Phenolic profiling, sugar composition and antioxidant capacity of arta (Calligonum comosum L.), a wild Tunisian desert plant

Calligonum comosum, commonly known as arta, occurs in Tunisia and North African deserts and it is often used in folk medicine. Total polyphenols, flavonoids, condensed tannins, and radical scavenging activities were determined in four extracts (water, methanol, hexane and ethyl acetate) of three organs of the plant (roots, stem and leaves). Comparison of plant extracts yield showed that methanol was the most effective for polyphenols and flavonoids extractions. The analysis of DPPH radical scavenging activity showed that leaves and stems exhibited higher activity (74.54% and 40.36%) compared to the roots (22.54%). Methanol extracts of the three organs were screened by HPLC/MS and the identified phenolic compounds were further quantified. Results showed that the presence of phytosterols and phenolic compounds was diverse among the three organs. In total, 12 flavonoids and 12 phenolic acids were identified. Flavanols (catechin (+) and epicatechin) and fiavonols (quercetrin) were predominant. In addition, saponin in C. comosum organs was analyzed for the first time and results showed a considerable quantity in roots (16.1 mg/g). Sugar contents and mineral composition were also investigated in three organs of C. comosum. The minerals K, Mg, Na, and Ca were detected as interestedly high quantities. The sugar contents were ranged between 8.09% for stem, and 1.43% for roots. The overall results showed that C. comosum is an excellent source of diverse bioactive molecules with high radical scavenging capacity, which could be an interesting material forindustrial purposes. Further studies on the isolation of such compounds appear to be of high interest.