The use of ampicillin/sulbactam (Unasyn) in treating inflammatory urological diseases

Unasyn is a combination of ampicillin, a bactericidal antibiotic, and sulbactam, an inhibitor of beta-lactamases. It was used in treatment of 36 patients with urogenital infections. The combination was administered intravenously and in the main intramuscularly. The treatment course amounted to 7-10 days. The average daily dose was 6 to 9 g. 22 patients with acute nonocclusive pyelonephritis were treated with the combination and its clinical and bacteriological efficacy was stated in 95 per cent of the cases. An excellent clinical effect of the combination was observed in 6 patients with acute epididymitis. A clinical improvement was also observed in the treatment of the patients with acute prostatitis and chronic renal infections. Unasyn proved to be a highly efficient antibacterial combination with regard to gram-positive flora and colon bacilli as representatives of gram-negative organisms. Satisfactory results were also stated in the treatment of infections caused by Proteus spp. Complete elimination of the pathogen was achieved in 57.7 per cent of the cases. No adverse reactions to Unasyn except pain in the site of the injection were recorded.     

Analysis of biochemical reactions in equilibrium: hydrolysis of penicillin and ampicillin

A general equilibrium model for a class of biochemical reactions was formulated, using the formalism of binding polynomials for the evaluations of the various species. Thermodynamic equilibrium constant was obtained from the observed equilibrium total concentrations of reactants at specified pH and certain ligand concentrations. Results for the hydrolysis of penicillin and ampicillin were analyzed with this equilibrium model. Predicted fractions of hydrolysis products at various pH values were calculated.     

Cycloferon efficacy in viral and bacterial diseases of children (clinical review)

The authors' findings and literature data on the pharmacotherapeut efficacy of cycloferon, an interferon inductor (immunomodulators) are described. The drug effect in the treatment of various socially significant children' diseases, including acute respiratory tract viral infection, bronchial asthma, allergic conditions with infection protection disturbances, mycoplasmic infection, bronchopulmonary complications of acute respiratory tract viral infection with low intensity of free radical oxidation is indicated. The use of cycloferon at the background of vaccination was shown to provide inhibition of the autoimmune processes causing postvaccinal complications in frequently ill children. The results of the use of cycloferon in the treatment of gastrointestinal tract and intestinal infections of both the viral and bacterial genesis are discussed. Cycferon is recommended to be used for correction of the intestine dysbiosis (the microflora level came to normal in 95% of the children). The use of the drug in surgical pathology and in particular in appendicular peritonitis for decreasing the postoperative complications and correction of the immune disturbances due to chronic viral hepatitis C and B in children under the complex therapy is described. The cycloferon safety and efficacy were confirmed by the postmarketing randomized trials.     

Kinetic studies on the mechanism of the penicillin amidase-catalysed synthesis of ampicillin and benzylpenicillin

Hydrophobic protein chromatography was used to prepare homogeneous fractions of penicillin amidase (EC 3.5.1.11) from E. coli. The apparent ratios of the rate constants for the deacylation of the acyl-penicillin amidase formed in the hydrolysis of phenylacetylglycine or D-phenylglycine methyl ester, by H2O and 6-aminopenicillanic acid (6-APA), were determined at different concentrations of the latter compound. The ratios were obtained from direct measurements of the initial rates of formation of phenylacetic acid and benzylpenicillin or D-phenylglycine and ampicillin. For the semisynthesis of ampicillin as well as of benzylpenicillin the ratio was found to depend on the concentration of 6-APA. This was observed for heterogeneous and homogeneous enzyme preparations. These results show that 6-APA must be bound to the acyl-enzyme before the deacylation, yielding ampicillin and benzylpenicillin, occurs. The dissociation constant KN for the formation of the complex was estimated to be approximately 10mM. This mechanism in which acyl-enzyme with and without bound nucleophile is involved, is in agreement with the principle of microscopic reversibility. Both acyl-enzymes can be deacylated by H2O. The finding that there is a specific binding site for 6-APA adjacent to the binding site for the phenylacetyl-(D-phenylglycyl-) group in the active site of the enzyme is supported by the observation that 6-APA acts as a mixed inhibitor in the hydrolysis of D-phenylglycine methyl ester. The ionic strength dependence indicates that the binding site for 6-APA of the acyl-enzyme is positively charged.     

Altered free calcium transients in pig kidney cells (LLC-PK1) cultured with penicillin/streptomycin

Summary The effect of a conventional antibiotic (penicillin/streptomycin) mixture on the widely used kidney epithelial cell line, LLC-PK₁, was investigated by measuring growth and intracellular free calcium. Free calcium concentration was the same in cells cultured for 3 to 7 wk with (“plus”) and without (“minus”) antibiotics both at rest and when challenged with high (14 mM) external calcium. When exposed to vasopressin, minus cells exhibited significantly smaller calcium transients than plus cells. A similar difference existed for transients elicited by a calcium ionophore, 4-br-A23187. After longer periods of culture (>20 wk), minus cells grew slower than plus cells but on reaching confluence (minus cells took 1 day longer) the morphologies and viabilities were indistinguishable. The finding that culture with penicillin/streptomycin reversibly modified some properties of LLC-PK₁ cells, at least partly through altered calcium homeostasis, is of importance for workers using this cell model to study drug effects and raises the general possibility of similar effects on other cultured cells.     

Single-dose treatment of gonococcal urethritis in males: evaluation of procaine penicillin,ampicillin and spectinomycin

Males with acute gonococcal urethritis were treated at random with 2.4 million units aqueous procaine penicillin G intramuscularly plus 1.0 g. probenecid orally, 3.5 g. ampicillin orally plus 1.0 g. probenecid orally, or 2.0 g. spectinomycin intramuscularly. The overall follow-up was 97%. All treatments were of equal efficacy, eradication of gonococcal disease being observed in 93 to 97% of treated patients. Treatment failures occurred in each drug group and pre-treatment isolates recovered from these cases showed decreased susceptibility to the agent used. Aqueous procaine penicillin G plus probenecid remains the preferred therapy for gonorrhea. For patients hypersensitive to penicillin, spectinomycin is currently a reasonable alternative drug. This agent, unlike procaine penicillin-probenecid, is probably ineffective against concurrent incubating syphilis, and future development of bacterial resistance is a definite possibility.     

A two-step, one-pot enzymatic synthesis of ampicillin from penicillin G potassium salt

A two-step, one-pot synthesis of ampicillin from penicillin G potassium salt (PGK) in aqueous buffer/organic co-solvent has been achieved. Ethylene glycol (EG) was chosen as the organic co-solvent. Factors including co-solvent content, enzyme loading, reaction temperature and substrate concentration were investigated. The optimum conditions were as follow: pH 8.0 phosphate buffer solution, 50% EG (v/v), 25 °C, 100 mM PGK and 300 mM d-phenylglycine methyl ester (D-PGM), 43.2 IU/ml IPA-750. The maximum yield was 57.3% after a reaction time of 17 h. It is the first report about the synthesis of ampicillin from penicillin G potassium salt in one-pot combining the enzymatic hydrolysis and the subsequent enzymatic condensation, and the novel methodology will have important application in the β-lactam antibiotics industry.     

Kinetically controlled synthesis of ampicillin with immobilized penicillin acylase in the presence of organic cosolvents

Penicillin acylase (PA) is used in the industrial production of 6-amino penicillanic acid (6-APA). However, by proper control of reaction medium, the enzyme can be used in the reverse synthesis of β-lactam antibiotics from the corresponding β-lactam nuclei and suitable acyl donors. Under thermodynamically controlled strategy, the use of organic cosolvents can favor synthesis over hydrolysis by lowering water activity and favoring the non-ionic reactive species. Under kinetically controlled strategy using activated acyl donors, organic solvents can favor synthesis by depressing hydrolytic reactions. Results are presented on the synthesis of ampicillin from phenylglycine methyl ester and 6-APA with immobilized Escherichia coli PA in the presence of organic cosolvents. Several solvents were tested in terms of enzyme stability and solubility of substrates. Ethylene glycol, glycerol, 1–2 propanediol and 1–3 butanediol were selected accordingly and ampicillin synthesis was performed in all of them. Best results in terms of yield and productivity were obtained with ethylene glycol, with which further studies were conducted. Variables studied were enzyme to limiting substrate ratio, acyl acceptor to acyl donor ratio, organic solvent concentration, pH and temperature. Experimental design based on a two-level fractional factorial design was conducted. pH was determined as the most sensitive variable and was further optimized. The best conditions for ampicillin synthesis in terms of productivity, within the range of values studied for those variables, were pH 7.4, 28°C, 36 U_S PA/mmol 6-APA, 3 mol PGME/mol 6-APA and 45 % (v/v) ethylene glycol concentration. Productivity was 7.66 mM ampicillin/h, which corresponds to a specific productivity of 7.02 μmol ampicillin/h U_S at 55 % yield. Productivity was lower than in buffer but product yield was higher because of the much lower relative hydrolysis rates.     

Free radicals properties of gamma-irradiated penicillin-derived antibiotics: piperacillin,ampicillin, and crystalline penicillin

The aim of this work was to determine the concentrations and properties of free radicals in piperacillin, ampicillin, and crystalline penicillin after gamma irradiation. The radicals were studied by electron paramagnetic resonance (EPR) spectroscopy using an X-band spectrometer (9.3 GHz). Gamma irradiation was performed at a dose of 25 kGy. One- and two-exponential functions were fitted to the experimental data, in order to assess the influence of the antibiotics’ storage time on the measured EPR lines. After gamma irradiation, complex EPR lines were recorded confirming the presence of a large number of free radicals formed during the irradiation. For all tested antibiotics, concentrations of free radicals and parameters of EPR spectra changed with storage time. The results obtained demonstrate that concentration of free radicals and other spectroscopic parameters can be used to select the optimal parameters of radiation sterilization of β-lactam antibiotics. The most important parameters are the constants τ (τ _1(A),(I) and τ _2(A),(I)) and K (K _0(A),(I), K _1(A),(I), K _2(A),(I)) of the exponential functions that describe free radicals decay during samples storage.     

Factors affecting the synthesis of ampicillin and hydroxypenicillins by the cell-bound penicillin acylase of Escherichia coli

1. The effect of pH, temperature, reactant concentration and reaction time has been investigated for the synthesis of benzylpenicillin, dl-alpha-hydroxybenzylpenicillin and d-alpha-aminobenzylpenicillin from 6-aminopenicillanic acid by the penicillin acylase of Escherichia coli. 2. Synthesis of penicillins from carboxylic acids proceeds most rapidly at pH5; with amides the optimum pH is higher (6-7) but the reverse reaction rapidly sets in. This can be counteracted by lowering the pH or adding more amide. Optimum temperatures are 35-40 degrees . 3. Most rapid synthesis of penicillin was obtained with the N-acylglycine and methyl ester derivatives of carboxylic acids. Increasing the amide/6-APA ratio above 1:1 raised the rate of synthesis of penicillins. 4. Preferential synthesis of d-alpha-hydroxybenzylpenicillin takes place in a reaction mixture containing dl-mandelic acid. 5. From d- and l-mandelamide, d- and l-alpha-hydroxybenzylpenicillins were prepared, the former being more bioactive than the latter. p-Hydroxy- and 3,4-dihydroxybenzylpenicillins were also prepared, the latter being more active against some Gram-negative bacteria than benzylpenicillin.