The smaller effect of cimetidine, relative to that of cimetidine, is explained by its smaller potency as a H2 receptor antagonist [ 5].
For Lys309Cys, the level of binding was on the limit of detection, and, compared with the smaller potency change of Arg292Cys with equivalent reduction in binding, suggested that a gating effect was also involved (Roberts and Evans, 2007).
Starting with an active compound of modest potency from a small focused screen, we were able to evolve this series to a lead molecule with high potency and selectivity versus other PDEs using structure-based design.
Efforts to treat gliomas and lymphomas in human patients by modulating system xc− activity with the low potency, metabolically unstable small molecule, sulfasalazine (SAS, Gout et al., 2001), were unsuccessful (Robe et al., 2009).
Traditional SAR studies guide improvements of small molecule potency and selectivity for a target.
Small compound inhibitors of these PPIs may have low potencies to bind other PPI interfaces and lead to side effects.
The Hill slopes were indistinguishable, but the EC50 value for azi-isoflurane was approximately 2-fold smaller (higher potency) than for isoflurane.
Changing the ester group in VU0155094 to the primary sulfonamide, 2, led to small losses of potency for mGlu7 and mGlu8 (∼1 3-fold), but a larger loss of potency for mGlu4 (>10 μM) (Table 1).
The introduction of polarity led to a small loss in potency (20) and the alternative pyridine isomer carrying the isopentylamine substituent (21) displayed a sevenfold loss in potency against the enzyme in comparison to 17.
However, similar truncation compounds 7 c and 7 h (both inactive) resulted in moderately active compounds (6 g, 117 μ m and 6 c, 115 μ m respectively), whilst this modification is associated with a small increase in potency for compound 1 c, 90 μ m (6 b, 35 μ m) and a large gain in potency for 7 e, 710 μ m (6 h, 23 μ m).
