Polychlorinated biphenyl (PCB) congeners with multiple ortho chlorine substituents and their metabolites exist as stable rotational isomers, or atropisomers, that are nonsuperimposable mirror images of each other. Additionally, the oxidation of certain axially prochiral PCBs, such as 2,2',4,6'-tetrachlorobiphenyl (PCB 51) and 2,2',4,5,6'-pentachlorobiphenyl (PCB 102), in the meta position of th...

The enantiomeric composition of polychlorinated biphenyl (PCB) atropisomers, including PCB 95, PCB 149 and PCB 132, was measured in 11 livers of harbour porpoises (Phocoena phocoena) from the southern North Sea. Non-racemic enantiomeric ratios (ERs) were found in some samples. The value of ERs in three of the four juvenile porpoises was equal or almost equal to one, while the ERs in all adults ...

Atropisomeric biaryl aldehydes undergo diastereoselective condensation with (-)-ephedrine and with a proline-derived diamine, with selectivity highly dependent on solvent, temperature and reaction conditions. Levels of thermodynamic control up to 5:1 may be obtained by heating the diamine with the aldehyde in a sealed tube. Alternatively, crystallisation-induced dynamic transformation allows is...

Aflatoxin B(1) (AFB(1)), a mycotoxin produced by Aspergillus flavus, is oxidized by cytochrome P450 enzymes to aflatoxin B(1)-8,9-epoxide, which alkylates DNA at N7-dG. Under basic conditions, this N7-dG adduct rearranges to yield the trans-8,9-dihydro-8-(2,6-diamino-4-oxo-3,4-dihydropyrimid-5-yl-formamido)-9-hydroxy aflatoxin B(1) (AFB(1)−FAPY) adduct. The AFB(1)−FAPY adduct exhibits geometric...

H(2)TFcP [TFcP = 5,10,15,20-tetraferrocenyl porphyrin(2-)] was prepared by a direct tetramerization reaction between pyrrole and ferrocene carbaldehyde in the presence of a BF(3) catalyst, while the series of MTFcP (M = Zn, Ni, Co and Cu) were prepared by a metallation reaction between H(2)TFcP and respective metal acetates. All compounds were characterized by UV-vis and MCD spectroscopy, APCI ...