We have identified a novel series of antidiabetic N-(2-benzoylphenyl)-L-tyrosine derivatives which are potent, selective PPARgamma agonists. Through the use of in vitro PPARgamma binding and functional assays (2S)-3-(4-(benzyloxy)phenyl)-2-((1-methyl-3-oxo-3-phenylpropenyl)+ ++amin o)propionic acid (2) was identified as a structurally novel PPARgamma agonist. Structure-activity relationships identified the 2-aminobenzophenone moiety as a suitable isostere for the chemically labile enaminone moiety in compound 2, affording 2-((2-benzoylphenyl)amino)-3-(4-(benzyloxy)phenyl)propionic acid (9). Replacement of the benzyl group in 9 with substituents known to confer in vivo potency in the thiazolidinedione (TZD) class of antidiabetic agents provided a dramatic increase in the in vitro functional potency and affinity at PPARgamma, affording a series of potent and selective PPARgamma agonists exemplified by (2S)-((2-benzoylphenyl)amino)-3-¿4-[2-(methylpyridin-2-ylamino+ ++)ethoxy ]phenyl¿propionic acid (18), 3-¿4-[2-(benzoxazol-2-ylmethylamino)ethoxy]phenyl¿-(2S)-((2- benzoylph enyl)amino)propanoic acid (19), and (2S)-((2-benzoylphenyl)amino)-3-¿4-[2-(5-methyl-2-phenyloxazol-4-y l)e thoxy]phenyl¿propanoic acid (20). Compounds 18 and 20 show potent antihyperglycemic and antihyperlipidemic activity when given orally in two rodent models of type 2 diabetes. In addition, these analogues are readily prepared in chiral nonracemic fashion from L-tyrosine and do not show a propensity to undergo racemization in vitro. The increased potency of these PPARgamma agonists relative to troglitazone may translate into superior clinical efficacy for the treatment of type 2 diabetes.

In an effort to discover a potent ultrashort-acting mu opioid analgetic that is capable of metabolizing to an inactive species independent of hepatic function, several classes of 4-anilidopiperidine analgetics were synthesized and evaluated. One series of compounds displayed potent mu opioid agonist activity with a high degree of analgesic efficacy and an ultrashort to long duration of action. These analgetics, 4-(methoxycarbonyl)-4-[(1-oxopropyl)phenylamino]-1-piperidinepropanoi c acid alkyl esters, were evaluated in vitro in the guinea pig ileum for mu opioid activity, in vivo in the rat tail withdrawal assay for analgesic efficacy and duration of action, and in vitro in human whole blood for their ability to be metabolized in blood. Compounds in this series were all shown to be potent mu agonists in vitro, but depending upon the alkyl ester substitution the potency and duration of action in vivo varied substantially. The discrepancies between the in vitro and in vivo activities and variations in duration of action are probably due to different rates of ester hydrolysis by blood esterase(s). The SAR with respect to analgesic activity and duration of action as a function of the various esters synthesized is discussed. It was also demonstrated that the duration of action for the ultrashort-acting analgetic, 8, does not change upon prolonged infusion or administration of multiple bolus injections.

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SUMMARYInhibitors of cyclic nucleotide phosphodiesterases are known to suppress lipopolysaccharide (LPS)-induced tumour necrosis factor-alpha (TNF-Q) production in vitro In human monocytes. The most potent of these have selectivity for type IV PDEs, suggesting that this class of PDE is the major type involved in the regulation of human TNF-« production. Using compounds of two distinct chemical structural classes, a quinazolincdionc (CP-77 059) and a 4 arylpyrrolidinone (rolipram). we show here that PDE-IV-specific inhibitors are also potent in stippressing LPSinduced TNF-rv production in vitro in sodium periodate-clicited murine macrophages (IC'syS of 1 and 33, respectively). We then report the in vivo anti-inflammatory effect of PDE-IV inhibition in five murine models of inflammation: (i) elevation of serum TNF-a induced by a subtethal LPS injection; {ii) LPS-indueed endotoxic shock; (iii) LPS/galactosamine-induced endotoxic shock; (iv) carrageenan-induced paw oedema; and (v) adjuvant arthritis. Following a sublcthal {5/(g/mouse) injection of LPS, serum TNF-a levels in miee peaked sharply, reaching concentrations of 3-12ng/ ml 90 min after injection. In this sublethal LPS assay. CP-77 059 was about 30 times more potent than rolipram, with a minimum effective dose of 01 mg/kg versus 3 mg/kg for rolipram. This rank order is in keeping with the relative in vitro ICsoS for CP-77059 and rolipram, as well as their relative Ki against the human PDE-IV enzyme (46 nM and 220 nM, respectively). In LPS-induced endotoxic shock, rolipram and CP-77 059 at relatively high doses of 30 and 10 mg/kg. respectively. significantly reduced serum TNF-ft levels, and also inhibited mortality 66%. In the LPS/ galactosamine shock model, in which mice are rendered exquisitely sensitive to LPS by coinjection with galaetosamine. oniy 01 ^ig of LPS/mouse Is necessary for serum TNF-cv elevation and death. Both rolipram and the CP-77059 caused dose-dependent reduction of serum TNF-rt and lethality. In the carrageenan-induced paw oedema model, in which there is a pronounced local TNF-(v response {without a serum TNF-a elevation), rolipram significantly inhibited paw swelling as well as localized TNF-cv levels in the paw. In the adjuvant arthritis model, a chronic model of inflammation also possessing localized TNF-a elevation in the inflamed paw, rolipram and CP-77059 suppressed ankle swelling and radiological evidence of joint damage. These data are consistent with a major role for PDE-IV in regulation of TNF-a production and inflammatory responses in murine systems. It suggests a potential therapeutic use for PDE-IV-specific inhibitors in inflammatory disease such as rheumatoid arthritis, septic shock and other inflammatory diseases where TNF-a has been postulated to be a contributing factor in the pathology ofthe disease.

The synthesis and biological evaluation of cAMP-specific phosphodiesterase (PDE IV) inhibitors is described. The PDE IV inhibitor 4-(3-butoxy-4-methoxybenzyl)imidazolidin-2-one (Ro 20-1724, 2) was used as a template from which to design a set of rigid oxazolidinones, imidazolidinones, and pyrrolizidinones that mimic Ro 20-1724 but differ in the orientation of the carbonyl group. The endo isomer of each of these heterocycles was more potent than the exo isomer in an enzyme inhibition assay and a cellular assay, which measured TNF alpha secretion from activated human peripheral blood monocytes (HPBM). Imidazolidinone 4a inhibited human PDE IV with a Ki of 27 nM and TNF alpha secretion from HPBM with an IC50 of 290 nM. By comparison, Ro 20-1724 is significantly less active in these assays with activities of 1930 and 1800nM, respectively.