Anti-neuraminidase activity of chemical constituents of Balanophora involucrata

Balanophora involucrata J. D. Hooker has been known to possess potential anti-inflammatory and antibacterial activities; however, its antiviral activity has not been evaluated so far. In order to find new neuraminidase inhibitors (NAIs), the neuraminidase (NA) inhibition activity of different B. involucrata extracts was evaluated. In this study, an in vitro NA inhibition assay was performed to identify which extract of B. involucrata exhibits (maximal) inhibitory activity against NA. Ultra high performance liquid chromatography/quadrupole time-of-flight–tandem mass spectroscopy (MS/MS) and molecular docking techniques were used to identify the specific compounds responsible for the anti-influenza activity of the extract, and to explore the potential natural NAIs. The ethyl acetate extract of B. involucrata exhibited significant inhibitory activity against NA with 50% inhibitory concentration (IC₅₀) value of 159.5 μg/mL. Twenty compounds were identified according to the MS/MS spectra; among them two compounds (quercitrin and phloridzin) showed obvious inhibitory activity against NA, with IC₅₀ of 311.76 and 347.32 μmol/L, respectively. This study suggested that B. involucrata can be a potential natural source of NAIs and may be useful in the fight against ferocious influenza viruses.     

Blood protein purification and simultaneous removal of nonenveloped viruses using tangential-flow preparative electrophoresis

Gradiflow is new technology allowing purification of important blood proteins from viral contaminated plasma. Protein purification is based on unique scalable tangential-flow preparative electrophoresis, and is distinct from current technology because protein purification and virus removal are performed in the same step. This one-step removal and purification exploits both the size and charge of target proteins. The medically important blood proteins, immunoglobulin G (IgG) and alpha-1-antitrypsin, were chosen to demonstrate the ability of this process to purify proteins from contaminated plasma. Clearance factors achieved by infectivity assays and polymerase chain reaction (PCR) that meet regulatory requirements demonstrated removal of canine parvovirus (CPV). CPV is a model virus for pathogenic nonenveloped viruses, including parvovirus B19, not adequately removed or inactivated by most processes currently in practice. The recovery of proteins from plasma with high purity, recovery, and function, while simultaneously removing viruses, provides blood products with a level of purity compatible with clinical use more quickly and cheaply than available techniques.     

Newly Emerging Strategies in Antiviral Drug Discovery: Dedicated to Prof. Dr. Erik De Clercq on Occasion of His 80th Anniversary

Viral infections pose a persistent threat to human health. The relentless epidemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health problem, with millions of infections and fatalities so far. Traditional approaches such as random screening and optimization of lead compounds by organic synthesis have become extremely resource- and time-consuming. Various modern innovative methods or integrated paradigms are now being applied to drug discovery for significant resistance in order to simplify the drug process. This review provides an overview of newly emerging antiviral strategies, including proteolysis targeting chimera (PROTAC), ribonuclease targeting chimera (RIBOTAC), targeted covalent inhibitors, topology-matching design and antiviral drug delivery system. This article is dedicated to Prof. Dr. Erik De Clercq, an internationally renowned expert in the antiviral drug research field, on the occasion of his 80th anniversary.     

Survival of Virus Particles in Water Droplets: Hydrophobic Forces and Landauer’s Principle

Many small biological objects, such as viruses, survive in a water environment and cannot remain active in dry air without condensation of water vapor. From a physical point of view, these objects belong to the mesoscale, where small thermal fluctuations with the characteristic kinetic energy of k_BT (where k_B is the Boltzmann’s constant and T is the absolute temperature) play a significant role. The self-assembly of viruses, including protein folding and the formation of a protein capsid and lipid bilayer membrane, is controlled by hydrophobic forces (i.e., the repulsing forces between hydrophobic particles and regions of molecules) in a water environment. Hydrophobic forces are entropic, and they are driven by a system’s tendency to attain the maximum disordered state. On the other hand, in information systems, entropic forces are responsible for erasing information, if the energy barrier between two states of a switch is on the order of k_BT, which is referred to as Landauer’s principle. We treated hydrophobic interactions responsible for the self-assembly of viruses as an information-processing mechanism. We further showed a similarity of these submicron-scale processes with the self-assembly in colloidal crystals, droplet clusters, and liquid marbles.     

木马病毒传播数学模型研究

随着网络行为同社会行为联系的进一步密切,网络攻击的最终目的越来越多地落在获取具体的经济意义上.病毒制造者和传播者在巨大利益的驱使下,利用木马技术进行各种网络盗窃、诈骗活动.计算机网络病毒传播模型是研究计算机网络病毒的手段和工具之一,根据木马病毒的特点,建立了木马病毒的数学模型,研究了影响病毒传播的参数及对应措施.