蜘蛛抱蛋根茎中的甾体皂甙

从蜘蛛抱蛋（ＡｓｐｉｄｉｓｔｒａｅｌａｔｉｏｒＢｌ．）根茎的甲醇提取物中分离得两个甾体皂甙。经波谱解析及化学降解证明其化学结构分别为薯芋皂甙元一３一Ｏ－［Ｂ－Ｄ－葡萄吡喃糖基（１→２）］－［Ｂ－Ｄ－木吡喃糖基（１→３）］－Ｂ－Ｄ－葡萄吡喃糖基（１→４）－Ｂ－Ｄ一半乳吡喃糖甙（即蜘蛛抱蛋甙ａｓｐｉｄｉｓｔｒｉｎ）及新静诺特皂甙元－３－Ｏ－［Ｂ－Ｄ－葡萄吡喃糖基（１→２）］～［Ｂ－Ｄ－木吡喃糖基（１→３）－Ｂ－Ｄ－葡萄吡喃糖基（１→４）一Ｂ－Ｄ－半乳吡喃糖甙,后者为一新试,命名为新蜘蛛抱蛋甙ｒｅｏａｓｐｉｄｉｓｔｒｉｎ。     

单条草的皂甙成分

从单条草（ＬｙｓｉｍａｃｈｉａｃａｎｄｉｄａＬｉｎｄｌ）全草中分离出３个皂甙类化合物,经波谱分析并结合化学方法鉴定为：报春花素Ａ３ＯβＤ吡喃木糖基（１→２）βＤ吡喃葡萄糖基（１→４）［βＤ吡喃葡萄糖基（１→２）］αＬ吡喃阿拉伯糖甙（１）、原报春花素Ａ３ＯβＤ吡喃木糖基（１→２）βＤ吡喃葡萄糖基（１→４）［βＤ吡喃葡萄糖基（１→２）］αＬ吡喃阿拉伯糖甙（ｌｙｓｉｋｏｉａｎｏｓｉｄｅ,２）和α菠甾醇葡萄糖甙（３）。其中１是新化合物,命名为单条草甙（ｃａｎｄｉｄｏｓｉｄｅ）。     

柴胡皂甙s的结构鉴定

从南柴胡（ＢｕｐｌｅｕｒｕｍｓｃｏｒｚｏｎｅｒｉｆｏｌｉｕｍＷｉｌｄ．）根中分得５个三萜皂甙。根据理化性质和波谱数据,鉴定其中新皂甙为３β,１６α,２３,２８四羟基齐墩果烷１１,１３（１８）二烯３ＯβＤ吡喃葡萄糖基（１→６）［αＬ吡喃鼠李糖基（１→４）］βＤ吡喃葡萄糖甙,命名为柴胡皂甙ｓ（ｓａｉｋｏｓａｐｏｎｉｎｓ）。另４个皂甙分别为柴胡皂甙ａ、ｃ、ｂ１、ｂ２。     

蜘蛛抱蛋属中甾体皂甙的分布

在文献资料和实验研究的基础上,本文总结了甾体皂甙在蜘蛛抱蛋属植物中的分布。发现单羟基的薯蓣皂甙元的配糖体一蜘蛛抱蛋皂甙(薯蓣皂甙元-3-O[β-D-葡萄吡喃糖基(1→2)]-[β-D-木吡喃糖基(1→3)]-β-D-葡萄吡哺糖基(1→4)-β-D-半乳吡哺糖甙),广泛存在于所研究过的这些植物中,而且是大部植物根茎的主要皂甙。它是蜘蛛抱蛋属植物的特征化学成分,表明该属是一个自然类群,甾体皂甙对它是有分类学意义的。     

滇重楼地上部分的两个微量皂甙

从滇重楼地上部分中分离出两个新的微量的甾体皂甙ＰｏｌｙｐｈｙｌｌｏｓｉｄｅⅢ和Ⅳ,根据化学降解和光谱分析,它们的化学结构分别为２７－羟基－偏诺皂皂甙元－３－Ｏ［ａ－Ｌ－鼠李吡喃糖基（１→２）］［ａ－Ｌ－鼠李吡喃糖基（１→４－ａ－Ｌ鼠李吡喃糖基（１→４）］－β－Ｄ－葡萄吡喃糖甙,２３β,２７－二羟基－偏皂甙元－３－Ｏ－［ａ－鼠李吡喃糖（１→２）］     

滇重楼地上部分的配糖体

从滇重楼ＰａｒｉｓｐｏｌｙｐｈｙｌｌａＳｍ．ｖａｒ．ｙｕｎｎａｎｅｎｓｉｓ（Ｆｒ．）Ｈ－Ｍ,地上部分,分离出４个微量的配糖体,经光谱分析和化学降解证明其化学结构分别为２５Ｓ－异钮替皂甙元－３－Ｏ－α－Ｌ－鼠李吡喃糖基（１→２）［α－Ｌ－鼠李吡喃糖基（１→４）］－β－Ｄ－葡萄吡喃甙（Ａ）,２６－β－Ｄ－葡萄吡喃糖基－纽替皂甙元－３－Ｏ－α－Ｌ－鼠李吡喃糖基（１→２）［α－Ｌ－鼠李吡喃糖基（１→４）－β－Ｄ－葡萄吡喃糖甙（Ｂ）,山奈酚－３－Ｏ－β－Ｄ－葡萄吡喃糖基（１→６）－β－Ｄ－葡萄吡喃甙（Ｃ）,７－Ｏ－α－Ｌ－鼠李吡喃糖基－山奈酚－３－Ｏ－β－Ｄ－葡萄吡喃糖基（１→６）－β－Ｄ－葡萄糖甙（Ｄ）。     

盾叶薯蓣地上部分的三个新甾体皂甙

从盾叶薯蓣Dioscorea zingiberensis Wright地上部分分离鉴定了四个甾体皂甙,经鉴定甙A为约莫皂甙元-3-O-[α-L-鼠李吡喃糖基(1→2)]-β-D-葡萄吡喃糖甙;甙B为24α-羟基约莫皂甙元-3-O-[α-L-鼠李吡喃糖基(1→2)]β-D-葡萄吡喃糖甙;甙C为约莫皂甙元-3-O-[α-L-鼠李吡喃糖基(1→2)][β-D-葡萄吡喃糖基(1→4)]-β-D-葡萄吡喃糖基;甙D为约莫皂甙元-3-O-[α-L-鼠李吡喃糖基(1→2)][β-D-葡萄吡喃糖基(1→3)]-β-D-葡萄吡喃糖甙。前三者为新化合物,分别命名为盾叶皂甙A_1、A_2、A_3(zingiberoside A_1、A_2、A_3),其中盾叶皂甙A_2的甙元为一新甾体皂甙元,命名为盾叶皂甙元(zingiberogenin)。     

滇产植物皂素成分的研究——Ⅹ.五指莲的两个新甾体皂甙(1)

从重楼属植物五指莲Paris axialis H.Li.根茎中分离到三个甾体皂甙,经化学降解,质谱,核磁共振谱分析,证明其中两个甙为新的化合物,即偏诺皂甙元-3-O-β-D-葡萄吡喃糖基(1→3)[α-L-鼠李吡喃糖基(1→2)]-β-D-葡萄吡喃糖甙(Ⅰ)和24α-羟基偏诺皂甙元-3-O-β-D-葡萄吡喃糖基(1→3)][α-L-鼠李吡喃糖基(1→2)]-β-D-葡萄吡喃糖(Ⅲ);另一个鉴定为薯芋皂甙元-3-O-β-D-葡萄吡喃糖基(1→3)[α-L-鼠李吡喃糖基(1→2)]-β-D-葡萄吡喃糖甙(Ⅱ)。     

四川蜘蛛抱蛋的甾体皂甙

从四川蜘蛛抱蛋（Ａｓｐｉｄｉｓｔｒａ ｓｉｃｈｕａｎｅｎｓｉｓ Ｋ。Ｙ。Ｌａｎｇ ｅｔ Ｚ。Ｙ。Ｚｈｕ）根状茎中分离得到三个甾体皂甙,经光谱和化学方法分别鉴定为２２－甲氧基－５β－呋喃甾烷－１β,３β,４β,５β,２６－五羟基２６－Ｏ－β－Ｄ吡喃葡萄糖甙（１）,蜘蛛抱蛋皂甙（２）和原蜘蛛抱蛋皂甙（３）。（１）是一个呋喃甾醇型单糖链的新皂甙,（３）是本植物的主要皂甙。     

闭鞘姜根中的甾体皂甙

从闭鞘姜「Ｃｏｓｔｕｓ ｓｐｅｃｉｏｓｕｓ（Ｋｏｅｎｉｇ）Ｓｍｉｔｈ」根茎中分离出五个化合物。经波谱解析和化学降解,证明其化学结构分别为胡萝卜甙（Ａ）：薯芋皂甙元３－Ｏ－ａ－Ｌ鼠李吡喃糖基（１－２）－β－Ｄ－葡萄吡喃糖甙（Ｂ）;薯芋皂甙元３－Ｏ－ａ－Ｌ－鼠李吡喃糖基（１－２）「ａ－Ｌ－鼠李吡喃糖基（１－４）」β－Ｄ葡萄吡喃糖甙（Ｃ）;薯芋皂甙元－３－Ｏ－ａ－Ｌ－鼠李吡喃糖基（１－２）「β－Ｄ－葡萄     

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.