Zwitterionic ionic liquids modulating two-dimensional hierarchically porous zeolitic imidazolate framework composites.

HYPOTHESIS: Two-dimensional hierarchically porous zeolitic imidazolate frameworks (H-ZIFs) show great promising applications in catalysis, gas separation, energy storage and sensing. Herein, a facile ionic-liquid-modulation approach is proposed for constructing H-ZIFs nanosheets with tunable thickness. EXPERIMENTS: Sulfo-functionalized zwitterionic ionic liquids (SFIL) have been designed as monodentate ligands to direct the formation of microporous nanosheets (ZIF-SFIL) in aqueous solution. Anions of SFIL have been tuned to modulate the coordination environment, enabling the control of the structure, thickness and pores of the nanosheets. FINDINGS: SFIL is demonstrated to pre-coordinate with Zn(II) to induce micropores with high specific surface areas (up to 1176 m2·g-1) and accelerate the nucleation of crystals. The BF4- anion serves as a competitive ligand to partially replace SFIL to cause structural defects, thus yielding hierarchically porous ZIF-SFIL nanosheets with high specific surface areas (270-466 m2·g-1) and variable thicknesses (from ca. 58 nm to ca. 455 nm). Benefiting from the versatile designability and multifunctionality of ionic liquids, the strategy in this work offers a facile approach for designing and constructing multifunctional materials with hierarchical pores.

Reversible fabrication and self-assembly of a gemini supra-amphiphile driven by dynamic covalent bonds.

A smart gemini supra-amphiphile behaving with pH/CO2 dual-sensitive hierarchical self-assembly was fabricated under the effect of dynamic covalent bonds. In the presence of an amino-functionalized cation, water-insoluble terephthalaldehyde, and an amphiphilic anion, the benzoic imine bond can initiate the transformation from a single-tailed supra-amphiphile to a gemini supra-amphiphile with increasing pH, followed by the subsequent evolution from micelles to vesicles. Reversible self-assembly and disassembly of the gemini supra-amphiphile can be realized via CO2/N2 treatment, thus inducing the fission and reversion of vesicles. Interestingly, the flexible nature of supra-amphiphiles allows for the hierarchical assembly of vesicles, leading to the formation of aqueous two-phase systems. Multiple responsive supra-amphiphiles have useful applications in the fabrication of smart supra-molecular materials, including self-healing materials, nanocarriers and chemosensors.

Flavokawain A inhibits Cytochrome P450 in in vitro metabolic and inhibitory investigations.

ETHNOPHARMACOLOGICAL RELEVANCE: Flavokawain A, the major chalcone in kava extracts, was served as beverages for informal social occasions and traditional ceremonials in most South Pacific islands. It exhibited strong antiproliferative and apoptotic effects against human prostate and urinary bladder cancer cells. AIM OF THE STUDY: The current study was purposed to investigate the interaction between Flavokawain A and Cytochrome P450, including the inhibitory effects of Flavokawain A on predominant CYP450 isotypes and further clarified the inhibitory mechanism of FKA on CYP450 enzymes. Besides, study about identifying the key CYP450 isotypes responsible for the metabolism of FKA was also performed. MATERIALS AND METHODS: In this study, probe-based assays with rat liver microsome system were used to characterize the inhibitory effects of FKA. Molecular docking study was performed to further explore the binding site of FKA on CYP450 isoforms. In addition, chemical inhibition experiments using specific inhibitors (a-naphthoflavone, quinidine, sulfamethoxazde, ketoconazole, omeprazole) were performed to clarify the individual CYP450 isoform that are responsible for the metabolism of FKA. RESULTS: FKA showed significant inhibition on CYP1A2, CYP2D1, CYP2C6 and CYP3A2 activities with IC50 values of 102.23, 20.39, 69.95, 60.22µmol/L, respectively. The inhibition model was competitive, mixed-inhibition, uncompetitive, and noncompetitive for CYP1A2, CYP2D1, CYP2C6 and CYP3A2 enzymes. Molecular docking study indicated the ligand-binding conformation of FKA in the active site of CYP450 isoforms. The chemical inhibition experiments showed that the metabolic clearance rate of Flavokawain A decreased to 19.84%, 50.38%, and 67.02% of the control in the presence of ketoconazole, sulfamethoxazde and a-naphthoflavone. CONCLUSION: The study showed that Flavokawain A has varying inhibitory effect on CYP450 enzymes and CYP3A2 was the principal CYP isoform contributing to the metabolism of Flavokawain A. Besides, CYP2C6 and CYP1A2 isoforms also play important roles in the metabolism of FKA. Our results provided a basis for better understanding the biotransformation of FKA and prediction of drug-drug interaction of FKA.

[Treatment of experimental chronic bacterial prostatitis with free-radical scavenger in rats].

OBJECTIVE: To evaluate the efficacy of free-radical scavenger in the treatment of chronic bacterial prostatitis (CBP). METHODS: Fifty-eight healthy male rats were randomly divided into a control group and four model groups (Groups A, B, C and D). The chronic prostatitis model was established in the latter groups through injecting E. coli into the ventral robe of the prostate according to document. Group A was untreated, Group B treated with free-radical scavenger vitamin C, Group C with salicylazosulfapyridine (SASP), Group D with SASP and vitamin C. Superoxide dismutase (SOD) and malondialdehyde (MDA) examinations were conducted in each group 2 months later. RESULTS: Vitamin C could significantly increase the level of SOD and decrease the level of MDA. There was significant difference between the model groups and the control one, as well as between the treated groups and the untreated one, but none among the treated groups. CONCLUSION: Free-radical scavenger may be useful for the treatment of chronic bacterial prostatitis.