Abstract：
Inulin, a polysaccharide characterized by a β-2,1 fructosyl-fructose structure terminating in a glucosyl moiety, is naturally present in plant roots and tubers. Current methods provide average degrees of polymerization (DP) but lack information on the distribution and absolute concentration of each DP. To address this limitation, a reproducible (CV < 10 %) high throughput (<2 min/sample) MALDI-MRMS approach capable of characterizing and quantifying inulin molecules in plants using matched-matrix consisting of α-cyano-4-hydroxycinnamic acid butylamine salt (CHCA-BA), chicory inulin-12C and inulin-13C was developed. The method identified variation in chain lengths and concentration of inulin across various plant species. Globe artichoke hearts, yacón and elephant garlic yielded similar concentrations at 15.6 g/100 g dry weight (DW), 16.8 g/100 g DW and 17.7 g/100 g DW, respectively, for DP range between 9 and 22. In contrast, Jerusalem artichoke demonstrated the highest concentration (53.4 g/100 g DW) within the same DP ranges. Jerusalem artichoke (DPs 9-32) and globe artichoke (DPs 9-36) showed similar DP distributions, while yacón and elephant garlic displayed the narrowest and broadest DP ranges (DPs 9-19 and DPs 9-45, respectively). Additionally, qualitative measurement for all inulin across all plant samples was feasible using the peak intensities normalized to Inulin-13C, and showed that the ratio of yacón, elephant garlic and Jerusalem was approximately one, two and three times that of globe artichoke. This MALDI-MRMS approach provides comprehensive insights into the structure of inulin molecules, opening avenues for in-depth investigations into how DP and concentration of inulin influence gut health and the modulation of noncommunicable diseases, as well as shedding light on refining cultivation practices to elevate the beneficial health properties associated with specific DPs.
摘要：
菊粉,一种以β-2,1果糖基-果糖结构终止于葡糖基部分为特征的多糖，天然存在于植物根和块茎中。目前的方法提供了平均聚合度(DP),但缺乏关于每种DP的分布和绝对浓度的信息。为了解决这个限制，一种可重复的（CV<10％）高通量（<2分钟/样品）MALDI-MRMS方法，能够使用由α-氰基-4-羟基肉桂酸丁胺盐（CHCA-BA）组成的匹配基质表征和定量植物中的菊粉分子，开发了菊苣菊粉-12C和菊粉-13C。该方法确定了各种植物物种中菊粉的链长和浓度的变化。地球朝鲜蓟心脏，Yacón和象大蒜在15.6g/100g干重（DW）时产生了相似的浓度，16.8g/100gDW和17.7g/100gDW，分别,DP范围在9和22之间。相比之下,在相同的DP范围内，菊芋的浓度最高（53.4g/100gDW）。菊芋(DP9-32)和洋蓟(DP9-36)显示出相似的DP分布，而yacón和大象大蒜的DP范围最窄和最广（分别为DP9-19和DP9-45）。此外,使用归一化为菊粉-13C的峰强度，对所有植物样品中的菊粉进行定性测量是可行的。并显示Yacón的比例，大象大蒜和耶路撒冷大约是一个，是地球朝鲜蓟的两倍和三倍。这种MALDI-MRMS方法提供了对菊粉分子结构的全面见解，为深入研究DP和菊粉浓度如何影响肠道健康和调节非传染性疾病开辟了途径，以及阐明精炼栽培实践，以提高与特定DP相关的有益健康特性。
