Glycoalkaloids are biologically active plant secondary metabolites that are produced by solanaceous plants. Purified glycoalkaloids were shown to exhibit enzyme-inhibiting activities and can potentially have an application in pharmaceutical and agrochemical industries. While the glycoalkaloid composition of solanaceous crops such as potatoes and tomatoes has been widely studied, glycoalkaloid composition of non-commercial Solanum spp. remains unknown. At the same time, wild and weedy Solanum spp. can act as a high yield source of glycoalkaloids with known and unique biologically active properties. Here we present a study on analysis and composition of glycoalkaloids in seven Solanum species: S. nigrum, S. melanocerasum, S. burbankii, S. sisymbriifolium, S. quitoense, S. caripense, and S. muricatum. Solanum spp. were grown under greenhouse conditions and extracted prior to fruit stage. The glycoalkaloid rich fraction was isolated using an aqueous methanol solution. Composition of glycoalkaloids in these fractions was analyzed using high performance liquid chromatography / high resolution mass spectrometry. Due to the lack of analytical standards, hidden target screening based on the neutral loss was used for glycoalkaloids assignment. The total glycoalkaloid content was quantified based on the relative solamargine response using external calibration curve. Alpha- and beta cholinesterase inhibition by glycoalkaloid fractions was measured using fluorimetric microplate method and expressed as half maximal inhibitory concentrations. Inhibition of leaves, steams, and roots extracts combined with the biomass yield was used to demonstrate the potential applicability of the specific species for commercial application.

Syamkumar Sivasankara

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