Scanning electron microscopy in the analysis of Asperugo procumbens L. grass

Introduction. Asperugo procumbens L. belongs to the borage family ( Boragináceae ) and is a widespread plant in the Russian Federation. According to recent studies, asperugi herb exhibits anti-inflammatory properties, is used for bronchial asthma, and has sedative, antispasmodic, and antidepressant effects. Despite the available data, Asperugo procumbens belongs to insufficiently studied plants, in particular, there is no information regarding the description of diagnostically important elements of its structure necessary for the formation of the "Authenticity" section when developing regulatory documentation for plant raw materials " Asperugo procumbens herba ". Aim. The purpose of the work was to establish the identification features of Asperugo procumbens grass using raster electronic microscopy. Materials and methods. The object in the work was naturally dried Asperugo procumbens grass, harvested independently in May 2023 during mass flowering in the Voronezh region. The study of the morphological characteristics of Asperugo procumbens using scanning electron microscopy was carried out on a JSM-6510LV (JEOL, Japan) electron microscope (Japan) after sputtering a thin graphite film with a carbon filament onto the surface of the analyzed object in a vacuum. Results and discussion. A study of the surface of both the leaves and the flower of Asperugo procumbens showed the presence of folding of the epidermis. Numerous simple unicellular coarsely warty hairs are found on the calyx leaves. The cells of the upper epidermis of the leaf are rounded, while the cells of the lower epidermis are narrow-rectangular. Stomata are anomocytic type. On both sides of the leaf there are simple unicellular hairs, with dense cell walls and an expanded base. As a result of the initial assessment of the presence of the main elements, it was shown that the prevailing content of potassium is in both the surface tissues of the leaf and the calyx, and magnesium, phosphorus and sulfur are found in greater quantities in the petals of the calyx, where nitrogen was not detected, and sodium and silicon are the leading contents in tissues of the upper side of the leaf. The presence of calcium is shown only in the tissues of the calyx petals. Conclusion. The study of the anatomical and morphological signs of Asperugo procumbens using scanning electron microscopy was carried out for the first time. As a result of the study, the main identification features of Asperugo procumbens grass were clarified and visualized, some features were established for the first time, and their topography was also revealed. As a result of a preliminary assessment of the presence of the most common elements, a difference in both qualitative and quantitative content in the tissues of the leaf and calyx petals was shown.