不同产地茅苍术水溶性成分的HPLC指纹图谱研究

采用HPLC-ELSD法建立了茅苍术[Atractylodes lancea(Thunb.)DC.]水溶性成分的指纹图谱,并对不同产地野生与栽培茅苍术水溶性成分的指纹图谱进行了比较分析.结果表明,采用HPLC-ELSD法获得的茅苍术水溶性成分指纹图谱稳定、可靠、重复性好;供试茅苍术水溶性成分的保留时间一般在65 min之内,共有16个典型的共有色谱峰;供试茅苍术样品的指纹图谱与对照模式色谱图的相似度较高,说明该指纹图谱可作为茅苍术水溶性化学成分的特征指纹图谱.江苏产野生与栽培茅苍术水溶性成分的化学组成基本一致,以倍半萜苷类为主,主要成分均为苍术苷A;湖北产野生茅苍术水溶性成分的倍半萜苷类总含量较高,但主要成分不是苍术苷A.     

茅苍术不同器官挥发油含量及其生长量的动态变化

以来自湖北英山的2年生茅苍术(Atractylodes lancea(Thunb.)DC.)为实验材料,研究了茅苍术的根、根茎、叶片、茎和花果在不同发育阶段挥发油的含量变化、分布模式及其与生长量的关系。结果表明,茅苍术的根、根茎、叶片、茎和花果中均含有挥发油,但主要存在于根茎中,占全株挥发油总量的81.79%;苍术酮、茅术醇、β-桉叶醇、芹烷二烯酮及苍术素为根茎挥发油的主要成分,占根茎挥发油总量的94.53%;β-桉叶醇和茅术醇的含量较高,占5种主要挥发油成分总量的74.85%;5种主要挥发油成分在不同器官中的形成及动态变化均不同。根茎挥发油成分在营养生长及生殖生长旺盛期积累缓慢,在营养生长及生殖生长后期积累迅速。根据研究结果确定南京地区茅苍术的最佳采收期为11月中下旬。     

茅苍术挥发油对三种内生真菌及七种外源真菌的抑菌活性

为了研究宿主植物次级代谢产物对内生真菌生长的抑制作用,以药用植物茅苍术及其内生真菌为材料,采用有机溶剂萃取法提取茅苍术挥发油,应用滤纸片扩散法和平板涂布法研究茅苍术挥发油对茅苍术内生真菌及其他外源真菌的抑菌作用.结果表明: 挥发油对3种内生真菌生长具有抑制作用;对酵母、水霉有很强的抑菌活性;对根霉、犁头霉抑菌作用不明显;对绿色木霉、黑曲霉的产孢具有抑制作用;对疫霉生长无抑制作用.在高浓度挥发油胁迫下,内生真菌菌丝分支增多,分支间距离变短,气生菌丝生长受到抑制.两种内生真菌对挥发油具有代谢转化能力,降低了其主要成分的含量.表明茅苍术挥发油对内生真菌生长具有限制作用,但内生真菌能够通过自身分解代谢适应茅苍术挥发油.     

水分胁迫对茅苍术根茎生长及挥发油含量的影响

通过控制茅苍术[Atractylodes lancea（Thunb．）DC．]不同生长期的土壤含水量，研究了轻度和重度干旱胁迫与涝渍胁迫对茅苍术根茎生长及挥发油含量的影响。结果表明，在不同生长期，茅苍术根茎生长和挥发油成分含量对不同土壤水分条件的反应不同，其中生殖生长期对水分胁迫较敏感，干旱和涝渍胁迫均会导致根茎生长量和挥发油含量下降。水分胁迫对茅苍术根茎生长量和挥发油含量的影响效应是一致的，导致根茎生长量显著下降的水分条件可使挥发油含量下降，对根茎生长量影响不显著的水分条件则有利于挥发油成分的积累。在果后期进行适当的涝渍胁迫（土壤含水量35．5％～38．5％）有利于茅苍术根茎生长和挥发油含量的提高。     

不同产地苍术药材化学成分的比较

江苏、安徽及湖北５个产地苍术（Ａｔｒａｃｔｙｌｏｄｅｓｌａｎｃｅａ（Ｔｈｕｎｂ．）ＤＣ．）商品药材的化学分析结果表明：它们在某些药材性状、一些常规化学成分、挥发油成分和含量上存在显著差异。江苏茅苍术根茎挥发油的化学成分复杂,由此探讨了它作为地道药材的特殊性。同时对苍术的“断面暴露稍久可析出结晶”的性状和《药典》（１９９０年版）规定的“层析谱上应显有苍术素斑点”的鉴别实验进行讨论。     

不同种源野菊及菊花脑花的挥发油成分分析

用GC-MS法对来源于不同产地的野菊(Dendranthema indicum L.)及菊花脑(D. nankingene Hand.-Mazz.)花的挥发油成分进行分析及鉴定。结果显示,河北产野菊、江苏产野生和栽培野菊、湖北产野菊及江苏产菊花脑花的挥发油相对含量分别为0.731%、0.226%、0.199%、0.219%及0.171%;它们的主要成分分别为樟脑(12.62%)和龙脑(8.06%)、2-甲氧基-1,7,7-三甲基-二环[2.2.1]庚烷(27.82%)和樟脑(27.56%)、2,6,6-三甲基-二环[3.1.1]-3-庚烯-4-醇乙酸酯(40.58%)和乙酸桃金娘酯(20.07%)、2,7,7-三甲基-二环[3.1.1]-2-庚烯-6-酮(25.10%)和2-亚乙基-6-甲基-3,5-庚二烯醛(17.66%)、龙脑(26.90%)和乙酸龙脑酯(18.60%)。主成分分析及聚类分析结果表明,河北产野菊花的挥发油成分与其他产地野菊花的挥发油成分差异显著,且菊花脑的挥发油成分与不同产地的野菊间也存在一定的差异。     

茅苍术药材不同年限部位品质差异研究

茅苍术药材不同部位的物质积累特征及品质差异尚不清楚,本研究针对这一问题研究该药材不同部位的性状、含水量、可溶性糖、淀粉、挥发油含量及成分差异,为阐明该药材不同部位的品质差异及有效成分在药材中的分布和积累规律提供帮助。本研究以2年生茅苍术药材为研究材料,根据其生长部位分离出一年生和二年生药材,利用扫描电子显微镜和常规形态鉴定方法研究药材性状差异,并利用水蒸气蒸馏法测定挥发油含量、蒽酮比色法测定可溶性糖和淀粉含量、GC-MS法分析挥发油成分。结果显示,在性状上,一年生药材断面颜色偏白,二年生药材稍偏黄,且一年生药材较二年生药材松软。与二年生药材相比,一年生药材可溶性糖含量低30.26%,含水量、淀粉、挥发油含量则无显著差异,但二者挥发油成分有所不同。GC-MS共检测出22个成分,15个为二者共有成分。一年生药材中β-桉叶醇和香附烯含量较二年生药材高,而莪术烯、石竹烯等8个成分含量较二年生药材低。茅苍术药材不同部位的性状、初生和次生代谢产物积累均有所差异。     

三种丛枝菌根真菌对茅苍术的生长、生理及主要挥发油成分的影响

在温室条件下研究了3种丛枝菌根真菌(arbuscular mycorrhizal fungus,AMF):Glomus etunicatum BGC AM0048(A1)、Glomus tortuosum BGC AM0001(A2)和Glomus mosseae BGC AM0045(A3)对茅苍术组培苗的成活率、生长、生理特性及挥发油积累的影响。结果表明:接种AMF均提高了茅苍术组培苗的移栽成活率;苍术苗移栽35 d后,3个接种组的菌根侵染率由高至低依次为A3(63.39%)、A2(47.81%)和A1(42.41%);菌株对苍术苗的生长促进作用与侵染率规律一致,以A3对苍术苗的生长促进作用最明显,苍术苗的单株株高、单株根长、单株叶片数较对照组分别增加了21.9%、65.%和38.7%,各项检测指标与对照组的差异均达到显著水平;AMF处理组叶片中抗病相关酶系(PAL、PPO和β-1,3-葡聚糖酶)、抗氧化酶系(SOD、CAT和POD)的活性和叶绿素含量均有不同程度的提高,且接种AM真菌均促进了苍术苗挥发油中3种主要成分苍术醇、β-桉叶油醇和苍术素的积累。不同的AMF与植物之间具有偏好性,在人工栽培中,G.mosseae BGC AM0045菌株可作为茅苍术苗菌根化处理的优良菌株。     

茅苍术资源再生的研究

通过对茅苍术Ａｔｒａｃｔｙ　ｌｏｄｅｓｌａｎｃｅａ（Ｔｈｕｎｂ．）ＤＣ．有性繁殖及营养繁殖后代的研究,论述其资源再生的若干生物学特性的基本规律。结果表明,茅苍术在根茎形态、干物质量、化学成分的种类和含量上都随年龄有一定的动态变化规律,并存在个体差异。繁殖方式对干物质量的增长速率无明显影响。根茎中挥发油成分的含量随年龄的变化有一下降后再缓慢增加的趋势。同时还讨论了两种繁殖方式在茅苍术生产中的意义。     

三种内生真菌对茅苍术组培苗的生长及主要挥发油成分的影响

采用3种内生真菌与茅苍术组培苗共培养技术,研究了内生真菌对茅苍术组培苗生长及其主要挥发油成分的影响。结果表明：培养4周后,接内生真菌小菌核菌（AL3）的植株平均单株根数最多,比对照多92.7%（P<0.01）,并极显著地提高了平均单株根系干质量,比对照高62.9%（P<0.01）;而接种内生真菌小克银汉霉（AL4）和孔球孢霉（AL12）对茅苍术组培苗的生长影响不显著;AL3、AL4和AL12极显著提高了茅苍术叶片PAL酶活力,分别比对照提高了5.8、8.0和11.1倍（P<0.01）;AL3处理组的POD（过氧化物酶）、CAT（过氧化氢酶）和SOD（超氧化物歧化酶）3种酶活性与对照相似;而AL4处理组的3种酶活性分别比对照降低了9.1%、37.1%和9.7%,AL12处理组的3种酶活性分别比对照提高了10.4%、21.2%和9.6%;AL3、AL4和AL12都对茅苍术叶片总多酚含量有极显著影响,分别比对照提高了179.8%、86.2%和84.1%（P<0.01）;接3种内生真菌都改变了挥发油中4种主要活性成分苍术酮、苍术醇、β-桉叶醇及苍术素的相对百分含量。     

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).