ABSTRACT
To find antibacterial candidate compounds, eighteen novel sulfonamide derivatives containing a fused-ring were designed and synthesized on the basis of previous studies, with structures confirmed by 1H NMR, 13C NMR and MS. Antibacterial activities of the products were evaluated by the agar dilution method. The results show that these derivatives have different degrees of inhibitory activity on the tested bacteria, with the compounds IIi and IIr the most potent. The MIC of IIi for S. aureus, E. coli and MRSA was 8, 32 and 16 μg·mL-1, respectively, and the MIC of the IIr was 8, 64 and 32 μg·mL-1, respectively. The anti-MRSA activities of the two compounds is significant and is worthy of further structural optimization and study.
ABSTRACT
OBJECTIVE: To design and synthsize a series of novel phosphonate derivatives. METHODS: First, the intermediates of aminophosphonate was prepared by solvent-free one-pot method using aromatic aldehyde, ammonium acetate, diethyl phosphite and Al(OTf)3 as raw materials. Then, using basic ionic liquid OH as catalyst, the target compounds were synthesized by the reaction of intermediate with sulfonyl chloride. And the antibacterial activities of the products were evaluated by the agar dilution method. RESULTS: Twelve title compounds were synthesized, and their structures were clearly established by 1H-NMR, 13C-NMR and MS. The results showed that the derivatives have different inhibitory activities against Gram-positive bacteria and Gram-negative bacteria, especially the compounds Ⅱe and Ⅱk showed better activity, the MIC of the former for S.aureus, E. coli, MRSA and MREC was 32, 64, 32, and 128 μg•mL-1, respectively, and the MIC of the latter was 16, 64, 32, and 64 μg•mL-1, respectively. Its antibacterial activities were significantly better than that of the control drug sulfadiazine, and close to that of gatifloxacin. CONCLUSION: These derivatives have potential antibacterial activity, which is worth for further structural optimization and study.
ABSTRACT
For the first time, sulfanilamide (SFD) was determined in otologic solution, human urine and serum by electroanalytical techniques on glassy carbon electrode (GCE). The cyclic voltammetry (CV) experiments showed an irreversible oxidation peak at +1.06 V in 0.1 mol/L BRBS (pH = 2.0) at 50 mV/s. Different vol-tammetric scan rates (from 10 to 250 mV/s) suggested that the oxidation of SFD on the GCE was a diffusion-controlled process. Square-wave voltammetry (SWV) method under optimized conditions showed a linear response to SFD from 5.0 to 74.7μmol/L (R = 0.999) with detection and quantification limits of 0.92 and 3.10μmol/L, respectively. The developed SWV method showed better results for detection limit and linear range than the chronoamperometry method. It has been successfully applied to determine SFD concentration in pharmaceutical formulation, human urine and serum samples with recovery close to 100%.
ABSTRACT
This study investigated the development of a novel approach to surface characterization of drug poly-morphism and the extension of the capabilities of this method to perform ‘real time’ in situ measure-ments. This was achieved using diffuse reflectance visible (DRV) spectroscopy and dye deposition, using the pH sensitive dye, thymol blue (TB). Two polymorphs, SFN-β and SFN-γ, of the drug substance sul-fanilamide (SFN) were examined. The interaction of adsorbed dye with polymorphs showed different behavior, and thus reported different DRV spectra. Consideration of the acid/base properties of the morphological forms of the drug molecule provided a rationalization of the mechanism of differential coloration by indicator dyes. The kinetics of the polymorphic transformation of SFN polymorphs was monitored using treatment with TB dye and DRV spectroscopy. The thermally-induced transformation fitted a first-order solid-state kinetic model (R2 ? 0.992), giving a rate constant of 2.43 ? 10 ? 2 s ? 1.