[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.

[1] Natural viriditoxin exists as a single atropisomer owing to restricted rotation about the C-C bond which joins the two naphthol rings.

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.

On mangroves, P. variotii's production of viriditoxin was linked to antagonism against bacteria.