Investigation of phytochemical content and biological activity of psephellus aucherianus (DC.) boiss. species

Plants have long been utilized in both traditional and modern medicine for the treatment, prevention, and management of various diseases due to the presence of numerous beneficial compounds in their structures. Turkey is among the richest countries in the world in terms of plant biodiversity. In addition to its diverse species richness, the flora of Turkey also harbors a substantial number of endemic species. This study aimed to explore the pharmaceutical potential of .Psephellus .aucherianus (DC.) Boiss., an endemic plant species of the Turkish flora, and to investigate its potential use as a natural source of antioxidants. Ethanolic extracts of the species were prepared, and its phytochemical composition was qualitatively and quantitatively determined using the LC-MS/MS method. Among 53 targeted secondary metabolites, 32 different compounds were identified. The species exhibited a notably rich bioactive and phytochemical profile. According to LC-MS/MS results, the flavonoids rutin (92.12 mg analyte/g extract) and hesperidin (103.52 mg analyte/g extract) were identified as major constituents. In addition, significant amounts of the flavonoids isoquercitrin (8.95 mg/g), cosmosiin (6.86 mg/g), nicotiflorin (6.18 mg/g), apigenin (2.37 mg/g), cynaroside (1.76 mg/g), quercitrin (1.29 mg/g), and astragalin (1.29 mg/g) were also detected. Furthermore, high levels of phenolic acids such as quinic acid (44.00 mg/g), chlorogenic acid (15.42 mg/g), and vanillic acid (2.70 mg/g) were found. The total phenolic content of the studied species was measured as 55.52 ± 0.59 mg GAE/g extract, and the total flavonoid content was 4.88 ± 0.21 mg RE/g extract. Antioxidant properties were evaluated through various test systems, including free radical scavenging (DPPH and ABTS), reducing power (CUPRAC and FRAP), phosphomolybdenum, and metal chelation assays. The results revealed the following activities: DPPH radical scavenging activity was 39.55 ± 0.17 mg TE/g, ABTS was 63.08 ± 0.45 mg TE/g, CUPRAC reducing power was 171.17 ± 1.96 mg TE/g, FRAP was 106.44 ± 2.07 mg TE/g, phosphomolybdenum total antioxidant capacity was 2.30 ± 0.01 mmol TE/g, and metal chelating activity was 17.94 ± 0.13 mg EDTAE/g. The enzyme inhibition effects of the extract were also examined against acetylcholinesterase, butyrylcholinesterase, tyrosinase, amylase, and glucosidase enzymes. The inhibition levels were determined as follows: AChE inhibition 2.89 ± 0.05 mg GALAE/g, BChE inhibition 2.42 ± 0.22 mg GALAE/g, amylase inhibition 0.38 ± 0.02 mmol ACAE/g, and tyrosinase inhibition 73.36 ± 2.49 mg KAE/g. No inhibitory activity was observed against the glucosidase enzyme. Overall, the analyses demonstrated that Psephellus aucherianus (DC.) Boiss. possesses a rich content of secondary metabolites and exhibits high antioxidant capacity, indicating its potential as a natural antioxidant source. Notably, it showed significant biological activity in terms of tyrosinase inhibition.