Viricides

For optimum disinfection in swimming pools, the pH is maintained in the 7.2 to 7.6 range where HOCl represents 69—47% of the FAC. By contrast, the HOBr fraction varies from 97 to 93%. Nevertheless, the bactericidal effectiveness of HOCl is greater than that of HOBr below pH 8 on a molar basis (8). However, above pH 8 the superiority of HOCl is overcome by the fact that the concentration of C10 exceeds that of HOCl above pH 7.5, whereas the concentration of HOBr stiU exceeds that of BrO up to pH 8.7. Hypochlorous acid is a better viricide than HOBr, but HOBr is more effective against certain algae (9). 

Virucide (viricide). An agency which kills viruses. 

Although many papers have been published on the virucidal (viricidal) activity of biocides there is little information available about the uptake of bioeides and their penetration into viruses of different types, or of their interaction with viral protein and nucleic acid. 

It seems likely that the future will see major developments in the use of metal complexes as bacteriocidal, viricidal, immunosuppressive, anti-arthritic and biocidal agents. One class of complexing agents that appears to have particular promise are the macrocyclic antibiotics, macrocyclic polyethers, polyamines and cryptates . In this group the ligand wraps around a metal ion to form a lipid-soluble complex... 

Adansonia digitata root-bark and leaf methanol extracts have shown high antiviral activity (against Herpes simplex, Sindbis and Polio), together with viricidal (direct inactivation of virus particles) and also intracellular antiviral activity, which could indicate the presence of multiple antiviral compounds, or a single compound with multiple actions (17, 27). Whether such studies will show... 

Among disinfectants, such as inorganic chloramines, chlorine and chlorine dioxide, the latest is the most efficient disinfectant for bacteria, having both the lowest effective dose and the shortest contact time [16], but human health problems can arise with its use [31]. Increasing pH increases the bactericidal activity of chlorine dioxide [32]. However, at higher pH values (> 7.0) chlorine becomes less effective because hypochlorite ions are formed. Increased pH levels (> 7.5) also convert dichloramines to monochloramines which are less bactericidal [16]. On the other hand, monochloramines are more efficient viricides than dichloramines [33]. 

J-Y MaiUard, AD Russell. Viricidal activity and mechanisms of action of biocides. Sci Prog 80 287-315, 1997. 

A series of species-specific pesticides avicides (birds), bactericides (bacteria), molluscicides (molluscs), nematicides (nematodes), pisci-cides (fish), rodenticides (rodents), and viricides (viruses). 

Antimicrobial agents against bacteria, fungi and organisms that attack seeds, roots and above-ground portions of plants viricidal against small RNA viruses... 

Ilin AI, Kulmanov ME (2004) Bactericide and viricidal pharmaceutical preparation for prophylaxis and treatment mono and mixtinfections, manner of prophy-laxis o/or treatment viral, bacterium and mixtinfection. Patent No. 15116... 

Together the three compounds contribute to what is known as the ree residual chlorine concentration. When chlorine is added, it reacts with organic matter and ammonia to form organochlorine compounds and chloramines [50.5]. So much chlorine has to be added that a break-point chlorination is obtained. Above the break-point the bactericidal effect is considered good and the viricidal effect moderate. 

Wutzler, P. and Sauerbrei, A., 2000. Viricidal efficacy of a combination of 0.2% peracetic acid and 80% (v/v) ethanol (PAA-ethanol) as a potential hand disinfectant. Journal of Hospital Infection 46, 304-308. 

A rapidly rising demand for Oseltamivir phosphate occurred in response to the risk of an avian influenza pandemic (virus H5N1) in mid- to late 2006 because the WHO recommended all countries to keep a sufficiently large stockpile of this product so that 25% of their population could be treated. According to present findings, the product has a viro-static effect on the H5N1 virus, i.e. it inhibits the replication of the virus but does not destroy the virus (viricidal). 

Some secondary metabolites of lichens were also reported to have antiviral effects. Perry and coworkers in 1999 reported the antiviral activity of ( )-usnic acids (50 and 51) against the Poho and Herpes simplex type 1 viruses [63]. The viricidal activity of parietin (3), a secondary metabolite of Teloschistes chrysophthalmus (L.) Th. Fr., was reported against Junin and Tacaribe arena viruses [85]. Tobacco mosaic virus inhibition potential of lichenan (73), a metabolite of many lichens, was also reported in the literature [86]. Usnic acid (50) was also reported to exhibit activity against same viruses as tested for parietin (3) [6] (Table 3). 

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