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T-2 & HT-2

 

T2 toxin HT2-toxin
Mycotoxines T2 and HT2

CAS N°
- formula :
- molecular weight : - white crystals :

UV absorption :

LD50 (bw mice) :
TDI:

[21259-20-1]
C24H34O9
466 amu
(mp = 151.5 °C)

< 200 nm

4 mg/kg (po)
0.06 µg/kg bw

[26943-87-2]
C22H32O8
424.49 amu
(mp = 152 °C)

< 200 nm

9 mg/kg (ip)
0.06 µg/kg bw

 


IN A FEW LINES :

ORIGINS :

T2 and HT2 mycotoxins

T-2 and HT-2 mycotoxins belong to the ‘trichothecene' group, and are mainly produced by Fusarium type moulds. These moulds develop on cereals in the fields, especially when the weather is wet and relatively cold during flowering. This is a specific feature of the Fusarium moulds as compared with Aspergillus moulds which produce aflatoxins, developing mainly upon storage and in warm areas. Multi-contamination (simultaneous presence of several trichothecenes) is common, but T-2 and HT-2 are more particularly widespread in some cereals such as oat.

 

 

CHEMICAL STRUCTURE :

There are over 150 different trichothecenes. Chemically, their common characteristic is a tetracyclic structure called ‘12,13-epoxytrichothecene'. They are divided into different types, the major ones being ‘type B', with a C-OR and a C=O in 7th and 8th positions, respectively (déoxynivalenol (DON), NIV, etc), and ‘type A' with a C-H in 7th position and a group other than carbonyl (isovalerate in the case of T-2 and HT-2, C-H in the case of DAS) in 8th position. Two acetates and one alcohol are also found in T-2. By hydrolysing the acetate in C-4, T-2 is converted into HT-2.

 

EFFECTS ON HEALTH :

Trichothecenes inhibit DNA and protein synthesis, but have no proven mutagen or carcinogenic effects. These toxins mainly affect the digestive system (DON is also called ‘vomitoxin') and can cause ‘alimentary toxic aleukia' and even lead to death. LD50s (intra-peritoneal) of T-2 and HT-2 for mice are between 5 and 10 mg/kg, while DON is 70. Even with no mortality, trichothecenes can result in high economic losses in cattle.

 

NORMS AND LEGISLATION (maximum levels in food products) :

Official standards are still missing for T-2 and HT-2 levels in food. It can be assumed that the range would be of about 100 µg/kg for the total T-2 + HT-2.


ROLE OF CODA-CERVA :

CODA-CERVA is the Belgian National Reference Laboratory for mycotoxins.

Since 2004, the laboratory has been carrying out measurments of T-2 and HT-2 for the FASFC (Federal Agency for the Safety of the Food Chain) in 100 to 150 samples per year. Between 2004 and 2009, analytical methods and quantification limits have greatly improved. Traditional methods relied on an early purification on immuno-affinity column. This method is expensive and inefficient. Moreover, it is reduced to 1 or 2 toxins for each type of column. The last method developed, currently under accreditation, makes use of the new UPLC-MS-MS tool and allows to measure various mycotoxins in a single non-purified sample.


SCIENTISTS RESPONSIBLE FOR THIS TOPIC :

 

Philippe Debongnie

 

Alfons Callebaut