Structural optimization of recently discovered new chemical entity, 2, 8-dicyclopentyl-4- methylquinoline (DCMQ; MIC= 6.25 μg/mL, M. tuberculosis H37Rv) resulted in the synthesis of four new series of ring-substituted quinolinecarboxylic acids/esters constituting 45 analogues. All new derivatives were evaluated for in vitro antimycobacterial activities against M. tuberculosis H37Rv. Certain ring-substituted-2-quinolinecarboxylic acid ester ...