Molecular phylogeny, phenolics content, and antimicrobial activity of some potential medicinal plant species of the Fabaceae family collected from different geographical regions of Saudi Arabia

The molecular identification and taxonomic classification of medicinal plants are essential using various molecular markers for their accurate identification, safe utilization, and genetic conservation. The internal transcribed spacer sequence of nuclear ribosomal DNA (nrDNA-ITS) revealed the clustering of collected plant species into various clades according to their sequence similarity. The estimated total phenolic content (TPC) and total flavonoid content (TFC) in the leaves of different plant species ranged from 29.98 to 80.28 mg GAE/g DW, and 26.39 to 60.45 mg QE/g DW, respectively. Among the plant species, the content of bioactive compounds, luteolin 7-rutinoside and quercetin 3-beta-D-glucoside were observed to be highest in Anagyris foetida, whereas p-coumaric acid was observed to be greatest in Astragalus spinosus. Among all plant species extracts tested, Anagyris foetida extract (AFE), Astragalus spinosus extract (ASPE), and Astragalus sieberi extract (ASIE) exhibited significant activities against the Escherichia coli (E. coli) strain, mainly AFE showed more effective activity against the E. coli pathogen (MIC-6.25 mu g/mL and MBC-12.50 mu g/mL). Thus, screened plant extracts of different species could be tested on other microorganisms to explore their medicinal properties to cure various diseases against pathogens as well as their application in the food industry as a food preservative.