辣椒红色素与辣椒碱的提取分离

以干辣椒粉为原料,用95％乙醇作溶剂进行索氏提取,溶剂的用量为原料质量的5倍,减压蒸馏回收溶剂至浸膏状,用石油醚溶解注入硅胶柱。用石油醚：丙酮（V/V）=5：1的复配液为洗脱剂把色素洗脱下来,回收洗脱液,得到深红色油状辣椒红色素产品。留在柱子上的辣椒碱则用75％乙醇作溶剂洗脱下来,去除溶剂,无水乙醚结晶得白色的矩形晶体。     

中低压制备色谱制备茜草蒽醌成分的研究

建立新的中低压制备色谱技术,分离纯化茜草蒽醌单体.先采用高压液相色谱技术分析所分离产物的纯度,再用核兹共振谱、红外、质谱分析确证单体的化学结构.结果表明:用中低压色谱分离茜草的乙醇提取物而得到的4个单体,其纯度分别为99.87％、99.56％、99.42％、98.21％,结构鉴定为从石油醚萃取物中分离得到的单体为大叶茜...     

向日葵根石油醚萃取部分化学成分研究

利用75%乙醇对向日葵根化学成分进行提取;再用萃取法将向日葵根化学成分乙醇提取物分为石油醚萃取物浸膏、乙酸乙酯萃取物漫膏、正丁醇萃取物浸膏;最后用常压硅胶色谱从石油醚萃取物漫膏中分离得到1个甾体类化合物A,经质谱、碳核磁共振和氢核磁共振谱鉴定,确定出其结构为β-谷甾醇。     

蕨菜黄酮分离鉴定

采用75%的乙醇提取经乙醚脱脂的蕨菜粉末,提取液回收乙醇后以石油醚、氯仿、乙酸乙酯、正丁醇依次萃取粗分段,硅胶柱层析、乙酸乙酯-甲醇系统对乙酸乙酯部位梯度洗脱,对其乙酸乙酯洗脱部分反复凝胶柱层析获得2个黄酮单体,分别鉴定为紫云英苷(1)、芦丁(2),其中化合物1为首次从蕨菜中分离得到。     

金银花油用于化妆品

金银花(Lonicera caprifoilum L.)原产亚洲,它和丁香花、百合花一样属花香型植物,在香料和化妆品工业中具有重要意义。金银花的另一个品种是Lonicera gigartea L.(忍冬科),上述两个品种在许多国家均有野生或栽培。 Lonicera capriflium L.和Lonicera gigartea均可用来从花中提取香料油。在法国南部地区,人们用石油醚提取Lonicera gigantea的花,获得0.33％浸膏,再用乙醇处理,获得23.8％的粘性橄榄绿色净油。此种净油经过蒸馏所获得的油呈黄色,得率为9％。     

牛蒡抗虫活性及抗虫成分的初步研究

为进一步开发牛蒡在生物抗虫农药方面的应用价值,对牛蒡提取物进行了抗卤虫活性测试,并对抗虫活性较强的组分进行GC-MS分析.将健康新鲜的牛蒡的乙醇粗提取物经水分散,分别用石油醚、乙酸乙酯和正丁醇萃取,对石油醚、乙酸乙酯、正丁醇和水四相提取物分别进行活性检测,结果表明它们对卤虫的半致死浓度IC50分别为0.13、0.17、1.25、0.19 mg·mL-1,其中石油醚相杀虫效果最好.对石油醚相的化学成分进行分析,共检测出51种成分,鉴定了其中39个化合物并测定了其相对含量,其中主要成分为棕榈酸乙酯(27.791％)、萜类化合物(21.311％)、饱和烃类(19.637％),这三类物质相对含量之和占总提取物的68.739％.     

Diphaladine A，扁枝石松中一个新的石松生物碱

从扁枝石松（Diphasiastrum complanatum）的95％乙醇提取物中分离得到1个新的石松生物碱,经波谱技术鉴定其结构,命名为diphaladine A（1）。同时还分离得到其它9个已知石松生物碱类化合物,其中obsctmmaine A（2）,L20,lycoposerramine—K,des—N—methyl—β—obscurine,des-N—methyl-α—obscurine,lycoflexion,和phlegmariurine B等7个化合物均为首次从该植物中分离得到。     

耐酸耐糖高产乙醇单倍体酵母菌株的选育

在收集大量酵母菌株的基础上,用废糖蜜作碳源,以测定残糖及乙醇产量为指标,经单孢子诱变得到两株活性高,发酵速度较快的稳产、高产酿酒酵母菌株(Saccharomyces cerevisiae)Z—B—4—M—88和Z—S—B—M—33。前者是耐酸菌,在pH4.0,15％糖度下乙醇产量达62.87mg/ml,比原始菌乙醇产量提高了11.2％;后者是耐糖菌,在20％糖度下乙醇产量为70.24mg/ml比原始菌的乙醇量提高11.9％。     

食用玉米黄色素不同溶剂提取方法的比较研究

用研磨和浸提法处理玉米淀粉饼渣,蒸馏色素浸提混合液,回收提取液,用不同比例的混合试剂提取以选择最佳方法。结果发现以石油醚∶乙醇＝３∶２和丙酮∶乙醇＝３∶２提取液效果最佳,色素产率高,色质好,提取溶剂回收率升高。     

固定化脂肪酶催化毛油合成生物柴油

本研究开发了一种用石油醚提取毛油的工艺,研究了以提取的毛油和甲醇为原料,用固定化Candida sp.99-125脂肪酶催化合成脂肪酸甲酯(FAMEs)的可行性。同时考察了磷脂对固定化酶活性、反应起始速率、固定化酶使用批次的影响以及毛油和精炼油对固定化酶使用批次等的影响。研究结果表明,用磷脂质量分数为1%的石油醚悬液浸泡过的脂肪酶比仅用石油醚浸泡过的脂肪酶初始转酯化速率显著下降。当大豆油中无磷脂时,15min时FAMEs的产率为26.2%;磷脂质量分数为5%时,FAMEs降为12.4%。当大豆油中磷脂质量分数小于1%时,固定化酶使用10个批次,FAMEs产率无明显变化。固定化脂肪酶催化石油醚浸提得到的大豆和小桐子毛油,经过10个批次反应FAMEs产率都保持在70%以上,该固定化酶直接催化毛油生产生物柴油具有良好的工业化前景。     

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.