Table 2. Inhibitory activities of 4b and its derivatives, 4c, 4d, 5b and 6, against ADAMTS-4 and -5. The inhibition of proteolysis was measured using either a short, 12-residue, peptide substrate (QF-peptide) or the protein substrate V1-5GAG. Values are presented as mean ± SEM (n = 3). ATS4, ADAMTS-4; ATS5, ADAMTS-5. NI a , not inhibiting at 50 μM. NI b , not inhibiting at 100 μM (< 10% inhibition compared with the DMSO