Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, Brazil.
Department of Biochemistry, Institute of Chemistry, University of São Paulo, Brazil.
Carbohydr Polym. 2018 Apr 15;186:159-167. doi: 10.1016/j.carbpol.2018.01.044.
Sodium alginate (Alg) reacted with antibiotic gentamicin sulfate (GS) in an aqueous-phase condition mediated by carbodiimide chemistry, in the molar ratios Alg: GS of (1:0.5), (1:1) and (1:2). The Alg-GS conjugated derivatives were characterized by elemental analysis for nitrogen content, Fourier transform infrared spectroscopy in the attenuated total reflection mode (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analyses (TGA) and water sorption measurements. XPS and FTIR-ATR analyses clearly indicated that GS molecules covalently attached to the backbone of the alginate chains by amide bond formation. The highest amount of GS bound to Alg (43.5 ± 0.4 wt%) and the highest swelling ratio (4962 ± 661%) were observed for the Alg-GS (1:2) sample. Bioluminescence assays with Pseudomonas aeruginosa PAO1/lecA:lux and colony forming counting of Staphylococcus aureus and Escherichia coli upon contact with all Alg-GS conjugates revealed microbicidal activity; however, Alg-GS (1:2) was the most efficient, due to the highest GS content.
海藻酸钠（Alg）与硫酸庆大霉素（GS）在碳二亚胺化学介导的水相条件下反应，摩尔比为 Alg:GS（1:0.5）、（1:1）和（1:2）。Alg-GS 共轭衍生物通过元素分析测定氮含量、衰减全反射模式傅里叶变换红外光谱（FTIR-ATR）、X 射线光电子能谱（XPS）、扫描电子显微镜（SEM）、热重分析（TGA）和水分吸附测量进行表征。XPS 和 FTIR-ATR 分析清楚地表明，GS 分子通过酰胺键形成共价连接到藻酸盐链的主链上。Alg-GS（1:2）样品的 GS 结合量最高（43.5±0.4wt%），溶胀比最高（4962±661%）。与 Pseudomonas aeruginosa PAO1/lecA:lux 的生物发光测定和与所有 Alg-GS 缀合物接触后的金黄色葡萄球菌和大肠杆菌的菌落形成计数显示出杀菌活性；然而，Alg-GS（1:2）是最有效的，因为它的 GS 含量最高。
