AN INVESTIGATION OF THE ACE INHIBITORY ACTIVITY, ANTIOXIDANT CAPACITY, AND PHYTOCHEMICAL CONSTITUENTS OF POLAR AND NON-POLAR EXTRACTS OF ZIZIPHUS JUJUBA FRUIT: STATISTICAL SCREENING THE MAIN COMPONENTS RESPONSIBLE FOR BIOACTIVITY

Herein, the angiotensin I-converting enzyme (ACE) inhibitory activity, antioxidant capacity, total polyphenol contents (TPC), and phytochemical profiles of polar and non-polar extracts of dried Ziziphus jujuba fruits were investigated, along with the statistical determination of the main components responsible for ACE inhibitory activity. The non-polar extract expressed the strongest ACE inhibitory activity (99.81%) among the extracts. The non-polar extract also exhibited the highest DPPH scavenging activity (IC50 of 30.63), linoleic acid/β-carotene bleaching capacity (89.31%), and TPC (59.47 mg GAE/g). The phenolic profiles of the extracts were identified by LC-MS/MS, and the presence of seven triterpenoid species in the extracts was examined using GC-MS techniques. The principal constituents included 19 phenolics, 2 organic acids, and 4 triterpenoids. A Pearson correlation and principal component analysis were conducted to find the correlation between individual phenolic compounds and ACE inhibitory activity.