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The virus inhibitory activity and selectivity of certain benzimidazole, benzotriazole, and naphthimidazole derivatives were determined with influenza B and polio type 2 viruses. Among the sixty-five compounds examined, several were highly active inhibitors of influenza B virus multiplication in the chorioallantoic membrane in vitro. The following compounds, listed in order of increasing inhibitory activity, were more than 100 times as active as benzimidazole: 5-(4'-toluenesulfonamido)-benzimidazole, 5-hydroxybenzotriazole-4-carboxy-α-naphthylamide, 4,5,6-trichlorobenzotriazole, 5-(3',4'-dichlorobenzenesulfonamido)-benzimidazole, 5-(3',4'-dichlorobenzenesulfonamido) - 1 - (3'',4'' - dichlorobenzenesulfonyl)-benzimidazole, 4-(p-chlorophenylazo)-5-hydroxybenzotriazole, and 4,5,6,7-tetrachlorobenzotriazole. However, none showed high selectivity. Of the sixty-five compounds studied with influenza virus, twenty-five were also examined with poliovirus type 2 in monkey kidney cells in vitro. Included in this group were five of the seven most active inhibitors of influenza virus, listed above. All five were more than 100 times as active in inhibiting poliovirus multiplication as the reference compound. In addition to these, two other compounds were highly active: 2-(α-hydroxybenzyl)-benzimidazole (HBB), and 2-(α-hydroxybenzyl)-5-chlorobenzimidazole, with relative inhibitory activities of 78 and 130, respectively. These two compounds, and the much less active 5,6-dichloro derivative of HBB, were the only ones which showed no, or only slight, toxic effects on cells at concentrations sufficient to cause considerable inhibition of poliovirus multiplication. Furthermore, HBB and the 5-chloro derivative were the only compounds which caused significant inhibition of the cytopathic effects of poliovirus. HBB, and its 5-chloro and 5,6-dichloro derivatives had no effect on the multiplication of influenza B virus in the chorioallantoic membrane. In addition, HBB failed to inhibit influenza B virus multiplication and cytopathic effects in monkey kidney cells. Inhibition of poliovirus-induced cell damage by HBB was characterized by the following features: the curves relating reduction in virus yield or cytopathic effects to concentration of the compound followed an approximately parallel course; somewhat higher concentrations were required to inhibit virus-induced cell damage than to reduce virus yield. HBB suppressed viral cytopathic effects for a period of time which varied directly with the concentration of compound, and inversely with the size of virus inoculum. The development of virus-induced cell damage in treated cultures on prolonged incubation was not due to inactivation of HBB. The inhibitory effect of HBB on virus-induced cell damage was reversible by removal of the compound. HBB inhibited viral cytopathic effects when given during the exponential increase phase in virus multiplication. Inhibition of virus-induced cell damage by HBB was demonstrated by photomicrographs. HBB did not inactivate the infectivity of poliovirus type 2. more...

The degree of inhibition of multiplication of influenza B virus, Lee strain, in membrane cultures in vitro appears to be directly related to the concentration of the inhibitory compounds used in this investigation. With each of the alkyl derivatives of benzimidazole, evidence for such a relationship was obtained in the range between 60 and 90 per cent inhibition of virus multiplication. Alteration of the structure of benzimidazole by substitution of alkyl radicals at various positions in either the benzene or the imidazole ring resulted in diverse differences in the capacity to inhibit influenza virus multiplication in vitro. Minor increases in inhibitory activity resulted when one to three methyl groups were introduced at certain positions in the molecule. Marked increases in inhibitory activity were achieved by more extensive substitution in either the benzene or the imidazole ring. The position and nature of substituent groups appeared to be of decisive importance. Among the more highly active compounds were 2,4,5,6,7-pentamethyl-benzimidazole, 5,6-diethylbenzimidazole, and 2-ethyl-5-methylbenzimidazole. Further extension of the alkyl chain at position 2 caused no significant change in the inhibitory activity of the derivative. The most active compounds studied caused 75 per cent inhibition of Lee virus multiplication in membrane cultures in vitro at concentrations of approximately 0.0002 M. Some of the implications of these findings are discussed. more...

Chloro derivatives of benzimidazole were found to be 2 to 3 times more active than corresponding methyl derivatives in causing inhibition of Lee virus multiplication in chorioallantoic membrane cultures in vitro. The most active benzimidazole derivative thus far tested is 5,6-dichloro-1-ß-D-ribofuranosylbenzimidazole (DRB); it caused 75 per cent inhibition of Lee virus multiplication in membrane cultures at a concentration of 0.38 x 10–4 M. On the other hand, 5,6-dimethyl-1-alpha;-D-ribofuranosylbenzimidazole, the moiety present in vitamin B12, failed to inhibit Lee virus multiplication at a concentration of 35 x 10–4 M. Other N-glycosides of 5,6-dichlorobenzimidazole were considerably less active than DRB. In single cycle experiments, the degree of inhibition of Lee virus multiplication by DRB in membrane cultures was not dependent on the amount of virus in the inoculum. This compound did not inactivate the infectivity of extracellular Lee virus, had no effect on virus-erythrocyte interaction, did not interfere with the adsorption of the virus by the host tissue, nor affect the release of newly formed virus from the membrane. The inhibitory effect of DRB on Lee virus multiplication, in contrast to that of 2,5-dimethylbenzimidazole, persisted after transfer of infected membranes into fresh culture medium not containing the compound. Both DRB and the 2,5-dimethyl compound caused 99 per cent inhibition of Lee virus multiplication without affecting oxygen uptake of the membrane. Tissue proliferation of membrane pieces in roller tube culture was not significantly affected by DRB at inhibitory concentration, whereas at equivalent concentration the 2,5-dimethyl compound did restrict cellular growth. At higher concentrations, both compounds caused retardation of cell proliferation. This effect was reversible on removal of either compound from the medium. The multiplication of several strains of influenza A and B viruses, i.e. Lee, MB, PR8, and FM1, was inhibited to the same degree by each of the two compounds; DRB was 35 times more active than the 2,5-dimethyl compound relative to each of the strains. DRB caused inhibition of Lee virus multiplication in intact embryonated chicken eggs and in mice without causing significant signs of toxicity in either host. Some of the implications of these findings are discussed in relation to the mechanism of the inhibition of influenza virus multiplication. more...

The chromanol of hexahydrocoenzyme Q 4 was found to prevent encephalomalacia in the chick, the resorption-gestation syndrome in the rat, and to cure nutritional muscular dystrophy in the rabbit. The chromanol of vitamin K 1(20) also prevented encephalomalacia in the chick. Other compounds including hexahydrocoenzyme Q 4 , chromenols of hexahydrocoenzyme Q 4 and coenzyme Q 10 , and tocopheryl quinone were inactive in preventing encephalomalacia and the resorption-gestation syndrome. The chromanol of vitamin K 1(20) was effective in shortening prothrombin time in vitamin K-deficient rats, while the chromanol of hexahydrocoenzyme Q 4 and the chromenol of coenzyme Q 10 were ineffective. more...

A �‘IT�� GIIN E-responsive mnacrocytic aneimiia in children has been described.’ The general nature of the anemia and its response to tocopherol are similar to that of the anemia which accompanies vitamin E deficiency in the n23 The monkey with anemia and creatinuria of vitamin E deficiency responds to treatment with the ti-chromanol of hexa� � � more...