Determination of bongkrekic acid and isobongkrekic acid in rice noodles by HPLC-Orbitrap HRMS technology using magnetic halloysite nanotubes.

The existing extraction and detection methods of bongkrekic acid (BKA) and isobongkrekic acid (IBKA) are complex, time-consuming and solvent-consuming. In this work, a simple and fast pre-concentration procedure based on Fe3O4/HNTs was developed for the determination of BKA and IBKA in rice noodles using HPLC-Orbitrap HRMS. The structure and morphology of Fe3O4/HNTs was characterized by means of XRD, SEM, FT-IR and VSM. Parameters affecting the extraction efficiency including adsorbent amount, pH, extraction time, type and volume of eluent were investigated by employing the response surface method. Results indicated that the proposed method had favorable linearity in the concentration range of 2-200 µg/L with a correlation coefficient >0.998. Method LOD and LOQ were 0.3 µg/kg and 1.0 µg/kg, respectively. Finally, the method was successfully applied to determine BKA and IBKA in rice noodle samples from southern China with recoveries ranging from 79.8% to 102.6% and relative standard deviation (RSD) of 4.2%-7.1%.

Description of a Mass Poisoning in a Rural District in Mozambique: The First Documented Bongkrekic Acid Poisoning in Africa.

Background: On 9 January 2015, in a rural town in Mozambique, >230 persons became sick and 75 died of an illness linked to drinking pombe, a traditional alcoholic beverage. Methods: An investigation was conducted to identify case patients and determine the cause of the outbreak. A case patient was defined as any resident of Chitima who developed any new or unexplained neurologic, gastrointestinal, or cardiovascular symptom from 9 January at 6:00 am through 12 January at 11:59 pm. We conducted medical record reviews, healthcare worker and community surveys, anthropologic and toxicologic investigations of local medicinal plants and commercial pesticides, and laboratory testing of the suspect and control pombe. Results: We identified 234 case patients; 75 (32%) died and 159 recovered. Overall, 61% of case patients were female (n = 142), and ages ranged from 1 to 87 years (median, 30 years). Signs and symptoms included abdominal pain, diarrhea, vomiting, and generalized malaise. Death was preceded by psychomotor agitation and abnormal posturing. The median interval from pombe consumption to symptom onset was 16 hours. Toxic levels of bongkrekic acid (BA) were detected in the suspect pombe but not the control pombe. Burkholderia gladioli pathovar cocovenenans, the bacteria that produces BA, was detected in the flour used to make the pombe. Conclusions: We report for the first time an outbreak of a highly lethal illness linked to BA, a deadly food-borne toxin in Africa. Given that no previous outbreaks have been recognized outside Asia, our investigation suggests that BA might be an unrecognized cause of toxic outbreaks globally.

Fermented corn flour poisoning in rural areas of China. III. Isolation and identification of main toxin produced by causal microorganisms.

Flavotoxin A was isolated from Pseudomonas cocovenenans subsp. farinofermentans culture in semisolid potato-dextrose-agar medium, which was isolated from fermented corn meal that had caused food poisoning outbreaks in China. The isolation, purification, and chemical structure of this toxin were studied. The NMR spectra, the uv spectra, and molar extinction coefficients, and the mass spectra of Flavotoxin A are in good agreement with those reported for bongkrekic acid. Therefore, Flavotoxin A and bongkrekic acid are the same organic chemical compound; the molecular formula is C28H38O7. The oral LD50 of the purified Flavotoxin A in mice was 3.16 mg/kg (1.53-6.15 mg/kg). The existence of bongkrekic acid in toxic fermented corn samples collected during food poisoning outbreaks was also confirmed. It is concluded that bongkrekic acid has played an important role in the outbreaks of fermented corn poisoning.