Sulfasalazine and its metabolites inhibit platelet function in patients with inflammatory arthritis.

The purpose of this study is to assess the effect of sulfasalazine and its metabolites on platelet function in patients with inflammatory arthritis (IA). One hundred thirty-five consecutive patients with an established diagnosis of IA were screened. Those with a history of cardiovascular disease (CVD), taking anti-platelet agents or non-steroidal anti-inflammatory drugs (NSAIDs) were excluded. A total of 32 patients were investigated, 15 taking sulfasalazine and 17 taking other disease-modifying anti-rheumatic drugs (DMARDs) and no sulfasalazine. These two cohorts were compared to 15 patients with stable CVD on long-term aspirin. The effect of sulfasalazine and its metabolites on arachidonic acid (AA)-induced platelet aggregation was also tested in vitro in samples from healthy donors (n = 18). Demographics, CVD risk factors and disease activity indices were similar in the sulfasalazine and other DMARD groups. AA-induced platelet aggregation was significantly inhibited in the sulfasalazine group (9 ± 7 %) and comparable to that in the aspirin group (10 ± 6 %). In contrast, there was no effect on AA-induced platelet aggregation in the other DMARDs group (77 ± 12 %) (p < 0.001). Furthermore, sulfasalazine therapy had no effect on platelet aggregation in response to multiple other agonists. Sulfasalazine and its metabolites (5-aminosalicylic acid and sulfapyridine) exerted an additive and dose-dependent inhibitory effect on AA-induced platelet aggregation in vitro (p < 0.001). The inhibition of AA-induced platelet aggregation by sulfasalazine is comparable to that achieved by aspirin and is dependent on both sulfasalazine and its metabolites. This represents a potential mechanism that may contribute to the known cardioprotective effect of sulfasalazine in patients with IA.

fac-Tris(4-amino-benzohydroxamato)iron(III) ethanol solvate.

In the structure of the title compound, [Fe(C(7)H(7)N(2)O(2))(3)]·CH(3)CH(2)OH, the Fe(III) atom is in a distorted octa-hedral O(6) environment with the three hydroxamate O atoms (and the three carbonyl O atoms) arranged in a fac configuration and one of the hydroxamate ligands being puckered. The methyl C atom of the ethanol solvent mol-ecule is disordered over two positions with occupancies of 0.626 (13) and 0.374 (13), respectively. The cocrystallized ethanol mol-ecule is hydrogen bonded to one of the hydroxamate O atoms. O-H⋯O and N-H⋯O inter-actions generate infinite three-dimensional networks along [100], [010] and [001].

Design, synthesis and evaluation of aspirin analogues having an additional carboxylate substituent for antithrombotic activity.

Acetylsalicylic acid (aspirin) is an effective long-term prophylaxis of thrombotic events such as heart attacks and strokes. It covalently inhibits prostaglandin-H-synthase by interacting with Arg120 or Tyr385 at the active site allowing delivery of its acetyl group to Ser530. However the structure has not been optimized to fit the active site. We have designed acetylsalicylate analogues with an additional carboxylate substituent which allows simultaneous interaction with Arg120 and Tyr385 whilst positioning the acetyl group in close proximity to Ser530. One of these, an ester derivative which unlike acetylsalicylic acid is non-acidic, may act as useful lead compound for further exploitation of this approach.