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Drimia species have been used since ancient times for their medicinal properties. Their bulbs are considered as the main source of secondary metabolites with biological activity but the chemical composition of the other plant parts has not yet been considered. The aim of this study is to contribute to the existing knowledge with new data on the total phenolic content, the antioxidant activity and the chemical profile of different parts of Drimia numidica. The total phenolic content was estimated by the Folin-Ciocalteu assay and the antioxidant activity with DPPH · and ABTS ·+ reagents. The separation and the identification of the compounds were performed with liquid chromatography combined with time-of-flight high-resolution mass spectrometry (LC/Q-TOF/HRMS). The extract of leaves presented the highest phenolic content while the highest antioxidant activity was presented by the extract of flowers. Results of the chemical analysis verify the presence of bufadienolides and phenolic compounds. Graphical abstract.

The emission ((57)Co) variant of Mössbauer spectroscopy, rarely used in biology-related studies, was applied to study binding and possible transformations of (57)Co(II) traces in live and dead (hydrothermally treated) cells of the rhizobacterium Azospirillum brasilense (strain Sp7) at T=80 K in frozen aqueous suspensions and as their dried residues. The Mössbauer parameters calculated from the spectra were compared with the similarly obtained data reported earlier for another A. brasilense strain, Sp245 (which differs from strain Sp7 by the ecological niche occupied in the rhizosphere and was found earlier to exhibit different metabolic responses under similar environmental conditions). Similarly to strain Sp245, live cells of strain Sp7, rapidly frozen 2 min and 1 h after their contact with (57)Co(2+) (measured in frozen suspensions), showed marked differences in their Mössbauer parameters, reflecting metabolic transformations of (57)Co(2+) occurring within an hour. However, the parameters for strains Sp7 (this work) and Sp245 (reported earlier), obtained under similar conditions, were found to significantly differ, implying dissimilarity in their metabolic response to Co(2+). This is in line with their different metabolic responses to several heavy metals, including Co(2+), detected earlier using Fourier transform infrared spectroscopy.