Defining the reactivity of nanoparticles to peptides through direct peptide reactivity assay (DPRA) using a high pressure liquid chromatography system with a diode array detector.

The possibility of inducing skin sensitization reactions following exposure to various chemicals can lead to skin diseases, and the evaluation of skin sensitivity to such substances is very important. However, as animal tests for skin sensitization are prohibited, the OECD Test Guideline 442 C was designated as part of an alternative testing method. Therefore, in this study, the reactivity of cysteine and lysine peptides to nanoparticle substrates was identified through HPLC-DAD analysis according to the skin sensitization animal replacement test method specified in the OECD Test Guideline 442 C.

Pre-validation study of spectrophotometric direct peptide reactivity assay (Spectro-DPRA) as a modified skin sensitization test method.

Skin sensitization is induced when certain chemicals bind to skin proteins. Direct peptide reactivity assay (DPRA) has been adopted by the OECD as an alternative method to evaluate skin sensitization by assessing a substance's reaction to two model peptides. A modified spectrophotometric method, Spectro-DPRA, can evaluate skin sensitization, in a high throughput fashion, to obviate some limitations of DPRA.

Sulfone-mediated syntheses of crocetin derivatives: regioselectivity of highly functionalized building blocks.

New C5 sulfone building blocks containing a masked polar end group have been devised for the efficient synthesis of carotenoids with polar termini. Chemoselectivity or the regiochemical issue of the highly functionalized units has been carefully addressed depending on the soft or hard nature of electrophiles. These building blocks have been successfully applied to the syntheses of crocetin derivatives, crocetin dial and the novel crocetin dinitrile.