Pharmacological Characterization of 2NTX-99 [4-Methoxy-N¹-(4-trans-nitrooxycyclohexyl)-N³-(3-pyridinylmethyl)-1,3-benzenedicarboxamide], a Potential Antiatherothrombotic Agent with Antithromboxane and Nitric Oxide Donor Activity in Platelet and Vascular Preparations

Abstract

Thromboxane (TX) A 2 , prostacyclin (PGI 2 ), and nitric oxide (NO) regulate platelet function and interaction with the vessel wall. Inhibition of TXA 2 , implemented synthesis of PGI 2 , and supply of exogenous NO may afford therapeutic benefit. 2NTX-99 [4-methoxy-N 1 -(4-trans-nitrooxycyclohexyl)-N 3 -(3-pyridinylmethyl)-1,3-benzenedicarboxamide], a new chemical entity related to picotamide, showed antithromboxane activity and NO donor properties. 2NTX-99 relaxed rabbit aortic rings precontracted with norepinephrine or U46619 (9,11-dideoxy-9␣,11␣-methanoepoxy-prosta-5Z,13E-dien-1-oic acid; EC 50 , 7.9 and 17.1 M, respectively), an effect abolished by 10 M 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (ODQ). 2NTX-99 inhibited arachidonic acid (AA)-induced washed platelet aggregation (EC 50 , 9.8 M) and TXB 2 formation (Ϫ71% at 10 M), and its potency increased in the presence of aortic rings (EC 50 , 1.4 M). In whole rabbit aorta incubated with homologous platelets, AA caused contraction and TXA 2 formation, reduced by 2NTX-99 (10 -40 M): contraction, Ϫ28 and Ϫ47%, TXA 2 formation, Ϫ37 and Ϫ75.4%, respectively, with concomitant increase in PGI 2 . 2NTX-99 (20 -40 M) inhibited U46619-induced aggregation in rabbit platelet-rich plasma (PRP) (Ϫ74 Ϯ 6.7 and Ϫ96 Ϯ 2.4%, respectively) and inhibited collagen-induced aggregation in human PRP (Ϫ48.2 Ϯ 10 and Ϫ79.2 Ϯ 6%), whereas ozagrel was ineffective. In human embryonic kidney 293 cells transfected with the TXA 2 receptor isophorm ␣ receptor, 2NTX-99 did not compete with the ligand,,1]-hept-2-yl]-5-heptanoic acid), or prevent inositol phosphate accumulation. After oral administration (50 -250 mg/kg), 2NTX-99 inhibited TXA 2 production in rat clotting blood (Ϫ71 and Ϫ91%); at 250 mg/kg, an area under the curve, 0 to 16 h, of 149.5 h/g/ml and a t 1/2 of 6 h were calculated, with a C max value of 31.8 Ϯ 8.2 g/ml. An excellent correlation between plasma concentrations and TXA 2 inhibition occurs. 2NTX-99 controls platelet function and vessel wall interaction by multifactorial mechanisms and possesses therapeutic potential.

Organic Nitrate Therapy, Nitrate Tolerance, and Nitrate-Induced Endothelial Dysfunction: Emphasis on Redox Biology and Oxidative Stress

“…The development of new nitrate hybrid molecules and the introduction of nitrate functions into established cardiovascular drugs represent another interesting field of nitrate development ( 198 ). There are several reports in the literature on nitrate hybrid molecules: Next to nicorandil ( 142 ), there may be a candidate 2NTX-99, a thromboxane synthase inhibitor or thromboxane receptor antagonist ( 30 ); GT-094, a nonsteroidal anti-inflammatory drug (NSAID) with • NO-releasing function (organic nitrate group) ( 125 ); the antifungal drug ketoconazole with a diazen-1-ium-1,2-diolate or an organic nitrate moiety ( 169 ); • NO-donor-tacrine hybrids as hepatoprotective anti-Alzheimer drug candidates ( 84 ); the NicOx compound nitroaspirin, reviewed in Gresele and Momi ( 119 ); • NO-releasing celecoxib analogs, inhibitors of inducible cyclooxygenase ( 44 ); and a vitamin E analog with • NO donor function ( 191 ).…”

Characterization of New Organic Nitrate Hybrid Drugs Covalently Bound to Valsartan and Cilostazol

“…There are several reports in the literature on nitrate hybrid molecules: nicorandil, a potassium channel opener with nitrate function [10,11]; 2NTX-99, a thromboxane synthase inhibitor and thromboxane receptor antagonist and NO-releasing group [12]; GT-094, a nonsteroidal anti-inflammatory drug with NO function [13]; the antifungal drug ketoconazole with a diazen-1-ium-1,2-diolate or an organic nitrate moiety [14]; NO-donor-tacrine hybrids as hepatoprotective anti-Alzheimer drug candidates [15]; the NicOx compound nitroaspirin, reviewed in Gresele and Momi [16]; NO-releasing celecoxib analogs, inhibitors of inducible cyclooxygenase [17]; a vitamin E analog with NO donor function [18]. Probably we could not list all examples that have been published during the last few years but our list provides an overview of the diversity of NO hybrids.…”

Cordycepin (3‘-deoxyadenosine) inhibits human platelet aggregation induced by U46619, a TXA2 analogue

“…PKC), can be considered. However, the fact that TXA 2 receptor binding compounds, TXA 2 receptor function blockers and TXA 2 synthase inhibitors (such as U46619, S18886, picotamide, 2NTX-99, 2-[(4-acetylphenyl)amino]-3chloro-1,4-naphthalenedione, terbogrel and NQ301) are structurally distinct (Berrettini et al 1990;Chang et al 1997;Guth et al 2004;Jin et al 2005;Buccellati et al 2006) seems to suggest that TXA 2 receptor and its directed pathway may not be a target molecule. Instead, it is notable that adenine nucleotide derivatives structurally related to cordycepin diminished platelet aggregation by blocking adenosine diphosphate (ADP) receptor (i.e.…”