Phenolic contents and biological activities of two endemic plants in Turkey

In the paper, the phenolic compounds and biological activity of Corydalis oppositifolia DC. and Senecio cilicius Boiss., the endemic plants growing in Turkey, were investigated for the first time. The ethanol extract of C. oppositifolia exhibited more potent antimicrobial activity while the ethanol extract of S. cilicius exhibited the highest radical scavenging activity on ABTS (81.4±1.1a mg TE g−1 extract) and DPPH (23.4±0.2a mg TE g−1 extract). In C. oppositifolia, the highest total flavonoid and phenolic acid contents were found to be in the ethanol (94.2±3.5a mg QE g−1 extract) and methanol (320.5±3.3c mg GAE g−1 extract) extracts, respectively. In S. cilicius, the highest total flavonoid and phenolic acid contents were found to be in the methanol (56.9±0.9c mg QE g−1 extract) and ethanol (568.0±3.3a mg GAE g−1 extract) extracts, respectively. The ethanol extract of C. oppositifolia has the most prominent activity against α-amylase, AChE and BChE whereas the methanol extract of this plant displayed the highest inhibitory activity against α-glucosidase. HPLC analysis of the ethanol extracts revealed that the major flavonoids were kaempferol and quercetin whereas the major phenolic acids were protocatechuic acid, gallic acid, gentistic acid and 2,4-dihydroxybenzoic acid. The findings suggested that the plants and their extracts have the potential to be used in the treatment of diseases such as diabetes and Alzheimer's diseases.