Abstract. Hot water extracts of coffee grinds and commercial instant coffee solutions have been shown to exhibit marked antiviral and virucidal activities against herpes simplex virus type 1 (HSV-1). Specifically, it has been shown that caffeine and N-methyl-pyridinium formate inhibit the multiplication of HSV-1 in HEp-2 cells. The present study examined the virological properties and the antiviral activity of caffeic acid against HSV-1. Caffeic acid inhibited the multiplication of HSV-1 in vitro, while chlorogenic acid, a caffeic acid ester with quinic acid, did not. These reagents did not have a direct virucidal effect. The one-step growth curve of HSV-1 showed that the addition of caffeic acid at 8 h post infection (h p.i.) did not significantly affect the formation of progeny viruses. An analysis of the influence of the time of caffeic acid addition, revealed that addition at an early time post infection remarkably inhibited the formation of progeny infectious virus in the infected cells, but its addition after 6 h p.i. (i.e., the time of the completion of viral genome replication) did not efficiently inhibit this process. These results indicate that caffeic acid inhibits HSV-1 multiplication mainly before the completion of viral DNA replication, but not thereafter. Although caffeic acid showed some cytotoxicity by prolonged incubation, the observed antiviral activity is likely not the secondary result of the cytotoxic effect of the reagent, because the inhibition of the virus multiplication was observed before appearance of the notable cytotoxicity.

Umesu phenolics were obtained from the salt extracts of Japanese apricot (Nanko-mume cultivar of Prunus mume Sieb. et Zucc.) as purified phenolics.The antiviral activities of umesu phenolics obtained were then examined against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), enveloped DNA viruses. The phenolics inhibited the multiplication of these viruses when added to the culture media of the infected cells. This inhibition occurred at phenolic concentrations at which they showed no severe cytotoxicity. One-step growth experiments showed that the eclipse period in the HSV-1 multiplication process was extended in the presence of umesu phenolics and that the addition of phenolics after the completion of viral DNA replication did not affect their multiplication. More drastic effects were observed on virucidal activities against HSV-1 and HSV-2; the infectivity decreased to 0.0001 when infected cells were incubated with 3 mg/ml phenolics at 30°C for 5 min. These results demonstrate the antiviral and virucidal activities of umesu phenolics and suggest a potential pharmacological use for these phenolics as a sanitizing or preventive medicine against superficial HSV infections. K E Y W O R D S antiviral, herpes simplex virus, phenolics, Prunus mume

These results indicate a unique nature of chlorous acid as a potent virucidal agent with tolerable tissue damage and reveal a merit and limitation as a disinfectant in the food hygiene and as a sanitizer in the health care fields.

Abstract. in the present study, dehydroascorbic acid inhibited the multiplication of viruses of three different families: herpes simplex virus type 1 (HSV-1), influenza virus type A and poliovirus type 1. although dehydroascorbic acid showed some cytotoxicity at higher concentrations, the observed antiviral activity was not the secondary result of the cytotoxic effect of the reagent, as the inhibition of virus multiplication was observed at reagent concentrations significantly lower than those resulting in cytotoxicity. Characterization of the mode of the antiviral action of dehydroascorbic acid against hSV-1 revealed that the addition of reagent at any time post infection inhibited the formation of progeny infectious virus in the infected cells, and a one-step growth curve showed that the addition of reagent allowed formation for an additional 2 h, but then almost completely suppressed it. these results indicate that the reagent inhibits hSV-1 multiplication after the completion of viral dna replication, probably at the step of the envelopment of viral nucleocapsids at the Golgi apparatus of infected cells. Introductionduring the course of studies on the antiviral activities of various natural products and their components (1-6), we previously characterized the antiviral activity of ascorbic acid against the multiplication of a variety of dna and RNA viruses under the defined in vitro conditions. We found that the antiviral activity of ascorbic acid was not due to its antioxidant activity since dehydroascorbic acid, an oxidized form of ascorbic acid without any reducing ability, also showed noticeable antiviral activities against those viruses (5). Previous characterization revealed that dehydroascorbic acid showed even stronger antiviral activity, though a much less cytotoxic effect in vitro than ascorbic acid. in addition, dehydroascorbic acid does not induce the formation of highly toxic free hydroxyl radicals, even in the presence of metal ions in culture medium. considering a potential therapeutic use of dehydroascorbic acid, we further characterized the mode of antiviral activities of this compound. Materials and methodsCells and viruses. mdcK, hEp-2 and Vero cells were grown in Eagle's minimum essential medium (mEm) containing 5% fetal bovine serum (FBS). herpes simplex virus type 1, strain F (HSV-1), influenza virus A/Aichi (H 3 n 2 ) and poliovirus type 1, Sabin vaccine strain, were used throughout the experiments. the viruses were propagated in Vero cells (for hSV-1 and poliovirus) in mEm supplemented with 0.5% FBS, or in MDCK cells (for influenza virus) in MEM supplemented with 0.1% bovine serum albumin (BSa) and acetylated trypsin (4 µg/ml). The viruses were stored at -80˚C until use. the amount of each virus was measured by a plaque assay as described previously (7-9).Effect of the reagent on the virus yields. dehydroascorbic acid was obtained from Wako chemicals. the reagent solution (1.0 m or 100 mm) was prepared by dissolving the reagents in hot water, and its acidity was neutralized with 1 N so...

A methanolic solution of trans-p-coumaric acid was exposed to ultraviolet radiation and a mixture solution of the trans and cis isomers was subjected to cellulose column chromatography, eluting with an aqueous 0.1% trifluoroacetic acid solution containing methanol (90:10, v/v). Separation of the trans and cis isomers was achieved. The identity of the cis isomer was confirmed by TLC, HPLC, and NMR. Since both the support and eluent are inexpensive, the cis isomers can be obtained economically on both the laboratory and industrial scales.