长舟马先蒿化学成分研究

为了进一步研究玄参科长舟马先蒿的化学成分,我们从其全草的乙醇提取物中分离得到1个新环烯醚萜苷和12个已知化合物。根据波谱数据(1D,2D-NMR,HSQC,HMBC,ROESY,MS)分别鉴定为gardoside methylester(1)、7-O-acetylgardoside methyl ester(2)、verbascoside(3)、leucosceptoside A(4)、jionoside D(5)、martynoside(6)、2″-O-acetylmartynoside(7)、uridine(8)、adenosine(9)、benzyl alcohol-O-β-D-xylopyranosyl-(1→2)-β-D-gluco-pyranoside(10)、2-phenylethyl O-β-D-xylopyranosyl-(1→2)-β-D-glucopyranoside(11)、apigenin(12)、lariciresinol-4′-O-β-D-glucopyranoside(13),其中7-O-acetylgardoside methyl ester(2)为一个新化合物。     

短瓣花中的微量新环肽成分

从中国民间草药短瓣花（Brachystemma calycinum D.Don)干燥根的乙醇提取物中分离得到4个新的微量环八肽,命名为短瓣花环肽A、B、C和D。经光谱分析鉴定。它们的结构分别为cyclo(Pro^1-Phe-Leu-Ala^1-Thr-Pro^2-Ala^2-Gly)(1)、cyclo(Pro^1-Ala-Phe-Trp-Asp-Pro^2-Leu-Gly)(2)、cyclo(Pro^1-Ⅱe-Gly-Pro^2-Val-Ala^1-Ala^2-Tyr)(3)和cyclo(Pro-OMet-Trp-Ⅱe-Gly-Ala-Leu-Asp)(4)。     

绿槽枝衣的化学成分

从地衣绿槽枝衣( Sulcaria virens) 中分离得到一个新的亚油酸异丙叉衍生物, 通过波谱学方法包括2D-NMR 确定其化学结构为: 9, 10-O-异丙叉基- (12 Z)-十八碳烯酸(1) 。同时还得到其它12 个已知化合物:( 9 Z, 12 Z )-十八碳二烯酸(2), 扁枝衣二酸(3), ( R ) -松萝酸(4), 枕酸甲酯( 5), 黑茶渍素(6) , virensic acid ( 7), abieslactone (8), 3α-羟基羊毛甾-7, 24-二烯-26, 23 R-内酯(9), 蒲公英赛醇(10 ), 蒲公英赛酮 ( 11 ), (22 E , 24 R )-5α, 8α-过氧麦角甾-6, 22-二烯-3β-醇(12) 和2, 2′-四氢角鲨烯(13)。     

Two New Triterpenes from the Orchid Pholidota yunnanensis Rolfe

Two novel triterpenes (1 and 2) were isolated from the orchid Pholidota yunnanensis Rolfe.Using chemical and spectral analyses (UV, IR, MS, 1D-NMR and 2D-NMR), these two triterpenes were established as 25-methylenecyclopholidonyl p-hydroxy-trans-cinnamate (1; named pholidotine A) and 25methylenecyclopholidonyl p-hydroxy-cis-cinnamate (2; named pholidotine B).     

Sceletium tortuosum的化学成分研究

为研究南非传统药用植物Sceletium tortuosum的化学成分,采用溶剂法对其地上部分进行提取和萃取,通过多种柱色谱、重结晶及高效液相色谱等方法进行系统地纯化分离,利用理化性质并结合现代分析方法鉴定化合物结构。从S.tortuosum乙酸乙酯部位中分离得到11个化合物,鉴定为3′,4′-dimethoxy[1,1′-biphenyl]-4-ol(1)、N-(4-hydroxyphenethyl)isobutyramide(2)、4-乙酰苯酚(3)、吲哚-3-甲醛(4)、7-酮-豆甾醇(5)、7-酮基-β-谷甾醇(6)、loliolide(7)、3,5,6-trihydroxy-7-megastigmen-9-one(8)、去甲基丁香色原酮(9)、cyclo(L-Pro-L-Ala)(10)、N-trans-feruloyl-3-methyldopamine(11)。化合物1～11均为首次从该属植物中分离得到,其中化合物1和2为新天然产物。     

仙茅苷丙--仙茅根茎的新酚苷成分

从仙茅(Curculigo orchioides Gaertn.)根茎中分离得到4个化合物,分别为curculigoside(1)、curculigoside B(2)、curculigoside C(3)和2,6-dimethoxyl benzoic acid(4).其中,化合物3为一个新的酚苷类成分,命名为仙毛苷丙,用现代波谱方法(1H-NMR、13C-NMR、2D-NMR和ESI-MS)鉴定其化学结构为5-羟基-2-O-β-D-吡喃葡萄糖基苄基-3′-羟基-2′,6′-二甲氧基苯甲酸酯.     

泽漆的化学成分研究

采用多种分离材料包括硅胶、Sephadex LH-20和反相RP-18从泽漆的95%乙醇提取物的正丁醇部位分离得到12个化合物,经过波谱学方法分别鉴定为Helioscopin D(1),Isofraxidin(2),Swertiamarin(3),13-Car-boxyblumenol C(4),4,4′-dimethoxy-3′-hydroxy-7,9′,7′9-diepoxyligan-3-O-β-D-glucopyranoside(5),(+)-Syringa-resinol-4′-O-β-D-glucoside(6),2S,3R-2,3-Dihydro-2-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-7-methoxy-benzofuran-5-(trans)propen-1-ol-3-O-β-glucoside(7),Quinquenin L1(8),(6R,9S)-megastigman-3-one-4,7-ene-9-ol-9-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside(9),2R,3R-2,3-Dihydro-2-(4′-hydroxy-3′-methoxyphenyl)-3-(glucosyloxymethyl)-7-methoxy-benzofuran-5-propanol(dihydrodehydrodiconiferyl-alcohol-β-D-glucoside)(10),Thy-midine(11),和Deoxyuridine(12)。其中化合物1为一个降倍半萜类新化合物,其余化合物从该种中首次分离。     

墨西哥落羽杉的化学成分

从墨西哥落羽杉(Taxodium mucronatum)枝叶中首次分离得到10个化合物,通过MS与NMR等方法将它们分别鉴定为quercetin 3′-methoxy-3-O-β-D-galactopyranoside(1),quercetin 3′-methoxy-3-O-β-D-arabinopyrano-side(2),quercetin 3′-methoxy-3-O-α-L-arabinofuranoside(3),quercetin(4),avicularin(5),quercetin 3-O-β-D-ga-lactopyranoside(6),(7′S,8′R)-4,7′-epoxy-3,3′-dimethoxy-4,9,3′,4′,9′-lignanepentol-4′-O-β-D-glucopyranoside(7),(7′S,8′S)-3,3′-dimethoxy-9,4′,9′-trihydroxy-4,8′-oxyneolignan-7′-O-β-D-glucopyranside(8),methyl shikimate(9)和β-sitosterol(10)。     

红树植物内生真菌Penicillium sp.中两个甾体化合物的研究

从红树植物内生真菌Penicillium sp.的发酵液中分离纯化了两个甾体类化合物,通过各种波谱实验(1D-NMR,2D-NMR,ESI-MS)确定为:麦角甾-4,6,8(14),22-四烯-3-酮(1)和麦角甾-5,7,22-三烯-3-醇(2),1对于3α-HSD脱氢酶在250μm浓度下有较弱的活性。     

类芒齿黄芪地下部分化学成分研究

为了解类芒齿黄芪( Astragalus camptodontoides)主要化学成分,从其地下部分甲醇提取物的乙酸乙酯部位分离出19个单体化合物,通过现代波谱分析及理化性质等手段分别鉴定为异补骨脂黄酮(1),4′-hydroxy-isolonchocarpin (2),5-去氧山豆根黄酮(3),shinflavanone (4),khonklonginols H (5),4′-O-methylpreglabridin (6),3′-hydroxy-4′-O-methylglabridin (7),4′-O-methylglabridin (8),8-prenyl-phaseollinisoflavan (9),xambioona (10),光甘草酚(11),粗毛甘草素H (12),methylnissolin (13),邻苯二甲酸异丁酯(14),邻苯二甲酸丁酯异丁酯(15),β-谷甾醇(16),胡萝卜苷(17),齐墩果酸(18),(2S,3S,4R,9E)-1,3,4-trihydroxy-2-[(2′R)-2′- hydr-oxytetraco-sanoylamino]-9-octadecene (19)。化合物1~19均为首次从该植物中获得,化合物1~7为首次从黄芪属(Astraga-lus)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.