中国双低菜粕抗营养因子研究注

对中国培养的3个双低油菜粕和加拿大卡诺拉的1个商品粕和相应的实验室脱脂种籽中寡聚糖、日粮纤维、硫苷和植酸等抗营养成分进行了研究。日粮纤维的组成包括碳水化合物成分－非淀粉多糖（包托中性糖和糖醛酸）和非碳水化合物成分（蛋白质、矿物质、木质素和多酚）。结果表明：4个品种双低菜粕中寡聚糖含量为2.0%－2.5%,品种间差异不大。过热加工显著增加了样品中日粮纤维中蛋白质含量,而非淀粉多糖变化不大。4个品种脱脂种籽中硫苷的种类和含量差异均较大;过热加工显著降低了商品加工的粕4－羟基－3－吲哚甲基硫苷的水平,但105℃的热处理时样品中仍存在黑芥子酶活性,表明热处理温度不足。另外,双低菜粕中还存在2.5%-3.0%的植酸,植酸磷含量为0.8%,占总磷含量的75％－80％。     

硫酸软骨素的降解及其降解产物抗氧化活性的测定

对高分子硫酸软骨素分别进行酸解及酶解,得到相同分子质量范围的硫酸软骨素低聚糖。从聚丙烯酰胺凝胶电泳、分子质量、紫外吸收图谱、硫酸基含量等方面对降解产物进行了表征,并检测了产物的DPPH自由基的清除能力及还原能力。结果表明,在控制条件下两种降解方法得到的硫酸软骨素低聚糖的重均分子量为5300～3500u,且组分基本相同;紫外分析表明,酸解得到的硫酸软骨素低聚糖含有不饱和糖醛酸,具有部分双键;与酶解产物相比,酸解产物的DPPH自由基的清除能力及还原能力较强。     

亚临界水提取大豆胚芽中异黄酮及低聚糖的研究

以大豆胚芽为原料、高压反应釜为反应容器,应用亚临界水为溶剂、采用高纯氮气加压提取大豆胚芽中异黄酮及大豆低聚糖。利用紫外分光光度法测定大豆异黄酮的含量。选取液料比、提取时间、提取温度、压力4个因素进行单因素试验,再进行正交试验优化亚临界水提取大豆异黄酮的条件。结果表明:在液料比25:1,浸提温度120℃,浸提时间40 min,浸提压力1.9 MPa的条件下,大豆异黄酮的得率是1.09%,大豆异黄酮粗提物的产率为6.52%,粗提物纯度是2.60%;大豆低聚糖粗提物产率是35.2%。     

黄原胶琥珀酸衍生物的抗氧化活性

黄原胶寡糖与琥珀酸酐反应,得到3种衍生物XGOSSA-1、XGOSSA-2和XGOSSA-3,对产物进行FT-IR表征,GPC法测定其相对分子质量分别为7 560、6 400和7 430,3种衍生物的丙酮酸质量分数分别为4.6%、4.9%和4.9%,还原糖质量分数分别为20.5%、19.4%和19.0%,取代度分别为0.18、0.32和0.43。考察3种衍生物对超氧阴离子自由基、羟基自由基、DPPH自由基和过氧化氢的清除活性以及还原能力。3种衍生物的抗氧化强弱顺序为:XGOSSA-1XGOSSA-2XGOSSA-3。即当相对分子质量,还原糖和丙酮酸质量分数相近时,随着取代度的升高,抗氧化能力下降。造成这种现象的原因可能是随着取代度增大,活性羟基数目减少,导致抗氧化性能降低。     

Gluco-oligosaccharides as potential prebiotics: Synthesis,purification, structural characterization,and evaluation of prebiotic effect

Prebiotics have long been used to modulate the gut microbiota and improve host health. Most established prebiotics are nondigestible carbohydrates, especially short-chain oligosaccharides. Recently, gluco-oligosaccharides (GlcOS) with 2–10 glucose residues and one or more O-glycosidic linkage(s) have been found to exert prebiotic potentials (not fully established prebiotics) because of their selective fermentation by beneficial gut bacteria. However, the prebiotic effects (non-digestibility, selective fermentability, and potential health effects) of GlcOS are highly variable due to their complex structure originating from different synthesis processes. The relationship between GlcOS structure and their potential prebiotic effects has not been fully understood. To date, a comprehensive summary of the knowledge of GlcOS is still missing. Therefore, this review provides an overview of GlcOS as potential prebiotics, covering their synthesis, purification, structural characterization, and prebiotic effect evaluation. First, GlcOS with different structures are introduced. Then, the enzymatic and chemical processes for GlcOS synthesis are critically reviewed, including reaction mechanisms, substrates, catalysts, the structures of resultant GlcOS, and the synthetic performance (yield and selectivity). Industrial separation techniques for GlcOS purification and structural characterization methods are discussed in detail. Finally, in vitro and in vivo studies to evaluate the non-digestibility, selective fermentability, and associated health effects of different GlcOS are extensively reviewed with a special focus on the GlcOS structure–function relationship.     

Biomimetic Thermo-Sensitive Hydrogel Encapsulating Hemangiomas Stem Cell Derived Extracellular Vesicles Promotes Microcirculation Reconstruction in Diabetic Wounds

Tissue repair and regeneration in ischemic areas require effective strategies for angiogenesis and microcirculation reconstruction. In this research, extracellular vesicles (EVs) derived from hemangioma stem cells (HemSC) are used as bio-functional materials for angiogenesis. In addition, a novel thermo-sensitive hydrogel based on chitosan (CS) and modified with hyaluronic oligosaccharides (oHA), is specially developed as an ideal carrier of HemSC-EVs. The oHA/CS^gel provides a sustained-release delivery system for EVs, enhances the angiogenic function of HemSC-EVs, and exerts other bio-functions to comprehensively accelerate tissue repair. The physical properties of EVs@oHA/CS^gel proved to be soft, highly elastic deformable, biocompatible, and can maintain the shape and structure of EVs. In vitro co-culture assay verifies the angiogenic effect of EVs@oHA/CS^gel, and this effect is also evaluated in a diabetic wound model. Compared to untreated group, the EVs@oHA/CS^gel group has only 26.9% wound area on day 14, and 226.8% blood flux mark on day 17. Pharmacological mechanisms of HemSC-EVs are predicted by RNA-seq, and cluster analysis of miRNAs predicted targets presents several up-regulated biological processes involving in angiogenesis and wound healing. In conclusion, it is suggested that EVs@oHA/CS^gel as a satisfying therapeutic system for microcirculation reconstruction in tissue repair.     

低聚糖改性对蛋清蛋白凝胶性影响研究进展

蛋清蛋白是一种营养价值丰富，具有多种功能特性的优质蛋白。低聚糖可通过糖基化反应与蛋清蛋白共价结合，其偶联物的功能特性较天然蛋清蛋白有所改善。文章综述了低聚糖—蛋清蛋白偶联物的凝胶机理，探讨了低聚糖改性蛋清蛋白凝胶的影响因素，梳理了低聚糖对蛋清蛋白功能特性产生的影响，并对低聚糖改性蛋清蛋白的加工应用进行了展望。     

The Diverse Antimicrobial Activities of Human Milk Oligosaccharides against Group B Streptococcus

Streptococcus agalactiae or Group B Streptococcus (GBS) is a Gram-positive bacterial pathobiont that is the etiological cause of severe perinatal infections. GBS can colonize the vagina of pregnant patients and invade tissues causing ascending infections of the gravid reproductive tract that lead to adverse outcomes including preterm birth, neonatal sepsis, and maternal or fetal demise. Additionally, transmission of GBS during labor or breastfeeding can also cause invasive infections of neonates and infants. However, human milk has also been shown to have protective effects against infection; a characteristic that is likely derived from antimicrobial and immunomodulatory properties of molecules that comprise human milk. Recent evidence suggests that human milk oligosaccharides (HMOs), short-chain sugars that comprise 8–20 % of breast milk, have antimicrobial and anti-biofilm activity against GBS and other bacterial pathogens. Additionally, HMOs have been shown to potentiate the activity of antibiotics against GBS. This review presents the most recent published work that studies the interaction between HMOs and GBS.     

Enabling Technologies in Carbohydrate Chemistry: Automated Glycan Assembly,Flow Chemistry and Data Science

The synthesis of defined oligosaccharides is a complex task. Several enabling technologies have been introduced in the last two decades to facilitate synthetic access to these valuable biomolecules. In this concept, we describe the technological solutions that have advanced glycochemistry using automated glycan assembly, flow chemistry and data science as examples. We highlight how the synergies between these different technologies can further advance the field, with progress toward the realization of a self-driving lab for glycan synthesis.     

Multiple-ion Management of Perovskites by Regulating Spatial Distribution of Hydroxyls in Oligosaccharides

Suppressing migrations of intrinsic and extrinsic ions (e.g., Pb²⁺, I^-, FA⁺/MA⁺, and Li⁺) in organic–inorganic hybrid perovskites is critical for alleviating the hysteresis and degradation of perovskite solar cells (PSCs). However, various additives reported for that purpose usually interact with one or two types of those ions, not inhibiting multiple-ion migrations simultaneously. Two oligosaccharides (β-cyclodextrin (β-CD) and maltotetraose (G4)), containing 14 hydroxyls (−OH) with different spatial distributions, for the suppression of multiple-ion migrations in PSCs is herein employed. Compared to linear arrangement of −OH in G4, annular distribution of −OH around wide and narrow rims of β-CD can form supramolecular multi-site interactions in a focal manner with various ions, more effectively capturing and immobilizing these migrated ions. With this multiple-ion management strategy, β-CD-based PSCs exhibit an impressive efficiency of 24.22% with negligible hysteresis and excellent device stability. This work highlights the significances of multi-site interactions and molecular configuration of the additive for inhibiting multi-ion migrations in PSCs.