Please see Table for a list of compounds, sources, and calculated values. All analytes were freshly made into 10 µM stocks in dimethyl sulfoxide (DMSO, spectrophotometric grade), aliquoted into argon filled amber 1.5 mL tubes, topped with argon again, and frozen at -20 o C for up to three months. For use in assay, samples were thawed and diluted to 1 µM working concentrations with DMSO.