Investigation of biological activities, phenolic and mineral compositions of Robinia pseudoacacia and Robinia hispida plant extracts

Diabetes is among the most common diseases in the world. Oxidative stress, which occurs when the balance between oxidant and anti-oxidant systems in the organism is disrupted in favor of oxidants, is among the causes of diabetes. However, changes in α-amylase and α-glucosidase enzymes that are involved in the carbohydrate breakdown mechanism also lead to diabetes. In this study, extracts of the above-ground parts of Robinia pseudoacacia and Robinia hispida plants, popularly known as white acacia and pink acacia, prepared in different solvents and concentrations were used. In these extracts, antioxidant activities were determined by TPC, TFC, DPPH and ABTS, FRAP, CUPRAC methods and antidiabetic activities were determined by α-glucosidase inhibition method. Phenolic compounds in plants and their amounts were compared with chromatographic LC-MS/MS analysis. Mineral content was determined by ICP-MS analysis. In addition, color analysis of plant extracts was made. Although the content of plant extracts differed in terms of phenolic and flavonoid substances, it was observed that the solvent type and concentration were an important factor in determining the content. When the two plant species were compared, extracts of pink acacia flowers and leaves showed better activity in terms of TPC, TFC, FRAP, CUPRAC, ABTS and DPPH. In the enzyme inhibition study, pink acacia flower extracts showed the highest activity. In the results of mineral analysis, the element with the highest amount in the extracts was found to be potassium. The identification of biologically active extracts is crucial for basic biological sciences, pharmaceutical applications, and future research.