Photochemical and bioactivity studies on nepeta congesta fisch. & mey. var. congesta fisch. & mey.

ABSTRACT PHYTOCHEMICAL AND BIOACTIVITY STUDIES ON NEPETA CONGESTA FISCH. & MEY. VAR. CONGESTA FISCH. & MEY. Ayşenur KARADEMİR Department of Pharmacognosy Anadolu University, Graduate School and Health Sciences, June 2021 Supervisor: Prof. Dr. Nilgün ÖZTÜRK In this study, extracts with different polarity (hexane, chloroform, ethylacetate, methanol) and infüsion prepared from the aerial parts of N. congesta Fisch & Mey. var. congesta Fisch. & Mey. (Lamiaceae), an endemic species collected from Eskişehir, were determined. The amount of total phenolic substance by spectrophotometric method and the amount of phenolic acids by reverse phase HPLC-DAD. In addition, antioxidant activities of extracts with different polarities, DPPH• free radical scavenging effect, ABTS•+ cation radical scavenging effect, metal chelating capacity, as well as acetylcholinesterase and butyrylcholinesterase enzyme inhibition activities were determined. The analysis of essential oil extracted by MSD-SPME technique was performed by GC-MS/FID. In the composition of the total essential oil (%97.8), 1,8-cineol (%61.7) and β-Burbonene (%12.4) were determined as the main components. The main phenolic acids of the infusion and methanol extracts with high total phenolic content were determined by the HPLC-DAD method, as in all Lamiaceae species, as rosmarinic acid. While DPPH•, ABTS•+ and metal chelating capacities of the same extracts were higher, acetylcholinesterase and butyrylcholinesterase inhibitory activities of the more apolar hexane and ethyl acetate extracts were found to be higher. In conclusion, the total phenolic content, phenolic acid compositions, antioxidant activities and acetylcholinesterase and butyrylcholinesterase inhibitory activities of different polarity extracts of N. congesta var. congesta, one of the endemic plant species for our country, were presented for the first time in this study. Keywords: Nepeta congesta var. congesta, Lamiaceae, Antioxidant, Anti-Alzheimer's, Rosmarinic asit.