Thin Layer Chromatographic Separation and Bioassay of a Novel Marine Bacterium Extract for Potential Anti-Methicillin Resistant Staphylococcus aureus Activity

Abstract

A novel marine red bacterium (coded BOcMFS2-18) was shown to be inhibitory against methicillin-resistant Staphylococcus aureus (MRSA). This study aims to determine the fraction/s from BOcMFS2-18 culture filtrate extract that contains the bioactive compound/s exhibiting anti-MRSA activity. Cup cylinder assays were done to monitor anti-MRSA activity in the growth cycle of BOcMFS2- 18 at 30°C incubation for 36 hours. Extracellular compounds were extracted thrice with ethyl acetate from the BOcMFS2-18 culture fdtrates. Normal and reversed phase silica-gel thin layer chromatography (TLC) were performed to separate the extract into fractions which were each tested for anti-MRSA activity. Anti-MRSA activity was observed after 30 hours of incubation which is within the stationary phase of the growth cycle of BOcMFS2-18. Under 366nm ultraviolet light, the BOcMFS2-18 fdtrate extract was shown to be separated into seven fractions in normal phase TLC and ten fractions in reversed phase high performance TLC. Cylinder cup assays showed that fraction 5, 6 and 7 from normal TLC and fraction 1, 2 and 3 from RP-HPTLC have anti-MRSA activity. The location of the anti-MRSA fractions in the TLC plates indicates the presence of relatively nonpolar components. Thus, non-polar fractions separated in normal TLC and RP-HPTLC contains the bioactive compound/s that has potential anti-MRSA activity.