大孔吸附树脂分离富集苜蓿皂甙的研究

本项工作以对苜蓿皂甙的吸附量和解吸率为指标筛选大孔吸附树脂。研究结果表明,X-5吸附树脂具有较好的吸附性能和解吸效果。研究应用正交试验方法进一步对大孔吸附树脂分离纯化苜蓿皂甙的工艺条件进行试验分析,确定苜蓿皂甙分离富集的最佳操作条件为:上样浓度8mg/mL,色谱柱的径高比1∶7,药材-树脂比例1∶3;吸附完全后,先以水洗脱,除去杂质,再以50%乙醇洗脱,可以得到纯度较好的苜蓿皂甙。     

大孔吸附树脂纯化海红果黄酮工艺的研究

通过采用大孔吸附树脂对海红果黄酮粗提液的静态吸附和解吸试验,从10种大孔吸附树脂中筛选出海红果黄酮纯化的最优树脂,考察了该树脂对诲红果黄酮的静态、动态吸附与解吸性能并对吸附与洗脱的最佳条件进行了研究.结果表明:NKA-9树脂对海红果黄酮有很好的吸附和解吸性能,其最优的动态吸附工艺条件为:上样液pH值为4.0,浓度5.15 mg/mL,上样量为4 BV,流速控制在2 BV/h.最优的解吸工艺条件为:洗脱剂为80％乙醇溶液,洗脱液用量为3 BV,洗脱流速控制在1 BV/h.在此优化条件下,海红果黄酮的吸附率、解析率、收率、纯度的平均值分别达到为(79.39±0.13)％,(84.14±0.11)％,(68.20±0.15)％和(28.81 ±0.06)％ (n=5).     

大孔吸附树脂分离纯化番石榴叶总黄酮的研究

考察大孔吸附树脂吸附分离番石榴叶总黄酮的工艺条件.以静态饱和吸附量、静态洗脱率、动态饱和吸附量、动态洗脱率为考察指标,比较了D101、AB-8两种大孔树脂分离纯化番石榴叶总黄酮的优劣.又以总黄酮回收率为指标,对最佳树脂吸附工艺参数进行了研究.在考察的2种树脂中,AB-8型树脂最适于番石榴叶总黄酮的分离纯化,其工艺条件为:4倍树脂体积50%乙醇洗脱,速度2mL/min.树脂可重复使用4次.其平均总黄酮回收率为87.47%.所得总黄酮纯度为74.03%     

王不留行黄酮苷的分离纯化及对细胞增殖活性的影响

本文以炒王不留行中王不留行黄酮苷含量为考察指标,采用动静态吸附试验相结合的方式,从大孔树脂型号、吸附时间、最大上样量和洗脱剂浓度等方面考察大孔吸附树脂对炒王不留行中王不留行黄酮苷的分离纯化工艺,得到了稳定可行的工艺路线和吸附参数。同时利用SRB法测定皂苷对内皮细胞增殖的影响。本研究可为炒王不留行中王不留行黄酮苷的大孔树脂分离纯化精制工艺的确定提供参考,同时进一步研究发现王不留行黄酮苷可显著促进内皮细胞增殖。     

聚酰胺树脂纯化竹壳类黄酮工艺的研究

采用聚酰胺吸附树脂对竹笋壳黄酮类化合物分离纯化,确定了聚酰胺吸附树脂对竹笋壳黄酮分离纯化的最佳工艺条件:制备5mg/mL的竹笋壳黄酮提取液90mL,调节pH=5,用1.8mL/min的流速上样后,用160mL的去离子水冲洗大量杂质,随后用120mL的60%乙醇溶液洗脱120mL。在此条件下,竹笋壳黄酮的纯度为58.4%,与大孔树脂纯化方法相比,该方法更具有良好的分离纯化效果。     

余甘原汁中多酚的大孔树脂提取分离及其抗氧化活性

为研究余甘子多酚的分离提取方法,本文以余甘原汁为原料,采用NKA-Ⅱ大孔吸附树脂,对上样量、洗脱剂、洗脱体积及洗脱速度等条件进行了考察,并对提取物的抗氧化活性进行了对比分析。通过试验确定了余甘原汁多酚的大孔树脂分离提取条件为:上样速度2BV/h,上样量0.8BV,洗脱剂为70%乙醇溶液,洗脱体积3BV,洗脱速度8BV/h,在此条件下NKA-Ⅱ大孔树脂对余甘原汁中多酚的吸附率可达到88.42%,洗脱率为90.93%,提取率为80.39%;对提取物的抗氧化活性分析显示,与分离前的余甘原汁干燥物相比,提取物的多酚和维生素C含量均提高了0.53倍,类超氧化物歧化酶活性(SODL)提高了1.4倍;铁离子还原能力(FRAP)明显高于分离前,对DPPH自由基、ABTS自由基及脂质氧化的半抑制浓度(IC50)均显著低于分离前的原汁干燥物,表明通过大孔吸附树脂分离,使余甘原汁中的多酚等抗氧化活性成分得到了有效的分离纯化。     

大孔吸附树脂对乳清分离蛋白酶解物的吸附特性研究

研究了大孔吸附树脂对乳清分离蛋白（WPI）酶解液的吸附特性。比较了6种大孔吸附树脂对WPI酶解物的静态吸附率与解吸附率。结果表明,DA201-C大孔吸附树脂最适合WPI酶解物的分离,其对WPI酶解液的动态吸附条件为：上样液浓度：10mg／mL;洗脱剂：75％乙醇溶液;洗脱剂流速：1BV／h。     

大孔吸附树脂分离纯化培养基残基中虫草素

采用大孔吸附树脂分离纯化人工蛹虫草培养基残基中的虫草素,以HPLC法测定样品中虫草素含量,筛选出了适宜的大孔树脂NKA-II。研究了pH、洗脱剂乙醇体积分数等因素对该树脂吸附性能及解析性能的影响。结果表明,NKA-II型树脂纯化虫草素的最佳吸附条件为pH9,吸附流速2BV/h,该树脂对虫草素的吸附量可达到16.5mg/g。洗脱工艺条件为2.5倍树脂柱体积的50%乙醇,NKA-II大孔树脂对虫草素的解析率可达到95%以上。     

大孔吸附树脂对金银花叶茎藤总黄酮的吸附性能

从金银花叶茎藤中提取总黄酮并用D-101大孔吸附树脂进行纯化,研究了D-101大孔吸附树脂对总黄酮的吸附及解吸附特性。结果表明,D-101树脂对金银花叶茎藤总黄酮分离纯化的最佳工艺参数为:上样液黄酮浓度0.538 mg/mL,静置吸附时间80 min,料液比1∶5(g∶mL),pH 2,流速为2 mL/min,以60 mL 75%的乙醇溶液洗脱,黄酮解吸率为94.5%,纯化后黄酮纯度为84.5%,是粗提液黄酮含量(16.8%)的5倍。金银花叶茎藤总黄酮在D-101树脂上的吸附等温线符合Langmuir等温吸附方程。吸附热力学参数表明吸附过程为自发、放热过程,吸附动力学可用Pseudo-second-order模型较好地拟合,30℃时其表观吸附速率常数为1.034×10-2g/mg.min。     

大孔吸附树脂纯化绿茄叶黄酮的工艺研究

研究大孔吸附树脂纯化绿茄叶黄酮粗提取物的最佳工艺。通过比较10种大孔吸附树脂纯化黄酮粗提取物的吸附及解吸性能,筛选出纯化树脂XDA-1,并考察XDA-1树脂对黄酮粗提取物的静态、动态吸附与解吸的性能。结果表明,XDA-1树脂对黄酮粗提取物纯化的最佳工艺参数:吸附平衡时间8 h,吸附浓度2.00 mg/m L,p H值3.0,温度25℃,上样流速2 BV/h;解吸平衡时间2 h,解吸剂为p H值为3.0的体积分数80%的乙醇溶液,解吸流速3 BV/h,纯化倍数2.37。该研究证实大孔吸附树脂纯化绿茄叶黄酮的方法简单可行,为绿茄叶黄酮的分离纯化提供了实验依据。     

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.     

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.     

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.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

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).     

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.