A study on the adsorption behaviors of three hydrophobic quinolones by ordered mesoporous CMK-3.

In this work, a series of ordered mesoporous carbon nanomaterials (CMK-3) have been synthesized by a hard-template method at temperatures of 80 °C, 100 °C and 130 °C, which can serve as adsorbents for efficient adsorption of quinolones in aqueous solutions. The physicochemical properties and the morphologies of these CMK-3 have been well characterized, showing mesoporous channels with the specific surface area reaching up to 1290 m2/g. Adsorption studies have been performed on three hydrophobic quinolones: norfloxacin (NOR), ciprofloxacin (CIP) and enrofloxacin (ENR), with the adsorption capacities of 403 mg/g, 479 mg/g and 510 mg/g, respectively, at room temperature. The adsorption kinetics of the three quinolones are in accordance with the pseudo-second kinetic model, and the adsorption isotherm curves conform to Langmuir isotherm model. Significantly, the adsorption thermodynamics confirms that the adsorption processes are spontaneous endothermic. Finally, the adsorption mechanism has been discussed, which can be attributed to the synergistic effect of pore diffusion, hydrophobic bond, and electron donor-acceptor interaction.

Beta-lactamase inhibitory component from the roots of Fissistigma cavaleriei.

Therapeutic control of beta-lactamase-producing bacteria has been a major clinical problem. Development of drug combinations containing the beta-lactamase inhibitors has given clinicians a novel approach to controlling resistant organisms. In our search for beta-lactamase inhibitors from natural resources, we found that the methanol extract of the roots of Fissistigma cavaleriei showed an inhibitory effect on beta-lactamase. Bioassay-guided isolation of the extract yielded an active compound that was identified as salicylsalicylic acid by physical and spectroscopic methods. The compound showed inhibitory effects on beta-lactamase in a dose-dependent manner with IC(50) values of 71 microM. Salicylsalicylic acid is not as potent as the original inhibitors such as clavulanic acid, but it may be developed to be potent beta-lactamase inhibitor by chemical modification.