1 0SL (3r)-1-(naphthalen-2-ylsulfonyl)piperidine-3-carboxylic acid 1.000 2 I99 (3r)-1-(3-hydroxy-9,10-dioxo-9,10-dihydroanthracene-2-sulfonyl)piperidine-3-carboxylic acid 0.759 3 I7V (3r)-1-(3,4-dihydroxy-9,10-dioxo-9,10-dihydroanthracene-2-sulfonyl)piperidine-3-carboxylic acid 0.733