Campanula macrostachya: biological activity and identification of phenolics using a liquid chromatography electrospray ionization tandem mass spectrometry system.

Abstract

It is known that some Campanula species are traditionally used because of their anti-allergic, spasmolytic, antiphlogistic, antioxidant, and antiviral properties. This study was designed to evaluate the phytochemical composition, antioxidant, α-amylase, and tyrosinase inhibitory activity of ethyl acetate, methanol, and water extracts of Campanula macrostachya Waldst. & Kit. ex Willd. Chemical compositions were analyzed by spectrophotometric and chromatographic methods. Antioxidant activities of the samples were tested by using five different test systems. Enzyme inhibitory activities of the extracts were also studied. As a result of the LC-ESI-MS/MS analyses, chlorogenic acid, hesperidin, and hyperoside were found to be the major compounds of the extracts, especially the MeOH extract (6559.59, 2499.22, and 2047.66 μg/g extract, respectively). Antioxidant activity tests have proven that MeOH extract showed higher activity than others (DPPH: 4.15 mg/mL, ABTS: 2.05 mg/mL, CUPRAC: 1.80 mg/mL, FRAP: 0.83 mg/mL, phosphomolybdenum: 1.69 mg/mL). Ferrous ion chelating activity of the water extract was 1.03 mg/mL. In α-amylase and tyrosinase inhibitory assays, EtOAc (IC50: 2.54 mg/mL) and MeOH (IC50: 1.51 mg/mL) extracts showed higher activity than the others did. In phosphomolybdenum, CUPRAC, FRAP, and tyrosinase inhibitory assays, the activity was strongly correlated with flavonoids, chlorogenic acid, hesperidin, and hyperoside. On the other hand, phenolic compounds have been found to contribute more to radical scavenging activity. Pearson correlation analysis showed that phenolics and flavonoids were not responsible for the α-amylase inhibitory activity of EtOAc extract.