Crystal structure and molecular docking studies of octahydrocycloocta[b]pyridine-3-carbonitriles as potential inhibitors against Mycobacterium tuberculosis
The compounds 1-benzyl-2-imino-4-p-tolyl-1,2,5,6,7,8,9,10-octahydrocycloocta[b]pyridine-3-carbonitrile (Ia) and 1-benzyl-2-imino-(4-methoxyphenyl-1,2,5,6,7,8,9,10-octahydrocycloocta {b]pyridine-3-carbonitrile (Ib) were synthesized. The crystal structures of the compounds were determined by single crystal X ray diffraction. The compounds C26 H27 N3 (Ia) and C26 H27 N3O (Ib) crystallize in the triclinic system (a = 10.2304(4) Å, b = 10.5655(4) Å, c = 11.8271(4) Å, α = 101.755(2) °, β = 106.934(2) °, γ = 114.071(2) ° and Z = 2 for I(a) and a = 10.2738(4) Å, b = 11.1654(5) Å, c = 11.4162(4) Å α = 98.549(2) °, β = 106.183(2) °, γ = 117.070(2) ° and Z = 2 for I(b)). In both compounds (Ia) and (Ib) the pyridine ring adopts a planar conformation and the cyclooctane ring adopts a twisted boat chair conformation. The synthesized compounds were screened for their antibacterial activities against the enzyme enoyl acyl carrier protein reductase, which is involved in the fatty acid biosynthesis of the mycobacterial cell wall. Both compounds showed good antibacterial activities. The synthesis of the compounds, their structure determination, their conformation, their intra- and intermolecular interactions and docking study results are given.
