Rapid analysis and characterization of multiple constituents of corn silk aqueous extract using ultra‐high‐performance liquid chromatography combined with quadrupole time‐of‐flight mass spectrometry

Corn silk is a well‐known traditional Chinese medicine that has been widely used for its antidiabetic, antioxidant, antihyperlipidemic, and other effects in China for thousands of years. Numerous studies have revealed that corn silk contains multiple bioactive constituents that are beneficial for human health. However, the constituents of corn silk in vivo remain ambiguous. In this study, high‐throughput ultra‐high‐performance liquid chromatography combined with quadrupole time‐of‐flight mass spectrometry technology using multivariate statistical analysis was established to systematically investigate the constituents migrating into blood from corn silk aqueous extract. As a result, 76 compounds were identified, including caffeic acid and ten of its derivatives, (E)‐p‐coumaric acid and two of its derivatives, ferulic acid and four of its derivatives, and five flavones. Among the identified constituents, 21 constituents, including nine prototype components and 12 metabolites derived from eight components, were characterized in sequence. Based on the significance of the results, the applied approach was powerful for the accurate determination and rapid screening of bioactive components from corn silk aqueous extract. The obtained results are valuable for the in‐depth understanding and further pharmacological study of corn silk aqueous extract.     

不同酸解聚麦秸产物分析及其动力学

以麦秸为研究对象,解聚剂为HCl、HNO₃和H₃PO₄,对解聚产物进行定性和定量分析,并利用动力学模型描述木糖及糠醛的产生过程。 结果表明,解聚液中的产物有葡萄糖、木糖、阿拉伯糖、纤维二糖、乙酸、糠醛、5-羟甲基糠醛。 通过引入变量(α,木糖/木聚糖的比值)利用Saeman动力学模型获得了不同温度下,木聚糖的水解速率常数、木糖的转化速率常数以及糠醛的生成速率常数。 HCl、HNO₃和H₃PO₄解聚麦秸,木糖的生成活化能分别为55.5、46.3和59.8 kJ/mol。 结合反应温度、反应时间、反应速率以及木糖和糠醛的浓度,确定最佳解聚条件为:硝酸作解聚剂,在130 ℃下水解95 min。     

水稻秸秆石油醚和乙醇萃取物的组成分析

用石油醚和乙醇在索式萃取器中对水稻秸秆进行了萃取,萃取物用傅里叶转换红外光谱仪（FTIR）和气相色谱 质谱联用仪（GC/MS）分析。 结果表明,乙醇和石油醚的萃取率分别为8%和6%。 萃取物中共检测到40种物质,主要分为醇酚（APs）、醛、酮、酸、酯、烃（HCs）及含氮化合物（ONs）7种类别。 其中,石油醚萃取物中酯、HCs和APs 3类物质含量较高,总的相对含量为91.7%;乙醇萃取物中HCs、酸、酯及APs含量较高,总的相对含量为83.9%。 该研究在开发稻秆的高附加值利用方面具有重要的基础理论意义。     

环氧氯丙烷改性稻草

环氧氯丙烷改性稻草;稻草;环氧氯丙烷;醚化;改性     

A Study on bioactivity of Corn Peptides with Low Molecular Weight（Ⅰ）——Effect of an Intake of them on Alcohol Metabolism in Rats

IntroductionIn the past few years,some researchers foundthat small peptides derived from the hydrolysate offood protein play an important role in regulatingautonomic nervous system,activating the cellularimmunity function,ameliorating the cardiovascularfunction,antioxidizng and antaging,etc.[1— 8] .Par-tial proteolysis is effective for improving the func-tional properties of protein.Small peptides havesome advantages compared to protein,such as lowosmotic pressure,fast absorption,good taste a…     

玉米淀粉固态电解质质子\电子杂化突触晶体管

随绿色可持续发展观念的深入人心,研究人员致力于寻找天然有机材料应用于功能性电子器件.淀粉以其低廉的价格、丰富的来源和优异的机械性能进入了科研人员的视野.淀粉可由玉米、马铃薯、甘薯和葛根等含淀粉的物质中提取而得,一般不溶于水,在和水加热至一定温度时,则糊化成胶状溶液.本文通过旋涂法将玉米淀粉的胶状溶液旋涂至氧化铟锡玻璃表面,然后在30?C恒温环境中晾干制备成固态胶合状薄膜.以此薄膜作为固态电解质制备了氧化铟锌突触晶体管,并实现了生物神经突触的双脉冲易化、学习记忆能力、高通滤波等可塑性行为的仿真.本研究以玉米淀粉固态胶合薄膜作为电解质大大降低了氧化物薄膜晶体管固态电解质的成本,且该电解质无毒性、来源丰富,将为人工神经网络的开发提供一种可选择的元件.     

甲苯/水双相体系中以稻草为原料合成糠醛

FeCl³为催化剂,在甲苯/水双相溶剂体系中,以稻草为原料经水解反应制备糠醛,其结构经¹H NMR和¹³C NMR确证。通过响应面分析获得的最佳反应条件为：催化剂质量分数23.09%,甲苯60 mL,溶剂比V（甲苯）: V（水）=1 : 1,料液比为67.5 g·L^-1,于177 ℃反应60 min,糠醛收率高达78.92%。     

玉米须提取液对尿液中草酸钙晶体形成的影响

本文采用X射线衍射(XRD)、红外光谱(FTIR)、扫描电子显微镜(SEM)等方法分析了玉米须提取液对正常人尿液中草酸钙晶体形成的影响,通过电导率法研究了草酸钙晶体生长的动力学过程,以及从生物矿化的角度对玉米须提取液影响尿液中草酸钙晶体的可能机理进行了探讨。由于玉米须提取液中有机酸或多糖的羟基、羰基等通过配位作用与Ca²⁺结合形成可溶性配位化合物,减少了Ca²⁺与Oxa^2-的结合能力,从而抑制了CaOxa的成核和生长。同时,可能由于玉米须提取液中有效成分与二水草酸钙(COD)的吸附点键合,增强了COD晶体在溶液中的热力学稳定性,进而抑制了COD晶体向热力学更稳定态的一水草酸钙(COM)晶体转变。结果显示,这种抑制作用随玉米须浓度增大而增大,且COD晶体尺寸随着玉米须浓度的增大而减小。玉米须抑制COD晶体向COM晶体转变的作用为开发预防和治疗尿结石的药物提供了启示。     

Fungal upgrading of wheat straw for straw-thermoplastics production

Combining biologic pretreatment with storage is an innovative approach for improving feedstock characteristics and cost, but the magnitude of responses of such systems to upsets is unknown. Unsterile wheat straw stems were upgraded for 12 wk with Pleurotus ostreatus at constant temperature to estimate the variation in final compositions with variations in initial moisture and inoculum. Degradation rates and conversions increased with both moisture and inoculum. A regression analysis indicated that system performance was quite stable with respect to inoculum and moisture content after 6 wk of treatment. Scale-up by 150× indicated that system stability and final straw composition are sensitive to inoculum source, history, and inoculation method. Comparative testing of straw-thermoplastic composites produced from upgraded stems is under way.     

A universal kinetic equation for characterising the fractal nature of delignification of lignocellulosic materials

A kinetic model was developed, based on the power law of growth and Avrami’s nuclei growth concepts, to describe the heterogeneous nature of pulping kinetics, taking into account the effects of chemical concentration and temperature. The general form of the kinetic equation is first order with a time-dependent rate coefficient. The model was statistically tested using published data obtained from delignification of lignocellulosic materials (hemp woody core, giant reed, wheat straw, cottonwood, bamboo and flax fibres). The activation energies of the delignification range from 71 to 136 kJ/mol. The p-values obtained from the regression analysis are significantly small indicating that all the estimates of the model parameters were significant with very high levels of confidence. The correlation coefficients R ² for these models range from 0.76 to 0.98.