Abstract
The present study reveals in vitro antioxidant properties and the phytochemical content of a novel Rheum species (Rheum telianum), which grows in Southeastern Anatolia. To perform the analysis, dried leaves and seeds of the plants were ground and extracted with ethanol to obtain plant secondary metabolites and antioxidant activity. Then, dried extracts were subjected to in vitro DPPH scavenging and Cupric reducing (CUPRAC), Fe(3+), and Ferric reducing antioxidant power (FRAP). In addition to the antioxidant capacity assays, quantitative phenolic, flavonoid, and secondary metabolite were determined through spectrophotometric and LC-MS/MS chromatographic methods. IC(50) values showed that both leaves and the seeds of the R. telianum have high inhibitory properties over DPPH radicals with 20.79 and 5.67 μg/mL, respectively. The samples' dominant secondary metabolites were evaluated through the LC-MS/MS analysis results. The inhibition effects of both leaves and the seeds of the R. telianum extracts on acetylcholinesterase and butyrylcholinesterase, α-glycosidase and human carbonic anhydrases II isoenzyme enzymes, which associated with some global diseases including Alzheimer's disease, type-2 diabetes mellitus and glaucoma were determined. In conclusion, the extracts' contents and functional relationship and the plants' possible usage in the food, medicine, and cosmetic industries was revealed.