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Other names
(-)-Viriditoxin
(M)-Viriditoxin | |
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3D model (JSmol)
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ChEBI | |
ChemSpider | |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Viriditoxin (VDT[1][2]) is a secondary metabolite produced by fungi.[3] Viriditoxin is a type of mycotoxin.[1] The biosynthesis of the compound has been investigated.[3]
It is produced by several Aspergillus species including A. aureoluteus,[4] A. brevipes,[5] and A. viridinutans in which it was first identified in 1971.[6] It has been isolated from Paecilomyces variotii, which was obtained from Nomura's jellyfish.[2] It is also produced by Cladosporium cladosporioides.[1]
Natural viriditoxin exists as a single atropisomer owing to restricted rotation about the C-C bond which joins the two naphthol rings. It has been confirmed by total synthesis to be twisted into the so-called M isomer.[6]
Viriditoxin is a secondary metabolite, a polyketide produced from multiple acetyl-CoA and malonyl-CoA units which are combined by a polyketide synthase (PKS) enzyme complex. A chain of eight acetate units are cyclised to give the three-ring system which forms half of the carbon framework of the final product. After selective methylation of one of the phenol groups and reduction of the pyrone ring, the resulting intermediate (semiviriditoxin) is dimerised by a laccase enzyme, generating specifically the minus M atropisomer.[7]
In nature, viriditoxin likely is used against microbial competition. On mangroves, P. variotii's production of viriditoxin was linked to antagonism against bacteria.[3]
A 2022 study found that it had potential as a leukemia treatment due to high cytotoxic potential and rapid kinetics of caspase activation when reacting to Jurkat leukemia and especially Ramos lymphoma cells; solid tumor cells were affected to a much lesser extent.[medical citation needed][1] Tests of viriditoxin on pregnant mice found little effect on the survival of their pups and there was no increase of abnormalities.[better source needed][8]