GC-MS/MS Quantification of EGFR Inhibitors, ß-Sitosterol, Betulinic Acid, (+) Eriodictyol, (+) Epipinoresinol, and Secoisolariciresinol, in Crude Extract and Ethyl Acetate Fraction of Thonningia sanguinea.

Medicinal plants are widely used in folk medicine to treat various diseases. Thonningia sanguinea Vahl is widespread in African traditional medicine, and exhibits antioxidant, antibacterial, antiviral, and anticancer activities. T. sanguinea is a source of phytomedicinal agents that have previously been isolated and structurally elucidated. Herein, gas chromatography combined with tandem mass spectrometry (GC-MS/MS) was used to quantify epipinoresinol, ß-sitosterol, eriodictyol, betulinic acid, and secoisolariciresinol contents in the methanolic crude extract and its ethyl acetate fraction for the first time. The ethyl acetate fraction was rich in epipinoresinol, eriodictyol, and secoisolariciresinol at concentrations of 2.3, 3.9, and 2.4 mg/g of dry extract, respectively. The binding interactions of these compounds with the epidermal growth factor receptor (EGFR) were computed using a molecular docking study. The results revealed that the highest binding affinities for the EGFR signaling pathway were attributed to eriodictyol and secoisolariciresinol, with good binding energies of -19.93 and -16.63 Kcal/mol, respectively. These compounds formed good interactions with the key amino acid Met 769 as the co-crystallized ligand. So, the ethyl acetate fraction of T. sanguinea is a promising adjuvant therapy in cancer treatments.

HPLC determination of certain flavonoids and terpene lactones in selected Ginkgo biloba L. phytopharmaceuticals.

The biologically active secondary metabolites of Ginkgo biloba extract EGb 761 in phytopharmaceuticals were analyzed using two simple, rapid, accurate and sensitive HPLC methods. The proposed methods were successfully applied in the determination of terpenes and flavonoids in four phytopharmaceutical preparations selected from the Egyptian market. The terpenes; ginkgolide A, ginkgolide B, and bilobalide were analyzed using RP 18 column with a mobile phase consisting of water/methanol/isopropanol (72.5:17.5:10, v/v) at a flow rate of 1 ml min-1 and UV detection at 220 nm. The flavonoids; quercetin and kaempferol were analyzed using RP 18 column in a step gradient elution with acetonitrile and water at pH 3.3 and flow rate of 1.5 ml min-1 with UV detection at 370 nm. The two HPLC methods were completely validated.