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.     

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     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV     

Similar aerosol emission rates and viral loads in upper respiratory tracts for COVID-19 patients with Delta and Omicron variant infection

Highlights
1 Aerosol emission rates of Delta or Omicron patients were similar.
2 Viral loads in upper respiratory tract of Alpha, Delta and Omicron patients were similar.
3 Viral loads in upper respiratory tract of vaccinated or unvaccinated Delta patients had no difference.     

Recombinant human interferon-α1b inhibits SARS-CoV-2 better than interferon-α2b in vitro

Highlights
1) A comprehensive evaluation method for anti-SARS-CoV-2 drugs was established based on RT-qPCR, TCID₅₀ method, and immunofluorescence.
2) A significant antiviral effect of rHuIFN-α1b was shown with EC₅₀=0.12 IU/mL in Vero cells and EC₅₀=0.52 IU/mL in Calu-3 cells, which was better than rHuIFN-α2b (EC₅₀=0.25 IU/mL in Vero cells and EC₅₀=2.48 IU/mL in Calu-3 cells).
3) rHuIFN-α1b has a good potential in the application of anti-COVID-19 therapy.     

Continued antigenic variation of highly pathogenic avian influenza A (H7N9) virus in laying hens in China, 2020–2021

Highlights
1. 13 strains of H7N9 viruses from laying hens in 2020 and 2021 were identified.
2. H7N9 viruses in China comprised at least 11 genotypes.
3. H7N9 viruses are high pathogenic in chickens, not in ducks.
4. The most H7N9 viruses cross-reacted poorly with H7-Re3 antiserum.
5. The H7-Re3 vaccine was unable to prevent H7N9 infection.     

CypA Regulates AIP4-Mediated M1 Ubiquitination of Influenza A Virus

Cyclophilin A (CypA) is a peptidyl-prolyl cis/trans isomerase that interacts with the matrix protein (M1) of influenza A virus (IAV) and restricts virus replication by regulating the ubiquitin–proteasome-mediated degradation of M1. However,the mechanism by which CypA regulates M1 ubiquitination remains unknown. In this study, we reported that E3 ubiquitin ligase AIP4 promoted K48-linked ubiquitination of M1 at K102 and K104, and accelerated ubiquitin–proteasome-mediated degradation of M1. The recombinant IAV with mutant M1 (K102 R/K104 R) could not be rescued, suggesting that the ubiquitination of M1 at K102/K104 was essential for IAV replication. Furthermore, CypA inhibited AIP4-mediated M1 ubiquitination by impairing the interaction between AIP4 and M1. More importantly, both the mutations of M1 (K102 R/K104 R) and CypA inhibited the nuclear export of M1, indicating that CypA regulates the cellular localization of M1 via inhibition of AIP4-mediated M1 ubiquitination at K102 and K104, which results in the reduced replication of IAV.Collectively, our findings reveal a novel ubiquitination-based mechanism by which CypA regulates the replication of IAV.     

Mink Circovirus Can Infect Minks,Foxes and Raccoon Dogs

正Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014; Ge et al. 2018).Sequence analysis has shown that MiCV is most closely     

病毒编码泛素及相关蛋白的研究进展

泛素(Ubiquitin, Ub)是一种由76个氨基酸残基组成的小分子蛋白,广泛存在于各种真核生物中,不同来源的泛素蛋白具有类似的结构、功能和免疫学特征.目前所知,泛素主要通过ATP依赖性的泛素-蛋白酶复合体通路(Ubiquitin-proteasomes pathway, UPP)途径,经泛素活化酶(E1)、泛素结合酶(E2)和泛素连接酶(E3)的梯级反应,高效并高度选择性地对胞质或胞核内蛋白进行完全或部分降解,泛素依赖性蛋白质降解涉及细胞周期调控、信号转导、DNA修复和蛋白质数量控制[1].另外,泛素还可作为分子伴侣参与核糖体的生物发生、DNA转录调控及其它多种生理功能[2].近年来发现,一些真核生物病毒,如杆状病毒、疱疹病毒、痘病毒、腺病毒和反转录病毒等,均编码泛素或能与泛素相互作用的蛋白.病毒编码的泛素和泛素相关蛋白与病毒粒子形成及病毒出芽增殖有关,也与宿主细胞凋亡调控、宿主免疫系统调控及病毒侵染宿主细胞的机理相联系.本文就这一方面的研究进展进行简述.     

动物病毒学的成就及展望

1我国动物病毒学领域50年的主要成就及相关科学家的贡献 动物病毒学是一门综合性学科,它是建立在生物化学、生物物理学、分子生物学、分子遗传学和生物高新技术等相关学科基础上,其中任一学科的每一次突破,都将带动动物病毒学的飞速发展.80年代以来,生物技术的出现和发展,先后创制了几十种疫苗,通过对免疫预防、诊断技术的系统研究,取得了前所未有的成果.近些年来,人们在病毒特性的研究方面,尤其是在病毒本身基因组结构分析、病毒培养技术、病毒诊断技术、病毒分子流行病学调查以及生物工程疫苗研制等诸多方面,取得了前所未有的巨大成就,标志着动物病毒学已经进入了一个崭新的时代.     

The reproductive biology of a riparian Mediterranean shrub, Nerium oleander L. (Apocynaceae)

This study presents data on the reproductive characteristics of Nerium oleander, an evergreen, sclerophyllous shrub inhabiting the banks of temporary streams in all countries around the Mediterranean seaboard. Two southern Spanish populations (El Garrobo and Grazalema) were selected to investigate flowering, dispersal and seed germination phenologies, together with morphological and functional traits of flowers, fruits and seeds. Observations on pollinator visitation, fruit set, and seedling survival were also carried out. Plants produce massive flower displays of showy, tubular flowers void of nectar that rely on insect cheating for pollination. Hand-pollinations and seed germination tests demonstrated full self-compatibility. Automatic selfing is prevented by spatial separation of stigma and anthers, and pollinators are thus necessary for reproduction. Low pollinator visitation rates are the rule, as indicated by the fact that observations spread over 2 years yielded only eight insect records. Percentage fruit set of open-pollinated flowers was found to be extremely low (0.1–4.9%), while hand-pollination increased fruiting levels to 34–50%. Direct and indirect evidence point to consistently pollen-limited reproduction in this species. If a large number of flowers within any inflorescence are pollinated artificially, however, resource limitations operate and pods from ovaries pollinated late in the season are aborted. On average, the maximum of ovaries developing into fruit within any inflorescence is 4. It is suggested that, in this nectarless species, about 80% of total are ‘excess’ flowers which contribute to increase pollinator attraction. Nerium oleander pollen is aggregated into a sticky substance, which allows the fertilization of many ovules after a single, probably rare, pollination event. Fruits are many seeded follicles (181 seeds per fruit on average), so that individual plants often liberate thousands of seeds in spite of the low percent fruit set. The hairy, water-dispersed seeds are released during the rainiest season in the year, and germination follows rapidly. All seedlings tracked died before completing 1 year of life, mostly because of desiccation during the first summer drought. Pollination by deceit in this Mediterranean species is discussed in terms of phylogenetic constraints within the mainly tropical family Apocynaceae.     

Design,synthesis and biological activities of tetrandrine and fangchinoline derivatives as antitumer agents

The isolation and modification of natural products is always a very important resources to anti-tumor drugs. Therefore, a novel series of tetrandrine and fangchinoline derivatives were designed and synthesized, and their antiproliferative activities against HepG2, MCF-7 cells were evaluated and described. From the activity result obtained, high to very high activity in vitro has been found, one of the tested compounds (compound 5d) exhibited the most significant cytotoxic effects. Compound 5d increased 29.2, 7.37 times anti-proliferative activity for HepG2 cells and MCF-7 cells compared to sunitinib (IC₅₀ = 16.06 μM and 25.41 μM). Finally flow cytometry determined that compound 5d could indeed inhibit the proliferation of HepG2 cells via inducing apoptosis.