Ochratoxin A (OTA) ...What is it?

Ochratoxin A (OTA)

What is it?

Ochratoxin A (OTA; C₂₀H₁₈ClNO₆) is a mycotoxin produced by species of only two genera of fungi - Penicillium and Aspergillus. Two species of Penicillium (P. verrucosum and P. nordicum), are now accepted as bona fide OTA producers. Members of the Aspergillus ochraceus group, and isolates of A. niger, A. carbonarius and A. terreus are also reported to produce OTA.
OTA is the most important and most commonly occurring of a group of structurally related compunds. Ochratoxin A consists of a polyketide-derived dihydroiso-coumarin moiety linked through the 12-carboxy group to phenylalanine. There are several analogues of OTA, such as ochratoxin B (which differs in structure from OTA in lacking the chlorine atom), ochratoxin C and ochratoxin ß, which are all fungal metabolites. However, OTA is the major compound found as a natural contaminant of plant material. OTA contamination is commonly associated with cereals, fresh grapes, dried vine fruit, wine, beer, coffee, and cocoa.