Even if one presumes a significant

enterohepatic recycling (biliary excretion of DON-GlcA to intestines) Z-VAD-FMK in vivo complete hydrolysis of the conjugate DON-GlcA by bacterial glucuronidase would occur before fecal excretion and before freezing of the fecal samples. Similar to the results obtained from the analysis of urine, traces of DON were observed in rat feces after administration of water due to the dietary DON intake. DOM-1 was not detected in the feces samples of this group, which could be explained by the higher method’s LODs and LOQs compared to DON and by only partial conversion. Following DON application, DON and DOM-1 were found in rat feces. The de-epoxidation of DON by rat gut microbes was demonstrated by Worrell et al. (1989). Furthermore, DOM-1 was determined as the major DON-metabolite in feces (Lake et al., 1987, Worrell et al., 1989 and Yoshizawa et al., U0126 solubility dmso 1983). In accordance, we observed DOM-1 amounts in feces exceeding those of DON in 5 out of 6 animals. Considerable amounts of DOM-1 (up to 78.1 nmol) were excreted even 24–48 after dosing. In the feces of rats dosed with D3G, the vast majority of the metabolites (99.5 ± 0.4%) was excreted in form of DON and DOM-1. Only traces of D3G were detected in three out of six samples 0–24 h after treatment. These

findings prove that the non-absorbed proportion of D3G is almost completely cleaved to DON and subsequently metabolized to DOM-1 in the gut. Our results are in line with in vitro Amino acid data from Berthiller et al. (2011), who showed that several intestinal bacteria have the capability to hydrolyze D3G to DON. Similarly,

Gareis et al. (1990) demonstrated that Z14G is completely cleaved during digestion, indicating that mycotoxin glucosides in general can be deconjugated in the digestive tract of mammals. We previously postulated that D3G is hydrolyzed to DON in distal parts of the intestine, since the toxin was found to be resistant to acidic conditions and several digestive enzymes (Berthiller et al., 2011). In total, we observed higher amounts of DON in rat feces after D3G treatment compared to DON treatment. As DON is mainly absorbed in the small intestine (Dänicke et al., 2004), our data lead to the assumption that D3G is hydrolyzed distal therefrom. However, detected amounts of DON in feces varied over a wide range (82–427 nmol), which impedes firm conclusions. Thus, further experiments with more specific study designs are necessary to verify this hypothesis. It should be emphasized here that the toxins were applied to the animals by gavage to ensure complete administration. These conditions are artificial, compared to the regular uptake of the compounds with feed. Further studies (e.g. with other animal species) shall take this into account, preferably delivering the compounds mixed into the diet. After DON application, the overall amount of the recovered analytes was 554 ± 64 nmol, representing 27.6 ± 3.6% of the administered dose. In urine, 14.9 ± 5.