Assessing chronic exposure to fumonisin mycotoxins: the use of hair as a suitable noninvasive matrix.

This study describes for the first time the accumulation of measurable levels of fumonisin mycotoxins in the hair of nonhuman primates (vervet monkeys, Cercopithecus aethiops) and rats exposed to contaminated feed. Hair was subjected to reflux with methanol, and the resulting extract was cleaned up on strong anion exchange (SAX) and C18 solid-phase sorbents. Fumonisins FB1, FB2, and FB3 as well as their hydrolysis products commonly known as aminopolyols, AP1 and AP2, were detected in monkey hair using high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC-ESI-MS). Despite matrix interferences, the two-stage mass spectrometric process (MS-MS) yielded product ion mass spectra, which served as diagnostic indicators thus providing unequivocal identification of FB1, FB2, and FB3 as well as AP1 and AP2. In vervet monkeys, the levels of exposure related well to the levels of toxin detected in hair, and levels as high as 5.98 mg FB1, 33.77 mg FB1, and 65.93 mg FB1/kg of hair were found in monkeys receiving control, low-dose, and high-dose contaminated diets, respectively. Hair was also analyzed from rats given either single gavage doses of 1 and 10 mg FB1/kg body weight or contaminated feed (50 mg FB1/kg), resulting in an exposure of approximately 4.25 mg FB1/kg body weight/day based on the measured daily feed intake. Analysis of rat hair over a four-week period indicated that mean levels up to 34.50 mg/kg and 42.20 mg/kg were detectable by the fourth week in the rats treated by gavage (10 mg FB1/kg body weight) and those receiving contaminated feed, respectively. This relationship indicates that hair can provide an easily applicable non-invasive matrix for assessing chronic exposure to fumonisin mycotoxins.

Alkaloids from Cyrtanthus elatus.

The alcoholic extract of the fresh bulbs of Cyrtanthus elatus yielded zephyranthine (1) and 1,2-O-diacetylzephyranthine (2), together with three other known alkaloids. Complete assignment of 1H and 13C NMR spectra of compounds 1 and 2 was done by employment of two-dimensional NMR techniques.

Determination of patulin in apple juice by high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

An HPLC-MS-MS method with selected reaction monitoring (SRM) for the determination of patulin in apple juice samples is described. Mass spectrometric detection was accomplished following atmospheric pressure chemical ionization (APCI) in both positive and negative ion modes. Collision induced dissociation (CID) of the protonated molecular ion led initially to the loss of H2O (fragment m/z 137). At higher energies CO is lost from both the protonated parent molecule (fragment m/z 127) and the dehydrated molecular ion (fragment m/z 109). In contrast, CID of the deprotonated molecular ion led initially to the fragment at m/z 109 corresponding to the loss of either CO2 or acetaldehyde, followed at higher CID energy by the loss of H2O (fragment m/z 135) and CO (fragment m/z 125) from the deprotonated molecular ion. Detection in the negative ion mode proved superior and a linear response was observed over the injected range from 6 to 200 ng patulin. Apple juice samples spiked with patulin between 10 and 135 microg/l were analyzed following liquid-liquid extraction with ethyl acetate and clean up with sodium carbonate. Utilizing reversed-phase HPLC with acetonitrile-water (10:90) at 0.5 ml/min, levels down to 10 microg/l were readily quantified and a detection limit of 4 microg/l was attainable at a signal-to-noise (SIN) ratio of 4. The MS data for the spiked samples compared well to the UV data and when plotted against each other displayed a correlation coefficient (R) of 0.99.

Alkaloids from Crinum macowanii.

Eleven alkaloids have been isolated from fresh bulbs of Crinum macowanii (Amaryllidaceae). Macowine is reported here for the first time. The structure and stereochemistry of this new alkaloid as well as of the known ones were determined by physical and spectroscopic methods.

Bioactive alkaloids from Brunsvigia radulosa.

A phytochemical investigation of the bulbs of Brunsvigia radulosa yielded the new alkaloid 1-O-acetylnorpluviine, together with the known structures 1-epideacetylbowdensine, crinamine, crinine, hamayne, lycorine, anhydrolycorin-6-one and sternbergine. All structures were established by spectroscopic evidence. Some of the 13C assignments which were reported for crinamine and hamayne were corrected by means of 2D NMR techniques. In order to provide a further structure for biological testing, crinamine was converted to apohaemanthamine. The alkaloids were tested for activity against two strains of cultured Plasmodium falciparum and for cytotoxicity with BL6 mouse melanoma cells.

Cytotoxic and antimalarial alkaloids from Brunsvigia littoralis.

Four known alkaloids, lycorine (1), 1,2-di-O-acetyllycorine (2), ambelline (3), and crinine (4) were isolated from the bulbs of Brunsvigia littoralis (Amaryllidaceae). 1H- and 13C-NMR spectra of 2 were completely assigned by means of 1D- and 2D-NMR techniques. The alkaloids (1-4) together with the synthesised 11-O-acetylambelline (3a) and 3-O-acetylcrinine (4a) were tested for antimalarial activity with two strains of cultured Plasmodium falciparum and for cytotoxicity with BL6 mouse melanoma cells. Structures 1 and 2 exhibited both antimalarial and cytotoxic activity.