The phytochemical content of some Astragalus species distributed in Bulgarian flora has been previously studied. Among other compounds, flavoalkaloids, acylated flavonoids, flavonoid triglycosides and cycloartane saponins have been isolated so far. The composition of the rest of the representatives of this genus in Bulgaria is not explored yet. The aim of this study was to perform a screening for the presence of selected rare secondary metabolites (flavoalkaloids, acylated flavonoids, flavonoid triglycosides and cycloartane saponins) in selected Astragalus species. Samples were collected in different phenological stages and from different locations in the country. A novel and rapid ultra-high performance liquid chromatography – high resolution electrospray ionisation mass spectrometry (UHPLC-HRESIMS) method was developed and applied. For the first time a flavoalkaloid glycoside was determined from extracts of A. onobrychis var. chlorocarpus and A. glycyphylloides. From A. depressus an acylated derivative of kaempferol was newly identified. The flavonol triglycosides camelliaside A, alcesefoliside and mauritianin were proved in samples of A. glycyphylloides, A. onobrychis var. chlorocarpus and A. cicer for the first time as well.

Phytochemical studies of ethyl acetate extracts from the roots and aerial parts of Gypsophila trichotoma revealed the presence of stigmast-7-en-3-ol, stigmasta-7,22-dien-3-ol (spinasterol), ergost-7-en-3-ol, stigmasta-3,5dien7-one, β-sitosterol, 22,23-dihydrospinasterone, vitexin, orientin, homoorientin and hyperoside. The structures of the compounds were determined by GC/MS and HPLC analyses.