The Different Composition of Coumarins and Antibacterial Activity of Phlojodicarpus sibiricus and Phlojodicarpus villosus Root Extracts.

Phlojodicarpus sibiricus, a valuable endangered medicinal plant, is a source of angular pyranocoumarins used in pharmacology. Due to limited resource availability, other pyranocoumarin sources are needed. In the present research, the chemical composition of a closely related species, Phlojodicarpus villosus, was studied, along with P. sibiricus. High-performance liquid chromatography and mass-spectrometric analyses, followed by antibacterial activity studies of root extracts from both species, were performed. P. sibiricus and P. villosus differed significantly in coumarin composition. Pyranocoumarins predominated in P. sibiricus, while furanocoumarins predominated in P. villosus. Osthenol, the precursor of angular pyrano- and furanocoumarins, was detected in both P. sibiricus and P. villosus. Angular forms of coumarins were detected in both species according to the mass-spectrometric behavior of the reference. Thus, P. villosus cannot be an additional source of pyranocoumarins because their content in the plant is critically low. At the same time, the plant contained large amounts of hydroxycoumarins and furanocoumarins. The extracts exhibited moderate antibacterial activity against five standard strains. The P. villosus extract additionally suppressed the growth of the Gram-negative bacterium E. coli. Thus, both Phlojodicarpus species are promising for further investigation in the field of pharmaceuticals as producers of different coumarins.

Plant Pyranocoumarins: Description, Biosynthesis, Application.

This overview article contains information about pyranocoumarins over the last 55 years. The article is based on the authors' phytochemical and physiological studies in vivo and in vitro as well as search and analysis of data in literature available on Google Scholar, Web of Science, PubMed, and ScienceDirect before January 2022. Pyranocoumarins are synthesized in plants of the Apiaceae, Rutaceae families, and one species in each of the Cornaceae, Calophyllaceae, and Fabaceae families can synthesize this class of compounds. The physiological role of these compounds in plants is not clear. It has been proven that these substances have a wide range of biological activities: anti-cancer, anti-spasmatic, and anticoagulant, and they also inhibit erythrocyte lysis and accumulation of triacylglycerides. The overview generalizes the modern understanding of the classification, structure, and biological activity of natural pyranocoumarins, and summarizes dispersed data into a unified scheme of biosynthesis. The review analyzes data on the localization and productivity of these substances in individual organs and the whole plant. It discusses a link between the unique structure of these substances and their biological activity, as well as new opportunities for pyranocoumarins in pharmacology. The article evaluates the potential of different plant species as producers of pyranocoumarins and considers the possibilities of cell cultures to obtain the end product.