| Plants, including invasive and native species, contain many secondary metabolites that have attained various pharmaceutical capabilities. Identification and separation of useful bioactive components could maximize their utilization.In the first part, apreparative separation method of total flavonoids from an invasive plant Flaveria bidentis was established using ten different kinds of macroporous resins (MRs). D4020 resin was chosen due to its high adsorption/desorption capacities.Optimized separation conditions with a recovery yield of 90%were as follows: pH 4.50, processing 16bed volume(BV), at 2.12mL/min flow rate, water (4BV) and 5 BV of 90% aqueous solution of ethanol. The total flavonoids content increased seven folds from 4.30 to 30% in the crude extract under the optimized conditions.. Isorhamnetin 3-sulfate and astragalin were separated through dynamic adsorption and desorption processes by employing resin D4020. Contents of 8.7% isorhamnetin 3-sulphate and 30.8% astragalin were obtained with 74.1% and 92.2% recoveries, respectively.Furthermore, isorhamnetin 3-sulfate and astragalin were purified by preparative high speed countercurrent chromatography (HSCCC), yielding 4.5 mg with thepurity of 96.48% and 24.4 mg with the purity of 98.46%, respectively.In the second part, an effective two-step HSCCC method, following normal phase and elution-extrusion mode of operation by using selected solvent systems (S), was established for separating phenolic compounds from mango flowers. In the first step, gallic acid of 3.7 mg with the purity of 98.87% and ethyl gallate of 3.9 mg with the purity of 99.55% were isolated by using hexane/ethylacetate/methanol/water S4 (HEMWat: (4:6:4:6, v/v)) in normal phase HSCCC from crude sample extract (200 mg), while ethyl digallate and ellagic acid were collected in the form of mixture fraction. During second step, further purification of the mixture was done by using dichloromethane/methanol/water S5 (DiMWat: (4:3:2 v/v)) following elution and extrusion HSCCC operation. Ethyl digallate of 3.8 mg with a high purity of 98.68% and ellagic acid of5.7 mg with the purity of 99.7% were separated. The structural confirmation of isolated phenolic compounds was demonstrated by HPLC, UPLC-QTOF/ESI-MS, and 1H and 13C NMR spectrometric analysis.In the third part of the study, the antioxidant potency of the isolated phenolic compounds from mango flowers was determined. Ethanopharmacological values of the ethanolic extract of mango flowers were investigated against pathogens as Staphylococcus aureus, Bacillus cereus,Klebsiella pneum and Escherichia coli. The minimum inhibition concentration (MIC) against each of the tested organism ranged from 1.00 to 2.50mg/mL.The established separation methods for the isolation of bioactive compounds can be extended to separate other therapeutically active compounds from the natural products. |
