Camphor-based symmetric diimines as inhibitors of influenza virus reproduction.

Influenza is a continuing world-wide public health problem that causes significant morbidity and mortality during seasonal epidemics and sporadic pandemics. The purpose of the study was synthesis and investigation of antiviral activity of camphor-based symmetric diimines and diamines. A set of C2-symmetric nitrogen-containing camphor derivatives have been synthesized. The antiviral activity of these compounds was studied against rimantadine- and amantadine-resistant influenza virus A/California/7/09 (H1N1)pdm09 in MDCK cells. The highest efficacy in virus inhibiting was shown for compounds 2a-e with cage moieties bound by aliphatic linkers. The therapeutic index (selectivity index) for 2b exceeded that for reference compounds amantadine, deitiforin and rimantadine almost 10-fold. As shown by structure-activity analysis, the length of the linker has a dramatic effect on the toxicity of compounds. Compound 2e with -C12H24- linker exhibited the lowest toxicity (CTD50=2216µM). Derivatives of camphor, therefore, can be considered as prospective antiinfluenza compounds active against influenza viruses resistant to adamantane-based drugs.

New quaternary ammonium camphor derivatives and their antiviral activity, genotoxic effects and cytotoxicity.

The synthesis and biological evaluation of a novel series of dimeric camphor derivatives are described. The resulting compounds were studied for their antiviral activity, cyto- and genotoxicity. Compounds 3a and 3d in which the quaternary nitrogen atoms are separated by the C5H10 and С9H18 aliphatic chain, exhibited the highest efficiency as an agent inhibiting the reproduction of the influenza virus A(H1N1)pdm09. The cytotoxicity data of compounds 3 and 4 revealed their moderate activity against malignant cell lines; compound 3f had the highest activity for the CEM-13 cells. These results show close agreement with the data of independent studies on toxicity of these compounds, in particular that the toxicity of compounds strongly depends on spacer length.

INFLUENZA SURVEILLANCE IN RUSSIA BASED ON EPIDEMIOLOGICAL AND LABORATORY DATA FOR THE PERIOD FROM 2005 TO 2012.

Exchange of information on and sharing of influenza viruses through the GISRS network has great significance for understanding influenza virus evolution, recognition of a new pandemic virus emergence and for preparing annual WHO recommendations on influenza vaccine strain composition. Influenza surveillance in Russia is based on collaboration of two NICs with 59 Regional Bases. Most epidemiological and laboratory data are entered through the internet into the electronic database at the Research Institute of Influenza (RII), where they are analyzed and then reported to the Ministry of Public Health of Russia. Simultaneously, data are introduced into WHO's Flu Net and Euro Flu, both electronic databases. Annual influenza epidemics of moderate intensity were registered during four pre-pandemic seasons. Children aged 0-2 and 3-6 years were the most affected groups of the population. Influenza registered clinically among hospitalized patients with respiratory infections for the whole epidemic period varied between 1.3 and 5.4% and up but to 18.5-23.0% during the peak of the two pandemic waves caused by influenza A(H1N1) pdm 09 virus and to lesser extent (2.9 to 8.5%) during usual seasonal epidemics. Most epidemics were associated with influenza A(H1N1), A(H3N2) and B co-circulation. During the two pandemic waves (in 2009-2010 and 2010-2011) influenza A(H1N1) pdm 09 predominated. It was accompanied by a rapid growth of influenza morbidity with a significant increase of both hospitalization and mortality. The new pandemic virus displaced the previous seasonal A(H1N1) virus completely. As a rule, most of the influenza viruses circulating in Russia were antigenic ally related to the strains recommended by WHO for vaccine composition for the Northern hemisphere with the exception of two seasons when an unexpected replacement of the influenza B Victoria lineage by Yamagata lineage (2007-2008) and the following return of Victoria lineage viruses (2008-2009) was registered. Influenza surveillance in Russia was improved as a result of enhancing capacity to international standards and the introduction of new methods in NICs such as rRT-PCR diagnosis, regular testing of influenza viruses for susceptibility to antivirals, phylogenetic analysis as well as organization of sentinel surveillance in a number of Regional Base Laboratories. Improvements promoted rapid recognition of the appearance a new pandemic virus in the country and enhancement of confirmation tests in investigation of influenza related death cases.

Synthesis and anti-viral activity of azolo-adamantanes against influenza A virus.

Chemotherapy and chemoprophylaxis of influenza is one of the most important directions of health protection activity. Due to the high rate of drug-resistant strains of influenza virus, there is a need for the search and further development of new potent antivirals against influenza with a broad spectrum of activity. In the present study, a set of di-, tri- and tetrazole derivatives of adamantane was efficiently prepared and their anti-influenza activities evaluated against rimantadine-resistant strain A/Puerto Rico/8/34. In general, derivatives of tetrazole possessed the highest virus-inhibiting activity. We demonstrated that several compounds of this set exhibited much higher activity than the currently used antiviral rimantadine, a compound of related structure. Moreover, we showed that these azolo-adamantanes were significantly less toxic. This study demonstrates that influenza viruses can be inhibited by adamantyl-azoles and thus have potential for developing antiviral agents with an alternate mechanism of action.

Photodynamic inactivation of influenza virus with fullerene C60 suspension in allantoic fluid.

BACKGROUND: Viruses are the most dangerous infectious contaminants of human donor blood and blood products. The purpose of the study was to investigate the virus-inactivating properties of fullerene suspension regarding influenza virus in allantoic fluid of chicken embryos. METHODS: Influenza virus was propagated in chicken embryos, water suspension of C60 fullerene was added to the allantoic fluid. The fluid was light-irradiated at constant oxygen flow through the specimen, and the dynamics of virus titer was studied by virus titration in MDCK cells. The morphology of virions was studied by electron microscopy (EM). RESULTS: Dramatic drop of infectious titer (8 to 1 log10 EID50) of the virus was observed within 2h after start of irradiation. No change of the titers was observed in control specimens without fullerene, or light, or oxygen. EM study revealed numerous defects of virions' morphology (destruction of outer membrane) leading to the loss of infectious properties of the virus. CONCLUSIONS: Water-insoluble fullerenes may be considered as a prospective way for inactivation of enveloped viruses in biological materials including blood products.