人参茎叶皂甙对高胆固醇饮食大鼠再灌注性心律失常和脂质过氧化的影响(英文)

研究人参茎叶皂甙(GSL)对高胆固醇饮食大鼠心肌再灌注性心律失常(RPA_r)和脂质过氧化的影响。方法:将胆固醇乳剂用灌胃法饲养大鼠14d,建立高脂血症模型,各组大鼠进行心肌缺血再灌注实验,观察高脂血症和GSL对大鼠心肌缺血再灌注2h后血丙二醇(MDA),超氧化物歧化酶(SOD)和一氧化氮(NO)水平的影响和对再灌注性心律失常发生率的影响。结果显示:(1)用胆固醇乳剂饲养大鼠14d,成功建立高脂血症模型。同时给予GSL14d有明显降脂作用。(2)高脂血症状态下,心肌缺血再灌注2h后,血MDA升高(p<0.01),SOD降低(p<0.01)和NO(p<0.05)降低,再灌注10min内RPAr的发生率增高。(3)GSL组再灌注后2h的血MDA降低,而SOD和NO水平显著升高;使RPAr发生率大为降低,无VF发生。实验显示高脂血症加重心肌缺血再灌注损伤和提高RPAr发生率及动物死亡率,GSL可减少高脂饮食大鼠脂质过氧化和诱导体内NO生成而减轻缺血再灌注心肌损伤,降低缺血再灌注性心律失常发生率。     

Five New Guaiane Sesquiterpenes from the Endophytic Fungus Xylaria sp. YM 311647 of Azadirachta indica

Five new guaiane sesquiterpenes, 1 – 5 , were isolated from the culture broth of the endophytic fungus Xylaria sp. YM 311647, isolated from Azadirachta indica A. Juss . The structures of these compounds were elucidated on the basis of spectroscopic analyses, and their inhibitory activities against five pathogenic fungi were evaluated. All guaiane sesquiterpenes showed moderate or weak antifungal activities in a broth microdilution assay.     

大豆饱和脂肪酸组分改良研究进展

为了更好地满足消费者的需要,遗传改良豆油中脂肪酸含量已经取得很大进展,并有3个油分改良的大豆品种已经商品化,其油分中亚麻酸的含量已经从原来的8%降到了1%,油酸含量也已从25%增加到80%,棕榈酸从11%降到小于4%。传统育种和基因工程育种都是遗传改良大豆油的手段。阐述了遗传改良、基因型和表现型的选择等多方法对脂肪酸的影响,总结了大豆饱和脂肪酸组翻改良的主要进展。     

利用鸡胚浸出液制作细菌培养基的研究

利用鸡胚浸出液制作的肉汤和琼脂平板培养基均能适合副鸡嗜血杆菌、大肠杆菌和沙门氏菌的生长,用平板计数法、麦氏比浊法和离心称重法分别对副鸡嗜血杆菌、大肠杆菌和沙门氏菌的培养产物进行含菌量、菌泥湿重测定,结果表明,鸡胚浸出济培养基培养的沙门氏菌产量是普通培养基培养的沙门氏菌产量的20倍以上,培养的副鸡嗜血杆菌产量是普通培养的3倍以上,而鸡胚浸出液培养基与普通培养基对大肠杆菌的培养数量则无明显差异。     

Synthesis and characterization of carboxymethyl-polyaminate chitosan and its adsorption behavior toward a reactive dye

Carboxymethyl-polyaminate chitosan (DETA-CMCHS), a novel kind of amphoteric chitosan derivative, was prepared and characterized by elemental analysis, and by IR and ¹H NMR spectroscopy. The adsorption behavior of Reactive Blue (RB2) on DETA-CMCHS was also studied. Results showed that the maximum value of adsorption capacity was 1185.71 mg/g at pH 3. The adsorption kinetic behavior was fitted with a second-order reaction rate equation. The adsorption was an exothermic, irreversible and entropy-reduced process according to thermodynamic parameters, such as standard Gibbs free-energy change, enthalpy change, and entropy change, all of which were calculated from adsorption equilibrium data.     

NPR1多肽抗体的制备和应用

根据NCBI GenBank中报道的NPR1一级结构信息,采用Blastn、Blastx、ExPASy和Protean等软件进行序列同源性和抗原性指数分析,获得三段序列特异性较高的多肽,并从中优选一段序列特异性多肽,采用9-氟甲氧羰基固相合成法获得序列特异性最好的多肽,采用HPLC和LC-MS测定合成多肽的浓度和分子量,试验表明目的多肽纯度达88%、目的多肽分子量为1.92234 kD。采用碳化二亚胺法将多肽与KLH进行偶联获得免疫原Pep-KLH,并将其免疫新西兰大白兔以获得抗血清和多克隆抗体,采用ELISA和Western blotting测定其效价和特异性,经ELISA检测表明抗血清和多克隆抗体可与Pep发生特异性免疫反应,经Western blotting试验表明抗血清和多克隆抗体可识别烟草叶片特异性条带,其相对分子量为65 kD,与预测分子量相符,表明利用该方法制备的NPR1多肽抗体具有较高特异性和灵敏度。     

冷应激大鼠睾丸细胞AR和ABP的检测

目的为研究冷应激大鼠睾丸细胞雄激素受体和雄激素结合蛋白的变化,本实验检测了睾丸细胞雄激素受体和雄激素结合蛋白的含量。方法采用放射配体—3H-睾酮结合分析法。结果冷应激实验组与对照组比较,雄激素受体最大结合量(单位:fmol/mgDNA)为143.38±9.47和87.46±15.11;雄激素结合蛋白(单位:fmol/mgpro.)为34.98±8.16和12.94±3.63;差异有显著性,P<0.05。结论冷应激导致睾酮水平下降的同时,反馈地引起其受体浓度增加的变化是机体代偿适应性反应。     

Differentiating the 2,3-diols of glucopyranosides by 4,6-O-benzylidene-protected-1,2-d-glucopyranosylorthoesters strategy

A facile and efficient method to differentiate the 2,3-diols of glucopyranosides based on 1,2-orthoesters strategy was developed. Stable thioglucosides were employed as the starting materials to prepare the corresponding 1,2-orthoesters. When treated with HCl aqueous solution and followed with Et₃N, differentiation of the 2,3-diols was efficiently achieved along with the generation of a convertible anomeric hydroxyl group. In addition, an easy and practical method based on NOE was proposed to determine whether the 1,2-orthoesters were endo-type or exo-type.