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Biomedical subjects

M G Quaglia

Publications and source records attributed to M G Quaglia.

At least 19 recordsLinked to original sources
PubMed1999

Enatioseparation and anti-rhinovirus activity of 3-benzylchroman-4-ones.

In a series of homo-isoflavonoids, chloro-substituted rac-3-benzylchroman-4-ones (3 d-f) showed an antiviral in vitro activity against selected picornaviruses. In order to study the anti-rhinovirus activity of each stereoisomer, racemic mixtures of 3 d and 3 e were successfully resolved by high-performance liquid chromatography, using a Whelk-O 1 column as chiral stationary phase. The CD spectra confirm that the two eluates of each compound are enantiomers but do not allow the assignment of their absolute configurations. The antiviral activity of the isomers and their racemates was tested in vitro against human rhinovirus serotype 1B and 14 infection, by means of the plaque reduction assay. All homoisoflavonoids tested exhibited an inhibitory effect on rhinovirus replication with an activity depending on virus serotype and compound. The two enantiomers of each compound and the corresponding racemate were equipotent, clearly showing that the configuration of the chiral center in position 3 does not influence the activity against both rhinovirus serotypes.

Antiviral Agents↗
PubMed1998

Human alpha1-glycoprotein acid as chiral selector in the enantioseparation of midodrine and deglymidodrine racemates by HPLC.

Human alpha1-acid glycoprotein (alpha1-AGP) has been used as a chiral stationary phase (CSP) for the enantioseparation of midodrine and deglymidodrine racemates in the same HPLC run. The imobilized AGP resulted as the best chiral selector for the enantioresolution of two compounds. Due to the modification of alpha1-AGP characters as a result of changing the composition of the mobile phase, an attempt study of the watery mobile phase (ionic strength and pH of the buffer, nature and concentration of the organic modifier) allowed for an increase in the enantioselectivity of the chromatographic system and an optimization of the resolution base-line of both enantiomeric pairs.

Chemistry Techniques, Analytical↗
PubMed1997

Determination of the binding of a beta 2-blocker drug, frusemide and ceftriaxone to serum proteins by capillary zone electrophoresis.

A modified Hummel-Dreyer method was used to study the binding of drugs with serum proteins by high performance capillary electrophoresis. The study was carried out to check the possible interaction between serum proteins and a highly selective beta 2-blocker, ICI 118551 (ICI). To prove the suitability of the method the protein binding of frusemide and ceftriaxone, drugs previously investigated, was also studied. The analyses were carried out by injecting a solution of s alpha(1)-acidic glycoprotein (alpha(1)-AGP) or human serum albumin in 70 mM NaH2PO4/Na2HPO4(pH 7.4) buffer into an uncoated fused silica capillary filled with the same buffer. In the capillary, maintained at a working temperature of 35 degrees C, a known amount of the ICI, frusemide or ceftriaxone was added. The method allows the bound drug to be determined directly.

Adrenergic beta-2 Receptor Antagonists↗
PubMed1997

The indirect UV detection in the analysis of ursodeoxycholic acid and related compounds by HPCE.

A high-performance capillary zone electrophoretic (HPCE) assay has been developed for the determination of ursodeoxycholic acid (UDCA) and its usual impurities. Considering the low molecular absorptivity of UDCA and its related compounds indirect UV detection was used. The electrophoretic capillary was filled with a background electrolyte (BGE) containing an UV absorbing ion: benzoic acid (BA) or 5,5-diethylbarbituric acid (DBA). To enhance the selectivity of the assay diimethyl-beta-cyclodextrines (D-beta-CDs) or trimethyl-beta-cyclodextrines (T-beta-CDs) have been added to the running buffer together with methylcellulose or urea. All considered impurities were well resolved with two buffers studied, with the exception of methylursodehoxycholate, a neutral compound.

Cholagogues and Choleretics↗
PubMed1995

Analysis of non-benzodiazepinic anxiolytic agents by capillary zone electrophoresis.

A simple capillary electrophoretic method was developed for the analysis of a new generation of serotonergic anxiolytics and their related substances: zalospirone, gepirone, ipsapirone and buspirone. All compounds run in a Tris/phosphate buffer at pH 3 as cations and the experimental conditions allowed good resolution of four drugs and their principal impurities. The analyses were made using two different kinds of capillary. The suitability of CZE and HPLC methods for the analysis of these non-benzodiazepinic anxiolytic agents and their impurities was compared.

Anti-Anxiety Agents↗
PubMed1995

HPTLC and reflectance mode densitometry of anthocyanins in Malva silvestris L.: a comparison with gradient-elution reversed-phase HPLC.

Aqueous alcoholic mallow flower extracts were analyzed both by HPTLC-densitometry in the reflectance mode at 530 nm and by reversed-phase HPLC with gradient elution. For the mallow flower anthocyanins the best chromatographic resolution was obtained by HPLC, which revealed only two main compounds, confirmed by FAB-MS: malvidin 3,5-O-diglucoside (malvin) and malvidin 3-O-(6"-O-malonylglucoside)-5-O-glucoside. The HPTLC densitometric method on cellulose plates provides accuracy, reproducibility and selectivity for the quantitative analysis of the anthocyanins and this method was shown to be much more sensitive than the HPLC-DAD system, at 530 nm. Both methods give comparable quantitative results for total anthocyanins when applied to mallow flowers from two different sources: Italy and Albania.

Anthocyanins↗
PubMed1993

Chiral discrimination and antipicornavirus activity of 6-oxazolinylisoflavan.

Racemic 6-oxazolinylisoflavan, a highly effective inhibitor of rhinovirus serotype 1B in vitro, was resolved by high-performance liquid chromatography on a chiral stationary phase in order to study the activity of the enantiomers against picornaviruses. The absolute configuration of the two isomers was determined by circular dichroism curves. The antipicornavirus activity of each isomer, separately collected, was evaluated in vitro against human rhinovirus serotype 1B, enterovirus 71, echovirus 6, coxsackievirus B4, and poliovirus type 2 by means of the plaque reduction assay. Both enantiomers were inhibitors of picornavirus replication with the degree of their activity depending on virus and isomer tested.

Antiviral Agents↗
PubMed1991

Enantiomeric separation of substituted flavanoids by LC-DAD.

A variety of racemic flavanoids with anti-rhinovirus activity have been resolved for the first time by HPLC, using a chiral stationary phase. Baseline separation was easily obtained for racemic 4',6-dichloroisoflavan (V). The absolute configurations of two enantiomers (Va and Vb) were established by comparing their circular dichroism curves with those of other known isoflavans. Both the isomers were tested against human rhinovirus serotype 1B infection in vitro; the S form was approximately four times more effective than the R form.

Antiviral Agents↗
PubMed1990

Determination of methyl bromide traces in some food products by HS-GC/MS.

A simple and rapid method has been developed for fast selective determination of residues of methyl bromide in food products. The method is based on the use of a GC/MS computer-aided system equipped with a headspace. Analysis of methyl bromide was carried out directly on the food products without preliminary extraction of fumigant. An MSD quadrupole mass spectrometer with data processing allowed rapid identification of the separated volatile compound in the samples. The technique of focusing on characteristic single ion monitoring for quantification of methyl bromide, compared with chromatographic peak area measurement, turned out to have a good degree of accuracy and sensitivity. The use of known amount of added methyl bromide allowed better evaluation of traces of this compound. The proposed method was applied to the analysis of methyl bromide residues in alimentary pastes, white flour, rice, hazelnuts, peanuts and dried mushrooms (boletus).

Food Analysis↗
PubMed1989

Photochemical fluorimetric analysis of phenylbutazone and its degradation products.

A room temperature photochemical spectrofluorimetric (RTPF) method has been developed for the assay of phenylbutazone (PB), and its major degradation products. Fluorescence spectral properties of PB, its degradation products, and their photoproducts are reported, as well as the optimal irradiation times (ranging from 4 to 45 min), which correspond to maximum fluorescence signals of photoproducts. Linear log-log calibration plots were obtained over a 50- to 1000-fold range of concentration, and limits of detection ranged between 1 ng/ml and 1.2 micrograms/ml. This has been shown to be a convenient technique, in terms of simplicity, short measurement times, sensitivity, and precision.

Indicators and Reagents↗
PubMed1989

Quantitative determination of Piroxicam and its impurities by HPTLC spectrodensitometry.

A rapid spectrodensitometric method for the determination of Piroxicam and its impurities is described. The procedure involves a HPTLC separation on Silica Gel F254 plates. Quantitative determinations are carried out using a spectrodensitometer at 310 nm. The proposed method is sensitive and the minimum amount detectable of Piroxicam impurities is around 10 ng.

Chromatography, High Pressure Liquid↗