Distribution of polyphenolic compounds, antioxidant potential, and free amino acids in Ziziphus fruits extract; a study for determining the influence of wider geography

Ziziphus fruits have attracted much attention within the field of medicine due to their high potential against central nervous system disorders. Abundance of secondary metabolites and their composition is key to the pharmaceutical potential and commercial qualities of plants. The in vitro antioxidant activities of Ziziphus nummularia (Burm. f.) and Ziziphus oxyphylla Edgew fruit extract were analyzed using 2,2‐diphenil‐1‐pycrilhydrazyl (DPPH) and 2,2′‐azino‐bis (3‐ethylbenzothiazoline)‐6‐sulfonic acid (ABTS) free radical scavenging assay methods. Phenolic profiles were explored using high‐performance liquid chromatography‐diode array detector (HPLC‐DAD). The result revealed high concentration of polyphenols and their antioxidant potential. In Z. nummularia, the total phenolic content (TPC) (80.270 ± 0.422 μg/ml), DPPH (62.03 ± 0.98 μg/ml), ABTS (66.32 ± 0.73 μg/ml), and TFC (90.683 ± 0.274 μg/ml) were recorded. However, in Z. oxyphylla, DPPH and ABTS values were 60.66 ± 0.56 μg/ml and 61.55 ± 0.77 μg/ml, respectively, indicative of the impacts of climate and soil nutrients. The overall screening of phytochemicals revealed that both the Ziziphus species contain diverse bioactive compounds, including spinacetine‐3‐O‐(2 feruloyl glucopyranosyl)‐glucopyranoside, kaempferol‐3‐O‐glucoside‐7‐O‐glucoside, and caffeic acid; p‐hydroxybenzoyl hexose, p‐coumaric acid, salicylic acid, and ellagic acid pentoxide. Additionally, the highest concentrated amino acid noted was of Lue 0.19 g/100 g with 596.00 retention time (RT), followed by Thr>Ale>Isl>Phya>Val in Z. nummularia. Similarly, the highest concentration of Lue amino acid was recorded as 0.18/100 g with 564.52 RT followed by Pr>Thr>Ale>Lue>Isl>Phya>Val in all genotypes of Z. oxyphylla. Reporting of polyphenols rich and stable species along with identification of favorable regions of cultivation for amino acid, polyphenols, and higher antioxidant potential may lead the way for the identification of elite clones of the species as well as may result in new drug discovery.