# Relationship between Total Antioxidant Capacity, Cannabinoids and Terpenoids in Hops and Cannabis  
[PERSON]  
1 Birosecutive Engineering Department, McGill University, Macdonald Campus, Ste-Anne-De-Bellevue, QC H9X 3V9, Canada; [EMAIL_ADDRESS] (P.W.A. )1 Birosecutive Engineering Department, McGill University, Macdonald Campus, Ste-Anne-De-Bellevue, QC H9X 3V9, Canada; philip. Antioxidants are bioactive compounds that, even in small amounts, slow or stop oxidation processes influenced by reactive oxygen species (ROS) or ambient oxygen enzymes [6; 7]. Various studies have reported that diverse naturally occurring antioxidants are found in medicinal plants at different concentrations and with varied physical and chemical properties [8; 9; 10; 11; 12; 13; 14; 15; 16]. Although antioxidants are classified as either lipid-soluble (hydrophobic) and water-soluble (hydrophilic), plant-based antioxidants such as phenolic compounds and vitamin C are mostly hydrophilic [17; 18]. Phenolic compounds (terpenes, flavonoids, and carotenoids) in plants act as structural polymers, attractants for insects, ultraviolet protectors, signal compounds, and defense response chemicals [19]. Hydrophobic antioxidants such as carotenoids and vitamin E protect cell membranes from lipid peroxidation [20]. Antioxidants may alternately be classified as enzymatic or non-enzymatic based on their catalytic action [18; 21]. Enzymatic antioxidants convert harmful oxidative products via a multi-step enzymatic process, in the presence of cofactors such as copper, zinc, manganese, and iron to stable hydrogen peroxide (H\({}_{2}\)O\({}_{2}\)), converting it to water [22]. Non-enzymatic antioxidants prevent the spread of free radicals [18]. Based on their direct or indirect antioxidant defense mechanism, plant antioxidants can be classified as primary or secondary [15; 23]. Primary antioxidants such as catalase act as chain-breaking antioxidants by reacting directly with free radicals [24]. Secondary antioxidants, including glutathione-s-transferase, work indirectly as singlet oxygen quenchers, peroxide decomposers, metal chelators, oxidative enzyme inhibitors and UV radiation absorbers [23]. Hops contain \(\alpha\)-acids (cohumulene, humulone, and adhumulone), \(\beta\)-acids (colupulene, n-lupulone and adlupulone), and xanthohumol, which are the precursors of bittering agents in beer [25]. Xanthohumol is the major prenylated flavonoid in hops and it is synthesized in glandular trichomes of hop infloresances [26]. Bitter acids in hops are formed from the acylation of one molecule of acyl-CoA and three molecules of malonyl-CoA to form phlorisovalerophenone [27; 28]. Hops may be considered a natural antioxidant since the \(\alpha\)-acids, \(\beta\)-acids, and xanthohumol present in this plant have significant hydroxyl radical scavenging and antioxidant activities [26; 29; 30]. A comparative study using three hop accessions (Calyposo, Cascade, and Cluster) demonstrated the presence of high antioxidant activity with the DPPH assay, measuring 342.3, 211.8, and 196.8 \(\mu\)g mL\({}^{-1}\), respectively [16]. Major active secondary compounds found in the cannabis plant are the cannabinoids [31], a group of chemical compounds that alter neurotransmission activity of the brain by acting on the cannabinoid receptors [32; 33; 34; 35; 36]. Research studies have shown that cannabinoids exhibit antioxidant properties [37; 38; 39]. Cannabinoids, like other antioxidants, interrupt free radical chain reactions, chelating free radicals by donating their electrons or hydrogen atom and transforming them into less active forms [18]. [PERSON] et al. (2021) showed that the degree of antioxidant activity by acidic and neutral cannabinoids can be attributed to the number of phenolic hydroxyl groups in individual cannabinoids. Cannabinoid acid (CBDA) (13.3%) and cannabidiol (CBD) (53.3%) showed significantly (\(p<0.05\)) greater scavenging power compared to tetrahydroconnabinolic acid (THCA) and tetrahydroconnabinol (THC), respectively.