Infection with Candida albicans can prove lethal in immuno-compromised patients. It is imperative to develop a vaccine against this common organism. The amphoteric derivatives of the mannan component of the Candida cell wall may present a prospective target for the development of such a vaccine; however, the radical processing by antigen-presenting cells of the immune system is not fully understood. In this work a set of tailor-made cationic and amphoteric derivatives of three different degrees of quaternization (DS_Q 0.14–0.38) has been prepared by chemical modification of ultrasonically-treated mannan and three carboxymethylated mannan derivatives (DS_CM 0.13–0.32). These were exposed to free-radical attack by OH, generated in situ by the Fenton reaction. Potential changes in composition, DS_Q, and molar mass distribution due to free-radical degradation were monitored by elemental analysis, NMR and FTIR spectroscopies, and size exclusion chromatography. A protective effect of quaternization against OH degradation was found. Non-isothermal thermogravimetric analysis found that the thermal stability of this mannan was also improved by chemical modification.

白色念珠菌感染可在免疫受损的患者中证明是致命的。必须开发一种针对这种常见生物的疫苗。念珠菌细胞壁甘露聚糖成分的两性衍生物可能是开发这种疫苗的预期目标。然而，对免疫系统的抗原呈递细胞的自由基加工尚不完全了解。在这项工作中，通过化学改性超声处理的甘露聚糖和三种羧甲基化甘露聚糖衍生物（DS _CM 0.13-0.32），制备了一组量身定制的具有三种不同季铵化程度的阳离子和两性衍生物（DS _Q 0.14-0.38）。这些人受到了Fenton反应原位生成的OH。通过元素分析，NMR和FTIR光谱以及尺寸排阻色谱法监测由于自由基降解而引起的组成，DS _Q和摩尔质量分布的潜在变化。发现季铵化对OH降解的保护作用。非等温热重分析发现该甘露聚糖的热稳定性也可以通过化学修饰得到改善。