Pharmacognostical studies on galanthus alpinus sosn. var. alpinus

ABSTRACT PHARMACOGNOSTICAL STUDIES ON GALANTHUS ALPINUS SOSN. VAR. ALPINUS In this thesis, Galanthus alpinus Sosn. var. alpinus which is a wild-growing species of Galanthus in our country, has been thoroughly investigated by four different approaches. Firstly, anatomical and microscobical studies on the aerial parts and bulbs of G. alpinus Sosn. var. alpinus have been carried out. Quality-control studies including, loss on drying, total ash, sulphated ash and hydrochloric acid-insoluble ash have been performed according to European Pharmacopoeia on drug specimens. The results were given as percentage values. Additionally, total alkaloidal contents of the drug specimens were determined by a titrimetric method. Galanthamine and lycorine, biologically important alkaloids of Amaryllidaceae family, were qualitatively and quantitatively investigated by using high pressure liquid chromatography (HPLC) in four different drug specimens prepared from G. alpinus Sosn. var. alpinus. Furthermore, capillary gas chromatography-mass spectrometry (CGC-MS) was used to determine the alkaloidal profile of four different drug specimens. As a result, fifteen alkaloids were detected in G. alpinus Sosn. var. alpinus. In the studies, where anticholinesterase activity guided isolation and structure elucidation investigations were carried out, total alkaloidal extract, prepared from powdered whole plant material dried at room temperature, was fractionated by colon chromatography and the obtained fractions were determined for their acetylcholinesterase and butytylcholinesterase inhibitory activity by using a microplate assay based on in vitro Ellman' s method. Accordingly, fractions which have anticholinesterase activity have been purified by different methods such as preparative colon chromatography, preparative thin layer chromatography and crystallization. The structures of the obtained compounds were elucidated by modern spectroscopic methods (1D, 2D NMR, MS). As a result of these studies, the Amaryllidaceae alkaloids, (-)-lycorine from the lycorine subgroup, (+)-homolycorine and (+)-8-O-demethylhomolycorine from the lycorenine subgroup, arolycoricidine from the narciclacine subgroup were isolated from G. alpinus Sosn. var. alpinus. Moreover, N-trans-feruloyl tyramine, O-methylnorbelladine, hordenine, nicotinic acid and two furofuran type lignanS, pinoresinol and epipinoresinol were isolated. In addition to this, (+)-Blumenol A, a terpenoid, was also obtained. Interestingly, the occurence of (+)-Blumenol A is new in Amaryllidaceae family. Other compounds are reported for the first time from the title species. Acetylcholinesterase ve butyrylcholinesterase inhibitory activities of isolated compounds were determined by using a microplate assay based on in vitro Ellman' s method. (+)-Homolycorine, (+)-8-O-demethylhomolycorine, hordenine and nicotinic acid showed significant activity in both of the assays. N-trans-feruloyl tyramine displayed only anti-butyrylcholinesterase and (+)-Blumenol A displayed only anti-acetylcholinesterase activity. The IC50 values of all active compounds were calculated. Keywords: Galanthus alpinus Sosn. var. alpinus; anticholinesterase activity guided isolation; quality control experiments