Imidazole Salicylate

The molecular complexes of 2-amino-1H-benzimidazolium 2-hydroxybenzoate (2ABHB) and 2-amino-1H-benzimidazolium pyridine 2-carboxylate (2ABP2C) were synthesised from a donor 2-aminobenzimidazole (2AB), and acceptors, 2-hydroxybenzoate (2HB) and pyridine 2-carboxylic acid (P2C) respectively. The brown colour single crystals were successfully grown by slow evaporation solution growth technique. The densities of grown crystals 2ABHB and 2ABP2C were measured by floatation method using carbon tetrachloride and xylene as solvents. The single crystal X-ray diffraction reveals the molecular structures of compounds 2ABHB and 2ABP2C. Both the structures contain positively charged 2-aminobenzimidazolium cation, 2ABHB contains negatively charged 2-hydroxybenzoate anion and 2ABP2C contains pyridine 2 carboxylic acid anions. ¹H and ¹³C NMR spectral analyses were used to predict the presence of proton and carbon in the title compounds. The FTIR and Raman spectra have been recorded to detect the vibrational modes of functional groups present in the 2ABHB and 2ABP2C compounds. The proton transfer between the cation and anion was confirmed by UV-Vis spectra of both compounds. For both the compounds, thermal behaviour and stability of the crystals were studied using thermogravimetric and differential thermal analyses technique respectively. Further, the anti-bacterial activity of 2ABHB and 2ABP2C complex against Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas eruginos and E. coli pathogens were investigated.

The distinction between extra-intestinal manifestations of ulcerative colitis (UC) and drug-induced pneumonia can often be difficult.

We describe the case of a 72-year-old male who presented fever and sub-acute respiratory insufficiency, after 4 months of treatment with mesalazine for ulcerative colitis (UC). Initial tests found serum C-reactive protein, eosinophil count and total IgE to be elevated. Routine bacteriological, fungal and mycobacterial cultures were negative. Bronchoalveolar lavage fluid cellularity was normal with elevated lymphocyte, neutrophil, and eosinophil counts (35 % mononuclear cells, 23 % lymphocytes, 28 % neutrophils, 14 % eosinophils). The diagnosis of organizing pneumonia (OP) with eosinophilic pneumonia component was confirmed after examination of a lung biopsy specimen. Clinical improvement occurred after cessation of mesalazine and initiation of prednisolone (1mg/kg/day). Nine months later, a recurrence of gastrointestinal symptoms required a 5 months reintroduction of an amino salicylate by topical therapy (4- acide aminosalicylique [ASA enemas]). There was no resurgence of the pneumonia.

Organizing pneumonia is a rare extra-intestinal manifestation of UC. There was no resurgence of OP after amino salicylate enemas rechallenge but mesalazine-induced pneumonia cannot be excluded.