Pharmacognostic researches on Xeranthemum annuum L.

Xeranthemum annuum L. (Asteraceae) is a plant species known as ?ölmez ot, kağıt otu? in our country and ?immortelle, everlasting flower? in English. In our thesis studies, neuroprotective effect of the extracts in various polarities prepared from the flower and root-stem parts of X. annuum was established using acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase inhibitory activities as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH), N,N-dimethyl-p-phenylendiamine (DMPD), and superoxide (SO) radical scavenging activity, ferric ion-chelating effect, ferric-reducing antioxidant power (FRAP), and phosphomolibdenum-reducing antioxidant power (PRAP) methods. Besides, total phenol and flavonoid contents were calculated spectrophotometrically and phytochemical profiles of the extracts were investigated by thin layer chromatography. According to data we obtained, while the extracts were completely inactive against AChE and tyrosinase, the ethanol and water extracts of the root-stem parts were found to possess the highest BChE inhibitory and antioxidant activity. This thesis has constituted the first study on X. annuum growing in Turkey in terms of biological activity and phytochemical content.Key words: Xeranthemum annuum, Asteraceae, Neuroprotective effect, Cholinesterase inhibition, Tyrosinase inhibition, Antioxidant activity