Phytochemical profiling and quantification of bioactive constituents in lyophilized khat (Catha edulis Forsk) leaf extract from central Uganda

Background Phenols, flavonoids, alkaloids, tannins, glycosides and volatile oils are only a few bioactive phytochemicals found in most plants including Catha edulis Forsk which is consumed daily in most regions of Uganda. Objective This study aimed to analyze and quantify the bioactive constituents in lyophilized leaf extract of Catha edulis (‘Kasenge’ variety) from central Uganda. Methods Total alkaloids, flavonoids, phenolic and saponins contents were determined using spectrophotometric techniques. The bioactive compounds in the Catha edulis leaves were identified using high-performance liquid chromatography (HPLC), and gas chromatography-mass spectrometry (GC-MS). Result The total alkaloids, phenolics, flavonoids and saponins contents were 0.0063 mg/g atropine equivalent, 0.099 mg/g gallic acid equivalent, 0.047 mg/g quercetin equivalent and saponins 0.69 mg/g diosgenin equivalent. High-performance liquid chromatography (HPLC) fingerprinting detected thirty-four characteristic phytochemical peaks while gas chromatography-mass spectrometry analysis identified twenty-one bioactive compounds including essential fatty acids and diterpenoids known for their antioxidant, antimicrobial, and anti-inflammatory properties with 9,12,15-Octadecatrienoic acid, 2,3-dihydroxypropyl ester (Z, Z, Z) constituting 35.01%, hexadecanoic acid, ethyl ester and methyl ester accounting for over 21% of the composition, phytol (10.38%), butyl 9,12-octadecadienoate (7.58%) and 2,4-Di-tert-butylphenol (3.22%). Conclusion Although the alkaloid content in the Kasenge khat variety was lower than that reported in khat from other regions, the phenolic and flavonoid concentrations were comparable, suggesting the potential antioxidant and anti-inflammatory benefits of this variety. Further research is recommended to explore its pharmacological properties and optimize cultivation practices to enhance the yield of bioactive compound.