This work aims to fill the gap in the present knowledge about the structure of pectin from Opuntia ficus-indica. The water-soluble pectin (WSP) fraction, extracted with the Microwave Assisted Extraction (MAE), was further deproteinated (dWSP) and analyzed through several biophysical and biochemical techniques. HPSEC, light scattering and FTIR data showed that dWSP is low methylated high molecular weight pectin. The biochemical structure of dWSP, after methanolysis, silylation, carboxyl reduction showed that dWSP belongs to rhamnogalacturonan I class. Then, dWSP was heat-modified (HM) to obtain small-molecular weight deproteinated fraction (HM-dWSP). Both species, dWSP and HM-dWSP, were tested in LAN5 and NIH 3T3 model cells to study their biological effect. Results indicated that both dWSP and HM-dWSP exerted cytotoxic activity affecting selectively LAN5 cancer cells, without any effect on NIH 3T3 normal cells.

中文翻译：

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仙人掌水溶性果胶的生化和生物物理表征及其潜在的细胞毒活性

这项工作旨在填补目前关于仙人掌果胶结构知识的空白。使用微波辅助提取 (MAE) 提取的水溶性果胶 (WSP) 部分进一步脱蛋白 (dWSP) 并通过多种生物物理和生化技术进行分析。HPSEC、光散射和 FTIR 数据表明 dWSP 是低甲基化的高分子量果胶。dWSP经甲醇分解、甲硅烷基化、羧基还原后的生化结构表明dWSP属于鼠李糖半乳糖醛酸Ⅰ类。然后，对 dWSP 进行热改性 (HM) 以获得小分子量的脱蛋白部分 (HM-dWSP)。dWSP 和 HM-dWSP 这两个物种都在 LAN5 和 NIH 3T3 模型细胞中进行了测试，以研究它们的生物学效应。