β-Lactam degradation catalysed by Cd2+ ion in methanol

Martinez, Juan Hernandez; Navarro, Pilar; García, Álvarez; Parras, P. J. Martinez De Las

doi:10.1016/s0141-8130(99)00052-5

Cited by 17 publications

(11 citation statements)

References 21 publications

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“…Comparing with the AMX NMR spectrum (Table 2), the chemical shift of CH 3(11) and H (4) of the AMX-S-oxide, which were shifted downfield, indicate that CH 3 (11) and H (4) are in a cis position relative to the bonded oxygen. Furthermore, CH 3 (10) and H (2) , which were shifted upfield, signify that CH (10) and H (2) are in a trans position relative to the bonded oxygen (Table 2; Fig.…”

Section: H Nmr Analysismentioning

confidence: 97%

“…A lone pair of electrons resides on the AMX sulfur atom giving it a tetrahedral molecular geometry, subsequently, the oxygen bonded sulfur turns into a chiral centre. As a result, the bonded oxygen may appear at two positions: isomer-a: cis to H (4) and CH 3 (11) and trans to H (2) and CH 3 (10) ; and isomer-b: trans to H (4) and CH 3 (11) and cis to H (2) and CH 3 (10) . In order to determine the position of the bonded oxygen, a nuclear Overhauser enhancement (NOE) experiment was conducted.…”

Section: H Nmr Analysismentioning

confidence: 99%

“…However, the major pathways of their degradation are similar, and lead to various breakdown products in a majority of the b-lactams. The degradation of penicillins has been well studied, and it was found that various metal ions, such as mercury, [8] zinc, [9,10] cadmium, [11] cobalt [12] and copper, [13] may catalyse the degradation of the b-lactam ring. Furthermore, it was determined [14] that hydrolysis of the b-lactam ring occurred in various aqueous acidic conditions.…”

Section: Introductionmentioning

confidence: 99%

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Investigation of an amoxicillin oxidative degradation product formed under controlled environmental conditions

2010

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Environmental context.Although amoxicillin is a widely used antibiotic, it is yet to be detected in the aquatic environment. This study traces the production of the amoxicillin-S-oxide degradation product, and shows that it is consistently obtained only under sunlight irradiation. This is the first study to demonstrate the formation, under controlled environmental conditions, of this chemically stable product of amoxicillin. Abstract.Amoxicillin (AMX) is a widely used penicillin-type antibiotic, and its presence in the environment has been widely investigated. The formation and structure of an oxidised degradation product (DP) of AMX are described in the present work. The experiments were carried out in buffer solution (pH 7.5) containing AMX at a concentration of 100 μg mL–1, with and without acid and in field secondary effluent. The DP, AMX-S-oxide (sulfoxide), was consistently obtained only under sunlight irradiation and was significantly augmented by the addition of humic acid (5 mg L–1) and mainly in field secondary effluent, which acts as a natural photo-sensitiser. The structure of the AMX-S-oxide DP was determined by an LC-MS technique using a mobile phase of deuterated and non-deuterated solvents. A 1H NMR spectrum was obtained for the pure compound isolated by preparative HPLC. Further confirmation of the AMX-S-oxide structure was achieved by comparison of its UV spectrum with those of the two oxidation products, AMX-S-oxide and hydroxylated AMX, obtained by the ozonolysis of AMX.

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Section: H Nmr Analysismentioning

confidence: 97%

Section: H Nmr Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Investigation of an amoxicillin oxidative degradation product formed under controlled environmental conditions

2010

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“…It has been established that methanol fixes in position trans with respect to the sulphur atom forming a tetrahedral structure [7].…”

Section: Introductionmentioning

confidence: 99%

“…The application of the NQR spectroscopy in the investigation of numerous biologically active systems has been widely reported in the literature [7][8][9][10][11], while the papers devoted to the analysis of NQR parameters in solutions are scarce and further investigation is needed.…”

Section: Introductionmentioning

confidence: 99%

DFT outlook of solvent effect on function of nano bioorganic drugs

Моллаамин

Monajjemi

2012

Physics and Chemistry of Liquids

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The different physicochemical properties including energies as well as NQR parameters of -carboline and of its synthetic benzodiazepine receptor, N-ethyl-3-carbamoyl--carboline have been explained in terms of the optimised structure of the solvated molecules at the B3LYP/6-311þþG** level of theory within the Onsager self-consistent reaction field solvation model. Apart from most of the gas phase calculations published on -carbolines, in this work, we have included solvation effects in order to predict the relative physicochemical properties of these compounds. It often means that the gas phase calculations are insufficient and therefore the inclusion of these solvation effects is necessary. In order to gain insight into typical solvent-ligand interactions, their total and relative energies as well as dipole moments have been determined in different solvents of variable polarity. To analyse the electrostatic interactions of particular bioactive atoms in both considered ligands with different solvents, the 14 N-NQR parameters have been determined for individual nitrogen atoms of the compounds considered. Our finding leads us to wonder that the physiological function of the two considered ligands of GABA receptor involves alertness and other related attributes of any consistency embedded in solvation effects.

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Spectrophotometric determination of penicillins in pure and pharmaceutical formulations using Folin‐Ciocalteu reagent

Singh

Maheshwari

2010

Drug Testing and Analysis

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A new combination of time, temperature, and alkali is described for the spectrophotometric determination of amoxicillin and ampicillin using Folin-Ciocalteu reagent. The method is based on the development of blue-coloured product due to the reduction of tungstate and/or molybdate in Folin-Ciocalteu reagent by amoxicillin and ampicillin in alkaline medium. The chromogenic reaction has λ(max) at 720 and 740 nm with molar absorptivity 1.6295 × 10⁴ and 0.1085 × 10⁴ l mol⁻¹ cm⁻¹ in the Beer's Law range 2-10 µg mL⁻¹ and 10-70 µg mL⁻¹ for amoxicillin and ampicillin, respectively. The method is reproducible, quick, inexpensive, and particularly helpful in determining the drug content in commercial dosage forms.

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β-Lactam degradation catalysed by Cd2+ ion in methanol

Cited by 17 publications

References 21 publications

Investigation of an amoxicillin oxidative degradation product formed under controlled environmental conditions

Investigation of an amoxicillin oxidative degradation product formed under controlled environmental conditions

DFT outlook of solvent effect on function of nano bioorganic drugs

Spectrophotometric determination of penicillins in pure and pharmaceutical formulations using Folin‐Ciocalteu reagent

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