Phenolic content variation in varieties and clones of Viburnum opulus L. flowers

Abstract

Introduction. Viburnum opulus L. is a deciduous shrub that belongs to Caprifoliaceae plant family. Viburnum opulus L, more known as European Cranberrybush, is found in natural habitats in Europe, Russia, and some regions in North Africa and North Asia [1]. Viburnum opulus L. is characterized by valuable nutritional and medical properties. Fruits and bark have been used in traditional medicine for a wide range of illnesses, including heart disease, coughs and colds, digestive troubles, and neurosis. The bark of V. opulus has been used to relieve menstrual and stomach cramps. In Ukraine, Viburnum opulus L. fruits are used in traditional cuisine as a component of drinks, sauces, and cakes. Studies show that the fruits of Viburnum opulus L. are rich in biologically active components with antioxidant, antimicrobial, uterine-relaxing and antispasmodic properties [2]. So far, most of the research has been carried out to analyze the total phenolic content and antioxidant activity of Viburnum opulus L. fruit and bark. However, little is known about the total phenolic content of other parts of the plants, such as flowers. The aim of this study is to analyze the total phenolic content in Viburnum opulus L. flowers. Materials and methods. 21 Viburnum opulus L. varieties and selected clones of flowers were used in the researchis being cultivated in Kaunas botanical garden (VDU KBS) of Vytautas Magnus University,. Flowers of each V. opulus L. genotype were collected at 3 different phenological stages - butonisation, full flowering and late flowering during May 2023 and June 2023, respectively. Ethanolic extracts of flowers were prepared for further analysis. To determine the total amount of phenolic compounds Folin–Ciocalteu spectrophotometric method was used. Results and discussion. The total amount of phenolic compounds in samples of flowers varied from 43,40 mg GAE/g (SD= 0,94 mg GAE/g) to 71,35 GAE/g (SD= 0,99 mg GAE/g). The highest total amount of phenolic compounds was determined in the end of May and the lowest on mid-May . V. opulus var. trilobum (Marshall) McAtee contained significant quantities of total phenolics. The lowest amount of total phenolics was found in V. opulus var. opulus 'Compactum'. Conclusions. This research significant differences the total amount of phenolic compounds in Viburnum opulus L. flowers during vegetation period. The results demonstrated the differences between varieties and clones of total phenolic content. In addition, our results indicate that flowers of Viburnum opulus L. are underutilized rich source of phenolics.