Hydrazone compounds represent an important area of research that includes, among others, synthetic approaches and biological studies. A series of 17 hydrazones have been synthesized by mechanochemical means. The fragments chosen were phenolic and furanyl aldehydes coupled with 12 heterocyclic hydrazines or hydrazinamides. All compounds can be obtained quantitatively when operating on a planetary ball mill and a maximum reaction time of 180 min (6 cycles of 30 min each). Complete spectroscopic analyses of hydrazones revealed eight compounds (3–5, 8–11, 16) present in one geometric form, six compounds (1, 2, 13–15) present in two isomeric forms, and three compounds (6, 7, 12) where one rotation is restricted giving rise to two different forms. The single crystal X-ray structure of one of the hydrazones bearing the isoniazid fragment (8) indicates a crystal lattice consisting of two symmetry-independent molecules with different geometries. All compounds obtained were tested for anti-infectious and antibacterial activities. Four compounds (1, 3, 5 and 8) showed good activity against Mycobacterium tuberculosis, and one (7) was very potent against Staphylococcus aureus. Most interesting, this series of compounds displayed very promising antileishmanial activity. Among all, compound 9 exhibited an IC₅₀ value of 0.3 µM on the Leishmania donovani intramacrophage amastigote in vitro model and a good selectivity index, better than miltefosine, making it worth evaluating in vivo.

The characteristics of Viper's bugloss (Echium vulgare) plant, its pharmacological properties, and extracts’ composition are presented in this study. Results of the literature analysis, data on the biologically active compounds and areas of use of this medicinal plant are summarized. Viper's bugloss (E. vulgare) is a species of flowering plant in the borage family Boraginaceae. It is native to most of Europe as well as western and central Asia. Viper's bugloss (E. vulgare) is a plant that has been utilized as food (honey), medicine, a poison, an oil, and as a dye and tannin-producing ornamental plant. Viper's bugloss (E. vulgare) is especially rich in pyrrolizidine alkaloids, flavonoids, phenolcarboxylic acids, sterones and naphthoquinones. In traditional medicine, Viper's bugloss (E. vulgare) is utilized as exhilarant and a mood stimulant. That is why one of the possible uses of this plant is considered to be treatment of depressive states. Like most representatives of Boraginaceae family, it has been insufficiently studied. No previous work quantifying flavonoids content of aerial parts of Viper's bugloss (E. vulgare) growing in Ukraine has been presented. Continuing the studies of this species, the aqueous and ethanolic extracts from Viper's bugloss (E. vulgare) aerial parts were obtained and their phytochemical composition was investigated. For the first time, the qualitative analysis of biologically active compounds in Viper’s bugloss’s extract as well as the quantitative analysis of flavonoids by aluminum chloride spectrophotometric method are reported. The experimental results showed that the total concentration of flavonoids was 2.59% in the extract. The maximum yield of extractives was found to be 16%. The obtained research data will be used in future investigations.