GC/MS Analysis of Amaryllidaceae Alkaloids in Galanthus gracilis

Abstract

structures, in the present study, we aimed to investigate the alkaloid composition of G. gracilis, collected from a different locality in Turkey, by GC/MS. In this study, the alkaloid extracts of Galanthus gracilis Celak. were examined by means of gas chromatography/mass spectrometry (GC/MS), and 20 alkaloids were reported. Homolycorine and 8-O-demethylhomolycorine are the main alkaloids in the extracts obtained from the aerial parts and bulbs, respectively. Additionally, the AChE inhibitory activity of the extracts prepared from the aerial parts and bulbs of G. gracilis was investigated by in vitro Ellmans method [10]. Potent inhibitory activity was recorded in the extracts of the bulbs and aerial parts of G. gracilis. To the best of our knowledge, this is the first report of a GC/MS study on the alkaloids of G. gracilis growing in Turkey. Based on the GC/MS analysis, a total of 20 alkaloids was detected in two different extracts prepared from G. gracilis (Table 1). The identified compounds possessed various Amaryllidaceae alkaloid skeleton types including phenanthridine, galanthamine, crinine, tazettine, lycorine, and homolycorine. Generally, homolycorine and tazettine type alkaloids were major components in the tested samples. Homolycorine was found to be the main alkaloid in the aerial part extract of G. gracilis (71.62%). Similarly, the extract obtained from the bulbs contained 8-O-demethylhomolycorine (44.39%), homolycorine (18.00%), and galanthindole (17.95%) in very high amounts. Tazettine was found to be present in both of the extracts (aerial parts, 18.41%; bulbs, 6.47%). Moreover, in the extracts of the bulbs, lycorine was detected (5.45%) and galanthamine was found in trace amounts. Due to the absence of related literature, GG-1 and GG-2 were not identified, but their mass fragmentation has specific properties for Amaryllidaceae alkaloids. AChE inhibitory activity potentials of the extracts were carried out using in vitro Ellmans method, and both of the extracts showed significant activity. The bulb extract of G. gracilis (IC 50 11.82 g/mL) was found to be more active than the extract of the aerial parts (IC 50 25.5 g/mL). Galanthamine was used as a positive control (IC 50 0.043 g/mL).