龙芽草化学成分研究

从药用植物龙芽草(Agrimonia pilosa Ledeb)全草的95%乙醇提取物中分离得到4个化合物,通过理化性质及波谱学方法分别鉴定为豆甾-5-烯-3β,7β-二醇(1)、豆甾-5-烯-3β7,α-二醇(2)、豆甾-3β6,α-二醇(3)和β-谷甾醇(4)。化合物1～3均为首次从龙芽草中分离得到。     

甘青青兰化学成分的研究

利用柱层析、薄层层析、重结晶等分离手段,对采自甘肃漳县的唇形科植物甘青青兰进行了化学成分的研究,从中分离得到10个化合物,经1H NM R、13C NM R等现代波谱技术鉴定它们分别为羽扇豆烷-20(29)-烯-28-酸-3-醇(1),羽扇豆烷-20(29)-烯-3,28-二醇(2),齐墩果烷-12-烯-28-酸-3-酮(3),乌苏烷-12-烯-28-酸-2,α3β-二醇(4),乌苏烷-12-烯-28-酸-3,β24醇(5),豆甾-3-酮(6),β-谷甾醇-3-O-葡萄糖基(6→1)-十六烷酸苷(7),β-谷甾醇(8),齐墩果酸(9),β-胡萝卜苷(10),其中化合物2~7为首次从该属植物中分离得到,而化合物1、8为首次从该植物中分离得到.     

绿玉树化学成分研究

采用正反相硅胶、Sephadex LH-20和HPLC等色谱手段对绿玉树Euphorbia tirucalli化学成分进行分离纯化,从绿玉树地上部分70%丙酮提取物中分离得到12个化合物。利用MS、1H NMR和13C NMR等现代波谱技术确定化合物结构为4α-去氧-巴豆醇-13-乙酸酯(1)、对映-3β,13S-二羟基-16-烯-14-阿替森酮(2)、羊毛甾醇(3)、3-表-粘霉烯醇(4)、齐墩果烷-9(11),12-二烯-3-酮(5)、β-香树烯酮(6)、齐墩果烷-18-烯-3-酮(7)、无羁萜(8)、4-豆甾烯-3-酮(9)、β-谷甾醇(10)、山奈酚-3-O-α-L-鼠李糖苷(11)和东莨菪内酯(12)。其中,化合物1、2、5~7、9和12为首次从该植物中分离得到。     

白头树化学成分研究

利用多种层析方法,从白头树(Garuga forrestii)树枝95%的乙醇提取物中分离得到10个化合物,通过理化性质和波谱分析,分别鉴定为13α,14β,17α-羊毛甾-7,24-二烯-1β,3β-二醇(1)、豆甾-5-烯-3β,7α-二醇(2)、豆甾-5-烯-3β,7β-二醇(3)、豆甾-3β,6α-二醇(4)、β-谷甾醇(5)、儿茶素(6)、(Z)阿魏酸二十四烷基酯(7)、(E)阿魏酸二十四烷基酯(8)、4-羟基-3-甲氧基苯甲酸(9)和1-甲氧基2,3苯并环戊烷(10).这些化合物均为该种植物首次报道.     

石山巴豆枝叶的化学成分研究

石山巴豆( Croton euryphyllus)为大戟科( Euphorbiaceae)巴豆属( Croton)植物,主要分布于西南各省的岩溶石山地区,民间用于杀虫和治疗跌打损伤。为了阐明其化学物质基础,该研究采用硅胶柱层析、Sephadex LH-20、HPLC等方法对石山巴豆枝叶醇提物进行分离纯化。结果表明：共分离得到16个化合物,分别鉴定为异毛叶巴豆萜(1), jatrophoidin (2),山藿香定(3),异山藿香素(4),山藿香素(5),赖百当-13-烯-8,15-二醇(6),7-酮基-β-谷甾醇(7),(22E)-5α,8β-表二氧麦角甾-6,22-二烯-3β-醇(8),豆甾烷-4-烯-6β-醇-3-酮(9),齐墩果烷-12-烯-2α,3β-二醇(10),东莨菪内酯(11),催吐萝芙木醇(12), lyratol F (13),罗布麻酚A (14),芹菜素(15),金色酰胺醇酯(16)。所有化合物均为首次从该植物中分离得到,其中化合物8－16为首次从巴豆属中发现。     

白木香内生真菌Botryosphae riarhodina A13固体发酵产物的分离鉴定

运用硅胶柱、反相硅胶柱、凝胶柱、HPLC和薄层制备等色谱技术及重结晶从白木香内生真菌Botryosphaeria rhodina A13的固体发酵产物中分离纯化了10个化学成分,通过化合物波谱数据及理化性质鉴定它们的结构分别为豆甾-4-烯-3-酮(1)、豆甾-5-烯-3β-醇-7-酮(2)、豆甾-4-烯-3,6-二酮(3)、(22E,24S)-5α,6α-环氧基-24-甲基胆甾-8(14),22-二烯-3β,7α-二醇(4)、5,4'-二羟-7-甲氧基黄酮(5)、香草酸(6)、对甲氧基苯甲酸(7)、尿嘧啶(8)、2-甲氧基对苯二酚(9)、2-甲基-3,5-羟基色酮(10)。其中化合物1~10均为首次从该属真菌中分离得到,化合物4具有细胞毒活性。     

红背山麻杆根中PTP1B抑制活性成分研究

运用硅胶和凝胶色谱等天然产物分离技术从红背山麻杆根中分离得到9个化合物,结合各化合物理化性质和光谱数据鉴定其结构,包括6个三萜类成分鲨烯(1)、乙酰基木油醇酸(2)、木栓酮(3)、3-乙酰氧基-12-齐墩果烯-28-酸甲酯(4)、马斯里酸(5)、马斯里酸甲酯(6)和3个甾醇成分β-谷甾醇(7)、β-谷甾醇-3-O-硬脂酸酯(8)、豆甾-4-烯-3,6-二酮(9)。化合物2、3和7为首次从该植物中分离得到,其余化合物均为首次从该属植物中分离得到。以体外酶学方法测定化合物PTP1B抑制活性,化合物2、5、6和8具有PTP1B抑制活性。     

大花美人蕉根的化学成分研究

为了解大花美人蕉(Canna generalis)的化学成分,从其根的乙醇提取物中分离得到8个化合物。通过波谱数据分析,分别鉴定为去氢催吐萝芙木醇(1)、3,4-二羟基苯甲酸乙酯(2)、咖啡酸乙酯(3)、豆甾-4,22-二烯-3,6-二酮(4)、豆甾-4-烯-3,6-二酮(5)、豆甾烷-3,6-二酮(6)、β-谷甾醇(7)和豆甾醇(8)。上述化合物均为首次从该植物中分离得到。     

元宝山冷杉化学成分的研究

采用色谱技术对元宝山冷杉的化学成分进行分离,根据波谱学方法确定化合物的结构。结果从元宝山冷杉中分离得到5个单体化合物,分别鉴定为:3α-甲氧基-9β-羊毛甾-7,24-二烯-26,23R-内酯(1)、β-谷甾醇(2)、6-甲基-3,7-二甲氧基山奈酚(3)、3-氧代-羊毛甾(9,11)-烯-24S,25-二醇(4)、豆甾-4-烯-6β-羟基-3-酮(5)。所有这些化合物均为首次从该植物中分离得到。     

纸莎草的化学成分研究

采用正相硅胶柱、Sephadex LH-20、高效液相色谱、MCI等色谱方法从纸莎草全株中分离得到19个化合物,采用1D、2D NMR、质谱等技术鉴定化合物的结构,分别鉴定为:α-香附酮(1)、香附酸(2)、广藿香烯酮(3)、4,5,6,7,8,8a-六氢-3,4,8,8-四甲基-1H-3a, 7-亚甲基甘菊环-4-醇甲酸酯(4)、(6S)4-烯-广藿香醇(5)、桉烷双烯萜(6)、β-谷甾醇(7)、(24R)-24-乙基胆甾烷-4-烯-3,6-二酮(8)、豆甾-4,22-二烯-3-酮(9)、(24R)-24-乙基-5α-胆甾烷-3β,5-二醇-6-酮(10)、豆甾醇(11)、豆甾-4-烯-6β-醇-3-酮(12)、豆甾-3,6-二酮(13)、豆甾-4-烯-3-酮(14)、顺,顺-9,12-十八(碳)二烯酸(15)、棕榈酸甲酯(16)、正二十八烷酸(17)、3-壬基环氧乙烷-2-甲酸甲酯(18)、9,10-二氯-十八烷酸甲酯(19)。所有化合物均为首次从纸莎草中分离得到。化合物1、2、3、5、6、10、12、13、16能够明显抑制TNF-α所诱导的质粒转染的HEK293T细胞中NF-κB信号通路的激活,IC_(50)值在34.96～98.23μM之间。     

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.