Baclofen is a racemic GABAB receptor agonist that has a number of significant pharmacokinetic limitations, including a narrow window of absorption in the upper small intestine and rapid clearance from the blood. Arbaclofen placarbil is a novel transported prodrug of the pharmacologically active R-isomer of baclofen designed to be absorbed throughout the intestine by both passive and active mechanisms via the monocarboxylate type 1 transporter. Arbaclofen placarbil is rapidly converted to R-baclofen in human and animal tissues in vitro. This conversion seems to be primarily catalyzed in human tissues by human carboxylesterase-2, a major carboxylesterase expressed at high levels in various tissues including human intestinal cells. Arbaclofen placarbil was efficiently absorbed and rapidly converted to R-baclofen after oral dosing in rats, dogs, and monkeys. Exposure to R-baclofen was proportional to arbaclofen placarbil dose, whereas exposure to intact prodrug was low. Arbaclofen placarbil demonstrated enhanced colonic absorption, i.e., 5-fold higher R-baclofen exposure in rats and 12-fold higher in monkeys compared with intracolonic administration of R-baclofen. Sustained release formulations of arbaclofen placarbil demonstrated sustained R-baclofen exposure in dogs with bioavailability up to 68%. In clinical use, arbaclofen placarbil may improve the treatment of patients with gastroesophageal reflux disease, spasticity, and numerous other conditions by prolonging exposure and decreasing the fluctuations in plasma levels of R-baclofen.
The pituitary glycoprotein hormones, luteinizing hormone and follicle-stimulating hormone (FSH), act through their cognate receptors to initiate a series of coordinated physiological events that results in germ cell maturation. Given the importance of FSH in regulating folliculogenesis and fertility, the development of FSH mimetics has been sought to treat infertility. Currently, purified and recombinant human FSH are the only FSH receptor (FSH-R) agonists available for infertility treatment. By screening unbiased combinatorial chemistry libraries, using a cAMP-responsive luciferase reporter assay, we discovered thiazolidinone agonists (EC50's = 20 μm) of the human FSH-R. Subsequent analog library screening and parallel synthesis optimization resulted in the identification of a potent agonist (EC50 = 2 nm) with full efficacy compared with FSH that was FSH-R-selective and -dependent. The compound mediated progesterone production in Y1 cells transfected with the human FSH-R (EC50 = 980 nm) and estradiol production from primary rat ovarian granulosa cells (EC50 = 10.5 nm). This and related compounds did not compete with FSH for binding to the FSH-R. Use of human FSH/thyroid-stimulating hormone (TSH) receptor chimeras suggested a novel mechanism for receptor activation through a binding site independent of the natural hormone binding site. This study is the first report of a high affinity small molecule agonist that activates a glycoprotein hormone receptor through an allosteric mechanism. The small molecule FSH receptor agonists described here could lead to an oral alternative to the current parenteral FSH treatments used clinically to induce ovarian stimulation for both in vivo and in vitro fertilization therapy.
The design, synthesis, characterization, and screening of a large, encoded thiazolidinone library are described. Three sets of 35 building blocks were combined by encoded split-pool synthesis to give a library containing more than 42 000 members. Building block selection was based in part on a novel small molecule follicle stimulating hormone receptor agonist hit and in part for diversity. HPLC/MS techniques were applied at the single-bead level to build confidence in the reliability of library construction. Application of two distinct screening strategies resulted in the identification of compounds with significantly improved potency over the initial hit. This work demonstrates the versatility of encoded libraries for preparing a large number of analogues of a given hit while simultaneously generating a large collection of compounds for screening against other targets.
4,426,391 A 1, 1984 Alexander et al. 4,760,057 A 7, 1988 Alexander 4,916,230 A 4, 1990 Alexander 5,401,868 A 3, 1995 Lund 5,733,907 A 3, 1998 Alexander 7,227,028 B2 6/2007 Gallop et al. 7,265,140 B2 * 9/2007 Josyula et al. ................ 514,376 7,511,158 B2 * 3/2009 Gallop et al. ................. 548,542 2005/0107334 A1 5/2005 Gallop et al. 2005/0222431 A1 10/2005 Gallop et al. 2006/01 11325 A1 5/2006 Gallop et al. 2006/01 11439 A1 5/2006 Gallop et al.
L'invention concerne des composes permettant d'obtenir des concentrations systemiques soutenues d'analogues du GABA apres administration a des animaux. L'invention concerne en outre des compositions pharmaceutiques contenant ces composes et des methodes faisant appel a ces derniers.
An improved method for reducing aromatic nitro compounds on solid-phase supports using sodium hydrosulfite is presented. Conditions have been optimized to enable the use of this reagent for reductions on both polyethyleneglycol-polystyrene (PEG) resins and traditional polystyrene (PS) resins.