NPEdia Guanine-7-oxide
Producing organism
Streptomyces sp.
Biological activity
cytotoxic activity
Guanine 7-N-oxide produced by Streptomyces sp. was found to inhibit in vitro the replication of herpes virus (Oncorhynchus masou virus, OMV), rhabdo virus (infectious hematopoietic necrosis virus, IHNV) and a bi-segmented double-strand virus (infectious pancreatic necrosis virus, IPNV) derived from salmonids with IC50 values of about 10 µg/ml, 20 µg/ml and 32 µg/ml, respectively. The agent was not toxic for the host cells (chinook salmon embryo, CHSE-214) at the IC50 concentrations. Labeling of IHNV viral RNA and host cellular DNA and RNA with [3H]uridine and [3H]thymidine during drug treatment showed that guanine 7-N-oxide did not reduce the incorporation of these precusors into RNA and DNA. The anti-IHNV activity of guanine 7-N-oxide was enhanced synergistically by neplanocin A, an inhibitor of RNA methylation. The mechanism of action of guanine 7-N-oxide is discussed, in regard to maturation of viral messenger RNA including capping.
isolation and structural determination
  • Nishii M, Inagaki J, Nohara F, Isono K, Kusakabe H, Kobayashi K, Sakurai T, Koshimura S, Sethi SK, McCloskey JA.: A new antitumor antibiotic, guanine 7-N-oxide produced by Streptomyces sp.
    J Antibiot, 38(10): 1440-1443 (1985) PMID: 3840795
  • biological activities
  • Hasobe M, Saneyoshi M, Isono K.: Antiviral activity and its mechanism of guanine 7-N-oxide on DNA and RNA viruses derived from salmonid.
    J Antibiot, 38(11): 1581-1587 (1985) PMID: 3841124
  • Hasobe M, Saneyoshi M, Isono K.: The synergism of nucleoside antibiotics combined with guanine 7-N-oxide against a rhabdovirus, infectious hematopoietic necrosis virus (IHNV).
    J Antibiot, 39(9): 1291-1297 (1986) PMID: 3781928
  • Additional information