青蛤多肽的酶法制备及对前列腺癌DU-145细胞的抑制活性

探讨青蛤多肽的制备工艺及体外抗前列腺癌DU-145细胞的活性。以氨基氮含量为检测指标,筛选最优酶种类并进行正交试验以获取最佳酶解青蛤内脏酶解工艺。经超滤截留、琼脂糖凝胶层析、高效液相色谱分离纯化及噻唑蓝（3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,MTT）活性筛选得到含有5 个氨基酸的多肽（Ile-Leu-Tyr-Met-Pro）。对所得多肽采用MTT法测定DU-145细胞增殖抑制率;采用倒置显微镜、Hoechst 33258染色及透射电子显微镜技术观察细胞形态学变化;采用荧光法检测细胞内活性氧（reactive oxygen species,ROS）水平;采用线粒体膜电位检测DU-145细胞凋亡情况;采用免疫组织化学法检测非转移性克隆23型（nm23H1）蛋白的表达。结果表明：制备青蛤多肽最佳酶是木瓜蛋白酶,最佳酶解条件是料液比1:4、pH 7.0、加酶量1 500 U/g、温度45.0 ℃、酶解时间4 h;所得多肽对DU-145细胞的增殖具有明显的抑制作用,且呈时间与剂量依赖性;处理后的DU-145细胞出现凋亡的形态学特征;其质量浓度和细胞内ROS的表达量呈正相关关系;线粒体膜电位降低率从4.22%提高到25.07%;免疫组织化学法结果显示nm23H1蛋白的表达量增加。青蛤多肽能明显抑制DU-145细胞的增殖,并通过诱导其发生凋亡而发挥作用。     

盘龙参内生真菌S-3产黄酮发酵条件的优化研究

盘龙参内生真菌S-3可产生黄酮类化合物,通过ITS法测序分析,S-3鉴定为嗜松青霉Penicillium pinophilum。为了增加内生真菌S-3产黄酮量,以单因素结合正交法优化S-3菌株发酵条件,结果表明,最佳发酵条件如下:发酵培养基组成为马铃薯100 g,玉米粉40 g,葡萄糖10 g,豆饼粉10 g,磷酸二氢钾3 g,硫酸镁1.5 g,水1 000 mL,pH6.7;发酵温度28℃,摇床转数160 r/min,发酵时间4 d。     

Phenolic antioxidants from Chinese toon (fresh young leaves and shoots of Toona sinensis)

Chinese toon (the fresh young leaves and shoots of Toona sinensis), known as a tree vegetable, belongs to the family of Meliaceae. It is one of the most popular vegetables in China. The 80% acetone extract of Chinese toon exhibited considerable antioxidant activity in the 1,1-diphenyl-2-picryldydrazyl (DPPH) radical-scavenging assay. Bioassay-guided purification of the extract led to the isolation of 12 phenolic compounds (1–12), whose structures were determined by detailed spectroscopic analyses, including UV, IR, MS, 1D and 2D NMR techniques. Of them, compounds 3–8 and 11 were isolated from T. sinensis for the first time. All of the isolated compounds were examined for their antioxidant activities by the DPPH method, and the results showed that gallic acid and its derivatives, gallotannins and flavonoids were the main constituents contributing to the antioxidant activity of Chinese toon. From the health point of view, Chinese toon is an ideal dietary vegetable with natural antioxidants.     

Quality control method of sterols in fermented Cordyceps sinensis based on combined fingerprint and quantitative analysis of multicomponents by single marker

In this study, we established a new pattern for differentiating and comprehensively evaluating the quality of fermented Cordyceps sinensis based on high-performance liquid chromatography (HPLC) fingerprint analysis combined with similar analysis (SA), principal component analysis (PCA), hierarchical cluster analysis (HCA), and the quantitative analysis of multicomponents by single marker (QAMS). These methods indicated that fermented Cordyceps sinensis samples could be categorized into one class by PCA and HCA. The fingerprints of fermented Cordyceps sinensis were established, and four HPLC peaks were identified as ergosterol, daucosterol, stigmasterol, and β-sitosterol in Jinshuibao capsules and tablets (two products of fermented Cordyceps sinensis). Ergosterol was chosen as the internal reference substance, and the relative correction factors (RCFs) between ergosterol and the other three sterols were calculated using the QAMS method. Moreover, the accuracy of the QAMS method was confirmed by comparing the relative error between the results of the method used with those of an external standard method (ESM). No significant difference between the two methods was observed. The total sterols content in Jinshuibao products were calculated by the QAMS method, and the total sterols content of the two products were similar. This study showed that the method established herein was efficient and successful in the identification fermented Cordyceps sinensis and may further act to facilitate systematic quality control of fermented Cordyceps sinensis products.     

阿根廷马黛茶与广东红茶挥发性成分比较分析

本研究以阿根廷马黛茶和广东红茶为研究对象,采用顶空固相微萃取-气质联用仪(HS-SPME-GC/MS),分析马黛茶和红茶的挥发性成分,探明其差异组分,明晰马黛茶的特征挥发性成分。结果表明:醇类是马黛茶(MD)和广东红茶中主要的挥发性成分种类。萜醇(24.34%)和萜酮(18.97%)是MD中主体挥发性成分,MD中香叶基丙酮(4.84%)相对含量高于优选5号红茶(YX5,1.14%)和大叶奇兰10号红茶(QL10,0.89%)。脂肪醛、萜醛、脂肪酮、脂肪醇和萜烯类挥发性成分在MD中相对含量高于YX5和QL10。甲氧基化合物是MD特征挥发性成分,相对含量为6.43%。芳香醇、酸类和酚类化合物在MD中没有检测到。萜醇和酯类是广东红茶的主体挥发性成分。水杨酸甲酯是酯类中相对含量最高的成分,YX5(14.79%)和QL10(12.04%)中相对含量高于MD(2.43%)。     

中草药提取液对冬虫夏草深层培养的影响

试验了11种中草药提取液对冬虫夏草液体培养生物量和多糖产量的影响。结果得出：这11种中草药水提液除川牛膝、黄精、山药对冬虫夏草的生物量有抑制作用外，其它几种中草药均有促进作用，增幅范围在0．007-0．94倍。该11种中草药均对冬虫夏草胞外多糖的产量有促进作用，其胞外多糖增幅在0．09～0．88倍；中药醇提液除川牛膝、石斛、黄芪对冬虫夏草的生物量有抑制作用外，其它几种中药促进作用的增幅在0．16～0．67倍。除山药和黄芪外均能提高冬虫夏草胞外多糖的产量，它的增幅在0．03～0．73倍。通过比较，最后实验了当归、党参、枸杞子、川牛膝的最适添加量，前三者在150g／L，后者在50g／L。在此条件下，生物量最大分别可达26．13、22．14、23．55、15．83g／L，胞外多糖的最大产量分别达到7160．2、7580．3、6830．5、6583．6g／L。以上11种中药对冬虫夏草胞内多糖也有一定的促进作用，但增幅不大。     

水热法主要提取因素对光皮木瓜多糖结构的影响

目的 优化水热法提取光皮木瓜(Chaenomeles sinensis)多糖的提取工艺条件,分析光皮木瓜不溶性多糖的组成和结构.方法 光皮木瓜样品经水热法提取、抽滤、冲洗,浓缩等操作,分别得到不溶性多糖、醇沉多糖和醇溶多糖,通过傅里叶变换红外光谱、扫描电子显微镜及X射线衍射分析不溶性多糖的组成和结构.结果 多糖的最佳提...     

茶饼病侵染对茶树游离氨基酸组分及含量的影响

为揭示茶饼病菌对茶树叶片中游离氨基酸组分及其含量的影响,以3个不同抗性品种茶树的病、健叶为试验材料,利用高效液相色谱法(HPLC)检测不同抗性品种茶树未感病和感病后鲜叶中氨基酸的组分和含量。结果表明:不同抗性品种未感病叶片中游离氨基酸的的种类和含量有差异,茶氨酸含量最高,其次是γ-氨基丁酸、蛋氨酸、胱氨酸;感病后氨基酸总量上升,高抗品种紫娟叶片中游离氨基酸的种类减少,含量下降,仅γ-氨基丁酸含量增加;中抗品种云抗10号叶片中游离氨基酸的种类增加,含量均增加;感病品种佛香1号叶片中游离氨基酸的种类不变,γ-氨基丁酸、茶氨酸、赖氨酸、色氨酸、精氨酸5种游离氨基酸的含量增加,其余氨基酸的含量下降,因而可以以此分析氨基酸与茶树抗病性的关系。本研究结果可为从生理生化角度探讨茶饼病致病机理提供基础数据。     

香椿干燥特性及其特征香气化合物热降解动力学

对香椿干燥过程中水分迁移规律进行研究,同时考察不同热处理条件对香椿的特征香气有机化合物之一2-巯基-3,4-二甲基-2,3-二氢噻吩（2-Mercapto-3,4-Dimethyl-2,3-Dihydrothiophene,MDD）稳定性的影响,分析MDD热降解的动力学以及热力学规律。结果表明：热处理温度越高,香椿干燥速率越快,符合传统的干燥速率变化规律。MDD降解过程符合一级动力学反应规律和Arrhenius模型,反应速率常数介于0.0155～0.0345min-1之间,并且随着处理温度的升高而增大,不同温度下半衰期分别为44.719、32.239、20.091 min,随着干燥处理温度的升高而呈现出减少的变化趋势,反应的活化能（Ea）为39.052 kJ/mol。焓变（ΔH）为正值说明MDD热降解过程是吸热反应,吉布斯自由能（ΔG）也为正值,说明MDD热降解反应为非自发反应。研究可为有效控制香椿加工生产过程特征风味物质的降解提供理论依据。