into accumulation dynamics of phenolic compounds, ascorbic acid and photosynthetic pigments in American cranberry while being introduced in Russia.