Direct synthesis of aflatoxin B1‐N7guanine adduct: A reference standard for biological monitoring of dietary aflatoxin exposure in molecular epidemiological studies

Vidyasagar, T.; Sujatha, N.; Sashidhar, R.B.

doi:10.1080/02652039709374552

Cited by 7 publications

(3 citation statements)

References 19 publications

(37 reference statements)

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“…For the synthesis of AFB 1 - N 7 -guanine (AFB 1 -Gua), based on previous reports (Vidyasagar et al. 1997 ), 0.12 mmol guanine was added to the solution containing 0.06 mmol of AFB 1 -epoxide in 1.1 mL DMSO and stirred for 15 min at room temperature. The product was purified using a Bond Elute PRS solid phase extraction (SPE) cartridge (1 mg, 6 mL, Agilent, Waldbronn, Germany).…”

Section: Methodsmentioning

confidence: 99%

Comparative metabolism of aflatoxin B1 in mouse, rat and human primary hepatocytes using HPLC–MS/MS

Gerdemann,

Cramer,

Degen

et al. 2023

Arch Toxicol

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Aflatoxin B1 (AFB1) is a highly hepatotoxic and carcinogenic mycotoxin produced by Aspergillus species. The compound is mainly metabolized in the liver and its metabolism varies between species. The present study quantified relevant AFB1- metabolites formed by mouse, rat, and human primary hepatocytes after treatment with 1 µM and 10 µM AFB1. The use of liquid chromatographic separation coupled with tandem mass spectrometric detection enabled the selective and sensitive determination of phase I and phase II metabolites of AFB1 over incubation times of up to 24 h. The binding of AFB1 to macromolecules was also considered. The fastest metabolism of AFB1 was observed in mouse hepatocytes which formed aflatoxin P1 as a major metabolite and also its glucuronidated form, while AFP1 occurred only in traces in the other species. Aflatoxin M1 was formed in all species and was, together with aflatoxin Q1 and aflatoxicol, the main metabolite in human cells. Effective epoxidation led to high amounts of DNA adducts already 30 min post-treatment, especially in rat hepatocytes. Lower levels of DNA adducts and fast DNA repair were found in mouse hepatocytes. Also, protein adducts arising from reactive intermediates were formed rapidly in all three species. Detoxification via glutathione conjugation and subsequent formation of the N-acetylcysteine derivative appeared to be similar in mice and in rats and strongly differed from human hepatocytes which did not form these metabolites at all. The use of qualitative reference material of a multitude of metabolites and the comparison of hepatocyte metabolism in three species using advanced methods enabled considerations on toxification and detoxification mechanisms of AFB1. In addition to glutathione conjugation, phase I metabolism is strongly involved in the detoxification of AFB1.

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Section: Methodsmentioning

confidence: 99%

Comparative metabolism of aflatoxin B1 in mouse, rat and human primary hepatocytes using HPLC–MS/MS

Gerdemann,

Cramer,

Degen

et al. 2023

Arch Toxicol

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“…Various analytical techniques including chromatographic and immunological methods, have been developed for the quantification of AFB 1 and its metabolites in food and biological samples. [8][9][10][11][12][13] The major objective of our work was to develop a rapid, sensitive, non-invasive immunoanalytical method for assessing the dietary exposure of humans to AFB 1 for field applications. Earlier, we reported a simple, sensitive enzyme-linked immunosorbent assay (ELISA) coupled with immunoaffinity chromatography for the quantitation of AFB 1 -N 7 -guanine adduct in urine using polyclonal antibodies.…”

Section: Introductionmentioning

confidence: 99%

“…Earlier, we reported a simple, sensitive enzyme-linked immunosorbent assay (ELISA) coupled with immunoaffinity chromatography for the quantitation of AFB 1 -N 7 -guanine adduct in urine using polyclonal antibodies. 12,13 We report here the application of this technique to the analysis of animal urine (given an oral dose of 1 mg of AFB 1 per kg body mass) and human urine obtained from people environmentally exposed to AFB 1 in their diet.…”

Section: Introductionmentioning

confidence: 99%

Quantification and validation of enzyme immunoassay for urinary aflatoxin B1–N7-guanine adduct for biological monitoring of aflatoxins

Nayak

Sashidhar

Bhat

2001

Analyst

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The aflatoxin B1-N7-guanine (AFB1-N7-guanine) adduct has been established as one of the relevant biomarkers of dietary aflatoxin (AFB1) exposure. Measurement of this adduct is potentially a useful dosimeter in molecular epidemiological studies. This paper reports the application and evaluation of a sensitive indirect competitive enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of urinary AFB1-N7-guanine adduct in high risk populations exposed to dietary aflatoxin. Earlier, we had reported a simple and rapid indirect ELISA method for AFB1-N7-guanine adduct in the urine and liver tissues using polyclonal antibodies specific to AFB1-N7-guanine adduct. The method was evaluated using a rodent model (Fischer 344), exposed to 1 mg kg-1 body mass of AFB1 and human urine samples obtained from a maize eating population, environmentally exposed to AFB1 through their diet. The levels of AFB1-N7-guanine adduct in rat and human urine ranged from 6.42 to 20.16 micrograms mg-1 creatinine and from 9.30 to 13.43 ng mg-1 creatinine, respectively. The level of AFB1 in the diet as estimated by ELISA ranged from 1000 to 3600 ng d-1. The interesting observation in these studies is that the females (in both rodents and human subjects) are more efficient than males at excreting the adduct. Total adduct (DNA bound adduct and guanine adduct excreted in urine) was found to be similar in male and female rats. However, 63% of the total adduct was accounted for in urine of female rats, whereas male rats excreted 47% of the total adduct in their urine. The present method may find wide application as a biochemical tool in molecular epidemiological studies with respect to human exposure to dietary aflatoxins.

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Optimization and validation of a LC-HRMS method for aflatoxins determination in urine samples

et al. 2020

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Mycotoxins exposure by inhalation and/or dermal contact can occur in different branches of industry especially where heavily dusty settings are present and the handling of dusty commodities is performed. This study aims to explore the possible contribution of the occupational exposure to aflatoxins by analysing urine samples for the presence of aflatoxins B1 and M1 and aflatoxin B1-N7-Guanine adduct. The study was conducted in 2017 on two groups of volunteers, the workers group, composed by personnel employed in an Italian feed plant (n=32), and a control group (n=29), composed by the administrative employees of the same feed plant; a total of 120 urine samples were collected and analysed. A screening method and a quantitative method with high resolution mass spectrometry determination were developed and fully validated. Limit of detections were 0.8 and 1.5 pg/mLurine for aflatoxin B1 and M1, respectively. No quantitative determination was possible for the adduct aflatoxin B1-N7-Guanine. Aflatoxin B1 and its adduct were not detected in the analysed samples, aflatoxin M1, instead, was found in 14 samples (12%) within the range 1.9-10.5 pg/mLurine. Only one sample showed a value above the limit of quantification (10.5 pg/mLurine). The absence of a statistical difference between the mean values for workers and the control group were compared suggests that in this specific setting, no professional exposure occurs. Furthermore, considering the very low level of aflatoxin Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation Click here to access/download;Authorship change form;12550_MYRE_Authorship_and_Disclosure_Form_DeSant Optimization and validation of a LC-HRMS method for aflatoxins

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Direct synthesis of aflatoxin B₁‐N⁷guanine adduct: A reference standard for biological monitoring of dietary aflatoxin exposure in molecular epidemiological studies

Cited by 7 publications

References 19 publications

Comparative metabolism of aflatoxin B1 in mouse, rat and human primary hepatocytes using HPLC–MS/MS

Comparative metabolism of aflatoxin B1 in mouse, rat and human primary hepatocytes using HPLC–MS/MS

Quantification and validation of enzyme immunoassay for urinary aflatoxin B1–N7-guanine adduct for biological monitoring of aflatoxins

Optimization and validation of a LC-HRMS method for aflatoxins determination in urine samples

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