Antibiotics antiviral action

The spectrum of biological activity displayed by tetramic acid-containing natural products is remarkable in its diversity it includes potent antibiotic, antiviral and antiulcerative properties, cytotoxicity and mycotoxicity, the inhibition of tumors (in mice and humans) as well as fungicidal action." Other members of this class are responsible for the pigmentation of certain molds and sponges. 

Actions Antibiotic, antiviral, anti-inflammatory, anti carcinogenic, expectorant, antiallergenic, laxative, antianemic, tonic, antifungal, immune stimulant, cell regenerator. 

Synthetic anti-viral agents discovered so far, tend to be specific for a limited range of viruses even so, they are usually wider in spectrum than available vaccines, and less expensive. Moreover their ability to treat an established viral infection injects new hope into the very area where viral immunotherapy fails. Antiviral action has rarely been found among antibiotics. 

Rifampin (4,2ob)y discussed in Section 4.0, inhibits replication of vaccinia virus in mouse cells (Heller et a/., 1969). Also rifamycin SV (4.20a) inhibits reverse transcriptase, the RNA-dependent synthesizer of DNA in viruses. Unfortunately, no clinical applications of these discoveries have been made. Apart from these and the phleomycins (Section 4.0, p. 115), antiviral action has rarely been found among antibiotics. 

In chapter eight, Buzzini et al. review naturally occurring 0-heterocycles with antiviral and antimicrobial properties, with paticular emphasis on the cat-echins and proanthocyanidins. Their modes of action as well as their synergy with currently used antibiotic molecules are also reviewed... 

Chandra et al.4> have shown that the antiviral activity of distamycin and their action on the template activity of DNA are dependent on the number of pyrrole rings in the molecule. The distamycin derivative with 5 pyrrole rings (distamycin/5) has 10 times higher antiviral activity than distamycin A (with 3 pyrrole rings), and is a better inhibitor of the RNA-polymerase reaction. It was therefore interesting to study the correlation between the antiviral activity and the inhibition of RNA-polymerase reaction by compounds I, II, III and IV. The effect of an equimolar concentration (8 x 10-5 M) of the distamycin derivatives on the template activity of DNA is shown in Table 9. The derivatives were added into the reaction mixture as described above. The highest inhibition was obtained with the natural antibiotic (distamycin A) followed by compounds IV, II and III, respectively. The cyclopentylpropionyl derivative, having no... 

Actions Antibacterial, antimicrobial, antiseptic, antiviral, antifungal, anthelmintic, antiparasitic. Of all herbs, it is perhaps the only true "antibiotic," the literal meaning of which is "antilife."... 

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