紫甘蓝色素的提取及组分的研究

从紫甘蓝中提取色素并研究色素的主要成分。通过正交实验确定了紫甘蓝色素的最佳提取条件:60%的乙醇溶液、料液比1∶50、pH=1、提取时间60min;经AB-8大孔吸附树脂纯化后,采用液相色谱-质谱法(LC-MS)对紫甘蓝色素的组分进行了分析,结果表明紫甘蓝色素主要有七种组分,是矢车菊花青素的一系列糖苷及其酰化物。     

蕨类植物花青素和原花青素成分及含量分析

以7目14科共44种蕨类植物为材料,对它们的花青素、原花青素和总黄酮含量进行检测。结果显示,44种蕨类植物均含有花青素,较为进化的水龙骨目植物的总花青素平均含量明显高于其它蕨类植物。矢车菊素、飞燕草素和天竺葵素是蕨类植物主要的花青素类型,其中乌毛蕨科植物富含矢车菊素,鳞毛蕨科植物富含飞燕草素。本研究中大部分蕨类含有原花青素,水龙骨目植物的原花青素平均含量高于其它蕨类。研究结果表明,蕨类植物中花青素和原花青素等黄酮类化合物的分布与植物科属相关,推测花青素与蕨类植物的生长发育和抗逆过程相关。     

真空低温工艺技术在黑胡萝卜花青素提取中的应用

通过单因素和正交试验优化了真空低温工艺技术提取黑胡萝卜花青素的工艺参数,比较了真空低温提取法和常压提取法对花青素提取的影响,利用色差检测技术建立了黑胡萝卜花青素提取过程颜色控制标准。结果表明:最优提取条件为提取温度35℃、液料比(L/kg)8∶1、提取时间100 min、真空度-0.05 MPa,在此条件下,黑胡萝卜花青素提取率为96.3%;提取温度对花青素提取影响最为显著,真空度影响最小。     

HPLC不同种类水果中花青素含量的测定

建立了水果中飞燕草色素、矢车菊色素、矮牵牛色素、天竺葵色素、芍药素和锦葵色素等6种花青素含量的高效液相色谱测定方法,并对该方法的线性、精密度、回收率、稳定性进行了方法学验证。利用本方法测定了10种水果中6种花青素含量,结果表明：强酸溶液提取并水解得到花青素的处理方式稳定好、精密度高、回收率好,液相条件分离效果好,定量准确度高。10种水果测定结果表明,不同种类水果中花青素含量差异显著,花青素总量高的水果中6种花青素单体的含量差异显著,且不同种类水果中优势花青素单体不同。     

玉米紫色植株色素主要成分的结构鉴定

玉米紫色植株色素是从新品种玉米的紫色植株中提取的红色素.高效液相色谱分析该色素含6种成分,经硅胶柱分离出两种主要成分,经紫外可见光谱、红外光谱法、核磁共振波谱法确定该两种主要成分分别是矢车菊素-3-葡萄糖苷和3',4'-二羟基花色素-3-葡萄糖苷,其含量分别占总量的45.96%和12.99%.玉米紫色植株色素是花色苷类色素.     

紫叶李叶黄酮提取工艺的响应面优化及最佳采收月份的确定

使用高效液相色谱仪测定不同条件下超声辅助提取紫叶李叶中矢车菊素-3-O-葡萄糖苷花青素、芦丁、槲皮素、山奈酚4种黄酮类物质的得率,并根据4种物质的活性,建立紫叶李叶中黄酮类物质得率权重计算公式。在单因素试验的基础上,采用Box-Behnken设计-响应面法优化紫叶李叶黄酮类物质提取工艺。应用最佳提取工艺处理不同月份紫叶李叶,并根据4种成分权重计算黄酮类物质得率,确定最佳采收月份。结果表明,紫叶李叶黄酮类物质最佳提取工艺为乙醇体积分数63.93%、液料比25∶1(mL/g)、提取温度44.08℃、提取时间41.62 min;最佳采收月份为8月份。此结果重复性好,可信度高,其中矢车菊素-3-O-葡萄糖苷花青素得率随时间变化最明显,且与日照条件显著相关,该试验对后期相关具体成分的提取具有借鉴意义。     

正交试验优化黑果枸杞果实中花青素的提取工艺

黑果枸杞(Lycium ruthenicum)是西北干旱区特有的小灌木,具有重要的生态和经济价值,而果实中花青素含量多寡是评判其经济价值的重要指标。为找到简单易行的花青素提取技术,本试验采用pH=30的盐酸-乙醇提取法,分别对不同提取溶剂浓度、物料比、提取时间、提取温度以及是否脱脂条件下的花青素提取率进行了研究,结果表明:在黑果枸杞不脱脂的情况下,用乙醇提取花青素的最优条件为pH=30的80%盐酸-乙醇、物料比为1:15、提取时间为5 h、提取温度为40℃,花青素的提取率达到0978%。该试验结果为实验室及产业化提取花黑果枸杞青素提供了较为准确的参数。     

山葡萄籽中原花青素的提取

研究了提取溶剂、温度、时间、料液比4个因素对山葡萄籽中原花青素得率的影响。确定最佳提取工艺：以70％丙酮为提取荆,在60℃条件下,提取120min,料液比为1：7,原花青素的得率为2．31％     

大鲵皮肤色素提取工艺及抗氧化研究

为优化大鲵皮肤黑色素的提取工艺条件,探讨大鲵皮肤黑色素组成成分及体外抗氧化活性,采用酶法和碱溶酸沉法提取大鲵皮肤黑色素,以氢氧化钠浓度、液料比、提取温度为影响色素提取率因素,优化黑色素提取工艺条件,用紫外-可见光谱仪、红外光谱仪和超高效液相质谱仪测定黑色素的光谱特性,测定其抗氧化性。结果表明:大鲵皮肤黑色素最佳提取工艺条件为氢氧化钠浓度1.5 mol/L、液料比1∶15、提取温度45℃,黑色素提取率达0.65%。大鲵皮肤黑色素的紫外最大吸收波长为214 nm,由真黑色素和脱黑色素两种色素组成,其对超氧阴离子自由基的清除率为30.51%,对羟基自由基的清除率为54.17%。大鲵皮肤黑色素具有一定的体外抗氧化能力。     

山樱花品种间花色差异的代谢组学研究

山樱花是世界著名的观花类植物，花色是其最重要的观赏特征。为探究影响山樱花品种间花色差异的代谢通路及关键代谢产物变化，该文利用LC-MS/MS技术对白色、绿色和粉色的山樱花品种进行花青素靶向代谢组学比较分析。结果表明：(1)共检测到42种花青素物质，主要包含矮牵牛素、飞燕草素、黄酮类化合物、锦葵色素、芍药花素、矢车菊素、天竺葵素和原花青素8种物质。(2)差异代谢花青素25种，包括11种下调、14种上调，其中有7种花青素在粉色花瓣中显著富集。(3)KEGG通路注释发现差异代谢物在花青素生物合成通路中显著富集，结合聚类结果发现矮牵牛素-3-O-葡萄糖苷是山樱花品种间花色差异产生的关键代谢物。该研究揭示了山樱花花色差异的代谢机理，为后续山樱花花色分子调控机制研究提供了一定的理论依据，也为新品种花色改良和选育提供了一定的科学参考。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.