Excretion of 14 C-Fumonisin B 1 , 14 C-Hydrolyzed Fumonisin B 1 , and 14 C-Fumonisin B 1 -Fructose in Rats

Incubation of fumonisin B(1) and D-glucose in aqueous solutions resulted in the formation of N-(1-deoxy-D-fructos-1-yl) fumonisin B(1) in addition to the previously reported N-(carboxymethyl) fumonisin B(1). N-(1-Deoxy-D-fructos-1-yl) fumonisin B(1) is the first stable product formed after the Amadori rearrangement of the Schiff base formed by the reaction of the primary amine of fumonisin B(1) and the aldehyde group of D-glucose. N-(1-Deoxy-D-fructos-1-yl) fumonisin B(1) was synthesized by reacting fumonisin B(1) with an excess of D-glucose in methanol and heating for 6 h at 64 degrees C. It was purified using C(18) and strong cation exchange solid-phase extraction cartridges and characterized by nuclear magnetic resonance and liquid chromatography-mass spectrometry. Subsequently, N,N-dimethylformamide was found to be a better reaction solvent, requiring reaction for only 2-3 h at 64 degrees C and eliminating the formation of methyl esters. Alkaline hydrolysis of N-(1-deoxy-D-fructos-1-yl) fumonisin B(1) gave a mixture of hydrolyzed fumonisin B(1) and hydrolyzed N-(carboxymethyl) fumonisin B(1).

Section: Introductionmentioning

confidence: 99%

N-(1-Deoxy-d-fructos-1-yl) Fumonisin B₁, the Initial Reaction Product of Fumonisin B₁ and d-Glucose

Poling

Plattner

Weisleder

2002

“…Besides, there have been some toxicological studies with heating products between FB 1 and fructose, but the chemical structures of these reaction products have not been described. Whereas FB 1 promoted hepatocarcinogenesis in diethylnitrosamine (DEN)-initiated rats, an equimolar amount of unidentified reaction products of FB 1 and fructose caused no development of altered hepatic foci (19), although FB 1 -fructose products are absorbed to a greater extent than FB 1 in rats (20,21). Using the brine shrimp assay for the toxicity assessment of fumonisins, NCM-FB 1 was 100-fold less effective than FB 1 (22).…”

Section: Introductionmentioning

confidence: 99%

Determination ofN-(Carboxymethyl)fumonisin B₁in Corn Products by Liquid Chromatography/Electrospray Ionization–Mass Spectrometry

Seefelder

Hartl

Humpf

2001

It is well-known that fumonisin B(1) (FB(1)) in corn meal decreases during baking, frying, and cooking, but it is still not exactly clear how heating affects the formation of N-(carboxymethyl)fumonisin B(1) (NCM-FB(1)), the reaction product of FB(1) and reducing sugars. In model experiments corn grits were spiked with FB(1) (2 mg/kg) and D-glucose (50 g/kg) or sucrose (50 g/kg) and manufactured into extrusion products at various temperatures (160--180 degrees C) and moisture levels (16--20%). A liquid chromatography/electrospray ionization-mass spectrometry method using isotopically labeled fumonisin FB(1)-d(6) as an internal standard was developed for the determination of NCM-FB(1). For sample cleanup solid-phase C18 cartridges were used. The detection limit achieved with this method was 10 ng/g (signal-noise ratio = 3:1) using the protonated molecule [M + H](+) signal of NCM-FB(1) (m/z 780) in the selected ion monitoring mode. Low concentrations of NCM-FB(1) (29-97 ng/g) were detected in all samples spiked with D-glucose and FB(1), whereas those spiked with FB(1) and sucrose showed only NCM-FB(1) in samples produced at 180 degrees C (NCM-FB(1) = 27 ng/g). Various corn-containing food samples from the German market were analyzed for the presence of NCM-FB(1), FB(1), and hydrolyzed fumonisin B(1) (HFB(1)). All samples were contaminated with FB(1) (22--194 ng/g) and HFB(1) (5--247 ng/g). Six of nine samples contained NCM-FB(1) in low concentrations ranging from 10 to 76 ng/g. From these data and the low toxicity of NCM-FB(1) it can be concluded that the significance of NCM-FB(1) in food seems to be a minor one.

“…It is likely that ceramide synthase inhibition, a key event in toxigenesis (52), requires the primary amino function of the molecule (50,52,53). Interestingly, Lu et al (50) reported that an FB 1 -sugar reaction product or products, in which the primary amine group was modified so that it could no longer react with OPA but which was not otherwise identified (55), was not toxic to rats, a finding which implies that fumonisins are detoxified when converted to fumonisin-sugar compounds. Second, LC-MS also eliminated the need for extract cleanup and therefore allowed simultaneous quantification of FB 1 , HFB 1 , and PHFB 1 using a single aliquot of extract.…”

Section: Resultsmentioning

confidence: 99%

Fate of Fumonisins during the Production of Fried Tortilla Chips

Voss

Poling

Meredith

et al. 2001

The fate of fumonisin B(1) (FB(1)), a mycotoxin found in corn, during the commercial manufacture of fried tortilla chips was studied. FB(1) and hydrolyzed FB(1) (HFB(1)) concentrations in four lots of corn and in the masa, other intermediates, liquid and waste byproducts, and fried chips were determined by HPLC. FB(1) concentrations in the masa and chips were reduced significantly, up to 80% in the fried chips, compared to that in the raw corn. HFB(1) was also found in the masa and chips, but at low concentrations compared to FB(1). LC-MS analyses corroborated HPLC findings and further showed the presence of partially hydrolyzed FB(1) (PHFB(1)), which, like HFB(1), was formed during the nixtamalization (cooking/steeping the corn in alkaline water to make masa) step and found predominantly in the cooking/steeping liquid and solid waste. No significant amounts of N-(carboxymethyl)-FB(1) or N-(1-deoxy-D-fructos-1-yl)-FB(1), indicative of fumonisin-sugar adduct formation, were found. Thus, FB(1) is removed from corn and diverted into liquid and waste byproducts during the commercial production of fried tortilla chips. Nixtamalization and rinsing are the critical steps, whereas grinding, sheeting, baking, and frying the masa had little effect.