5-Benzoyl-1-methylpyrrole-2-acetic acids as antiinflammatory agents

An Electrophilic Approach to the Palladium-Catalyzed Carbonylative C-H Functionalization of Heterocycles

A palladium-catalyzed approach to intermolecular carbonylative C-H functionalization is described. This transformation is mediated by P(t)Bu3-coordinated palladium catalyst and allows the derivatization of a diverse range of heterocycles, including pyrroles, indoles, imidazoles, benzoxazoles, and furans. Preliminary studies suggest that this reaction may proceed via the catalytic formation of highly electrophilic intermediates. Overall, this provides with an atom-economical and general synthetic route to generate aryl-(hetero)aryl ketones using stable reagents (aryl iodides and CO) and without the typical need to exploit pre-metalated heterocycles in carbonylative coupling chemistry.

Synthesis of Tolmetin Hydrazide-Hydrazones and Discovery of a Potent Apoptosis Inducer in Colon Cancer Cells

Tolmetin hydrazide and a novel series of tolmetin hydrazide-hydrazones 4a-l were synthesized in this study. The structures of the new compounds were determined by spectral (FT-IR, (1)H NMR) methods. N'-[(2,6-Dichlorophenyl)methylidene]-2-[1-methyl-5-(4-methylbenzoyl)-1H-pyrrol-2-yl]acetohydrazide (4g) was evaluated in vitro using the MTT colorimetric method against the colon cancer cell lines HCT-116 (ATCC, CCL-247) and HT-29 (ATCC, HTB-38) to determine growth inhibition and cell viability at different doses. Compound 4g exhibited anti-cancer activity with an IC50 value of 76 μM against colon cancer line HT-29 (ATCC, HTB-38) and did not display cytotoxicity toward control NIH3T3 mouse embryonic fibroblast cells compared to tolmetin. In addition, this compound was evaluated for caspase-3, caspase-8, caspase-9, and annexin-V activation in the apoptotic pathway, which plays a key role in the treatment of cancer. We demonstrated that the anti-cancer activity of this compound was due to the activation of caspase-8 and caspase-9 involved in the apoptotic pathway. In addition, in this study, we investigated the catalytical effect of COX on the HT-29 cancer line, the apoptotic mechanism, and the moleculer binding of tolmetin and compound 4g on the COX enzyme active site.

Synthesis of 5-Phenyl 2-Functionalized Pyrroles by Amino Heck and Tandem Amino Heck Carbonylation Reactions

2-Methyl-, 2-(methoxycarbonyl)methyl-, and 2,2-[(ethoxycarbonyl)(methoxycarbonyl)]methyl-5-phenylpyrroles are prepared from the corresponding 3-butynyl and 4-(methoxycarbonyl)-3-butynyl phenyl ketone O-pentafluorobenzoyl oximes by amino Heck cyclization and tandem amino Heck carbonylation, respectively.

Synthesis, Acute Toxicity, and Analgesic Activity of New Derivatives of Pyrrole

Ten pyrrole derivatives (including six new compounds) were synthesized and evaluated as potential platform for analgesic agents' development. Acute intraperitoneal toxicity and analgesic activity studies (acetic acid writhing test) were performed on mice with acetylsalicylic acid used as a reference substance. Products 3c, 3d, 3e, and 3h exhibited a dose-dependent activity demonstrating 1.5 to 2.5-fold better protections than the reference. The most prospective compounds comprised salicylic acid moieties, whose 4-substituted derivatives were related to lower acute toxicity and considerable activity. 4-[3-(Ethoxycarbonyl)-2-methyl-5-(3,4-dimethoxy-phenyl)-1H-pyrrol-1-yl]-2-hydroxy-benzoic acid 3c was pointed out as the most prospective substance due to its lower acute toxicity (378 mg/kg body weight, intraperitoneally) and highest analgesic activity (up to 89.3% protection) in a dose range of 1/10 to 1/40 parts of LD(50).

Simultaneous determination of tolmetin and its metabolite in biological fluids by high-performance liquid chromatography

A highly sensitive and selective high-performance liquid chromatographic assay has been developed for the separation and quantitation of tolmetin and its major metabolite in human biological fluids, viz. plasma, urine and synovial fluid. Analysis of plasma and synovial fluid required only 0.5 ml of the sample. The sample was washed with diethyl ether and extracted with diethyl ether-chloroform (2:1). The extracted compounds were injected onto a reversed-phase column (RP-2) and absorbance was measured at 313 nm. The standard curves in plasma were found to be linear for both tolmetin and the metabolite at concentrations from 0.04 to 10.0 microgram/ml. Urine samples (0.5 ml) were diluted (1:1) with methanol containing the internal standard and were directly injected onto the reversed-phase (RP-2) column. Standard curves of tolmetin and metabolite in urine were linear in the range 5-300 microgram/ml. Serum and synovial fluid concentrations of tolmetin and its metabolite in patients receiving multiple doses of tolmetin sodium were determined using the assay procedure.

Stability-indicating assay for tolmetin sodium in solid dosage forms

A spectrophotometric assay for determining tolmetin sodium in pharmaceutical solid dosage forms is described. Tolmetin sodium is separated from common pharmaceutical excipients and probable degradation products. Recovery, precision, and accuracy data are provided. Two TLC methods are included which can be used to monitor qualitatively the stability of aged dosage forms.

Inhibition of ferrous iron induced oxidation of arachidonic acid by indomethacin

The molecular mechanism by which indomethacin exerts its inhibitory effects on the prostaglandin endoperoxide synthetase enzyme is unknown. In the present study we have explored the possibility that indomethacin might interact with Fe++ in the enzyme to produce its inhibitory effect. For this study we made use of the recent discovery that Fe++ alone can oxidize arachidonic acid, and the interaction of this fatty acid with the metal can be detected by following reduction of nitroblue tetrazolium (NBT) or by conversion of the Fe++ to Fe+++. Indomethacin markedly inhibited NBT reduction in the presence of arachidonic acid and Fe++ when the indomethacin had been preincubated with the Fe++. Indomethacin also inhibited the conversion of Fe++ to Fe+++ by arachidonic acid. Results obtained by varying the concentrations of indomethacin and arachidonic acid and measuring inhibition of the conversion of Fe++ to Fe+++ by the indomethacin are consistent with a one to one complex forming between indomethacin and Fe++. The complex between indomethacin and Fe++ separates on prolonged incubation of the complex with arachidonic acid. The nature of the binding is suggested by a molecular model. Our results suggest that indomethacin may act to inhibit the prostaglandin endoperoxide synthetase enzyme by complexing Fe++ in the enzyme. Ibuprofen and tolmetin, two other prostaglandin synthetase inhibitors, also inhibit the interaction of Fe++ with arachidonic acid suggesting this may be a general mechanism for this type of drug.

Determination of tolmetin in human plasma by GLC and spectrophotometric procedures

GLC and spectrophotometric methods for the determination of tolmetin in plasma were developed. The methods can detect tolmetin in concentrations above 0.5 mug/ml. The plasma levels obtained with a 600-mg dose of tolmetin to a human subject are reported.