Synthesis and Pharmacokinetic studies of Effective and Safe New Antimicrobial Derivatives of Substitited Hydroquinoxaline-2,3-diones

A series of 1,4-disubstituted octahydroquinoxaline-2,3-dione derivatives was prepared through two steps reaction. The latter involves the formation of N,N-disubstituted cyclohexane-1,2-diamine derivatives (la-g) through reductive alkylation of 1,2-cyclohexanediamine with different acetophenones in presence of sodium cyanoborohydride. Fusion of compounds (1a-g) with diethyl oxalate affording the target compounds (2a-g). Elucidation of structures of compounds (2a-g) was based upon different spectral data as well as the elemental methods of analyses. In addition, mass spectrometry and X-ray diffraction analyses were carried out. Moreover, the lipophilicity of the target compounds as expressed from the Clog P. Most of the test compounds (2a-g) showed weak to moderate antibacterial and antifungal activities against most of the used bacterial and fungal strains in comparison to norfloxacin and clotrimazole as reference drugs respectively. The pharmacokinetics of the most active hydroquinoxaline-2,3-diones derivative (2e) was determined  in  Rabbit plasma after intravenous and oral administration by a  simple, sensitive and selective high-performance liquid chromatographic (HPLC) assay with ultraviolet detection (HPLC-UV). Norfloxacin (NFL) was used as internal standard. The mean Cmax, tmax and AUC0-8h were 16.50 ± 2.10 µg/ml, 2 ± 0.11h and 74.84 ± 5.11 µg h/ml respectively for compound (2e).  The mean elimination half-life (t0.5e), absorption half-life (t0.5a), elimination rate constant ke and absorption rate constant ka values were 3.11 ± 0.22h, 0.60 ± 0. 1h, 0.231± 0.03 h-1 and 0.1.155 ± 0.13 h-1, respectively. The absolute bioavailability is 80.96% indicating good absorption after oral administration.