The thermal reactivities of cellulose and hemicellulose are significantly different in cell walls when compared with isolated components and differ in Japanese cedar (softwood) and Japanese beech (hardwood). Uronic acid bound to xylan promotes the thermal degradation of cellulose and hemicellulose, and its effect is different depending on the form of free acid (acting as an acid catalyst) or metal uronate (acting as a base catalyst). We evaluated the location of uronic acid in the cell wall by identifying the components affected by demineralization in pyrolysis of cedar and beech wood. The thermal reactivities of xylan and glucomannan in beech were changed by demineralization, but in cedar, glucomannan and cellulose reactivities were changed. Therefore, the location of uronic acid in the cell wall was established and differed between cedar and beech; close to glucomannan and xylan in beech, but close to glucomannan and cellulose in cedar. Such information is important for understanding the ultrastructure and pyrolysis behavior of softwood and hardwood cell walls.

中文翻译：

---

通过矿物对热反应性的影响评估日本雪松和日本山毛榉木细胞壁中的糖醛酸基团的位置

与孤立的成分相比，纤维素和半纤维素的热反应性在细胞壁上显着不同，在日本雪松（软木）和日本山毛榉（硬木）中也不同。与木聚糖结合的尿酸促进了纤维素和半纤维素的热降解，其作用因游离酸（用作酸催化剂）或金属尿酸盐（用作碱催化剂）的形式而异。我们通过鉴定在雪松和山毛榉木热解过程中受脱盐作用影响的成分来评估糖醛酸在细胞壁中的位置。脱矿作用改变了山毛榉中木聚糖和葡甘露聚糖的热反应性，而雪松中的葡聚糖和纤维素反应性也发生了变化。因此，确定了尿酸在细胞壁中的位置，并且在雪松和山毛榉之间有所不同。在山毛榉中接近葡甘露聚糖和木聚糖，但在雪松中接近葡甘露聚糖和纤维素。这些信息对于了解软木和硬木细胞壁的超微结构和热解行为非常重要。