The use of analytical methods for quality control of promising active pharmaceutical ingredients among derivatives of 4-oxoquinoline- 3-propanoic acids

Due to a global increase of microbial resistance to antimicrobial drugs the search for new antibiotics is vital for modern medicinal chemistry. 3-Quinolin-4-one propanoic acids have the molecular similarity with fluoroquinolone antibiotics and are prospective scaffold to create antimicrobial drugs. On the example of 3-(2-methyl-4-oxo-1,4-dihydroquinoline-3-yl) propanoic acid the analytical methods that can be used for quality control of promising active pharmaceutical ingredients (API) among derivatives of 3-(2-methyl-4 oxo-1,4-dihydroquinoline-3-yl) propanoic acids have been analyzed and tested. The necessity of their inclusion in the list of control methods of 13C NMR-spectroscopy, due to which the problem of the tautomeric forms of 3-(2-methyl-4-oxo-1,4-dihydroquinoline-3-yl) propanoic acid is uniquely solved, has been shown. Specific related substances, which are by-products of the synthesis of 3-(2-methyl-4-oxo-1,4-dihydroquinoline-3-yl) propanoic acid – 1,2,3,4,9,10- hexahydroacridine-2,9-dione and 6a-hydroxy-5,6,6a, 8,9,14,15,16a, 17,18-decahydro-7,16-dioxa -5.14-diazaheptacene-9,18-dione, have been identified using liquid chromatography-mass spectrometry (LC-MS/MS). Recommendations for the use of UV- and IR-spectroscopy to develop quality control methods for 3-(2-methyl-4-oxo-1,4-dihydroquinoline-3-yl) propanoic acid have been proposed.