Improvement of the pharmacopoeial identification of burr marigold herb by macro- and microscopic characteristics

Abstract

Aim. To improve the national monograph of burr marigold (Bidens tripartita L.) herb on macro- and microscopic characteristics of the raw material. To achieve this goal, a comparative macroscopic analysis of various species of burr marigold and an extended microscopic analysis of all parts of the plant that are part of the raw material were carried out.

Materials and methods. The study objects were 7 samples of the medicinal plant raw material of Bidens tripartita L. identified and registered at the premises of the State Enterprise “Pharmacopoeia Center”. They were provided by various domestic manufacturers; a sample of the whole raw material of B. frondosa L. collected in the Akhtyrsky district of
the Sumy region; a sample of the whole raw material of B. cernua L. provided by a domestic pharmaceutical enterprise. The raw material was harvested in the period of budding and the beginning of flowering. The dry raw material was
subject to the macroscopic analysis. The microscopic analysis was performed on the powder of the raw material sifted through a sieve with a hole diameter of 355 since according to the requirements of the European Pharmacopoeia and the State Pharmacopoeia of Ukraine this was a standardized procedure for determining the diagnostic signs of the medicinal plant raw material by microscopy.

Results and discussion. As a result of the macroscopic analysis, it has been found that the raw material of Bidens tripartita L. is a mixture of the whole or fragmented stems with leaves, leaves, anthodia, and achenes. Stems are green or greenish-purple, round-oval, longitudinally grooved. Leaves are green or brownish-green, with a dentateserrated edge, opposite, with a 3-5-parted lamina with lanceolate lobes narrowed into short, slightly winged petioles. Inflorescences are erect anthodia, their width is almost equal to the height. Fruits are flattened achenes, at the apex with 2 or 3 awns, twice as short as the achene. The awns and lateral ribs of the achenes are covered with bristles, which tips are directed downwards. As a result of the microscopic analysis of Bidens tripartita L. powder, diagnostic
signs of all parts of the raw material have been found, namely: fragments of the lamina with veins, along which secretory channels with reddish-brown contents pass; fragments of the lamina from the upper or lower epidermis with the basic cells with sinuous walls, stomata anomocytic type, covering caterpillar form trichomes of 9–18 thin-walled cells, rarely thick-walled covering trichomes of 2-13 cells; fragments of the stem epidermis of rectangular elongated cells with thickened walls; fragments of the epidermis of the inner leaves of the involucres of elongated rectangular thin-walled cells and articulated branched secretory channels; fragments of epidermis of tubular flowers from polygonal cells with rounded papillary outgrowths; rounded pollen grains with spinous exine; fragments of the testa with pigmented darkbrown cells of the hypodermis and the adjacent lower layer of elongated yellowish sclereids.

Conclusions. The sections “Identification A and B” (macro- and microscopic signs of the raw material) of the national monograph “Burr marigold herbN” of the SPhU 2.2 have been improved, and it allows to more accurately identify all parts of the medicinal plant raw material. The additions developed are included to the SPhU 2.5 in the text of the monograph “Burr marigold herbN”.