Evaluation of bioactive flavonoids in Citri Reticulatae Pericarpium from different regions and its association with antioxidant andα-glucosidase inhibitory activities

Background:To explore the differences of 14 batches of Citri Reticulatae Pericarpium from different regions.Methods:The main aim of this study was to develop a high-performance liquid chromatography method-photodiode array detection for determining the contents of five flavonoids and the chromatographic fingerprints of Citri Reticulatae Pericarpium from different regions.Theα-glucosidase inhibitory activities and antioxidant properties of Citri Reticulatae Pericarpium,based on free-radical scavenging assays against 1,1-diphenyl-2-picrylhydrazyl,2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),and hydroxyl radicals,were estimated and compared.Results:Among the tested compounds,the content of hesperidin(13.386-68.235 mg/g)was the highest and that of hesperitin(0.045-0.277 mg/g)was the lowest.In comparing different sources of Citri Reticulatae Pericarpium,the contents of narirutin in Citri Reticulatae Pericarpium from Guangdong(0.824-0.851 mg/g)and Sichuan(1.069-1.204 mg/g)provinces of China were lower than in other provinces.In contrast,nobiletin(8.429-12.237 mg/g)and tangeretin(3.947-4.613 mg/g)were most abundant in Guangdong sources of Citri Reticulatae Pericarpium,followed by samples from Sichuan Province(nobiletin:6.761-7.658 mg/g;tangeretin:3.422-3.933 mg/g).Correlation analysis showed that nobiletin and tangeretin were the main contributors to the antioxidant capacity,and narirutin was the main active component inhibiting theα-glucosidase activity of Citri Reticulatae Pericarpium.Conclusion:This work revealed that the intrinsic quality of Citri Reticulatae Pericarpium was affected by different growing regions,which provides a scientific basis for controlling the quality of Citri Reticulatae Pericarpium and rationally developing and utilizing Citri Reticulatae Pericarpium.

Inhibitory Ability of Children with Developmental Dyscalculia

Inhibitory ability of children with developmental dyscalculia（DD） was investigated to explore the cognitive mechanism underlying DD.According to the definition of developmental dyscalculia,19 children with DD-only and 10 children with DD＆RD（DD combined with reading disability） were selected step by step,children in two control groups were matched with children in case groups by gender and age,and the match ratio was 1：1.Psychological testing software named DMDX was used to measure inhibitory ability of the subjects.The differences of reaction time in number Stroop tasks and differences of accuracy in incongruent condition of color-word Stroop tasks and object inhibition tasks between DD-only children and their controls reached significant levels（P〈0.05）,and the differences of reaction time in number Stroop tasks between dyscalculic and normal children did not disappear after controlling the non-executive components.The difference of accuracy in color-word incongruent tasks between children with DD＆RD and normal children reached significant levels（P〈0.05）.Children with DD-only confronted with general inhibitory deficits,while children with DD＆RD confronted with word inhibitory deficits only.

Cucurbitane-Type Triterpene Glycosides from Momordica charantia and Their α-Glucosidase Inhibitory Activities

Ten cucurbitane-type triterpene glycosides,including five new compounds named charantosides H(1),J(2),K(3),momor-characoside A(4),goyaglycoside-l(5),and five known compounds(6-10),were isolated from the EtOAc extract of Momor-dica charantia fruits.The chemical structures of these compounds were identified by 1D and 2D NMR and HRESIMS spectroscopic analyses.Configurations of new compounds were determined by ROESY correlations and comparison of their 13C NMR data with literature reported values.All compounds were evaluated for their inhibition againstα-glucosidase,in which compounds 2,5,7,8,9 showed moderate inhibitory activities with IC50 values ranging from 28.40 to 63.26μM comparing with the positive control(acarbose,IC5087.65±6.51μM).

α-Glucosidase inhibitors isolated from medicinal plants

Objective:α-Glucosidase inhibitors can be used as a new class of antidiabetic drug.By competitively inhibiting glycosidase activity,these inhibitors help to prevent the fast breakdown of sugars and thereby control the blood sugar level.This study provides a wealth of information aboutα-glucosidase inhibitors isolated from medicinal plants;this knowledge will be useful in finding more potent antidiabetic candidates from the natural resources for the clinical development of antidiabetic therapeutics.Results:411 compounds exhibitingα-glucosidase inhibitory activity were summarized and isolated them from medicinal plants.The compound classes isolated include:terpenes(61)from 14 genus,alkaloids(37)from 11 genus,quinines(49)from 4 genus,flavonoids(103)from 24 genus,phenols(37)from 9 genus,phenylpropanoids(73)from 20 genus,sterides(8)from 5 genus,and other types of compounds(43).Conclusion:Compounds withα-glucosidase inhibitory activity are abundant in nature and can be obtained from several sources.They have highα-glucosidase inhibitory potential,and can be clinically developed for treating diabetes mellitus.

α-Glucosidase inhibitor produced by an endophytic fungus, Xylariaceae sp. QGS 01 from Quercus gilva Blume

Xylariaceae sp.QGS 01,an endophytic fungus isolated from the stem of Quercus gilva Blume showed high-glucosidase inhibitory activity.α-Glucosidase inhibitor have the role as one of carbohydrate-hydrolyzing enzymes to postpone absorption of glucose in the digestive organs.The α-glucosidase inhibitor constituents were isolated from the ethyl acetate extract of the mycellium of endophytic fungi Xylariaceae sp.QGS 01 using a bioassay-guided fractionation technique.Further separation and purification of the active fraction led to the isolation of constituents with strong inhibitory activities against-glucosidase:8-hydroxy-6,7-dimethoxy-3-methylisocoumarine(1)with inhibitory concentration(IC50)values against-glucosidase from Saccharomyces cerevisiae of 41.75μg/mL,while quercetin as the standard had an IC50 value of 4.80g/mL.The results of the present study showed that the endophytic fungus Xylariaceae sp.QGS 01 is potentially a rich source of antidiabetic medicine.

α-Glucosidase Inhibition by New Schiff Base Complexes of Zn(II)

There are many reports that divalent alkaline earth, first-row transition metals, and Zn(II) ions have α-glucosidase inhibitory effects. Cu(II) and Zn(II) ions, in particular, have strong α-glucosidase inhibitory effects. Several Schiff bases also display α-glucosidase inhibitory effects. In this study, we focused on safe and highly effective complexes including Zn(II) ion. We prepared and characterized the Zn(II) complexes with four different Schiff bases (N-salicylidene-β-alanine (N-sβ), N-N’-bis (salicylidene) ethylenediamine (N-bsE), N, N’-bis (salicylidene)-phenylenediamine (N-bsP), and 1-[(2-dimethylaminoethylimino) methyl]naphtholate (DMN)) and investigated their α-glucosidase inhibitory effects in vitro, using α-glycosidases from Saccharomyces sp. and rat small intestine, and in vivo, using a sucrose tolerance test. The Zn(II) complexes with DMN showed the highest in vitro and in vivo α-glucosidase inhibitory effects in this study.

红曲糟源酶解蛋白肽的功能性评价

【目的】研究不同蛋白酶对红曲糟酶解的效果,并对其酶解液进行功能性评价,为红曲糟源蛋白肽的研发制备提供理论支持。【方法】以提高蛋白含量后的红曲糟为原料,利用碱性蛋白酶、胰蛋白酶、动物蛋白酶、木瓜蛋白酶、菠萝蛋白酶、胃蛋白酶、复配酶制剂F106、酵母抽提酶等不同蛋白酶进行酶解,考察其酶解率、1,1-二苯基-2-三硝基苯肼(DPPH)和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)自由基清除抗氧化能力、黄嘌呤氧化酶(Xanthine oxidase,XOD)和血管紧张素转化酶(Angiotensin converting enzyme,ACE)抑制活性等生物活性功能。【结果】蛋白酶解率最高的为动物蛋白酶和胰蛋白酶酶解处理,分别为(71.43±1.03)%和(70.20±0.32)%。DPPH自由基清除抗氧化能力最优的是胃蛋白酶、碱性蛋白酶和酵母抽提酶酶解处理,蛋白肽的半数效应浓度(Median effective concentration,EC50)分别为(2.78±0.34)mg·mL^(-1)、(3.02±0.03)mg·mL^(-1)、(3.24±0.65)mg·mL^(-1);ABTS自由基清除抗氧化能力、XOD抑制活性能力最优的均为胃蛋白酶和碱性蛋白酶酶解液,其蛋白肽的EC50值分别为(1.54±0.07)mg·mL^(-1)、(6.45±0.27)mg·mL^(-1)和(10.71±0.06)mg·mL^(-1)、(17.68±0.04)mg·mL^(-1),二者的XOD半数抑制指数分别为(1.28±0.01)、(1.78±0.03);ACE抑制活性最优的为碱性蛋白酶酶解液和木瓜蛋白酶酶解液,蛋白肽的EC50值均为(0.27±0.01)mg·mL^(-1),半数抑制指数分别为(118.40±3.53)、(98.35±1.95)。【结论】红曲糟源蛋白经不同蛋白酶酶解后的肽段具有不同的生物活性,其中以胃蛋白酶酶解的XOD抑制活性能力较强,碱性蛋白酶和木瓜蛋白酶酶解的ACE抑制活性较优。

Screening of probiotics with efficient α-glucosidase inhibitory ability and study on the structure and function of its extracellular polysaccharide

Inhibition ofα-glucosidase activity is an important strategy in lowering the concentration of blood sugar.In this paper,using domestic and foreign characteristic food-derived substances as the sources of lactobacillus,the performance of them were evaluated by measuring the strains’α-glucosidase inhibitory ability.Finally,the cell-free extracellular supernatants(CFS)of Lactobacillus rhamnosus LB1lac10 was determined to have the highest α-glucosidase inhibition ability.Based on the Nanopore third-generation sequencing technology platform,the genome of LB1lac10 was sequenced and functional gene annotation was performed.After that,the biological activity and structural composition of the exopolysaccharide produced by L.rhamnosus LB1lac10 were studied.The purified exopolysaccharide EPS1-1 also showed efficientα-glucosidase inhibitory ability.The structure and conformation characteristics of EPS1-1 were further analyzed.The EPS1-1 from L.rhamnosus LB1lac10 had a molecular weight of 88,650 Da,and it was mainly composed of mannose,glucuronic acid,glucose,xylose,galactose,and arabinose.From the FT-IR and NMR analyses,EPS1-1 had functional groups of a typical polysaccharide structure and contained two types of glycosidic bonds with α-configuration pyranose.The main glycosidic bond corresponded to→4)-α-D-Glcp-(1→,which might be an important reason why EPS1-1 could inhibit α-glycosidase.Thermodynamic studies showed that EPS1-1 had high heat resistance to meet the needs of food processing.The results suggested that L.rhamnosus LB1lac10 could be used as a potential probiotic to lower blood sugar,and the EPS1-1 has the potential to serve as a naturalα-glycosidase inhibitor to regulate the concentration of blood glucose.

不同提取方法对黄精多糖理化特性和生物活性的影响

为比较不同提取方法对黄精多糖理化特性和生物活性的影响,该文以黄精根茎为原料,分别用水提法(Water Extraction,WE)、酶解法(Enzyme Extraction,EE)、超声辅助法(Ultrasonic-assisted Extraction,UE)提取黄精多糖(Polygonatum sibiricum Polysaccharides,PP),比较了不同提取方法对黄精多糖得率、化学组成、理化特性(持油力、醇溶性、吸湿性)、生物活性(抗氧化活性、α-葡萄糖甘酶抑制活性、α-淀粉酶抑制活性)、单糖组成及分子量大小的影响。结果表明:酶解法较其他两种提取方法相比,具有较高的得率(8.11%)、总糖含量(52.79%)、持油力(5.67 g/g)、吸湿率(25.28%)和重均分子量(5.343×10^(5) g/mol)。三种提取方法得到的多糖对2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS^(+))的半数抑制质量浓度IC_(50)(mg/mL)分别为0.41、0.23、0.25;对1,1-二苯基-2-三硝基苯肼(DPPH)的半数抑制质量浓度IC50(mg/mL)分别为0.19、0.16、0.18;对α-葡萄糖甘酶的半数抑制质量浓度IC50(mg/mL)分别为2.14、1.98、2.06;对α-淀粉酶的半数抑制质量浓度IC50(mg/mL)分别为0.62、0.41、0.58。三种多糖均为酸性多糖,单糖组成以葡萄糖为主。通过红外光谱检测到3种多糖均具有多糖特征官能团,电镜扫描结果呈现不同的结构特征。综上,不同提取方法对黄精多糖的理化特性、生物活性、单糖组成和微观结构的影响有差异,酶解法是一种可以提高多糖理化性质和生物活性的有效方法,黄精多糖具有一定生物活性和可开发利用价值。

Flavonoids from Litchi(Litchi chinensis Sonn.) Seeds and Their Inhibitory Activities on α-Glucosidase

With the bioactivity-guided method,a new flavanone glycoside,together with nine known flavonoids were isolated from 50% aqueous ethanol of litchi（Litchi chinensis Sonn.） seeds.The chemical structure of the new compound was elucidated via 1D and 2D nuclear magnetic resonance（NMR） techniques and mass spectrometry to be （2S）-pinocembrin-7-O-（6＂-O-α-L-arabinosyl-β-D-glucopyranoside）（1）,and the nine known compounds were determined to be quercetin（2）,phlorhizin（3）,pinocembrin-7-O-glucoside（4）,kaempferol-7-O-β-D-glucopyranoside（5）,onychin（6）,nairutin（7）,narcissin（8）,pinocembrin-7-O-[（6＂-O-β-D-glucopyranoside）-β-D-glucopyranoside]（9） and pinocembrin-7-O-[（2＂,6＂-di-O-α-L-rhamnopyranosyl）-β-D-glucopyranoside]（10）.Some of the isolated flavonoids were tested for their inhibitory effects on α-glucosidase.And compounds 2 and 3 showed stronger inhibitory activity than positive control.

儿童执行功能对数学能力的预测模型

使用数点数广度任务(C-span)、Stroop任务、威斯康星卡片分类任务(WCST)测查儿童的执行功能,用《小学儿童数学能力测查量表》(一年级)、《韦克斯勒儿童智力测量》分别测查儿童的数学能力和智力,对64名小学一年级儿童的执行功能(抑制、转换、刷新)和数学能力的关系进行了研究,相关分析和回归分析发现,数学能力与执行功能任务测量都有显著相关,抑制、转换和刷新都分别对数学能力存在显著回归效应;在此基础上,建立了执行功能及其对儿童数学能力的预测模型。结果表明,抑制控制、转换和刷新都能对数学能力产生直接影响,但抑制控制还通过转换和刷新对数学能力产生间接影响。说明儿童数学能力的认知差异,主要在于抑制控制能力的差异,而抑制控制的差异又导致转换和刷新能力表现的差异。

聚胺水基钻井液特性实验评价

室内合成的聚胺强水化抑制剂SD-A可有效抑制黏土水化分散,与国外同类产品Ultrahib性能相当。聚胺水基钻井液配方为:4%膨润土浆+3%SD-A+0.5%SD-E+1%PAC-LV+0.3%XC+3%SD-506。与聚合醇、阳离子、KCl/聚合物钻井液相比,二级膨润土在聚胺水基钻井液中的膨胀率最小,岩屑回收率最高,表明聚胺水基钻井液抑制页岩水化分散能力强。聚胺水基钻井液120℃热滚16 h前后的流变性能稳定,热滚后动塑比为1.07,高于油基钻井液。在400 mL聚胺水基钻井液中分别加入144 g NaCl、8 g CaCl2和80 g劣土后,体系流变性发生不同程度的改变,而滤失量变化较小,其中CaCl2对体系流变性影响最大。结果表明聚胺水基钻井液的抗污染能力较强。屈曲硬度实验、耐崩散实验和黏结实验等新型实验方法表明,聚胺水基钻井液的抑制性接近甚至超过油基钻井液,清洁润滑性优良,其EC值为12 g/L,符合环保要求。另外,简要分析了聚胺水基钻井液的抑制机理。

乳酸菌代谢产物对大肠杆菌和金黄色葡萄球菌抑制作用的研究

从燕糖酸奶中分离出乳酸菌,研究热、酶、pH值处理等对乳酸菌代谢产物抑制大肠杆菌和金黄色葡萄球菌效果的影响。结果表明:乳酸菌发酵液的最终pH值为39.;乳酸菌代谢产物具有良好的热稳定性以及较好的抗蛋白酶活性和抗过氧化氢酶活性;pH值处理对乳酸菌代谢产物的抑菌能力具有明显影响,pH值越低乳酸菌代谢产物的抑菌能力越强。

幼儿预见能力的发展及与抑制控制、心理理论的关系

预见是预测未来会发生什么或者需要什么的能力,是对未来自我状态进行的推理。该研究由两部分实验组成。实验1以3～5岁幼儿为研究对象,采用Atance和Meltzoff(2005)的非言语研究范式,探讨了预见能力的发展特点。结果表明,4岁以后,幼儿能够根据未来的需要选择适宜的物品。实验2以4～6岁幼儿为研究对象,考察了预见与抑制控制和心理理论能力的关系。结果发现,抑制控制对幼儿的预见能力存在直接的预测效力,而心理理论则是通过抑制控制作为中介变量间接地作用于预见过程。

抑制控制对学前儿童语言能力的影响

本研究对63名学前儿童的认知控制、注意控制、动作控制和语言能力进行测试,并采用路径分析技术考察这三种抑制控制机制对学前儿童语言能力的影响效果。结果表明,学前儿童的认知控制、注意控制和动作控制对其语言能力都有显著的直接影响;认知控制通过注意控制和动作控制对语言能力有显著的间接影响,注意控制通过动作控制对语言能力也有显著的间接影响。根据这一研究成果,教师在组织语言教学活动时,就应充分考虑这些抑制控制机制的影响,如交代规则时最好一次活动一个规则;在实施双语教育时必须考虑儿童是否有能力抑制控制已经获得的针对母语的优势反应等。

数学学习困难初中生的中央执行系统特点

为揭示数学学习困难学生的认知过程加工特点,筛选上海111名初中生(男生46名,女生68名,平均年龄11.97岁)比较数学困难学生(55名)与数学优秀学生(56名)的中央执行系统的表现差异,通过反应停止任务和Flanker任务考察抑制能力以及注意控制能力。结果发现各种抑制和注意控制条件下,数困组学生的正确率低于数优组;在具有干扰情况下的成绩更能有效预测数学成绩;中央执行系统能力在初中总体具有上升发展趋势,数困生的发展具有波动性。因此,数学学习困难在中央执行系统中的缺损主要是对抗干扰的能力不足,而非简单的加工速度。

抗高温抗盐阳离子降滤失剂CHSP-Ⅰ的合成及其应用

本文介绍了抗高温抗盐阳离子降滤失剂CHSP-Ⅰ的合成方法，评价了CHSP-Ⅰ的抑制性能、抗高温抗盐降滤失性能，简介了CHSP-Ⅰ在塔里木、南海、渤海等油田应用的实例。该降滤失剂能耐200℃以上高温，抗钙能力强，可抗盐至饱和，具有良好的抑制性能和降滤失作用，与其它处理剂配伍性良好，适用于各种水基钻井液体系。

儿童早期近似数量表征的发展与特点

对儿童早期近似数量表征的研究表明,近似数量表征能力在儿童早期不断发展并逐步精确;儿童早期近似数量表征与数学能力存在相关或预测关系;对数学学习困难儿童的近似数量表征是否存在缺陷,研究者们还存在着分歧;抑制控制可能是影响近似数量表征与数学能力之间关系的重要中介变量;干预在一定程度上能改善近似数量表征能力。这些研究成果不仅能够加深对儿童早期数学认知发展的认识,为今后的相关研究提供思路和方向,而且为儿童早期数学教育实践提供了重要的科学依据。

小学生近似数量系统敏锐度的发展趋势及其与数学能力的关系:抑制控制的中介作用

采用测量法和问卷法考察了172名小学生近似数量系统敏锐度的发展,以及抑制控制在近似数量系统敏锐度与数学能力关系中的中介效应。结果表明:(1)随着年龄增长,小学生的近似数量系统敏锐度逐渐提高;(2)近似数量系统敏锐度(负相关序列中的韦伯系数)和抑制控制均能显著正向预测小学生的数学能力;(3)抑制控制在小学生近似数量系统敏锐度(负相关序列中的韦伯系数)与数学能力的关系中起部分中介作用。

伽师瓜贮藏中拮抗酵母的筛选及性能初探

伽师瓜储藏期的腐败病一直是制约新疆伽师瓜生产发展的主要障碍,已成为新疆伽师瓜生产中亟待解决的问题,生物防治是解决这一问题的重要途径。本研究通过与病原菌对峙培养试验,从伽师瓜中分离筛选对果实腐烂病原菌有拮抗作用的2株酵母菌(J2和J5),并对拮抗酵母J2的生物抑制能力进行了初步研究。