Ginger X. Yang

The discovery of sulfonylated dipeptides as Potent VLA-4 antagonists

Directed screening of a carboxylic acid-containing combinatorial library led to the discovery of potent inhibitors of the integrin VLA-4. Subsequent optimization by solid-phase synthesis afforded a series of sulfonylated dipeptide inhibitors with structural components that when combined in a single hybrid molecule gave a sub-nanomolar inhibitor as a lead for medicinal chemistry. Preliminary metabolic studies led to the discovery of substituted biphenyl derivatives with low picomolar activities. SAR and pharmacokinetic characterization of this series are presented.

N-Tetrahydrofuroyl-(l)-phenylalanine derivatives as potent VLA-4 antagonists

Given the proposed involvement of VLA-4 in inflammatory processes, a program to identify orally active VLA-4 antagonists was initiated. Herein, we report the discovery of a N-tetrahydrofuroyl-(L)-phenylalanine derivative (17) and related analogues as potent VLA-4 antagonists with good oral bioavailability.

Substituted tetrahydrofuroyl-1-phenylalanine derivatives as potent and specific VLA-4 antagonists.

A series of substituted tetrahydrofuroyl-1-phenylalanine derivatives was prepared and evaluated as VLA-4 antagonists. Substitution of the alpha carbon of the tetrahydrofuran with aryl groups increased the specificity for VLA-4 versus alpha(4)beta(7) while amide substitution increased the potency of the series without increasing the specificity. Substitution of the beta carbon of the tetrahydrofuran with keto or amino groups slightly improved the specificity for VLA-4 versus alpha(4)beta(7) but with a significant loss in binding affinity for VLA-4.

Constraining the amide bond in N-Sulfonylated dipeptide VLA-4 antagonists

The integrin VLA-4 is implicated in several inflammatory disease states. In search of non-peptidic antagonists of VLA-4, rotational constraints were imposed on the amide bond of prototypical N-sulfonylated dipeptide VLA-4 antagonists. By judicious structural modification of the side chains, trisubstituted imidazoles with moderate binding potencies were obtained, for example, 19, VLA-4 IC(50)=237 nM.

N-isonicotinoyl-(L)-4-aminophenylalanine derivatives as tight binding VLA-4 antagonists.

A series of isonicotinoyl-(L)-aminophenylalanine derivatives was prepared and evaluated as VLA-4 antagonists. These compounds exhibit subnanomolar binding affinity to VLA-4 and significant off-rates. The interplay between off-rate, protein binding and pharmacokinetics is discussed.

Discovery of a Potent and Selective DGAT1 Inhibitor with a Piperidinyl-oxy-cyclohexanecarboxylic Acid Moiety.

We report the discovery of a novel series of DGAT1 inhibitors in the benzimidazole class with a piperdinyl-oxy-cyclohexanecarboxylic acid moiety. This novel series possesses significantly improved selectivity against the A2A receptor, no ACAT1 off-target activity at 10 μM, and higher aqueous solubility and free fraction in plasma as compared to the previously reported pyridyl-oxy-cyclohexanecarboxylic acid series. In particular, 5B was shown to possess an excellent selectivity profile by screening it against a panel of more than 100 biological targets. Compound 5B significantly reduces lipid excursion in LTT in mouse and rat, demonstrates DGAT1 mediated reduction of food intake and body weight in mice, is negative in a 3-strain Ames test, and appears to distribute preferentially in the liver and the intestine in mice. We believe this lead series possesses significant potential to identify optimized compounds for clinical development.

Potent DGAT1 Inhibitors in the Benzimidazole Class with a Pyridyl-oxy-cyclohexanecarboxylic Acid Moiety

We report the design and synthesis of a series of novel DGAT1 inhibitors in the benzimidazole class with a pyridyl-oxy-cyclohexanecarboxylic acid moiety. In particular, compound 11A is a potent DGAT1 inhibitor with excellent selectivity against ACAT1. Compound 11A significantly reduces triglyceride excursion in lipid tolerance tests (LTT) in both mice and dogs at low plasma exposure. An in vivo study in mice with des-fluoro analogue 10A indicates that this series of compounds appears to distribute in intestine preferentially over plasma. The propensity to target intestine over plasma could be advantageous in reducing potential side effects since lower circulating levels of drug are required for efficacy. However, in the preclinical species, compound 11A undergoes cis/trans epimerization in vivo, which could complicate further development due to the presence of an active metabolite.