零陵香挥发油成分研究

本文报告自报春花科排草属植物零陵香(Lysimachia foenumgraecum Hance)的全草提取出挥发油,收率0.17%,呈黄绿色,具浓厚芳香。用气相色谱-质谱-计算机联用仪(Finnigan4021型)进行了挥发油成分分析,结果在零陵香挥发油中共鉴定出59个成分;其中酸性成分20个,以十六酸(hexadecanoic acid)、十七酸(heptanoic acid)等含量较多;中性和酚性成分39个,以六氢金合欢烯酰丙酮(hexahydrofarnesylacetone)等的含量较多,它在植物中是较罕见的成分,并且是首次在零陵香植物中发现。本文还用气相色谱仪(Perkin-Elmer Sigma 2B 型)和标准品对零陵香挥发油中成分进行了对照鉴定。     

鄂西香茶菜中挥发油成分分析

采用水蒸汽蒸馏法分别从鄂西香茶菜的叶、花和果实中提取挥发油,并用气相色谱-质谱联用技术（GC-MS）对其挥发油中的化学成分进行分离和结构鉴定,运用气相色谱峰面积归一化法确定各成分的相对百分含量。从鄂西香茶菜的3种挥发油中共鉴定出39种成分,分别从叶、花及果实中鉴定出18、19和23种成分,其中只有6种成分在这3个部位都被鉴出,3种不同部位得到的挥发油成分差异较大。它们的挥发油中主要成分为单萜、倍半萜和二萜类化合物。     

小黄皮叶挥发油的化学成分

利用水蒸气蒸馏法提取小黄皮叶挥发油,运用毛细管气相色谱-质谱联用法对挥发油进行了分析,分离出40个峰,鉴定了其中的37种成分,所鉴定成分占挥发油总量的99.87%,其主要化学成分为单萜及倍半萜类化合物。     

连翘挥发油成分分析

从连翘果实中提取了挥发油,用气相色谱-质谱联用法分析其挥发油的化学成分,鉴定出β-蒎烯、香桧烯、α-蒎烯等56个化合物,并用气相色谱测定了挥发油中各成分的相对含量,其鉴定率达93.37％。     

圆瓣姜花根茎挥发油的化学成分

利用水蒸汽蒸馏法提取圆瓣姜花根茎挥发油,运用毛细管气相色谱-质谱联用法对挥发油进行了分析,分离出60个峰,鉴定了其中的51种成分,所鉴定成分占挥发油总量的97.32%,其主要化学成分为单萜及倍半萜类化合物。     

臭茉莉叶挥发油化学成分的研究

利用GC-MS联用技术研究了臭茉莉叶挥发油的化学成分,应用色谱峰面积归一化法计算各成分的相对百分含量.分离出49个峰,鉴定了其中的34种成分,所鉴定的组分占挥发油总量的95.17 %.     

缬草挥发油化学成分的研究

采用气相色谱-质谱联用仪对产于太白县的缬草根和茎叶中的挥发油成分分别进行分析,从根中鉴定出45种成分,以茎叶中鉴定出67种成分,并用GC测定了每一成分在该挥发油中的含量。     

中药郁金挥发油成分及挥发油中蜡质成分研究

对中药郁金挥发油成分进行ＧＣ－ＭＳ－ＤＳ分析,共分离得到１３７个气相色谱峰,鉴定出７３种成分,其中３６种为首次鉴定出。首次,作者对其挥发油中蜡质成分进行分离,经ＧＣ－ＭＳ－ＤＳ分析得其主要成分为长直链烷烃和长直链脂肪酸。     

石油菜挥发油和超临界流体萃取物化学成分的GC-MS分析

首次利用水蒸气蒸馏法和超临界流体萃取法(SFE)对石油菜地上部位进行提取,分别获得挥发油和SFE萃取物,采用气相色谱-质谱联用技术(GC-MS)结合计算机数据库检索对这两种提取物的化学成分进行了分析鉴定,采用峰面积归一化法测定了其中各个化学成分的相对含量。从挥发油中共分离出39个色谱峰,鉴定了其中28个化学成分,已鉴定出的成分的相对含量总和占化合物检出总量的91.90%,化合物类型均为萜类。从SFE萃取物中共分离出136个色谱峰,鉴定了其中65个化学成分,已鉴定出的成分的相对含量总和占化合物检出总量的58.17%,化合物类型包括萜类、芳香族类和脂肪族类。挥发油和SFE萃取物均含有α-蒎烯、石竹烯和桉油烯醇,其他成分则存在较大差异。     

三白草不同部位及鱼腥草挥发油成分的GC-MS比较分析

采用水蒸气蒸馏法提取,气相色谱-质谱联用技术(GC-MS)对三白草不同部位及鱼腥草挥发油化学成分进行定性和定量分析。共分离鉴定出88个化合物,从三白草地上部分鉴定出36个,根茎中鉴定出31个,分别占挥发油总量的73.38%和95.53%,其中仅13个共有成分;从鱼腥草中鉴定出50个化合物,占挥发油总量的74.59%。三白草地上部分与根茎挥发油中化学成分含量和组成有明显差异,且均不含有甲基正壬酮。     

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.