Research on mycotoxin glucosides (masked mycotoxins)

Abstract

For the detection of new glucoside derivatives of mycotooxins (masked mycotoxins), screening based on the accurate mass was carried out through the high resolution mass spectrometry measurement with LC-MS (LC-Orbitrap MS). Consequently, mono-glucoside derivatives of type B trichothecenes (nivalenol and fusarenon-X) in wheat grains infected with Fusarium strains and those of the type A trichothecenes (T-2 toxin, HT-2 toxin, neosolaniol, diacetoxyscirpenol, and monoacetoxyscirpenol) in corn powder reference material were detected, respectively. Di-glucoside derivatives were also found for T-2 toxin and HT-2 toxin. These findings indicate that the presence of masked mycotoxins is not limited to some specific mycotoxins such as deoxynivalenol and zearalenone, but likely with the other Fusarium mycotoxins.Fusarium fungi are plant pathogens infecting cereals such as wheat, barley, and corn, and some of them produce mycotoxins, such as trichothecenes (Fig. 1). and zearalenone (ZEN, Fig. 2). In Japan, the infection of grain by Fusarium fungi is occasionally serious, since those crops are usually planted during the rainy season. Among the Fusarium mycotoxins, deoxynivalenol (DON, Fig. 1), which belongs to the type B trichothecenes, is considered the most important 1) and many countries have set regulatory limits for DON in commodities and foods 2) .Recently, the existence of DON-3-glucoside (DON3G) (Fig. 3) in cereal grain and beer was reported 3),4) . Similar glucoside derivatives for other Fusarium mycotoxins including ZEN-14-glucoside (ZENG) (Fig. 3) were also found in plant 5),6) . Since these derivatives are usually not detected by the conventional analytical methods, they are called "masked mycotoxins" 7),8) . The existence of ZEN-14-sulphate (ZENS) was reported in another study 9) , and also regarded as a masked mycotoxin. Hydrolysis of masked mycotoxins to their original aglycons has also been reported 7),8),9),10) , therefore it is suggested that they are suggested to present an additional, potential risks of mycotoxins.Thus far, reports on the natural contamination of masked mycotoxin were mainly limited to those of DONG and ZENG (Fig. 3). However, it seemed to be very likely that glucoside derivatives of other mycotoxins also should exist considering that Fusarium fungi produce several different type of mycotoxins (Fig. 1, 2).

Detoxification of Mycotoxins through Biotransformation

“…The structures of transformed products (99 and 100) were deduced on the basis of accurate mass measurements of characteristic ions and fragmentation patterns by using high-resolution liquid chromatography-Orbitrap mass spectrometric analysis. Although their absolute structures were not clarified, 3-OH glucosylation appeared to be the most probable ( Figure S43) [74,75]. As the authors used Fusarium sp.…”

Modified Fusarium Mycotoxins in Cereals and Their Products—Metabolism, Occurrence, and Toxicity: An Updated Review

“…As mentioned in the introduction, the natural occurrence of modified mycotoxins in cereal grains is investigated by using plant enzymes from substances produced by the enzymatic system of fungi, related to fungal infections of plants. DON and ZEN are biosynthesised mainly by F. graminearum and F. culmorum , which are mainly responsible for FHB [ 83 , 84 , 85 ], although F. avenaceum may also be involved. It is thought that the geographic distribution of F. graminearum and F. culmorum may depend on weather conditions, including temperature and relative humidity.…”

Microbial Inhibition of Fusarium Pathogens and Biological Modification of Trichothecenes in Cereal Grains

“…Trichothecene glucosides have been isolated from Fusarium infected plant material [ 69 ]. The group of masked mycotoxins comprises not only some specific mycotoxins, such as DON and zearalenone, but also other Fusarium mycotoxins [ 70 ].…”