PMC

Pathways of acyloxy nitroso compound hydrolysis.

Nitroso hetero-Diels–Alder reaction between Boc-nitroso compound 54 and dienes 55.

Labeling of purified 38C2. A) Synthesis of nitroso and diene compounds for 38C2 conjugation. B) UV‐induced fluorescence of labeled 38C2. Stepwise, 38C2 was labeled with β‐lactam containing diene compound first, followed by nitroso labeling; preclicked, diene, and nitroso compound was reacted prior to labeling with 38C2. C) Electrospray ionization‐mass spectrometry (ESI‐MS) characterization of labeled 38C2. The deconvoluted spectra were overlayed and plotted.

Cross‐reactivity of dapsone‐ and nitroso dapsone‐responsive T‐cell clones. Dapsone‐ and nitroso dapsone‐responsive CD4⁺ and CD8⁺ clones were cultured with irradiated autologous EBV‐transformed B cells and either dapsone (100‐500 µmol/L) or the nitroso metabolite (5‐20 µmol/L) in triplicate cultures for 48 h. T‐cell proliferative responses were assessed through the addition of [³H]‐thymidine. A, Mean cross‐reactivity data for 153 clones divided according to the drug antigen peripheral blood mononuclear cells were cultured with to generate clones and CD phenotype. B, Pie charts showing number of clones with a particular cross‐reactivity profile (compound specific, weekly cross‐reactive (cross‐reactive compound displaying 10%‐50% response detected with comparator) and strongly cross‐reactive (cross‐reactive compound displaying > 50% response detected with comparator). C, Representative clones displaying each response profile. D, Relative quantification of dapsone and azoxy dimer in cultures containing nitroso dapsone (30 µmol/L), autologous EBV‐transformed B cells, and T‐cell clones. E, Absolute quantification of dapsone formation in cultures containing nitroso dapsone (30 µmol/L), autologous EBV‐transformed B cells, and T‐cell clones. Left hand graph shows the standard curve for dapsone (concentration range: 5 nmol/L‐1 µmol/L). Right hand side graph shows the time‐dependent formation of dapsone [Colour figure can be viewed at wileyonlinelibrary.com]