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The in vitro activity against herpes simplex virus type 1 of 3-methyl-but-2-enyl caffeate isolated from poplar buds or prepared by synthesis was investigated. Under conditions of one or multiple multiplication cycles, this compound, which is a minor constituent of propolis, was found to reduce the viral titer by 3 log10, and viral DNA synthesis by 32-fold.

Summary — The in vitro effect of propolis on several DNA and RNA viruses including herpes simplex type 1, an acyclovir resistant mutant, herpes simplex type 2, adenovirus type 2, vesicular stomatitis virus and poliovirus type 2, was investigated. The inhibition of poliovirus propagation was clearly observed through a plaque reduction test and a multistep virus replication assay with a selectivity index equal to 5. At the concentration of 30 μg/ml, propolis reduced the titer of herpes simplex viruses by 1 000, whereas vesicular stomatitis virus and adenovirus were less susceptible. In addition to its effect on virus multiplication, propolis was also found to exert a virucidal action on the enveloped viruses HSV and VSV.propolis / herpes simplex virus / adenovirus / vesicular stomatitis virus / poliovirus / antiviral activity

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The prooxidant effect of ~-tocopherol was investigated during linoleic acid autoxidation in an aqueous media, at pH 6.9. oeTocopherol (1.25 x 10 -4 M) was added to linoleic acid (2.5 x 10 -3 M) and the linoleic acid autoxidation rate was evaluated using 2 methods: spectrophotometric measurement at 234 nm exhibited an important increase of conjugated dienes after ~-tocopherol addition, especially during the first 4 days, and gas chromatographic measurement of unoxidized linoleic acid showed an important degradation of linoleic acid in the presence of a-tocopherol. During the prooxidant reaction, a-tocopherol was rapidly oxidized; it was detected as traces by thin layer chromatography after 4 days of experimentation. Two oxidation products of a-tocopherol have been identified: a-tocopherylquinone and a dimer of c~-tocophero[.

We evaluated, in cell cultures, the action of a series of 19 aporphine alkaloids against Herpes simplex virus type 1 (HSV-1). On the basis of viral titre reduction, six alkaloids were found to be active. The mode of action of the three most potent inhibitors, oliverine HCl, pachystaudine, and oxostephanine, was studied. These compounds did not have any virucidal or prophylactic effect but they were shown to interfere with the viral replicative cycle. Although DNA synthesis was reduced, their exact target remains to be elucidated. In the discussion, some structure-activity relationships are considered.

A series of 18 aporphinoids have been tested in vitro against human poliovirus. The aporphines (+)-glaucine fumarate (1), (+)-N-methyllaurotetanine (4), (+)-isoboldine (7), and (-)-nuciferine, HCl (10) were found to be active with selectivity indices > 14. The nature of the 1, 2-substituents of the isoquinoline moiety appeared to be critical for antipoliovirus activity. An SAR study demonstrated the importance of a methoxyl group at C-2 on the tetrahydroisoquinoline ring for the induction of antipoliovirus activity. Molecular modeling of some compounds in this series revealed the close similarities between the three-dimensional conformational features of the inactive 1,2-substituted derivatives (+)-boldine (6) and (+)-laurolitsine (5) with derivatives containing the 1,2-(methylenedioxy) moiety, which were generally found to be inactive as exemplified by (+)-cassythicine (9).

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