Derivatization of Ptx was successfully carried out by esterification of its C-2'-hydroxyl group by methacrylic acid in the presence of EDC and DMAP. The disappearance of the C2' hydroxyl group at 3.64 ppm and appearance of vinylic protons at 5.7 and 6.2 ppm on the purified product, as shown on the 1 H-NMR spectrum, together with LC/MS analysis, confirmed the successful formation of PtxMA with 63 % yield. (Figure ).