思茅藤的化学成分研究

从思茅藤(Epigynum auritum (schneid.)Tsiang et P.T.Li)的茎皮中分离到一个新的化合物,命名为思茅藤甙(Epigcoside)Ⅰ和已知化合物Ⅱ。通过光谱分析和化学反应证明,其结构为Ⅰ(+)—儿茶素-3-O-α-D-葡萄吡喃糖(1→6)-β-D葡萄吡喃糖甙((+)-catchin—3-O-α-D-glucopyranosyl-(1→6)-β—D-glucopyranoside;Ⅱβ-谷甾醇β-D-葡萄糖甙(β-sitosterol-β-D-glucoside)。     

水竹叶蜕皮激素水龙骨素B的分离鉴定

我们曾先后报道了从水竹叶(Murdannia triquetra(Wall)Brückn)中分离并鉴定了β-蜕皮激素(β-ecdysone)(化合物Ⅰ),α-去氧-β-蜕皮激素(α-deoxy-β-ecdysone)(化合物Ⅱ),揭示了水竹叶属植物中蜕皮激素的新存在。近来我们又从水竹叶中分离出一个微量成份(化合物Ⅲ)。由~(13)C 核磁共振和~1H 核磁共振、红外光谱、质谱和气相色谱等分析,表明化合物Ⅲ比β-蜕皮激素在甾体母核部分多一个以羟基形式存在的氧原子,该羟基应以β-构型连接在 C_5位上。从而说明化合物Ⅲ为5β-羟基-β-蜕皮激素     

水竹叶蜕皮激素研究再报

前报报道了水竹叶[Murdannia triquetra(wall.)Brückn]存在对昆虫具有生理活性的物质——蜕皮激素,其主要成分之一为β-蜕皮激素(化合物Ⅰ)。最近,我们从水竹叶中又分离鉴定了微量的脱羟-β-蜕皮激素(化合物Ⅱ),含量为0.004%(占全株干重)。     

美丽马醉木叶化学成分的研究

从美丽马醉木(Pieris formosa D.Don)叶中分离得到马醉木亭(Ⅰ)、β-谷甾醇(Ⅱ)、β-香树脂醇(Ⅲ),蒲公英醇(Ⅳ)4个已知化合物。     

狭叶香蒲花粉（蒲黄）中的亲脂性成分

从狭叶香蒲(Typha angustifolia L.)的干燥花粉中分离到5个化合物,经理化试验和波谱分析其中4个化合物的结构确定为7-甲基-4-三十烷酮(7-methyl-4-triacontanone,Ⅰ)、6-三十三烷醇(6-tritriacontanol,Ⅱ)、二十五烷(pentacosane,Ⅲ)和β-谷甾醇棕榈酸酯(β-sitosterol patmitate,Ⅳ),另外还分得一个化合物Ⅴ。Ⅳ是降低血清胆固醇的有效成分。Ⅰ、Ⅱ是新化合物。     

■岗通城虎化学成分的研究(Ⅱ)

<正> (山弄)岗通城虎Aristolochia longgangensis C.F.Liang.在前文我们曾报导从其根中分得结晶性单体(Ⅰ—Ⅺ),其中四个(Ⅰ、Ⅱ、Ⅲ、Ⅳ)经鉴定为尿囊素(Allantion)、马兜铃酸(Aristolochic acid)、马兜铃酸C(Aristolochic acid C)和马兜铃内酰胺-β-D-葡萄糖甙(Aristololactam-β-D-glucoside)。本文报导另外三个化合物(Ⅶ、Ⅴ、Ⅸ)的鉴定,它们分别为马兜铃内酰胺AⅡ(Aristololactam AⅡ),朱砂莲内酰胺     

万年蒿中两个新贝壳杉烷型二萜的分离与结构测定

自菊科蒿属植物万年蒿(Artemisia sacrorum Ledeb.)地上部分首次分得3个单体化合物(两个贝壳杉烷型二萜和一个酸性化合物),经理化常数测定及光谱分析(UV,IR,~1H-NMR,~(13)C-NMR,MS)鉴定其结构分别为3α,16α-二羟基贝壳杉烷-200-O-β-D-葡萄糖甙(Ⅰ)(3α,16α-dihydroxykaurane-20-O-β-D-glucoside(Ⅰ)),3α,6α-二羟基贝壳杉烷-19-O-β-D-葡萄糖甙(Ⅱ)(3α,16α-dihydroxykaurane-19-O-β-D-glucoside(Ⅱ))和1,4-二咖啡酰奎宁酸(Ⅲ)(1,4-dicaffeylquinic acid(Ⅲ))。(Ⅰ)和(Ⅱ)为两个未见报道的新化合物。     

枸骨叶的化学成分研究

采用溶剂提取和柱层析色谱分离,根据化合物理化性质和光谱数据鉴定其结构.结果从枸骨叶中分离得到9个化合物,分别为羽扇豆醇(1)、3,28-乌苏酸二醇(2)、熊果酸(3)、异鼠李黄素(4)、山奈酚-3-O-β-D-葡萄糖苷(5)、地榆苷Ⅰ(6)、槲皮苷-3-O-β-D-葡萄糖苷(7)、异鼠李素-3-O-β-D-葡萄糖苷(8)、冬青苷Ⅱ(9).化合物7和8为首次从冬青属植物中分离得到,化合物5为首次从该植物中分离得到,同时首次报道了化合物9的13CNMR数据.     

刺异叶花椒的化学成分研究

从芸香科花椒属植物刺异叶花椒(Zanthoxylum dimorphophyllum var. spinifolium)中分得五个已知的化合物,其中四个为生物碱:氧化勒(木党)碱(oxyavicine)(Ⅰ);铁屎米酮(canthin-6-one)(Ⅱ);乙氧基白屈菜红碱(ethoxychelerythrine)(Ⅲ);勒(木党)碱(avicine)(Ⅳ);另一化合物为β-谷甾醇(β-sitosterol)(Ⅴ)。     

槐果皮中的脂溶性成分

首次对槐（Sophora japonica)果皮进行了化学成分研究,从其石油醚部分分离得到了7个化合物,它们的结构经波谱和化学方法确定为：（Z）－1,1′－biindenyliden(Ⅰ),lupenone(Ⅰ),β-sitosterol(Ⅲ),p-ethoxybenzoic acid(Ⅳ),hexacosoic acid(Ⅴ),nonadecyl alcohol(Ⅵ)和eicosanol(Ⅶ),其中化合物Ⅰ为新天然产物,其它均为首次从该植物中分离得到。     

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.