The study of tannins of night-scented stock (Matthiola bicornis (Sibth. & Sm.) DC.) raw materials of Queen of Night and Evening Scent cultivars

Abstract

Tannins belong to the most common group of biologically active compounds of plant origin – phenolic compounds – and are a large group of secondary metabolites of plants that have tanning properties and a characteristic astringent taste. There are hydrolyzed and condensed tannins. Tannins are characterized by a wide range of pharmacological activity: antioxidant, astringent, antibacterial, antiviral, anti-inflammatory, antimutagenic, antitumor, gastroprotective, antiulcer, antidiarrheal, antihemorrhoidal, antiatherosclerotic hemostatic. In the industry, tannins are used for tanning leather and fur, pickling textile fibers, giving tartness to drinks, for making inks and as a food additive E181. The wide distribution of tannins in the plant world and their use in medical practice determine the relevance of determining their quantitative content in promising plant species, in particular such as night-scented stock (Matthiola bicornis (Sibth. & Sm.) DC.).

The aim of the study was qualitative and quantitative analysis of tannins in raw materials of night-scented stock (Matthiola bicornis (Sibth. & Sm.) DC.) Tsarytsia Nochi (Queen of the Night) and Vechirnii Aromat (Evening Scent) cultivars. The objects of our study were stalk-threshed grass, stalks, roots and seeds of Night-scented stock Queen of the Night and Evening Scent cultivars. Procurement of raw materials was carried out in the Kharkiv region in the summer of 2020. The presence of tannins in the studied raw materials was confirmed by chemical reactions with 1% aqueous solutions of gelatin, iron (III) ammonium sulfate and quinine hydrochloride. For this purpose, aqueous extracts of the studied types of raw materials were previously obtained by extraction in a water bath. The content of tannins in stalk-threshed grass, stalks, roots and seeds of the night-scented stock Queen of the Night and Evening Scent cultivars determined by differential spectrophotometry according to the method of the general article of the State Pharmacopoeia of Ukraine.

The formation of turbidity, which disappeared with the addition of excess gelatin solution, the formation of a white amorphous precipitate with a solution of quinine hydrochloride and the appearance of dark green color with a solution of iron (III) ammonium sulfate indicated the presence of condensed tannins in the studied raw materials. The content of tannins in terms of pyrogalol and completely dry raw material in the grass threshed from the stalks of night-scented stock was 0,78±0,04 % and 0,69±0,03 %, in the stalks – 0,29±0,01 % and 0,35±0,02 %, in the roots – 0,24±0,01 % and 0,26±0,01 %, in the seeds – 0,49±0,02 % and 0,60±0,03 % for Queen of the Night and Evening Scent cultivars, respectively. The results of the experiment showed that the content of tannins in the grass threshed from the stalks was more than 1,1 times higher in the raw material of night-scented stock of the Queen of the Night cultivar, in seeds and stalks the content of tannins was dominated by the cultivar Evening Scent, which contained almost 1,2 times more than in similar raw materials of another cultivar, and in the roots of both cultivar of night-scented stock used for the study tannins were contained in approximately the same amount. Comparing the quantitative content of tannins by raw materials, for the variety Queen of the Night they were mostly found in grass threshed from the stalks, then their number decreased in seeds and stalks, and their lowest content was in roots (yes, these compounds in threshed grass of this variety accumulated 1,6 times more than in seeds, almost 2,7 times more than in stalks and about three times more than in roots). For the Evening Scent cultivar, the tannin content decreased similarly in a line of grass threshed from the stalks – seeds – stalks – roots. The amount of tannins in threshed grass of this variety was about 1,1 times higher than in seeds, almost twice as high as in stalks and more than 2,5 times higher than in roots. The results of further research can be used in the development of quality control methods for the studied raw materials and indicate that night-scented stock is a promising plant for further in-depth pharmacognostic study and development of new drugs based on its raw materials.

Key words: Matthiola bicornis (Sibth. & Sm.) DC., tannins, spectrophotometry

DOI: 10.5281/zenodo.6350249