酶解法提取黄芩中黄芩素的工艺研究

本文对黄芩药材中黄芩苷的酶解条件和黄芩素的提取工艺进行研究,以样品中黄芩素的含量为指标,采用正交实验对影响酶解的温度、时间和药材粒度进行考察;以黄芩素的提取率为指标,经正交实验优选乙醇浓度、用量、回流次数和时间。得出如下较理想的酶解条件和提取工艺:黄芩药材粉碎至10~20目,加水6倍,于60℃保温10 h;酶解后的黄芩药材加8倍量70%乙醇回流提取2次,每次1 h。黄芩素的提取率大于70%,工艺稳定可行。     

模拟连续逆流提取黄柏中小檗碱工艺研究

本文优化实验室模拟连续逆流提取设备工艺对黄柏中小檗碱进行提取,并用连续逆流提取设备进行中试放大。在单因素设计实验基础上采用正交设计实验优化实验室小试模拟连续逆流提取黄柏中小檗碱的工艺(提取温度、硫酸浓度和提取时间),为新型连续逆流提取设备中试条件优化提供一种实验室模拟方法,并采用中试连续逆流提取设备对黄柏中小檗碱提取工艺进行验证。正交设计实验结果和极差分析结果表明三个提取因素对提取效果的影响大小顺序是:提取温度硫酸浓度提取时间。最佳提取条件为:提取温度90℃,8倍体积的0.5%稀硫酸溶液作为提取溶剂,提取4 min,换料次数12次。在优化提取条件下小檗碱提取得率为3.6%,小檗碱提取率达到90.3%。根据实验室小试模拟所得各项实验参数,预设中试连续逆流提取器各项提取参数:提取温度90℃,转速4 rpm,总提取时长20 h,小檗碱提取率达90.5%。该工艺较小檗碱提取传统工艺能显著提高提取效率和有效降低提取溶剂用量。     

正交实验法优化黄柏中黄连素的酶碱法提取工艺

为了提高黄柏中黄连素的提取得率与效率,采用传统方法碱提法与酶解辅助提取相结合来优化黄柏中黄连素的提取工艺。以黄连素浸提率为评价指标,考察纤维素酶浓度、酶解时间、料液比及浸提时间对提取效率的影响。在单因素实验的基础上,通过正交实验分析各因素的作用大小以及它们之间的交互作用。优选出黄柏中黄连素的酶碱法提取最佳工艺条件为:纤维素酶浓度15‰、酶解时间1 h、料液比1∶7、浸提时间7 h,在该条件下黄连素的浸提率可达8.99%。该提取工艺浸提率高,成本低,稳定性好,可用于生产上黄柏中黄连素的提取。     

响应面法优化酶法提取枸杞多糖的研究

选用响应面法优化及正交实验法进行淀粉酶提取枸杞多糖实验设计及分析。通过单因素实验后,正交实验确定淀粉酶酶解提取枸杞多糖的最佳条件为:pH=5.0,温度50℃,时间80 min,加酶量为0.5%,枸杞多糖提取率12.1%;响应面分析确定淀粉酶酶解提取枸杞多糖的最佳条件为酶解温度49.56℃、酶解时间140 min、酶浓度0.3%,枸杞多糖提取率为13.25%。酶法提取枸杞多糖比传统热水浸提提高了枸杞多糖的提取率,反应条件温和,而且通过响应面法进行实验设计和优化比正交实验法能得到更高的枸杞多糖提取率。     

硫酸软骨素快速提取法研究

硫酸软骨素是用于治疗冠心病、神经系统疼痛及链霉素引起的肝脏障碍和肝炎辅助治疗的药物,来源于动物的软骨。本文采用先高温蒸煮后加稀碱与酶解相结合的方法提取药物,并用氯仿反萃取,较其他方法缩短了原工艺一半流程,提高了纯度,减轻了碱盐提取所带来的环境污染。     

忽地笑中石蒜碱酶法提取及分离工艺研究

对复合酶法提取忽地笑石蒜碱的工艺进行优化,并用阳离子交换树脂分离石蒜碱。以纤维素酶与果胶酶的水溶液为提取溶剂,采用L9(34)正交试验考察了酶解p H、酶加入量、酶解时间和酶解温度等影响因素,以石蒜碱得率为指标,得最优提取工艺为:料液比1∶10,p H 4.5,酶添加量4%,酶解温度50℃,提取时间2.0 h,石蒜碱得率为0.1750%。D-001树脂纯化条件为:上样液p H为2,以3 BV/h流速上样,以含1.5 mol/L氨水的70%乙醇洗脱,流速为3 BV/h,初步分离后石蒜碱含量为15.28%。研究结果可为石蒜碱工业化生产提供参考。     

酶解法提取纯化虎杖提取物中自藜芦醇的工艺研究

本文对虎杖提取物中虎杖苷的酶解条件及苷元白藜芦醇的提取纯化工艺进行研究,以样品中自藜芦醇的含量为指标,对纤维素酶、β-葡萄糖苷酶、复合酶进行筛选,结果表明以复合酶的水解效率最高:采用正交实验对影响复合酶酶解的因素:加酶量、温度、酶解时间进行考察;并对酶解后提取物中自藜芦醇的提取纯化工艺进行研究.得出如下较理想的酶解条件和提取纯化工艺:虎杖提取物,加水(pH 5)10倍,加20%的复合酶,于50℃保温24 h;酶解后的提取物经水、乙醇-水、碱溶液分步溶解沉淀,得白藜芦醇粗品,含量可达65%,工艺稳定可行.     

酶法提取桑葚多糖的工艺研究

利用纤维素酶从桑葚中提取桑葚多糖,通过单因素实验和L9(34)正交实验研究酶用量、酶解时间、酶解温度对桑葚多糖提取率的影响。实验结果表明:纤维素酶能够显著提高桑椹多糖的提取率,并且提取温度是最重要的影响因素,其次是酶解时间,酶用量在此实验范围内对测定结果的影响最小,提取的最佳工艺条件为:酶解温度45℃,酶解时间150 min,酶用量4.0 mL。     

酶辅助法提取透骨草中总黄酮及抗氧化性研究

本文采用纤维素酶辅助法提取透骨草中总黄酮,即先用纤维素酶酶解透骨草,再用乙醇回流法提取透骨草中的总黄酮。分别固定提取剂乙醇浓度为70%,料液比为1∶20 g/m L,初步探究了纤维素酶浓度、酶解p H、酶解温度、酶解时间四个单因素对透骨草总黄酮提取率的影响。设计正交实验确定了酶辅助法提取透骨草中总黄酮的较佳条件:纤维素酶浓度为2 U/m L、酶解p H=4.5、酶解温度为45℃、酶解时间2 h,总黄酮提取率为1.27%。本文初步探究了透骨草总黄酮提取液对羟自由基的清除活性,对照实验结果表明透骨草提取液对羟自由基清除活性要高于相同浓度的芦丁与二丁基羟基甲苯。     

酶法辅助乙醇优选牡丹种皮总黄酮

研究适合于以牡丹种皮为原料提取总黄酮的方法,对其提取方法工艺条件进行优化。考察了酶种类、浓度、酶解孵育温度、孵育时间和pH值等因素对提取工艺的影响,并在单因素实验基础上,利用正交实验法进行工艺优化。考察结果表明在果胶酶0.05 mg·mL^-1、酶解孵育温度45℃、pH4.5条件下进行酶解孵育180 min后,总黄酮得率最高可达74.839 mg·g^-1,相对于乙醇提取法牡丹种皮总黄酮得率显著提高。     

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.     

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     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.