Dietary Supplements Based on Red Yeast Rice—A Source of Citrinin?

Citrinin (CIT) is secondary metabolite of filamentous molds. This mycotoxin has nephrotoxic, hepatotoxic, embryocidal, and fetotoxic properties. It is also produced by several species of the three genera Penicillium spp., Aspergillus spp., and Monascus spp., which are used to make red yeast rice (RYR). The material for this study consisted of 15 dietary supplements containing an extract of fermented red rice, available on the Polish market. Samples were extracted using a MeOH–H2O mixture, cleaned-up with an immunoaffinity CitriTest HPLC column, and quantified by HPLC–FLD. None of the analyzed samples contained CIT above the established limit of detection (LOD). Studies on the presence of toxic metabolites in red yeast rice show the importance of regulating this product and of clear information on the label regarding the standardized amounts of monacolin.

Efficacy of Different C18 HPLC Analytical Columns in the Analysis of Fumonisins B1 and B2 in Different Matrices

Fumonisins B1 and B2 are carcinogenic and commonly contaminate corn and corn-based products. Analysis of such toxins using C18 HPLC column is officially accredited but still unknown if all column types can effectively separate FB1 and FB2 or not. The present study evaluated the efficiency of 5 analytical columns with different dimensions, particle sizes, and porosities to determine these toxins in both agar cultures of Fusarium verticillioides and cornflakes. Interestingly, the traditional column 150mm of length with 5µm porous particles had close retention times to those of the short-fused core column 75mm of length with 2.7 µm reflecting in time and solvents saving. Using Sep-Pack C18 for clean-up played an important role in enhancement the limit of quantification (LOQ) for cornflake samples (5-13.7 and 16.1-39 µg kg-1 for FB1 and FB2, respectively). However, it was relatively higher for fungal culture samples that were not passed through the cleaning-up step (11.5-16 and 28.1-46.3 µg kg-1 for FB1 and FB2, respectively). Overall, the lowest LOQ was obtained using the shorter fused core column. Finally, using such clean-up in the extraction of FB1 and FB2 from spiked cornflakes samples gave good recoveries (>80%) using all tested columns.

New dibenzocyclooctadiene lignan from Schisandra chinensis (Turcz.) Baill. fruits

Repeated column chromatography using Sephadex LH-20, silica gel (SiO2), and octadecyl SiO2 (ODS) as well as preparative HPLC column chromatography led to isolation of a new dibenzocyclooctadiene lignan along with four known ones, gomisin L2 (1), L1 (2), M1 (3), and M2 (4). Their chemical structures were fixed based on MS, IR, and NMR data analyses. In addition, the stereochemistry of atropisomers, the absolute configuration of the axial chirality in a biphenyl structure, was confirmed by a CD experiment. The new lignan was named gomisin M3 (5).

Low-coordinate organophosphorus compounds: some stereochemical considerations

Utilizing 2,4,6-tri-tert-butylphenyl as a sterically demanding group (abbreviated as Mes*), we have been successful in isolation, characterization, physical and chemical property investigation of low-coordinate organophosphorus compounds such as those carrying P=P and P=C bonds. Diphosphene, 1-phosphaethene, 1,3-diphosphaallene, 1-phosphaallene, and 3,4-diphosphinidenecyclobutenes are discussed in terms of stereochemistry including E/Z isomerization around P=P or P=C bond and R/S resolution of rotational isomers around crowded P–C bonds with chiral HPLC column. (π-Allyl)palladium complexes ligated with 3,4-diphosphinidenecyclobutene are useful in such catalytic organic reactions as the Tsuji-Trost reaction by which from a chiral s-alcohol, the corresponding chiral amine is obtained with retention of chirality suggesting double inversion process.