Screeninig for phytotoxicity crude exctracts from the flora of crete and phytochemical investigation of Bellis longifolia
In continuation of our research for the discovery of bioactive compounds from plants of the flora of Crete  we have screened 65 plant species for their phytotoxic activity. Different plant parts have been extracted and 249 extracts have been evaluated for their phytotoxic activity in Lactuca sativa L. (Asteraceae) and Agrostis stolonifera L. (Graminae). Among the most potent extracts was the methanolic extract of Bellis longifolia which is an endemic plant of Crete that had never been investigated. The metahnolic extract of B. longifolia was elaborated by a very efficient technique, the countercurrent chromatography (CCC) using a step-gradient method. For this purpose a series of five biphasic systems consisting of the solvents n-Hex/BuOH/EtOH/H2O were used and led to the isolation of ten compounds. Four flavonoids, one phenolic compound, two triterpenes and three triterpene saponins were isolated and structural elucidated using NMR and HRMS. It is interesting that the three saponins, 3-β-D-fucopyranosyl-bayogenin, 3-β-D-fucopyranosyl-polygalacic acid and 28-β-D-fucopyranosyl-(1→2)-[O-α-L-rhamnopyranosyl]-polygalacic acid are new natural products.
References: 1. Fokialakis et al. J. Nat. Med. 2007, 61, 38–45.