A series of carboxylic acids were prepared from a propargylglycine scaffold and tested for efficacy as matrix metalloproteinase (MMP) inhibitors. Detailed SAR for the series is reported for four enzymes within the MMP family. The inhibitors were typically potent against collagenase-3 (MMP-13) and gelatinase A (MMP-2), while they spared collagenase-1 (MMP-1) and only moderately inhibited stromelysin (MMP-3). Compound 40 represents a typical inhibition profile of a compound with reasonable potency. Introduction of polar groups was required in order to generate inhibitors with acceptable water solubility, and this often resulted in a loss of potency as in compound 63. High serum protein binding proved to be a difficult hurdle with many compounds such as 48 showing >99% binding. Some compounds such as 64 displayed approximately 90% binding, but no reliable method was discovered for designing molecules with low protein binding. Finally, selected data regarding the pharmacokinetic behavior of these compounds is presented.
A series of hydroxamates was prepared from an aminoproline scaffold and tested for efficacy as matrix metalloproteinase (MMP) inhibitors. Detailed SAR for the series is reported for five enzymes within the MMP family, and a number of inhibitors, such as compound 47, display broad-spectrum activity with sub-nanomolar potency for some enzymes. Modifications of the P1' portion of the molecule played a key role in affecting both potency and selectivity within the MMP family. Longer-chain aliphatic substituents in this region of the molecule tended to increase potency for MMP-3 and decrease potency for MMP-1, as exemplified by compounds 48-50, while aromatic substituents, as in compound 52, generated broad-spectrum inhibition. The data is rationalized based upon X-ray crystal data which is also presented. While the in vitro peroral absorption seemed to be less predictable, it tended to decrease with longer and more hydrophilic substituents. Finally, a rat model of osteoarthritis was used to evaluate the efficacy of these compounds, and a direct link was established between their pharmacokinetics and their in vivo efficacy.
Semi-automated 96-well plate solid-phase extraction (SPE) was used for sample preparation of fluprostenol, a prostaglandin analog, in rat plasma prior to detection by gas chromatography-negative chemical ionization tandem mass spectrometry (GC-NCI-MS-MS). A liquid handling system was utilized for all aspects of sample handling prior to SPE including transferring of samples into a 96-well format, preparation of standards as well as addition of internal standard to standards, quality control samples and study samples. SPE was performed in a 96-well plate format using octadecylsilane packing and the effluent from the SPE was dried in a custom-made 96-well apparatus. The sample residue was derivatized sequentially with pentafluorobenzylbromide followed by N-methyl-N-trimethylsilyltrifluoroacetamide. The derivatized sample was then analyzed using GC-NCI-MS-MS. The dynamic range for the method was from 7 to 5800 pg/ml with a 0.1-ml plasma sample. The methodology was evaluated over a 4-day period and demonstrated an accuracy of 90-106% with a precision of 2.4-12.9%.