Crystal Growth, Single Crystal Structure, and Biological Activity of Thiazolo-Pyridine Dicarboxylic Acid Derivatives

Four novel TPDCA derivatives were prepared via a supersaturation method combining TPDCA with water, N -methyl-2-pyrrolidone (NMP), Na(PO 2 H 2 ), and ammonia solution: 2(C 9 H 7 NO 5 S)H 2 O ( 1 ), (C 9 H 7 NO 5 S)C 5 H 9 NO ( 2 ), (C 9 H 7 NO 5 S)Na(PO 2 H 2 ) ( 3 ), and (C 9 H 5 NO 5 S)(NH 4 ) 2 (H 2 O) ( 4 ). Their crystal structures were determined by single-crystal X-ray diffraction. Compounds ( 1 ) and ( 2 ) crystallize in the monoclinic space groups P 2 1 and P 2 1 / c , respectively, whereas compounds ( 3 ) and ( 4 ) crystallize in the triclinic space group P 1̅. Weak and moderate hydrogen bonds were detected in the four compounds. In the biological tests, ( 1 ) and ( 3 ) exhibited significant antibacterial activity against Escherichia coli and Staphylococcus aureus ; in addition, ( 1 ) was cytotoxic against leukemia HL-60 cells with the IC 50 value of 158.5 ± 12.5 μM.