RHA™ anti-Ochratoxin monoclonal antibody, clone OTA

Ochratoxin, a secondary metabolite produced by Aspergillus or Penicillium, widely contaminates agricultural products such as cereals, fruits and nuts, and feed, causing serious economic losses. Ochratoxins are nephrotoxic, hepatotoxic, enterotoxic, carcinogenic, teratogenic, and immunotoxic, posing a great threat to human and animal health. Ochratoxins contain ochratoxins A, B, and C, of which ochratoxin A (OTA) is the most prevalent and relevant mycotoxin.

In the chemical structures of all three toxins, the amino acid L-phenylalanine is linked by an amide bond to substituted dihydroisocoumaric acid. The chlorine substituent is the distinguishing feature of the OTA structure and correlates with the toxicity of OTA. The non-chlorinated form of OTA is ochratoxin B (OTB). OTA compounds are white, crystalline, and tasteless, with poor solubility in water but moderate solubility in polar organic solvents such as chloroform and ethanol. The carboxylic and phenolic hydroxyl groups in OTA can cause OTA to behave in different forms in aqueous solvents depending on the pH, including non-ionic, monoanionic (OTA^-), and dianionic (OTA^2-). Due to the isocoumarin molecule, OTA emits intense fluorescence upon absorption of UV light, which is significantly pH-dependent. OTA is rapidly absorbed and systemically distributed in humans and animals, but elimination and excretion are very slow, resulting in accumulation in the body. OTA is bound to plasma proteins and is poorly metabolized in vivo, with plasma half-lives ranging from a few days in rodents and pigs to several weeks in non-human primates and humans. It is metabolized primarily by hydrolysis to OTalpha, which is then bound to glucuronic acid.

Figure 1. Chemical structure of ochratoxin A, B, and C
(Source: EFSA CONTAM Panel (EFSA Panel on Contaminants in the Food Chain), et al. 2020)

OTA is classified as a Group 2B carcinogen by the International Agency for Research on Cancer (IARC), and many countries limit its levels in agricultural foods. In the European Union, the Maximum Allowable Intake (MAI) for OTA is 3 μg/kg in cereals and cereal products, 2 μg/kg in wine and grape juice, and 0.5 μg/kg in foods for infants and young children. Preventing fungi from both infecting and producing mycotoxins is the most effective way to control mycotoxin contamination, but complete avoidance of fungal infections during plant growth is almost impossible to achieve, so more preventive measures are opting for removal of OTA contamination or detoxification of OTAs at the post-harvest or post-production stage.

anti-Ochratoxin mAb