Abstract: Methods for enhancing detection by mass spectroscopy (MS) and/or chromatographic separability of carbonyl-containing compounds such as steroids are disclosed. Reaction of a carbonyl compound with a sulfonhydrazide compound provides a sulfonhydrazone with enhanced ionization efficiency during the electrospray ionization process. In a particularly disclosed embodiment, derivatization of catechol estrogens with p-toluenesulfonhydrazide enhances both detection by atmospheric pressure ionization-MS (API-MS), such as electron spray ionization-MS (ESI-MS) and separation by liquid chromatography (such as HPLC) under reverse phase conditions. In yet other embodiments, the sulfonhydrazone is further reacted with a sulfonyl halide under alkaline conditions to derivatize hydroxyl groups in the compound. Prior formation of the sulfonhydrazide derivative protects the carbonyl bond of the compound during subsequent alkaline reaction with the sulfonyl halide.

Abstract: The present invention provides compound of the formula (I): in which at least two of R1, R2, R3, R4, R5, and R6 are N2O2M and related compounds, substrates, compositions, and methods of using such compounds and compositions to treat biological disorders in which a polyphasic release of nitric oxide would be beneficial.

Abstract: Disclosed is a mouse in which expression of the gene encoding the CTLA-4 receptor is suppressed. Also disclosed is a nucleic acid construct useful in preparing such a mouse, and a cell line containing such construct.