ORAL PRES.: Characterizations of Ipomoea reptans extracts through HPLC and HPTLC fingerprint development, phytochemical profiling, and in-vitro cytotoxicity and antioxidant activity determination

For several centuries, natural products have played a very important role in our daily life. The secondary metabolites of medicinal plants form a main source of natural antioxidants compound. The present study aims developing and finding the best conditions to separate bioactive compounds from various I. reptans fractions by both high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) approaches. The results revealed that the HPLC fingerprint analysis produces more peaks and a better separation than HPTLC, while HPTLC analysis helped identifying the classes of the active compounds in some fractions and confirming the similarity between fractions. The evaluation of phytochemical bioactive constituents of the I. reptans fractions was performed using standards methods. The results showed the presence of carbohydrates, alkaloids, phenolics and flavonoids in the ethyl acetate-methanol and methanol fractions. Terpenoids and cardiac glycoside constituents were found in hexane-dichloromethane, dichloromethaneethyl acetate, ethyl acetate, ethyl acetate-methanol, methanol and aqueous fractions. The cytotoxicity of different I. reptans fractions was tested using the brine shrimp assay and the results revealed the ethyl acetate-methanol and methanol fractions as the more active fractions. Furthermore, the antioxidant scavenging activity of several fractions was determined by DPPH and ABTS assays. The DPPH results revealed the ethyl acetatemethanol and methanol fractions as the most potent, and this was confirmed by the ABTS results. In addition, the aqueous fraction possessed a higher ABTS radical scavenging activity. Current work focuses on the separation and purification of the bioactive compounds from the active fractions using reversed phase (RP-18) open column chromatography (OCC), thin layer chromatography (TLC) and HPLC according to the same method that was used to develop the chromatographic fingerprints. In the final stage, the chemical structures of isolated pure compounds will be elucidated by several techniques, like Nuclear Magnetic Resonance (1DNMR & 2D-NMR), Infrared Spectroscopy (IR) and Mass Spectrometry (MS).