Ballota saxatilis from Jordan: Evaluation of Essential Oil Composition and Phytochemical Profiling of Crude Extracts and Their In-Vitro Antioxidant Activity

Abstract

The chemical composition of essential oil extracted from the aerial parts of Ballota saxatilis Sieber ex C.Presl from Jordan has been elucidated by gas chromatography–mass spectrometry (GC-MS). Additionally, aqueous methanol (BsA), Butanol (BsB) and water (BsW) extracts were screened for their total phenol content (TPC), total flavonoid content (TFC), and antioxidant activities using the 2,2 Diphenyl-1-picrylhydrazyl (DPPH) and 2,2-Azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS) methods. The most potent extracts were screened for their phenolic acids and flavonoid content using liquid the chromatography–mass spectrometry (LC-MS) technique. The results indicated that the essential oil predominantly contained cis-pinane (14.76%), β-caryophyllene (8.91%) and allo-aromadendrene epoxide (6.39%). Among the different extracts investigated, the BsB fraction had the most TPC and TFC (455.79 ± 1.03 µg gallic acid/g dry extract; 272.62 ± 8.28 µg quercetin/g dry extract, respectively) and had the best radical and radical cation scavenging activities, as determined using the DPPH and ABTS methods. Quantitative and qualitative LC-MS analyses of BsA and BsB using LC-MS revealed each of the kaempferol-3-O-rutinoside (30.29%), chrysoeriol-7-glucoside (7.93%) and luteolin 7-o-glucoside (7.76%) as the main constituents of the BsA fraction. The BsB fraction was rich in 7,4′-dimethoxy-3-hydroxyflavone (34.68%), kaempferol-3,7,4′-trimethyl ether (29.17%) and corymbosin (9.66%) and lower concentration levels of kaempferol-3-O-rutinoside (1.63%) and chrysoeriol-7-glucoside (0.51%).