Nickel release from metal items in contact with skin: a comparison of methods and practical implications for regulation in Europe.

Contact allergy to Nickel is the most prevalent contact allergy in western societies. This has led to regulation for metallic items that come into prolonged and direct contact with the skin, such as buttons on clothing, belt buckles, jewelry and watches. In Europe, the legal provision is based on a test in which there is a limit to the amount of nickel that may be released from the item to an artificial sweat solution (EN 1811). This test is costly and has reproducibility issues. The resulting undertesting of items placed on the market, leads to many nickel releasing non-compliant articles being available in spite of the regulations that are in place. In this study, the performance of the standard release test is compared to the performance of a rapid nickel spot test based on dimethylglyoxime (DMG-test). The data suggest that using the rapid DMG-test for compliance testing is sufficiently equivalent to the current gold standard of EN 1811. Previously published comparisons between the DMG-test and EN 1811 did not consider the effect of accelerated wear and corrosion testing according to EN 12472. This study shows that by applying EN 12472, the number of deviating results between the DMG-test and EN 1811 decreases significantly. Regarding consumer protection, it is necessary for wear and corrosion resistance to be considered.

Attempts toward the synthesis of the peptaibol antiamoebin by using the 'azirine/oxazolone method'.

The two segments, 1-9 and 10-16, of the peptaibol antibiotic antiamoebin I, i.e., the nonapeptide Ac-Phe-Aib-Aib-Aib-D,L-Iva-Gly-Leu-Aib-Aib-OH (15) and the heptapeptide Z-Hyp-Gln-D,L-Iva-Hyp-Aib-Pro-Pheol (34), have been prepared as mixtures of the epimers containing D,L-Iva. All α,α-disubstituted α-amino acids were introduced by the 'azirine/oxazolone method', in which amino or peptide acids are coupled with the corresponding 2H-azirin-3-amines, followed by selective hydrolysis of the terminal amide bond. The amino acids Hyp and Gln were introduced as Z-protected(4) ) (2S,4R)-4-(tert-butoxy)proline (19) and methyl N-[bis(4-methoxyphenyl)methyl]glutamine (26). Coupling of peptide segments was achieved via the 'mixed anhydride' method, the DCC/HOBt or TBTU/HOBt strategy. The crystal structure of the segment 6-9 was determined by X-ray crystallography and displayed the presence of a ß-turn conformation.