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Investigation of furans, pyrroles and pyrazolones identified 3-pyridyl-2,5-diaryl-pyrroles as potent, orally bioavailable inhibitors of p38 kinase. 3-(4-pyridyl-2-(4-fluoro-phenyl)-5-(4-methylsulfinylphenyl)-pyrrol e (L-167307) reduces secondary paw swelling in the rat adjuvant arthritis model: ID50 = 7.4 mg/kg/b.i.d.
BACKGROUND: There is scarce information in the literature about a possible association between atopy and certain clinical manifestations of NSAID sensitivity. OBJECTIVES: (1) To evaluate the prevalence of atopy in patients proved to be sensitive to cyclooxygenase inhibitors. (2) To assess cross-reactivity to two alternative NSAIDs, paracetamol (acetaminophen) and nimesulide. METHODS: NSAID-sensitive patients attending an allergy clinic and unselected controls were prick tested with inhalant allergens. Oral challenges with NSAIDs were carried out by the single-blinded (SBOC) method. Clinical data about personal and family history of allergic and atopic diseases were obtained by a careful review of the medical records and by direct questioning by experienced allergists. RESULTS: Fifty patients had positive SBOCs to the suspected NSAID and only these were studied. A personal history of atopic diseases was present in 41 patients (82%) and 7 controls (14.5%), and a family history in 24 patients (48%) and 6 controls (12.5%). Prick skin tests with aeroallergens were positive in 39 of 45 patients tested (86.6%) and in 14 of 48 controls (29.1%), (P = .0001). Skin test positivity rates were higher in patients with cutaneous challenge reactions who responded to only one NSAID (single reactors) in comparison to cross-reactors (P = .04). The most frequent clinical manifestations of NSAID sensitivity were (1) cutaneous (angioedema, urticaria) in 34 patients, (2) blended (cutaneous plus respiratory) in 12, (3) respiratory in 3, and (4) anaphylactoid in 1. Aspirin, pyrazolone, paracetamol, and ibuprofen were the drugs more frequently implicated in these reactions. Cross-sensitivity with paracetamol and nimesulide were 32% and 25%, respectively. CONCLUSIONS: The prevalence of atopy is increased in challenge-proven NSAID-intolerant patients. The atopic condition may represent an important risk factor for developing reactions to these drugs. Paracetamol and nimesulide are relatively safe alternative choices in those patients, although their use still carries some risk of unwanted reactions.
Dysprosium has been determined by resonance light scattering (RLS) method in the presence of 1,6-bi(1'-phenyl-3'-methyl-5'-pyrazolone-4'-)hexanedione (BPMPHD) at pH 5.5. The Dy-BPMPHD system has three characteristic peaks at 358, 399 and 450 nm, especially the peak at 358 nm, which is proportional to the concentration of Dy(3+) in the range of 1.0 x 10(-10)-1.0 x 10(-5) mol l(-1). The detection limit (S/N=2) is 5.6 x 10(-12) mol l(-1). Synthetic samples are determined satisfactorily. A new sensitive method for detection of dysprosium has been proposed.
The effectiveness of indomethacin treatment (1 mg/kg) as an antipyretic was tested in patients after cranial trauma or brain surgery involving the centromedial forebrain. Indomethacin was effective in reducing temperature in 10 of 11 cases which showed a dipyrone-resistant hyperthermia developing in the first 24 hours after brain damage, while no significant antipyretic effect was seen in hyperthermic cases developing more than 72 hours after cranial trauma or brain surgery. Biochemical tests estimating the effect of indomethacin, and pyrazolone derivatives on the arachidonic acid metabolism showed significant effects of indomethacin only in influencing cyclooxygenase activity and no effect of any drugs on lipoxygenase actions. In view of these observations, the use of indomethacin is recommended as a treatment for neurogenic hyperthermia.
Sensitivities of the following derivatives of oligosaccharides in MS and LC/MS with frit FAB and ESI interfaces were compared under the conditions where samples were supplied to the probes in solutions at constant rates: 2-aminopyridine, 4-aminobenzoic acid ethyl ester (ABEE), 1-phenyl-3-methyl-5-pyrazolone (PMP) as well as 4-methoxyphenyl analogue, 2-aminoethanethiol, and 2-aminobenzenethiol. In FAB-MS, maltopentaose labeled with ABEE gave the most abundant [M + H]+ ions in positive ion mode when ionized in thioglycerol or glycerol matrix supplied in 50% (v/v) aqueous methanol. The lowest limit of detection was obtained for this compound in these matrices in water. The [M - H]- ion in negative ion mode was also abundant in all matrices examined in both 50% (v/v) aqueous methanol and water. On the other hand PMP derivatives gave the highest sensitivities in ESI-MS under the optimized conditions. On the basis of these findings, authentic oligosaccharides and oligosaccharides derived from a few glycoprotein samples were analyzed by LC/MS with frit FAB and ESI interfaces. The results indicated the usefulness of these derivatives for simultaneous microanalysis of oligosaccharides.
Bioisosteric substitution was used as a tool to generate several new structural alternatives to the thiazolidine-2,4-dione and tetrazole heterocycles as potential antidiabetic agents. Among the initial leads that emerged from this strategy, a family of acidic azoles, isoxazol-3- and -5-ones and a pyrazol-3-one, showed significant plasma glucose-lowering activity (17-42% reduction) in genetically obese, diabetic db/db mice at a dose of 100 mg/kg/day x4. Structure-activity relationship studies determined that 5-alkyl-4-(arylmethyl)pyrazol-3-ones, which exist in solution as aromatic enol/iminol tautomers, were the most promising new class of potential antidiabetic agent (32-45% reduction at 20 mg/kg/d x4). Included in this work are convenient syntheses for several types of acidic azoles that may find use as new acidic bioisosteres in medicinal chemistry such as the antidiabetic lead 5-(trifluoromethyl)pyrazol-3-one (hydroxy tautomer) and aza homologs of the pyrazolones, 1,2,3-triazol-5-ones (hydroxy tautomer) and 1,2,3,4-tetrazol-5-one heterocycles. log P and pKa data for 15 potential acidic bioisosteres, all appended to a 2-naphthalenylmethyl residue so as to maintain a similar distance between the acidic hydrogen and arene nucleus, are presented. This new data set allows comparison of a wide variety of potential acid mimetics (pKa 3.78-10.66; log P -0.21 to 2.76) for future drug design.
Pyrazole-, pyrazolone- and isoxazole-containing systems were prepared from 3,4-dihydro-6-(hexyloxy)-1(2H)-naphthalenone, 3,4-dihydro-6-(hexadecyloxy)-1(2H)-naphthalenone,3,4-dihydro-6(2-dimethylaminoethyloxy)-1-(2H)-naphthalenone, 3,4-dihydro-7-hexyloxy-1(2H)-phenanthrone, and 3,4-dihydro-7-(2-dimethylaminoethyloxy)-1(2H)-phenanthrone. A number of compounds derived from 7, 8-dihydro-5(6H)-quinolinone were also synthesized and characterized. Both hydrophilic and lipophilic groups were incorporated into certain systems as well as cidal groups. The compounds were screened for their in vitro inhibitory activity against Bacillus subtilis and Pseudomonas fluorescens. Structure-acitivity relationships among the molecular systems are discussed.
Pyrazole-, isoxazole-, and pyrazolone-containing systems were prepared from 3,4-dihydro-5,6,7-trimethoxy-1(2H)-naphthalenone, 3,4-dihydro-6,7,8-trimethoxy-1(2H)-naphthalenone, and 3,4-dihydro-6,7,8-trimethoxy-1(2H)-phenanthrone. Primarily, the pyrazoles displayed inhibition of growth in the microbial screens and in tissue culture. Correlation of the heteroatom distances between the oxygen atoms of two methoxy groups and a nitrogen atom in the pyrazole function with the percent plating efficiency on KB cell growth suggests increased inhibition as the (OA-N)/(OB-N) ratio deviates from one. No trend was observed in relating the OA-N-OB angle and activity for the examples studied.
A series of 2,4-dihydro-5-[4-(1H-imidazol-1-yl)phenyl]-3H-pyrazol-3-ones was synthesized and evaluated for positive inotropic activity. Only compounds with two small alkyl groups at C-4 showed significant activity. The structure-activity relationships for optimal inotropic activity are presented and compared with those of the 4,5-dihydro-3(2H)-pyridazinone series. The phosphodiesterase inhibitory activity is also reported and correlated with the substitution pattern at C-4 in the pyrazolone ring.
Three-component condensation of 4-piperidinones (7), 5-pyrazolones (8), and malononitrile (4) proceeds chemically and electrochemically and is a convenient one-step means of synthesis of substituted 6-amino-5-cyanospiro-4-(piperidine-4')-2H,4H-dihydropyrazolo[3,4-b]pyrans (12). The electrochemical reactions proceed under milder conditions and with yields 12-15% greater than those of the reactions catalyzed by chemical bases.
In the last several years, it has been proposed that neutrophil- and oxygen-dependent microvascular injuries may be important factors in the gastrointestinal toxicity of nonsteroidal antiinflammatory drugs (NSAIDs). In addition, after oral administration, reduced levels of gastric mucosal adenosine triphosphate in response to mitochondrial damage constitute the earliest event on topical mucosal erosions. In these experiments, we compared the implication of active oxygen, lipid peroxidation levels and neutrophil infiltration in gastric mucosal injury induced by the analgesic-antipyretic drugs, dipyrone (pyrazolone derivative) and acetaminophen (nonacidic drug), both with relatively weak antiinflammatory effects, with diclofenac (an acidic NSAID). After 6 hr of oral administration, dipyrone (120 and 500 mg/kg) did not provoke macroscopic lesions on rat gastric mucosa. Only the highest dose (1000 mg/kg) induced slight erosions similar to the same dose of acetaminophen without modifications in lipid peroxidation levels or myeloperoxidase activity. The area of mucosa with lesions, the increase in neutrophil infiltration, and concentration of TBA-reactive substances was significantly higher with diclofenac (50 mg/kg). By contrast, inhibition in superoxide dismutase activity was observed. In a dose-dependent manner, dipyrone and diclofenac decreased the levels of endogenous gluthatione, and the highest dose (1000 mg/kg) also inhibited glutathione peroxidase activity. None of treatments induced changes in xanthine oxidase activity, an index of ischemic condition. These findings confirm the favorable gastric tolerability of dipyrone, since only the highest dose produced weak mucosal lesions similar to that obtained with acetaminophen, and this effect only could be related to a diminished glutathione metabolism. In contrast, diclofenac induced significant erosions, and the data obtained indicate that the enhancement of oxidative stress plays an important role in the pathogenesis of damage.
BACKGROUND: We assessed the reliability of basophil activation test (FAST) and sulphidoleukotriene production (CAST) in the in vitro diagnosis of allergy to metamizol, evaluating its sensitivity and specificity. METHODS: Twenty-six patients allergic to metamizol and 30 control individuals were studied. Skin tests with metamizol, FAST, and CAST were performed. RESULTS: FAST sensitivity was 42.3% and specificity 100%. The PPV of FAST is 100% and the NPV 99.4%. The likelihood ratio for a positive value cannot be calculated because the specificity is 100% and the likelihood ratio for a negative value is 0.58. CAST sensitivity was 52%, and specificity 90%. The PPV of the test is 5% and the NPV 99.5%. The likelihood ratio for a positive result was 5.2 and that for a negative result 0.53. FAST detects a larger number of cases when patients are studied within the first 6 months after the clinical reaction (chi = 4.2, P = 0.04) than later. Together with skin tests, FAST allowed detection of 69.2% patients allergic to metamizol, the same as CAST 76%. The joint use of the three techniques allowed identification of 76.9% of cases. CONCLUSIONS: FAST and CAST are useful for the diagnosis of allergy to pyrazolones. Its usefulness clearly increases when recent reactions are studied.
Zinc(II) and cadmium(II) acetates were reacted in methanol under various experimental conditions with thiosemicarbazones derived from beta-keto amides or beta-keto esters (HTSC). Some of these reactions afforded thiosemicarbazonate complexes [M(TSC)2] with IR and NMR spectra compatible with N,S-coordination, but most gave complexes [ML2], where HL is a substituted 2,5-dihydro-5-oxo-1H-pyrazole-1-carbothioamide resulting from cyclization of the HTSC. Some of these pyrazolonates and two of the HL ligands were studied by X-ray diffractometry, and their structures are discussed. Surprisingly, the reactions of zinc(II) acetate with HTSC in 1:1 mol ratio usually gave a third, previously unreported type of complex with a dideprotonated ligand, [Zn(L-H)], which was also formed when [ZnL2] and Zn(OAc)2 interacted at room temperature in 1:1 mol ratio. These L-H complexes are highly insoluble in all common solvents, which hinders their characterization but suggests that they are polymeric in nature.
An aggregation parameter-based methodology for determining acid and neutral drugs in pharmaceutical dosage forms is presented. The method is based on competitive self-assembly in ternary dye-surfactant-drug aqueous mixtures. Dyes bearing charge of opposite sign to that of surfactants bind to surfactant to form mixed dye-surfactant aggregates, which are monitored from changes in the spectra features of the dye. The drug competes with the dye to interact with the surfactant to form drug-surfactant aggregates, which results in a decrease in the surfactant to dye binding degree proportional to the drug concentration in the aqueous solution. Coomassie Brilliant Blue G (CBBG) and didodecyldimethylammonium bromide (DDABr) were the dye and surfactant reactant used, respectively. The suitability of the surfactant to dye binding degree (SDBD) method to determine drugs with very different molecular structure: propionic (flurbiprofen, ibuprofen, naproxen and ketoprofen) and acetic (diclofenac, felbinac and zomepirac) acids, indolines (indomethacin and sulindac), glycyrrhetinic acid derivatives (carbenoxolone and enoxolone), salicylates (diflunisal and phenyl salicylate), oxicams (meloxicam, piroxicam and tenoxicam), pyrazolones (phenylbutazone and sulfinpyrazone) and hydrocortisones (dexamethasone and prednisolone) has been proved. The proposed method was successfully applied to the determination of drugs in commercial formulates (effervescent granulates, tablets, suppositories, gels and blisters) with a minimum sample treatment (dilution of liquid samples and dissolution of solid samples).
Eighty patients suffering from tension-type headache for an average of 21 years were asked to report on all drugs they had ever taken (type, dosage, duration of intake, efficacy) or were taking currently. The patients had consumed on average 6.3 different drugs. The cumulative doses of derivatives of para-aminophenol, pyrazolone, and salicylic acid in some cases reached a maximum of several kilograms. Most drugs were classified by the patients as "moderately effective". The rating "very effective" was assigned primarily to barbiturates; however, barbiturates are no longer used as components of compound analgesic drugs in Austria. At the time of investigation, patients consumed 2.5 (mean) different drugs, primarily as compound preparations. Seventeen patients (21%) showed signs of possible analgesics- or ergotamine-induced headache and were therefore advised to undergo withdrawal therapy. Our results show that patients with tension-type headache are at considerable risk of becoming drug-dependent and of acquiring analgesics-induced headache.
Inclusion of phenacetin among 'proven' human carcinogens by the IARC in 1987, raised concerns about the carcinogenic potential of acetaminophen, its major metabolite. Acetaminophen has been implicated as a possible causal agent in the development of cancer of the renal pelvis. The bladder and renal pelvis, which derive from the same embryological structure, share the same transitional type of epithelium. Past studies have been inconclusive on the possible relationship among these analgesics and bladder cancer but no large, highly detailed study of this association has been conducted. A population-based case-control study conducted in Los Angeles, California, involved 1514 incident bladder cancer cases and an equal number of controls who were matched to the index cases by sex, date of birth (within 5 years) and race. Detailed information on medication use and prior medical conditions was collected through in-person interviews. Regular use of analgesics was not associated with an increased risk of bladder cancer in either men or women. In fact, compared with non- or irregular users, regular analgesic users were at a decreased risk of bladder cancer overall (odds ratio (OR) = 0.81, 95% confidence interval (CI) = 0.68-0.96). However, there were clear differences in both the direction and strength of the associations between the different formulation classes of analgesics and bladder cancer risk. Intake of phenacetin was positively related to bladder cancer risk in a dose-dependent manner while intake of its major metabolite in humans, acetaminophen, was unrelated to risk. Intake of all classes of NSAIDs, except pyrazolon derivatives, were negatively associated with bladder cancer risk, with suggestive evidence that the protective effect varies in strength by subcategories of formulation. Acetic acids seemed to exhibit the strongest protective effect, whereas aspirin/other salicylic acids and oxicam showed the weakest protection.
An exact account of previous drug intake was obtained in 42 patients with acute agranulocytosis. Because of the multiplicity of administered drugs, often in the form of multiple-drug preparations, it was possible in only a minority of cases to ascribe with any degree of certainty a causative role to any particular drug. But outstanding as possible causes were thyrostatic drugs and pyrazolone. But no conclusion could be drawn as to the incidence of agranulocytosis with regard to these drugs because of the absence of data on the frequency that they are prescribed and the unknown number of fatal cases of agranulocytosis. The results indicate that multiple drug treatment and in particular the unnecessary prescribing of multiple-drug preparations makes it difficult to ascertain side-effects of drugs. They once again point to the need of frequent checks of white cell count in the drug treatment of pyrexial diseases.
Twelve new compounds were designed as 5-aryl-1H-pyrrole analogs of celecoxib (CAS 169590-42-5) and were synthesized by Paal-Knorr cyclization in three series according to 1H-substitution: derivatives with salicylic acid, pyrazolone or isonicotinamide residues. The average physico-chemical and steric similarity between the prototype and the new analogs (completed with two previously synthesized related products) was assessed to be 82 % and therefore considered as a reliable prerequisite for spatial compatibility and effective binding to the cyclooxygenase (COX) enzymes. The anti-inflammatory effects were determined in acute inflammation model using the carrageenan-induced rat paw edema assay on male Wistar rats (180-200 g) at doses of 10, 20 and 40 mg/kg, i.p. Six of the new products showed higher percent of inhibition (up to 100 %) compared to the highly selective COX-2 inhibitor celecoxib and the nonselective indometacin (CAS 53-86-1) used as reference compounds. Ethyl 1-(1,5-di-methyl-3-oxo-2-phenyl-2,3-dihydro-1H-4-pyrazolyl)-2-methyl-5-phenyl-1H-3-pyrrolecarboxylate (2b), ethyl 5-(4-chlor-ophenyl)-2-methyl-1-[(4-pyridylcarbonyl) amino]-1H-3-pyrrolecarboxylate (3c) and 5-[3-acetyl-2-methyl-5-(4-methylphenyl)-1H-1-pyrrolyl] -2-hydroxybenzoic acid (4b) were pointed out as the most active representatives of each of the three tested sub-series.