Aromatic Disulfides Research Articles

QSAR and molecular docking studies on designing potent inhibitors of SARS-CoVs main protease.

Background: Severe acute respiratory syndrome coronavirus (SARS-CoVs) have emerged as a global health threat, which had caused a high rate of mortality. There is an urgent need to find effective drugs against these viruses. Objective: This study aims to predict the activity of unsymmetrical aromatic disulfides by constructing a QSAR model, and to design new compounds according to the structural and physicochemical attributes responsible for higher activity towards SARS-CoVs main protease. Methods: All molecules were constructed in ChemOffice software and molecular descriptors were calculated by CODESSA software. A regression-based linear heuristic method was established by changing descriptors datasets and calculating predicted IC50 values of compounds. Then, some new compounds were designed according to molecular descriptors from the heuristic method model. The compounds with predicted values smaller than a set point were constantly screened out. Finally, the properties analysis and molecular docking were conducted to further understand the structure-activity relationships of these finalized compounds. Results: The heuristic method explored the various descriptors responsible for bioactivity and gained the best linear model with R2 0.87. The success of the model fully passed the testing set validation, proving that the model has both high statistical significance and excellent predictive ability. A total of 5 compounds with ideal predicted IC50 were found from the 96 newly designed derivatives and their properties analyze was carried out. Molecular docking experiments were conducted for the optimal compound 31a, which has the best compound activity with good target protein binding capability. Conclusion: The heuristic method was quite reliable for predicting IC50 values of unsymmetrical aromatic disulfides. The present research provides meaningful guidance for further exploration of the highly active inhibitors for SARS-CoVs.

Mechanically Robust and Room Temperature Self-Healing Ionogel Based on Ionic Liquid Inhibited Reversible Reaction of Disulfide Bonds.

Although highly desired, it is difficult to develop mechanically robust and room temperature self-healing ionic liquid-based gels (ionogels), which are very promising for next-generation stretchable electronic devices. Herein, it is discovered that the ionic liquid significantly reduces the reversible reaction rate of disulfide bonds without altering its thermodynamic equilibrium constant via small molecule model reaction and activation energy evolution of the dissociation of the dynamic network. This inhibitory effect would reduce the dissociated units in the dynamic polymeric network, beneficial for the strength of the ionogel. Furthermore, aromatic disulfide bonds with high reversibility are embedded in the polyurethane to endow the ionogel with superior room temperature self-healing performance. Isocyanates with an asymmetric alicyclic structure are chosen to provide optimal exchange efficiencies for the embedded disulfide bonds relative to aromatic and linear aliphatic. Carbonyl-rich poly(ethylene-glycol-adipate) diols are selected as soft segments to provide sufficient interaction sites for ionic liquids to endow the ionogel with high transparency, stretchability, and elasticity. Finally, a self-healing ionogel with a tensile strength of 1.65±0.08MPa is successfully developed, which is significantly higher than all the reported transparent room temperature self-healing ionogel and its application in a 3D printed stretchable numeric keyboard is exemplified.

Room-temperature self-healing and recyclable polyurethane elastomers with high strength and superior robustness based on dynamic double-crosslinked structure

Mechanically robust elastomers with the functionalities of room-temperature self-healing ability and even recyclability provide new opportunities to revolutionize next-generation flexible electronics. However, it remains a great challenge to synthesize such materials due to the conflicting requirements of the self-healing ability and mechanical robustness for the dynamicity of crosslinks. Herein, a room-temperature self-healing and recyclable polyurethane (PU) elastomer with ultrahigh mechanical performance is constructed by synergistically incorporating dynamic disulfide bonds and multiple hydrogen bonds (H-bonds) into a PU chain. The introduction of diazolidinyl urea (DU) motifs forms strong H-bonds and branching crosslinking points, improving the robustness of the crosslinked structure, and the fast metathesis of the aromatic disulfide bonds mainly contributes to the dynamicity of the crosslinked network. The resulting PU elastomers exhibit high tensile strength (14.08 MPa), toughness (64.6 MJ m−3), superior elastic restorability, outstanding self-healing capability (∼81% at room temperature), and multiple recyclability. Furthermore, a wearable sensor based on this elastomer is constructed to monitor different human motions, demonstrating the potential application in wearable electronics.

Vanillin-Based Epoxy Vitrimers: Looking at the Cystamine Hardener from a Different Perspective.

Epoxy vitrimers encompass many advantages compared to traditional epoxy materials such as recyclability, repairability, and reprocessability. These properties are induced by the incorporation of dynamic reversible covalent bonds. Recently, the incorporation of aromatic disulfide bridges that are dynamic has expanded the development of new eco-friendly epoxy materials. Herein, we studied a bio-based aliphatic disulfide based on cystamine as a hardener with a vanillin-derived bio-sourced epoxy to prepare fully bio-based epoxy vitrimers. This article provides a comparative study between cystamine and an aromatic disulfide benchmark hardener issued from petrol resources. This work demonstrated that the presence of this aliphatic hardener has a significant influence not only on the reactivity, but most importantly on the resulting dynamic properties. An interesting yet counterintuitive accelerating effect of the dynamic exchanges was clearly demonstrated with only 2 to 20% of molar fraction of cystamine added to the aromatic disulfide formulation. A similar glass transition was obtained compared to the purely aromatic analogue, but relaxation times were decreased by an order of magnitude.

Mechanically robust and recyclable siloxane elastomers enabled by adjustable dynamic polymer networks for electronic skin

Siloxane elastomers as substrate materials have recently attracted much interest in the applications of flexible electronics. Nevertheless, excellent mechanical properties, self-healing properties and recyclability can rarely be satisfied with single material simultaneously. In this study, multistrength hydrogen bonds and dynamic disulfide bonds were introduced into the siloxane to achieve high stretchability, good mechanical strength, comparative self-healing capacity and excellent recyclability. By adjusting the ratio of the two types of hydrogen bonding networks, the prepared elastomers exhibit tunable mechanical properties, stretchability, toughness and a coordinated self-healing efficiency of 25–80%. Benefiting from the aromatic disulfide, the siloxane elastomer exhibits significant improvement in tensile strength of ∼4.67 MPa, tensile strain of ∼1086% and toughness of ∼27.36 MJ m−3 with 75% healing efficiency. Furthermore, a self-healing flexible bifunctional sensor was constructed by encapsulating liquid metal alloy between the elastomers layers to detect the pressure and multiple human motions.

DESARROLLO DE RESINAS VITRÍMERAS PARA APLICACIONES AERONÁUTICAS

Due to the environmental challenges the aeronautical industry is facing, the development of recyclable aeronautical chemistries have recently raised huge interest. Within this context, different alternatives are being considered with the aim of obtaining new resins with current thermoset resin chemical and mechanical performance, while showing reprocessing, repairability and recyclability capabilities, like thermoplastics. New vitrimer resins, based on dynamic covalent chemistry, become a very attractive alternative to combine the main advantages of aeronautical thermosets (processing conditions / temperature, means, properties…) and thermoplastics (recycling, welding…). Therefore, they can be the solution to overcome the current limitations of thermoset epoxy resin, which is widely used in composite airframe. This project, framed within the national funding PTA (Plan Tecnológico Aeronáutico), was focused on the preliminary development of aeronautical vitrimer resin for composite airframe. It was proposed as continuation of the EU Horizon 2020 consortium AIRPOXY led by CIDETEC, where a first generation of aeronautical RTM vitrimer was developed and characterised, while a second generation vitrimer development was only started. This chemistry is based on the use of dynamic aromatic disulfides as hardener. In the first 2021 project phase, following key activities were performed: Definition of targets or reference values for aeronautical infusion resin Second generation of infusion vitrimer: development completion and characterization Flat CFRP laminates with second generation vitrimer: production and thermoforming trials. Next steps of the project in 2022 and 2023, will be focused on developing, evaluating and demonstrating an aeronautical prepreg based on vitrimer resin with higher Tg in line with current aeronautical resin values.

Epoxy-Based Catalyst-Free Self-Healing Elastomers at Room Temperature Employing Aromatic Disulfide and Hydrogen Bonds.

In this paper, catalyst-free room-temperature healing epoxy vitrimer-like materials (S-vitrimer) are introduced. The S-vitrimer can be healed at room temperature without any external stimuli such as solvent, pressure, heat, and catalyst through an aromatic disulfide exchange reaction and a hydrogen bond because the glass transition temperature of the S-vitrimer is lower than room temperature. Self-healing materials are attracting widespread attention nowadays with their potential to increase the durability of the materials. However, there is still elevating need for research, considering the limitations of various self-healing methods. To the best of our knowledge, epoxy-based catalyst-free room-temperature healing materials have not been investigated until now, yet they are promising to make self-healing easier. Moreover, the S-vitrimer showed higher healing efficiency when healed for a longer time and at a higher temperature. Especially when healed at room temperature for 96 h, the S-vitrimer presented an 80% healing efficiency. The S-vitrimer also showed an 80% healing efficiency when healed at 60 °C for 48 h. To investigate the factors affecting self-healing behavior, three control experiments were carried out. Control experiments showed that the S-vitrimer is healed mainly due to a disulfide exchange reaction, but hydrogen bonds also contribute to self-healing behavior. Also, it was found that tightly packed segments can hinder self-healing through control experiments.

An Environmental-Inert and Highly Self-Healable Elastomer Obtained via Double-Terminal Aromatic Disulfide Design and Zwitterionic Crosslinked Network for Use as a Triboelectric Nanogenerator.

Due to the ongoing development of portable/mobile electronics, sources to power have received widespread attention. Compared to chemical batteries as power sources, triboelectric nanogenerators (TENGs) possess lots of advantages, including the ability to harvest energy via human motions, flexible structures, environment-friendliness, and long-life characteristics. Although many self-healable TENGs are reported, the achievement of a muscle-like elasticity and the ability to recover from inevitable damage under extreme conditions (such as a high/low temperature and/or humidity) remain a challenge. Herein, a "double-terminal aromatic disulfide" on a structure with zwitterions as branched chains is reportedto engineer the high-efficient self-healable elastomer for application in a flexible TENG. The as-designed material exhibits a repeatable elastic recovery (at 250% elongation) and a self-healing efficiency with an ultimate tensile stress of 96% over 2h, representing an improvement on previously reported disulfide-based elastomers. The elastomer can autonomously recover by 50% even at a subzero temperature of -30°C within 24h. The elastomer-based TENG, as a self-driven sensor for detecting human behavior, is demonstrated to exhibit stable outputs and self-healing in the temperature range of -30 to 60°C, and so is expected to promote the development of self-powered electronics for next-generation human-machine communications.

Design and properties of dynamic self‐healing polyurea molecule based on disulfide bonds

AbstractAlthough thermosetting polymer materials have excellent mechanical properties, they are less self‐healing, recycling than thermoplastic polymer materials, which may cause a serious waste of resources. Herein, a series of polyurea materials with high mechanical strength, good properties of self‐healing and recycling are prepared by adjusting the ratio of polyether polyol and introducing disulfides into the synthesis of polyurea prepolymer in an innovative way. The composite polyurea (FHPUA) materials with tensile strength over 47 MPa and elongation at break of 720% are prepared. The experimental results show that by adjusting the content of aromatic disulfide, the tensile strength is further increased to 52 MPa, and the heat resistance of the material is improved. Through five self‐healing experiments, the surface of the material recovers as before even after continuous heating at 70°C for 1 h. In addition, the tensile strength of the material recovers 86.56% and the elastic modulus recovers 70.21% after four recycling experiments. In practical application, it is expected to fill the shortcomings of traditional polyurea such as micro cracks, short service life and poor performance, and have great potential applications in the fields of coating layer of heavy‐duty conveyor belts, encapsulation film of electronic devices and building facade coating.

Interlocked Covalent Adaptable Networks and Composites Relying on Parallel Connection of Aromatic Disulfide and Aromatic Imine Cross-Links in Epoxy

Covalent adaptable networks (CANs) relying on dynamic cross-links have been developed to make the cross-linked polymeric materials and composites degradable. However, due to the reversibility of dynamic bonds, the CANs and composites suffer accidental degradation and failure upon a certain stimulus (moisture, acid/base, reductant/oxidant, etc.) in the application environment. Herein, inspired by parallel circuits, interlocked covalent adaptable networks (ICANs) were prepared by one-pot reactions from epoxy monomers and two curing agents that contained different dynamic bonds of aromatic disulfide and aromatic imine bonds, resulting in dual dynamic parallel cross-links in homogeneous epoxy networks. The ICANs exhibited outstanding mechanical properties and improved stability, relying on the topological interlocking structure. The ICANs could be unlocked and became degradable only when two stimuli were both applied to completely break the cross-links of disulfide bonds and imine bonds. When applying ICANs as a matrix to form carbon fiber-reinforced polymer (CFRP) composites, the resulted CFRP inherited the interlocking properties from the ICANs, exhibiting improved stability and nondestructive recyclability. Maintaining the degradable properties, the interlocking structure of networks provided a facile way to optimize the stability of CANs and their composites.

Self-Healing and Reprocessable Oleic Acid-Based Elastomer with Dynamic S-S Bonds as Solvent-Free Reusable Adhesive on Copper Surface.

In the last decade, the application of dynamic covalent chemistry in the field of polymeric materials has become the subject of an increasing number of studies, gaining applicative relevance. This is due to the fact that polymers containing dynamic functions possess a structure that affords reprocessability, recyclability and peculiar self-healing properties inconceivable for "classic" polymer networks. Consequently, the synthesis of a dynamic covalent chemistry-based polymer and its chemical, thermal, and mechanical characterizations are reported in the present research. In particular, oleic acid has been used as starting material to follow the founding principles of the circular economy system and, thanks to the aromatic disulfide component, which is the foundation of the material dynamic characteristics, the obtained polymer resulted as being reprocessable and self-healable. Moreover, the polymer can strongly interact with copper surfaces through the formation of stable Cu-S bonds. Then, the application of the polymer as a solvent-free reusable adhesive for copper was investigated by lap joint shear tests and comparisons with the properties of an analogous material, devoid of the disulfide bonds, were conducted.

The Spatial Distribution Patterns, Physicochemical Properties, and Structural Characterization of Proteins in Oysters (Crassostrea hongkongensis).

Protein content, a vital component determining the nutritional quality of oysters, is unevenly distributed in different parts of oyster. In this study, the spatial distribution (visceral mass, mantle, gill, and adductor) patterns and structural characteristics of proteins, including water–soluble proteins (WSP), salt–soluble proteins (SSP), acid–soluble proteins (ASP) and alkali–soluble proteins (ALSP) of oysters (Crassostrea hongkongensis) were investigated with the amino acid analyzer, circular dichroism spectroscopy (CD), fourier transform infrared spectroscopy (FTIR), and fluorescence spectroscopy. The results showed that oyster proteins were mainly distributed in the visceral mass and mantle. The protein composition was WSP, SSP, ALSP, and ASP in descending order, which conformed to the ideal amino acid pattern. Variations in secondary structure, molecular weight distribution, and thermal denaturation temperatures of the oyster proteins were observed. SSP had wider bands (16–270 kDa) than those of ASP (30–37 kDa) and ALSP (66–270 kDa). Among the four proteins, the SSP of the mantle showed the highest thermal stability (87.4 °C), while ALSP of the adductor muscle had the lowest the lowest the peak denaturation temperature (Tm) (53.8 °C). The proportions of secondary structures in oyster proteins were different, with a higher proportion of solid protein β–folds, and the exposure of aromatic amino acid residues and disulfide bonds and the microenvironment in which they were located were also different.

ON ASSESSING THE MORBIDITY OF THE POPULATION ASSOCIATED WITH THE ATMOSPHERIC AIR QUALITY ON THE EXAMPLE OF A RUSSIAN CONSTITUENT ENTITY

According to the World Health Organization (WHO), 24% of the global burden of diseases and 23% of all deaths associate with environmental factors. The presence of chemical impurities in the air can have an adverse effect on the health of the population. A connection has been established between the increased content of chemical impurities in the air and the development of such pathologies as diseases of the respiratory system, circulatory system, the formation of malformations, etc. Many countries implement projects to improve air quality. For the purpose of targeted development of management decisions aimed at minimizing the adverse impact of atmospheric air on the health of the population, the study of the morbidity of the population associated with the impact of priority atmospheric air hazard factors is relevant. The research goal is to characterize the morbidity of the population associated with air quality (on the example of Krasnoyarsk Krai) to identify the priority factors of atmospheric air that form the greatest contribution to the associated morbidity. The qualitative characteristics of the atmosphere and the level of morbidity of the population in Krasnoyarsk Krai are estimated on the basis of official data of federal and industry statistics. The analysis of the primary morbidity of the population, designated by the WHO as an indication of the effect of environmental factors, has been carried out. The authors calculate the number of third-party cases of diseases associated with the quality of the atmosphere and determine the priority risk factors. High proportions of air samples that do not meet the standards for the content of heavy metals, benz(a)pyrene, xylenes (59% of samples) have been registered over the territory of Krasnoyarsk Krai. Since 2012, there has been an increase of 0.2%–6.4% in the indicators of primary morbidity, indicated by the WHO as an indicator of the effect of environmental factors and a significant increase in congenital anomalies (the growth rate is 93.2%). Up to 231 thousand third-party cases of diseases of the general population with diseases affecting the respiratory organs, circulatory system, hematopoietic organs, nervous system, eyes and their appendages determine the presence of aromatic hydrocarbons, nitrogen dioxide, hydroxybenzene (as well as its derivatives), benz(a)pyrene, nitrogen oxide, ammonia, dihydrosulfide and carbon disulfide, sulfur dioxide in the air in concentrations exceeding the standards. The most substantial number of diseases associated with air quality forms in the class of respiratory diseases (2020 – 587.4 cases per 100 thousand population, 64.5% of the total air-associated morbidity).

A high‐performance self‐healing polyurea material based on exchangeable aromatic disulfide

AbstractHigh‐performance polyurea materials demonstrate promising applications in the field of aerospace, military, etc. During processing and use, however, the formation of cracks may cause serious degradation of material properties. Self‐healing polyurea should be an effective way to address this issue. Here, an innovative polyurea material, which exhibited excellent mechanical properties and self‐healing abilities, was synthesized from the commercially available poly(propylene glycol) bis(2‐aminopropyl ether), isophorone diisocyanate, and 2‐Aminophenyl disulfide (APD). The rigid benzene ring in APD is beneficial to the mechanical properties of polyureas, simultaneously the irregular structure of APD prevents the hard segments from stacking tightly, which facilitates the exchange of disulfide bonds to achieve the self‐healing function. Furthermore, the microstructure, mechanical properties and self‐healing ability of the polyureas are highly dependent on the amount of APD. The obtained SPU‐4 exhibits robust mechanical strength (tensile stress of 21.2 MPa), outstanding stretchability (strain of 1006%), high rigidity (Young's modulus of 248.1 MPa), and excellent energy absorption (toughness of 139.7 MJ·m−3), besides, with heat stimulation, the self‐healing efficiencies based on strength and elongation could reach 92.7% and 74.5%, respectively. The excellent properties allow the material to show broad potential in the practical applications such as protection, energy absorption, etc.

Aromatic disulfide epoxy vitrimer packaged electronic devices: Nondestructive healing and recycling

Electrical and electronic equipment (EEE) that greatly enhances global living standards has become indispensable in modern societies. In EEE, most electronic devices are protected by epoxy electronic packaging that exhibits outstanding mechanical property, high electrical resistivity and excellent solvent resistance. However, due to thermolability of electronic components and insolubility of epoxy, it is impossible to heal and recycle the packaged electronic devices non-destructively, resulting in a huge amount of e-waste during manufacturing and consumption. Herein, aromatic disulfide epoxy vitrimer packaged electronic devices were proposed, in which nondestructive healing and recycling were achieved. The epoxy vitrimer was prepared from aromatic disulfide-based epoxy and aliphatic amines at moderate temperature (≤100 °C), resulting in highly cross-linked networks, excellent solvent resistance and good thermal stability. The tensile strength was ∼71.9 MPa and the glass transition temperature was ∼115 °C. Moreover, it exhibited comparable electrical resistivity to reference epoxy, while lower dielectric constant was observed. In epoxy vitrimer packaged LED light, cracks could be readily healed at 150 °C through aromatic disulfide metathesis in networks, while the epoxy vitrimer exhibited topology freezing transition at ∼118 °C. Besides, relying on reactions between aromatic disulfide bonds and outer thiol groups, the epoxy vitrimer packaged LED light, printed circuit board and integrated circuit could be non-destructively recycled, while the epoxy vitrimer was degradable on demand. The aromatic disulfide epoxy vitrimer packaged electronic devices with nondestructive healing and recycling properties provide a better way to deal with substandard electric products and retired ones, leading to e-waste reducing, resource recycling and environment-friendly development in EEE.

Unsymmetrical aromatic disulfides as SARS-CoV-2 Mpro inhibitors: Molecular docking, molecular dynamics, and ADME scoring investigations

COVID-19 pandemic caused by very severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) agent is an ongoing major global health concern. The disease has caused more than 452 million affected cases and more than 6 million death worldwide. Hence, there is an urgency to search for possible medications and drug treatments. There are no approved drugs available to treat COVID-19 yet, although several vaccine candidates are already available and some of them are listed for emergency use by the world health organization (WHO). Identifying a potential drug candidate may make a significant contribution to control the expansion of COVID-19. The in vitro biological activity of asymmetric disulfides against coronavirus through the inhibition of SARS-CoV-2 main protease (Mpro) protein was reported. Due to the lack of convincing evidence those asymmetric disulfides have favorable pharmacological properties for the clinical treatment of Coronavirus, in silico evaluation should be performed to assess the potential of these compounds to inhibit the SARS-CoV-2 Mpro.In this context, we report herein the molecular docking for a series of 40 unsymmetrical aromatic disulfides as SARS-CoV-2 Mpro inhibitor. The optimal binding features of disulfides within the binding pocket of SARS-CoV-2 endoribonuclease protein (Protein Data Bank [PDB]: 6LU7) was described. Studied compounds were ranked for potential effectiveness, and those have shown high molecular docking scores were proposed as novel drug candidates against SARS-CoV-2. Moreover, the outcomes of drug similarity and ADME (Absorption, Distribution, Metabolism, and Excretion) analyses have may have the effectiveness of acting as medicines, and would be of interest as promising starting point for designing compounds against SARS-CoV-2. Finally, the stability of these three compounds in the complex with Mpro was validated through molecular dynamics (MD) simulation, in which they displayed stable trajectory and molecular properties with a consistent interaction profile.

QSAR Study on Aromatic Disulfide Compounds as SARS-CoV Mpro Inhibitor Using Genetic Algorithm-Support Vector Machine

COVID-19 is a type of pneumonia caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). This virus causes severe acute respiratory syndrome and 2 million active cases of COVID-19 have been found worldwide. A new strain of the SARS-CoV-2 virus emerged that proved to be more virulent than its predecessor. Regarding the design of a new inhibitor for this strain, SARS-CoV Main Protease (Mpro) was used as the target inhibitor. In the in silico development, the Quantitative Structure-Activity Relationship (QSAR) method is commonly used to predict the biological activity of unknown compounds to improve the process of drug design of a disease, including COVID-19. In this study, we aim to develop a QSAR model to predict the activity of aromatic disulfide compounds as SARS-CoV Mpro inhibitors using Genetic Algorithm (GA) – Support Vector Machine (SVM). GA was used for feature selection, while SVM was used for model prediction. The used dataset is set of features of aromatic disulfide compounds, along with information on the toxicity activity. We found that the best SVM model was obtained through the implementation of the polynomial kernel with the value of R2­­train and R2test­ scores are 0.952 and 0.676, respectively.

Rapid self-healed vitrimers via tailored hydroxyl esters and disulfide bonds

Conventional epoxy vitrimer containing single type of dynamic covalent bonds constitutes a class of polymer materials that integrates the advantages of thermoplastics and thermosets. However, the response of single type of dynamic covalent bond is slow, so it is very meaningful to combine multiple dynamic covalent bonds with adjustable proportions into one network for endowing vitrimers with diversified properties, especially rapid self-healing performances. Based on this consideration, we designed a series of epoxy vitrimers containing β-hydroxyl esters and disulfide bonds with adjusting any proportions. To this end, carboxylic acid-extended epoxy resins containing dynamical β-hydroxyl esters were first prepared through chemical reactions between conventional epoxy resin and suberic acid (SA), and then cured by aromatic disulfides (SS) to form vitrimers containing β-hydroxyl esters and disulfide bonds. Here, the SA part offers soft segments and dynamic β-hydroxyl esters, the curing agent SS part supplies hard segments and dynamic disulfide bonds. The properties of vitrimers with dual dynamic bonds are easily tailored by changing the ratio of SA and SS. Vitrimers with dual dynamic bonds exhibit excellent rapid self-healing properties closing to 80% after healing only 10 min, and the theoretical healing efficiencies are in good agreement with the actual values.

Aromatic disulfides as potential inhibitors against interaction between deaminase APOBEC3G and HIV infectivity factor.

APOBEC3G (A3G) is a member of cytosine deaminase family with a variety of innate immune functions. It displays activities against retrovirus and retrotransposon by inhibition of virus infectivity factor (Vif)-deficient HIV-1 replication. The interaction between A3G N-terminal domain and Vif directs the cellular Cullin 5 E3-ubiquitin ligase complex to ubiquitinate A3G, and leads to A3G proteasomal degradation, which is a potential target for anti-HIV drug. Currently, there are very few reports about stable small molecules targeting the interaction between A3G and Vif. In this study, we screened two series of small molecules containing carbamyl sulfamide bond or disulfide bond as bridges of two different aromatic rings. Five asymmetrical disulfides were successfully identified against interaction between A3G and Vif with the IC 50 values close to or smaller than 1 μM, especially, not through covalently binding with A3G or Vif. They restore the A3G expression in the presence of Vif by inhibiting Vif-induced A3G ubiquitination and degradation. This study opens a way to the discovery of new anti-HIV drugs.

Methods of Inactivation of Highly Pathogenic Viruses for Molecular, Serology or Vaccine Development Purposes.

The handling of highly pathogenic viruses, whether for diagnostic or research purposes, often requires an inactivation step. This article reviews available inactivation techniques published in peer-reviewed journals and their benefits and limitations in relation to the intended application. The bulk of highly pathogenic viruses are represented by enveloped RNA viruses belonging to the Togaviridae, Flaviviridae, Filoviridae, Arenaviridae, Hantaviridae, Peribunyaviridae, Phenuiviridae, Nairoviridae and Orthomyxoviridae families. Here, we summarize inactivation methods for these virus families that allow for subsequent molecular and serological analysis or vaccine development. The techniques identified here include: treatment with guanidium-based chaotropic salts, heat inactivation, photoactive compounds such as psoralens or 1.5-iodonaphtyl azide, detergents, fixing with aldehydes, UV-radiation, gamma irradiation, aromatic disulfides, beta-propiolacton and hydrogen peroxide. The combination of simple techniques such as heat or UV-radiation and detergents such as Tween-20, Triton X-100 or Sodium dodecyl sulfate are often sufficient for virus inactivation, but the efficiency may be affected by influencing factors including quantity of infectious particles, matrix constitution, pH, salt- and protein content. Residual infectivity of the inactivated virus could have disastrous consequences for both laboratory/healthcare personnel and patients. Therefore, the development of inactivation protocols requires careful considerations which we review here.