Bioactive compounds from saffron flowers

Abstract

Introduction. Biologically active compounds of natural origin can provide significant health benefits as anti-inflammatory, antiviral and antioxidant agents on a par with synthetic drugs. Various chemical constituents such as coumarins, carotenoids, flavonoids, steroids, fatty acids, stilbenes and terpenoids are isolated from plant origin, which to a large extent exhibit a wide spectrum of pharmacological activities. Therefore, the approach to the search for natural components for the treatment of inflammatory and viral diseases with medicinal plants is of great interest. The production of “saffron” (Crocus sativus stigmas) yields a large mass of by- products. For every kilogram of spices produced, about 150,000 kg of flowers are produced, which are usually discarded as waste [1]. However, plant flowers accumulate various metabolites, such as phenolic compounds, amino acids, and carboxylic acids, which have potential antioxidant activity [2] . Aim. In this study, sixteen phytochemical compounds were isolated from flowers of Crocus sativus L. (Iridaceae) by column chromatography and the antioxidant and anti-inflammatory activities were established. Isolation was carried out by using chromatographic techniques and the structures were elucidated by 1D and 2D NMR spectroscopy. Material and Methods. Crocus sativus (Saffron) flowers were collected from the plantation in the village Lyubimivka (Ukraine) in November 2017 (CWN, voucher specimen No. CWN0056541). The flowers were taken manually, then stigmas were separated. Crocus petals were air-dried at room temperature with suitable ventilation and then powdered. Ethyl acetate fraction of ethanolic extract of Crocus flowers was separated using silica gel column chromatography eluted with chloroform-ethanol (in different proportion) as solvent system. The isolated compounds were subjected for further spectral analysis (MS, 1H-NMR). Superoxide anion generation assay of the flowers ethanol extract (70% v/v) induced by fMLF/CB in human neutrophils was used to evaluate effects on respiratory burst. Nuclear transcription factor NRF2 activity was evaluated in HacaT normal cells and in Huh7 cancer cells. Conclusion. The hydroalcoholic extract of Crocus sativus flowers was subjected to various column chromatographic methods and 16 phenolic compounds were isolated. Among them, kaempferol 3-O-β-D-sophoroside (sophoraflavonoloside) (1) and apigenin 7-O-glucoside (cosmosiin) (2) were isolated for the first time from this raw material from Ukraine. [...].