Separation and retention of both polar and nonpolar compounds by the same stationary phase can be a useful approach for analyses of complex samples. Biological samples encompass a broad range of polarities and varied chemical properties. A gradient elution run with acetonitrile-water as the mobile phase was used for the separation of polar and non polar compounds from Aphanothece halophytica using ODS C18 column with photo diode array detection. The various fractions collected were identified through Electrospray ionisation-mass spectrometry (ESI-MS) and Nuclear Magnetic Resonance (NMR) analyses. The High Performance Liquid Chromatography (HPLC) method provided good baseline separation of all the compounds in 15 min without the need for sample derivatization. Retrospective review of ESI-MS and NMR data identified the major compounds as nostocyclamide, trimethylglycine, phosphatidyl glycerol.
Keywords: Aphanothece halophytica, bioactive compounds, HPLC, ESI-MS, NMR, nostocyclamide.