Conjugation of methotrexate (MTX) (MW 454) with different molecular weights of polyethylene glycol (PEG) including methoxy-peg (mpeg) 750 D and 5000 D and diol-peg 35000 D led to compounds that are physicochemically highly different from the parent compound, MTX. In this study, an HPLC system consisting of C8 column and UV detector (?=342 nm), using a mixture of 30:70 v/v phosphate-citrate buff...

A most effective and less energy demanding method of producing fatty esters, diol esters, by esterifying fatty acids, with neopentyl and ethylenglycol alcohols in the presence of an acidic ion exchange resin catalyst(polyestyrendivinylbenzensulfated) was investigated at elevated temperature. In this process an azeotroping agent, toluene, was used to facilitate continuous removal of water by dis...

To obtain enantiopure compounds, the so-called chiral high performance liquid chromatography (HPLC) method, i.e., HPLC using a chiral stationary phase, is very useful, as reviewed in the present Special Issue. On the other hand, normal HPLC (on silica gel) separation of diastereomers is also useful for the preparation of enantiopure compounds and also for the simultaneous determination of their...