鞭檐犁头尖中的苯丙素甙类化合物

从天南星科植物鞭檐犁头尖的根茎中分离得到3个化合物,运用波谱技术(UV,IR,^1HNMR,^13C NMR and 2D NMR)对它们的化学结构进行解析,分别鉴定为松柏甙(1),甲基松柏甙(2)和硝酸钾(3)。从鞭檐犁头尖中分离得到苯丙素甙类化合物尚属首次。     

南海海绵Dysidea sp.的化学成分研究

从我国南海陵水地区采集的一种未定种海绵Dysideasp中首次分离到7个化合物,经MS,NMR等光谱技术,确定了结构分别为胆固醇(1),过氧化麦角甾醇(2),cholesl-7-en-9a,11α-epoxy-3β,5α,6β,19-tetraol-6-monoacetate(3),甲基尿嘧啶(4),尿嘧啶(5),甲基尿嘧啶脱氧核糖核苷(6),尿嘧啶脱氧核糖核苷(7)。其中化合物3的^1H NMR和^13C NMR数据通过二维NMR实验首次得到了全归属。     

从中国红豆杉细胞培养物中分离鉴定紫杉醇

中国红豆杉(Taxus chinensis(Pilger．)Rehd)细胞在培养过程中合成了紫杉醇,我们利用固液分离、大孔吸附树脂吸附富集、有机溶剂萃取、硅胶柱层析、低压硅胶柱层析、重结晶等方法,从中国红豆杉的细胞培养物中分离纯化了紫杉醇,用多种核磁共振波谱方法(^1H NMR,^13C NMR,DEPT,^1H-^1H-COSY,NOESY,HMQC,HMBC)结合质谱(FABMS),红外光谱、紫外光谱等方法鉴定了它的化学结构,证明与源于天然红豆杉植物材料提取的紫杉醇为同一物质。     

田基黄(口山)酮成分的研究

采用萃取,硅胶及凝胶柱色谱等方法从田基黄全草中分离得到了7个San酮类化合物,利用UV、IR、^1H NMR、^13C NMR、MS等波谱技术将他们的结构分别鉴定为6-脱氧异巴西红厚壳素(1)、异巴西红厚壳素(2)、1,3,5,6-四羟基San酮(3)、1,3,6,7-四羟基San酮(4),1,3,5,6-四羟基-4-异戊烯San酮(5)、1,3,5-三羟基San酮(6)和bijaponicaxanthone(7),其中化合物3、4和6为首次从该植物中分得的San酮类化合物。     

假地枫皮中二萜酸类化合物研究

从八角属植物假地枫皮的石油醚提取物中分离出5个二萜酸类化合物,经波谱数据分析(^1H NMR、^13C NMR、^1H-^1H COSY、NOESY、HSQC和HMBC),分别鉴定为4-epi-dehydroabietic acid(1)、4-epi-sandaraeopinaric acid(2)、4-epi-abietic acid(3)、4-epi-isopimaric acid(4)和8,11,13,15-abietatetraen-19-oic acid(4)。     

台湾扁柏化学成分研究进展

从植物台湾扁柏（Chamaecyparis obtusa var．formosana）中提取分离得到一百多种化合物,这些化合物大多结构新颖、具有较强生理活性,主要有倍半萜类、双萜类、木酚素类、固醇类以及其它化合物。本文综述了从该植物中得到的各类化学成分的结构和^13C NMR谱图数据。     

珠芽蓼果实化学成分研究

利用硅胶柱层析分离和Sephadex LH20纯化等方法从珠芽蓼果实分离得到6个化合物,经^1H NMR、^13C NMR等技术及理化性质鉴定为β-谷甾醇、胡萝卜苷、没食子酸、正丁基—β—D吡喃果糖苷、槲皮素—5—O—β—D—葡萄糖苷、蔗糖。6种化合物均为首次从该植物分离得到。     

长毛风车子的化学成分研究

对采自海南三亚的长毛风车子(Combretum pilosum Roxb)的化学成分进行研究。应用硅胶、Sephadex LH-20等柱色谱技术进行分离纯化,并运用现代波谱技术(EI-MS,1H NMR,13C NMR)进行结构鉴定。从长毛风车子中分离得到了7个化合物,分别为木栓酮(1)、常春藤皂苷元(2)、植物醇(3)、香荚兰醛(4)、β-谷甾醇(5)、乌苏酸(6),羽扇豆醇(7)。以上化合物均为首次从该植物中分离得到。     

鸦胆子的化学成分

对苦木科鸦胆子属植物Brucea javanica（L）Merr的成熟果实鸦胆子提取物的化学成分进行分离鉴定。鸦胆子乙醇提取物经氯仿萃取,硅胶柱色谱分离,通过波谱（^1H NMR,^13C NMR）分析和化学方法鉴定其结构。从中药鸦胆子中分离得到6个苦木内酯类化合物即brusatol（1）、bmeeine D（2）、bruceine E（3）、bruceine F（4）、bmceine A（5）、bruceoside A（6）,另外还有β-谷甾醇（β-sitosterol,7）、胡萝卜苷（daueosterol,8）。     

黄花棘豆生物碱成分研究

采用硅胶柱层析、Sephadex LH-20和半制备HPLC等色谱手段对草原毒草黄花棘豆(Oxytropis ochrocephala Bunge)生物碱成分进行分离纯化,从全草提取物中分离得到8个生物碱成分。利用MS、1H NMR和13C NMR波谱技术鉴定化合物结构为槐定碱(1)、槐胺(2)、异槐定碱(3)、苦参碱(4)、7,11-去氢苦参碱(5)、槐果碱(6)、羽扇豆碱(7)和苦马豆素(8)。化合物1~6为首次从棘豆属植物中分离得到。     

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.