Underexplored potential of Viburnum opulus L. inflorescences: Phenolic profiling across flowering phenophases

Viburnum opulus L., commonly known as guelder rose, is known for its medicinal properties, primarily attributed to its fruits and bark [ 1 ] [ 2 ]. However, the phenolic composition of its inflorescences remains inadequately explored. This study aims to elucidate the phenolic profiles of cultivated V. opulus inflorescences at different flowering stages, highlighting their potential as valuable sources of bioactive compounds. Inflorescence samples were collected during three distinct flowering stages: the beginning of flowering, massive flowering, and the end of flowering. Ethanolic extracts were analyzed using high-performance liquid chromatography (HPLC) and spectrophotometric assays to evaluate the antioxidant activity. The results revealed significant variations in phenolic and antioxidant activity across the flowering stages. Notably, chlorogenic acid was the predominant compound during all flowering stages, constituting approximately 35-65% of the total identified phenolics. Kaempferol, quercetin, and isorhamnetin derivatives predominated the flavonoid profile with significant differences during the flowering stages. The antioxidant activity during the beginning of flowering was determined by the amount of identified phenolic acids and, in certain species, tended to increase at the end of flowering due to the elevated flavonoid quantities. These findings suggest that the phenolic composition of V. opulus inflorescences is dynamic and stage-dependent. The high phenolic compound diversity in inflorescences suggests that they are an underutilized resource for pharmaceutical, nutraceutical, and functional food applications. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany