Antioxidant Capacity and HPLC Determination of Phenolic in Different Organs of Calligonum polygonoides Subspecies comosum

Background: Calligonum polygonoides subsp. comosum is a perennial desert plant. Most of the previous chemical investigation of this plant was performed on the whole herb but there were no data about quantification of active constituent in different organs of C. polygonoides. 
Materials and Methods: in vitro antioxidant activity, total phenolic, and total flavonoid contents of the different organs were determined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH), Folin–Ciocalteu, and aluminum chloride (AlCl3) methods, respectively. Quantitative analysis of the phenolic compounds was determined in the different organs of the plant using high-performance liquid chromatography (HPLC). 
Results: Both bark and leaves showed the highest radical scavenging activity with the values of 450.30 and 398.10 μg/g ascorbic acid equivalent, respectively. The total phenolic content of the samples was in the range of 27.9–281.5 μg/g gallic acid equivalent and total flavonoid content of the samples was in the range of 53.9–257.4 μg/g rutin equivalent where the leaves and bark showed the highest contents. HPLC analysis showed that flavonol glycosides content was higher in all organs compared to the aglycones. Flowers and fruits were the richest organs in flavonols, whereas leaves, stems, and bark were the richest in taxifolin and catechin. 
Conclusion: Depending on the obtained results C. polygonoides is an excellent source of natural antioxidants.