Selaginellin A and B, two novel natural pigments isolated from Selaginella tamariscina

Two new unusual natural pigments were first isolated from the whole herbs of Selaginella tamariscina. The structure of selaginellin A (1) was established as (R,S)-4-[(4'-hydroxy-3-((4-hydroxyphenyl)ethynyl)biphenyl-2-yl)(4-hydroxyphenyl)methylene]-2,5-cyclohexadien-1-one and selaginellin B (2) as (R,S)-4-[(4'-methoxy-4-(methyl)-3-((4-methoxyphenyl)ethynyl)biphenyl-2-yl)(4-methoxyphenyl)methylene]-2,5-cyclohexadien-1-one, along with four known biflavonoids, amentoflavone (3), hinokiflavone (4), heveaflavone (5), and 7'-O-methylamentoflavone (6). Their chemical structures were elucidated by spectral analysis of electrospray ionization mass spectroscopy (ESI-MS), one-dimensional nuclear magnetic resonance spectroscopy (1D-NMR) and two-dimensional-nuclear magnetic resonance spectroscopy (2D-NMR) including (1)H-NMR, (13)C-NMR, distortionless enhancement by polarization transfer (DEPT) and heteronuclear multiple bond coherence (HMBC), and single-crystal X-ray diffraction techniques.     

A new dihydrobenzofuran lignanoside from Selaginella moellendorffii Hieron

A new lignanoside, （7R,8S）-7,8-dihydro-7-（4-hydroxy-3,5-dimethoxyphenyl）-1＇-formyl-3＇-y-methoxyl-8-hydroxymethylbenzo- furan-4-O-β-D-glucopyranoside （moellenoside A）, was isolated from Selaginella moellendorffii Hieron. Its structure was determined by spectroscopic evidences. 2007 Wei Sheng Feng. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.     

Neolignans and Caffeoyl Derivatives from Selaginella moellendorffii

Ten new phenolic compounds including the six neolignans 1 – 3 and 6 – 8 and four caffeoyl derivatives, i.e., myo‐inositol 1‐caffeate ( 9 ), myo‐inositol 6‐caffeate ( 10 ), myo‐inositol 5‐caffeate ( 11 ), and paucine 3′‐β‐D ‐glucopyranoside ( 12 ) were isolated from the whole plants of Selaginella moellendorffii (caffeic acid=3‐(3,4‐dihydroxyphenyl)prop‐2‐enoic acid). Their structures were established by spectroscopic and chemical methods.     

A new flavone glycoside from Selaginella moellendorffii Hieron.

From the ethanol extract of Selaginella moellendorffii Hieron., a new flavone O-glycoside and three known flavone C-glycosides have been isolated and identified as 5-carboxymethyl-4'-hydroxyflavone-7-O-β-D-glucopyranoside 1, 6,8-di-C-β-D-glucopyrano-sylapigenin 2, 6-C-β-D-glucopyranosyl-8-C-β-D-xylopyranosyl apigenin 3, 6-C-β-D-xylopyranosyl-8-C-β-D-glucopyranosylapi-genin 4, respectively. Their structures were elucidated by spectroscopic methods.     

Expression of Human Hepatitis B Virus Surface Antigen Gene in Transgenic Tobacco

Expression of Human hepatitis B virus surface antigen (HBsAg) gene in plant was reported for the first time. The recombinant plasmid pRoKⅡ-HBsAg was constructed by inserting HBsAg gene into the downstream of CaMV 35S promoter of binary vector pRoKⅡ and then introduced into Agrobacterium tumefaciens LBA4404. The kanamycin-resistant plants were obtained by Agrobacterium-mediated transformation system. It was shown that HBsAg gene was expressed in transgenic tobacco plants and their progenies by ELISA. The spherical particles of ψ 22 nm in the leaf extract of trangenic tobacco were observed by immunosorbent electron microscopy.     

Modulation of Fatty Acid Synthase Enzyme Activity and Expression during Hepatitis C Virus Replication

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Highlights? Enzymatic activity of FASN was investigated by ABPP methods during HCV replication ? During HCV replication the activity and expression of FASN increases ? Cellular triglyceride levels rise with increased FASN enzyme activity in Huh7 cells ? Active FASN does not colocalize with HCV replication complexes during HCV replication     

Cordycepin Inhibits Virus Replication in Dengue Virus-Infected Vero Cells

Dengue virus (DENV) infection causes mild to severe illness in humans that can lead to fatality in severe cases. Currently, no specific drug is available for the treatment of DENV infection. Thus, the development of an anti-DENV drug is urgently required. Cordycepin (3′-deoxyadenosine), which is a major bioactive compound in Cordyceps (ascomycete) fungus that has been used for centuries in Chinese traditional medicine, was reported to exhibit antiviral activity. However, the anti-DENV activity of cordycepin is unknown. We hypothesized that cordycepin exerts anti-DENV activity and that, as an adenosine derivative, it inhibits DENV replication. To test this hypothesis, we investigated the anti-DENV activity of cordycepin in DENV-infected Vero cells. Cordycepin treatment significantly decreased DENV protein at a half-maximal effective concentration (EC50) of 26.94 μM. Moreover, DENV RNA was dramatically decreased in cordycepin-treated Vero cells, indicating its effectiveness in inhibiting viral RNA replication. Via in silico molecular docking, the binding of cordycepin to DENV non-structural protein 5 (NS5), which is an important enzyme for RNA synthesis, at both the methyltransferase (MTase) and RNA-dependent RNA polymerase (RdRp) domains, was predicted. The results of this study demonstrate that cordycepin is able to inhibit DENV replication, which portends its potential as an anti-dengue therapy.     

A New Biflavone from Selaginella pulvinata Maxim

Selaginella pulvinata Maxim. distributes all over the country of China and is used for the treatment for haemor rhage. [1] We studied on the chemical constituents of S. pulvinata in order to find the active compounds. Dried stems and leaves of S. pulvinata (6.5 kg) were extracted with 70% ethanol twice. The extract was evaporated under vacuum and than suspended in water, extracted with petroleum and EtOAc sequentially. The EtOAc extract was chromatographed on silica gel, eluted with CHCl3-MeOH. As a result, a novel biflavone, named pulvinatabiflavone, was obtained from fractions 75 ～ 78. Its structure was determined on the basis of spectroscopic analysis as 5,5″, 4′″ trihydroxy-7,7″-dimethoxy-[4′-O-6″]-biflavone (compound 1).     

Doxycycline Interferes with Zika Virus Serine Protease and Inhibits Virus Replication in Human Skin Fibroblasts

Zika virus (ZIKV) represents a re-emerging threat to global health due to its association with congenital birth defects. ZIKV NS2B-NS3 protease is crucial for virus replication by cleaving viral polyprotein at various junctions to release viral proteins and cause cytotoxic effects in ZIKV-infected cells. This study characterized the inhibitory effects of doxycycline against ZIKV NS2B-NS3 protease and viral replication in human skin cells. The in silico data showed that doxycycline binds to the active site of ZIKV protease at a low docking energy (−7.8 Kcal/mol) via four hydrogen bonds with the protease residues TYR1130, SER1135, GLY1151, and ASP83. Doxycycline efficiently inhibited viral NS2B-NS3 protease at average human temperature (37 °C) and human temperature with a high fever during virus infection (40 °C). Interestingly, doxycycline showed a higher inhibitory effect at 40 °C (IC50 = 5.3 µM) compared to 37 °C (9.9 µM). The virus replication was considerably reduced by increasing the concentration of doxycycline. An approximately 50% reduction in virus replication was observed at 20 µM of doxycycline. Treatment with 20 µM of doxycycline reduced the cytopathic effects (CPE), and the 40 µM of doxycycline almost eliminated the CPE of human skin cells. This study showed that doxycycline binds to the ZIKV protease and inhibits its catalytic activity at a low micro-molecular concentration range. Treatment of human skin fibroblast with doxycycline eliminated ZIKV infection and protected the cells against the cytopathic effects of the infection.     

Expression of Hepatitis B Surface Antigen Gene in Ginseng Cells

The recombinant plasmid pBIBSa containing the HBsAg DNA fragment was transferred into Agrobacte-rium tumefaciens strain LBA4404 directly. Ginseng cells were transfected with A. tumefaciens carrying pBIBSa and the ginseng cell lines carrying HBsAg-S gene were obtained. The presence of target gene in the transfect cells was confirmed by PCR and RT-PCR. A clear band at the site of 700 bp was observed by agarose electrophoresis analysis of the samples containing the target gene. HBsAg expressed by the transgeni...     

New cytotoxic apigenin derivatives from Selaginella doederleinii

75%aqueous ethanol extract from the whole herbs of Selaginella doederleinii was isolated,and two new apigenin derivatives,doederflavones A(1) and B(2),together with ten known compounds(3-12) were characterized.Their structures were assigned by extensive spectroscopic methods including 1D/2D NMR and HR-ESIMS.Compounds 1-6 bear an aryl substituent at the C-8 or C-6 positions in ring A of apigenin skeleton.Compounds 1 and 2 were evaluated for their in vitro cytotoxicity against four human cancer cell lines A549,MCF-7,SMMC-7721,and LoVo,both of which exhibited significant cytotoxicity against A549 with IC_(50) values of 0.82 μmol/L and 1.32 μmol/L,respectively.     

Uncinoside A and B, two new antiviral chromone glycosides from Selaginella uncinata

Five compounds have been isolated from the dried whole plants of Selaginella uncinata, two of them were new chromone glycosides, 5-hydroxy-2,6,8-trimethylchromone 7-O-beta-D-glucopyranoside (uncinoside A) and 5-acetoxyl-2,6,8-trimethylchromone 7-O-beta-D-glucopyranoside (uncinoside B). Their structures were elucidated by spectroscopic methods including one- and two-dimensional NMR techniques. The other three compounds were identified as 8-methyl eugenitol, amentoflavone and hinokiflavone. Uncinoside A and B showed potent antiviral activities against respiratory syncytial virus (RSV) with IC(50) value of 6.9 and 1.3 microg/ml, moderate antiviral activities against parainfluenza type 3 virus (PIV 3) with IC(50) value of 13.8 and 20.8 microg/ml, respectively.     

国内外酶免疫试剂检测乙肝病毒标志物的比较

报道了国产与美国Ａｂｂｏｔｔ公司生产的ＨＢＶＥＬＩＳＡ诊断试剂盒,对３０例来自昆明医学院传染科门诊及住院部标本同时进行ＨＢｓＡｇ、抗－ＨＢｓ、ＨＢｅＡｇ、抗－ＨＢｅ及抗－ＨＢｃＩｇＭ检测,对两试剂阳性符合率进行了比较研究,并采用滴定ＨＢｓＡｇ及抗－ＨＢｓ阳性血清的方法,表明两试剂敏感性极为相似,而国产试剂对抗－ＨＢｃＩｇＭ阳性检出率大大提高于Ａｂｂｏｔｔ试剂。     

Isolation and Purification of Recombinant HBsAg of Human Hepatitis B Virus from Silkworm Larvae

Recombinant HBsAg coded by preS1-preS2-S regions of hepatitis B virus was expressed in Bombyx mori silkworm larvae. Recombinant HBsAg was expressed (30–40 μg/mL, 0.1% of the total amount of extracted protein) by larvae infected with recombinant baculovirus rBmNPV-Hep-preS1-S containing cDNA of HBsAg strictly by the polyhedrin gene promoter. Recombinant HBsAg consisting of a polypeptide of molecular weight ∼36 kDa (p36) was purified by gel filtration and affinity chromatography to 92% purity. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 477–480, September–October, 2005.     

A Fluorescence Assay Based on GoldMag-CS Nanoparticles for Hepatitis B Virus DNA

A sensitive fluorescence assay for hepatitis B virus (HBV) DNA was developed based on the dissociation of bio-bar-code DNA probes from GoldMag-CS nanoparticles (NPs) and magnetic separation. In this method, the target sequence (HBV DNA) was recognized through sandwich hybridization by the catching probes and the detection probes. Catching probes were modified with biotins, and were specifically bound on streptavidin-coated 96-well microplates; detection probes were all attached on the GoldMag-CS nanoparticles, which also bound bio-bar-code strands with fluorescent tags. Bio-bar-codes were dissociated from the NPs by dithiothreitol (DTT) after DNA target recognition and magnetic separation, and then quantified. Streptavidin-coated 96-well microplates diminished the nonspecific binding of DNA-conjugated GoldMag-CS nanoparticles, thus lowering the background; and GoldMag-CS nanoparticles provided easy separation and significant signal amplification. Together, these two effects brought about the detection limit as low as 7.52 fM.     

3D-QSAR Analysis of a Series of Dihydroquinolizinone Derivatives as a Hepatitis B Virus Expression Inhibitor

In this study, we explored a three-dimensional quantitative structure-activity relationship(3D-QSAR) model of 63 HBV viral gene expression inhibitors containing dihydroquinolizinones. Two high predictive QSAR models have been built, including comparative molecular field analysis(CoMFA) and comparative molecular similarity indices analysis(CoMSIA). The internal validation parameter(CoMFA, q~2 = 0.701, r~2 = 0.999; CoMSIA, q~2 = 0.721, r~2 = 0.998) and external validation parameter(CoMFA, r~2_(pred = 0.999); CoMSIA, r~2_(pred = 0.999)) indicated that the models have good predictive abilities and significant statistical reliability. We designed several molecules with potentially higher predicted activity on the basis of the result of the models. This work might provide useful information to design novel HBV viral gene expression inhibitors.     

New adenine analogues and a pyrrole alkaloid from Selaginella delicatula

Phytochemical study on the n-BuOH extract of Selaginella delicatula lead to the isolation, characterization and structure elucidation of two new adenine analogues, delicatulines A (1) and B (2), one new pyrrole alkaloid (4), and five known compounds (3, 5–8). These new substances all contain an aliphatic chain in their parent nucleus, which were unusual to find in plants. In the present study, they were identified from Selaginellaceae for the first time. The structures and absolute configurations of these new compounds were determined by a combination of NMR and CD spectroscopic analyses. Compounds 1, 3 and 4 were evaluated for their inhibitory activities on HBV surface antigen and HBV DNA in HepAD38 cells. The results showed that these compounds had only weak or no inhibitive effects on HBV.     

由质谱分析数据建立乙肝病人与健康人的分类模型

建立运用表面加强激光解吸电离-飞行时间质谱获取乙肝病人和健康人血清蛋白指纹图谱数据,并用偏最小二乘(PLS)变量筛选法建立乙型肝炎(HBV)病人和健康人的分类模型,最终得到分类模型的交叉检验相关系数达0.97以上,判别准确率显著提高.对模型进行分析,找出对乙型肝炎病人和健康人的差异有重要影响的因素或变量.这些变量为某些质荷比区间内特定蛋白的峰强度值,反映这些质荷比区间内蛋白量的增加或减少,与乙肝病的形成有密切关系,可作为重要的生物标志物,进一步加以研究.本研究采用所得模型的拟合值等一些信息来做分类图,能较好地表达回归模型的分类效果.