Anna Maślanka

TLC-UV analysis of indole compounds and other nitrogen-containing bases in the fruiting bodies of Lactarius deterrimus

We have developed a TLC method with densitometric detection for identification and quantification of 5-methylcytosine, tryptamine, melatonin, tryptophan, indoleacetic acid, and indole in the fruiting bodies of the mushroom Lactarius deterrimus. The compounds were separated on silica gel plates with fluorescence indicator F254 by use of two mobile phases — butane-1-ol—glacial acetic acid—water, 12 + 3 + 5 (v/v), and isopropanol—25% NH3—water, 8 + 1 + 1 (v/v). Densitometry was performed at λ = 280 nm. The method was characterized by LOD and LOQ from 0.026 to 0.179 μg, recovery from 97.65 to 101.65%, precision (RSD) from 0.71 to 1.76%, and a wide linear range, from 0.015 to 0.96 mg mL−1, for the different components.

Early lifetime zinc supplementation protects zinc-deficient diet-induced alterations

Preclinical and clinical data indicate the involvement of zinc in the pathophysiology and therapy of depression. A relationship between zinc-deficiency and depression symptoms was recently proposed. The present study investigated alterations in spontaneous locomotor activity and zinc concentrations in the serum, hippocampus and frontal cortex; these alterations were induced by subjecting rats to a zinc-deficient diet, prior subjected after birth to zinc-supplemented diet. Body weight was significantly reduced in animals subjected to the four-week zinc-deficient diet compared to those subjected to the zinc-adequate diet. The two-week zinc-deficient diet induced a significant increase in locomotor activity in all measured time periods (5, 30 and 60 min by 44-62%). The four-week zinc-deficient diet did not affect locomotor activity, while the six-week zinc-deficient diet resulted in a 45% increase in the 5 min time period. Serum zinc concentrations were significantly reduced (by 29%) in animals subjected to the four-week zinc-deficient diet but not in those subjected to the two- or six-week zinc-deficient diets. The zinc-deficient diet did not influence the zinc concentration in the examined brain regions regardless of the length. These results indicate that post-birth supplementation with zinc may protect zinc-deficient diet-induced rapid alterations in zinc homeostasis.

Simultaneous analysis of hydrochlorothiazide, triamterene, furosemide, and spironolactone by densitometric TLC

A new chromatographic and densitometric method has been established for identification and quantitative analysis of hydrochloro-thiazide, triamterene, furosemide, and spironolactone, which are present, together, in complex drugs used to treat hypertension. For separation, silica gel F254 plates were used with hexane-ethyl acetate-methanol-water-acetic acid 8.4:8:3:0.4:0.2 (v/v) as mobile phase. Densitometric measurements were performed at 264 nm selected for all of the constituents. The method is specific for the analyte constituents examined, and characterized by high sensitivity; LOD is from 0.022 to 0.150 μg per band, LOQ from 0.068 to 0.450 μg per band, recovery from 97.10 to 101.02%, and linear range from 0.060 to 2.650 μg per band. The method is characterized by good precision with RSD from 0.66 to 0.96%.

Densitometric Determination of Impurities in Pharmaceuticals. Part VIII. Simultaneous Determination of Fluoxetine and (1RS)-3-Methylamino-1-phenylpropan-1-ol, N-methyl-3-phenylpropan-1-amine, and C-1 as Drug Impurities

A densitometric TLC method has been developed for identification and quantification of fluoxetine and its impurities — (1RS)-3-methyl-amino-1-phenylpropan-1-ol, N-methyl-3-phenylpropan-1-amine, and C-1, the last of which has not previously been analyzed. The compounds were separated on silica gel 60 F254 HPTLC plates, with chloroform-methanol-25% ammonia, 45 + 4.5 + 0.5 (v/v), as mobile phase. UV and visible densitometric scanning were performed at λ = 260 and 530 nm, respectively, after visualization of the chromatograms with ninhydrin solution. The method enables good separation of the constituents (RF = 0.20, 0.41, 0.52, and 0.67) with sufficiently high detection limit and recovery for the individual constituents.

Use of TLC with densitometric detection for determination of impurities in chlorpromazine hydrochloride, trifluoperazine dihydrochloride, promazine hydrochloride, and doxepin hydrochloride

A TLC-densitometric method has been established for determination of impurities in chlorpromazine hydrochloride, trifluoperazine dihydrochloride, promazine hydrochloride, and doxepin hydrochloride. Statistical analysis of the data showed the method is precise and highly sensitive. Results from linear regression analysis of the calibration plots were indicative of good linear relationships over wide ranges of concentration. Application of densitometric U.V. detection at 254 nm and at the wavelengths of maximum absorbance of the substances resulted in increased detectability of zones in the chromatograms compared with visual inspection under a U.V. lamp. The conditions described enable objective quantitative evaluation of the limiting concentrations of impurities.

Spectrophotometric method for simultaneous determination of valsartan and substances from the group of statins in binary mixtures

Abstract Applicability of derivative spectrophotometry for the determination of valsartan in the presence of a substance from the group of statins was checked. The obtained results indicate that the proposed method may be effective by using appropriate derivatives: for valsartan and fluvastatin - D1, D2 and D3, for valsartan and pravastatin - D1 and D3, for valsartan and atorvastatin - D2 and D3. The method was characterized by high sensitivity and accuracy. Linearity was maintained in the following ranges: 9.28-32.48 mg mL-1 for valsartan, 8.16-28.56 mg mL-1 f or fluvastatin, 14.40-39.90 mg mL-1 for atorvastatin and 9.60-48.00 mg mL-1 for pravastatin. Determination coefficients were in the range of 0.989-0.999 depending on the analyte and the order of derivative. The precision of the method was high with RSD from 0.1 to 2.5 % and recovery of individual components was within the range of 100 ± 5 %. The developed method was successfully applied to the determination of valsartan combined with fluvastatin, atorvastatin and pravastatin in laboratory prepared mixtures and in pharmaceutical preparations.

Analysis of 5-Methyltryptamine, L-Tryptophan, 5-Hydroxy-L-Tryptophan, and Melatonin in the Bulbs of Garlic by Thin-Layer Chromatographic Method Coupled with Densitometric Detection

Thin-layer chromatography (TLC) methods coupled with densitometric detection were employed in analyses for the presence of non-hallucinogenic indole compounds in methanol extracts from the garlic (Allium sativum L.) bulbs originating from China, Georgia, Spain, Mexico, and Poland, and from granulated garlic in the form of seasoning (commercial product). Four indole compounds for which the garlic bulbs were analyzed, were detected: 5-methyltryptamine, L-tryptophan, 5-hydroxy-L-tryptophan, and melatonin, the amounts of which ranged from 4.2 to 199.6 mg kg−1 dry weight. In contrast, only 3 indole compounds were found in the garlic bulbs from Spain: 5-methyltryptamine, L-tryptophan and melatonin (85.7, 120.1, and 9.6 mg kg−1 dry weight, respectively). The total amount of indole compounds in the extracts from the garlic bulbs from China was the highest (415.4 mg kg−1 dry weight), while the amounts in the others (from Georgia, Spain, Mexico, Poland) were similar and ranged from 215.4 to 283 mg kg−1 dry weight. The granular, freeze-dried garlic contained the lowest content of indole compounds, and their total amount was only 207 mg kg−1 dry weight.

Dependence of the kinetic and thermodynamic parameters on hydrophilic–lipophilic character of alprazolam, clonazepam, diazepam, doxepin and haloperidol in alkaline environment

Examination of the stability of clonazepam, diazepam, alprazolam, haloperidol, and doxepin in basic solutions was performed, together with an assessment of the kinetic (k, t0.1i t0.5) and thermodynamic (Ea, ΔH(++)i ΔS(++)) stability-indicating parameters, which were compared with the lipophilicity (logP) of the studied drugs. It was observed that the calculated values of Ea, ΔH(++) and ΔS(++) for the studied drugs increased from 41.04 kJ/mol to 125.50 kJ/mol, from 37.82 kJ/mol to 122.24 kJ/mol and from -167.09 J/Kmol to 53.02 J/Kmol, respectively, along with an increase of lipophilicity (logP) from 2.12 to 4.30 for the most hydrophilic alprazolam to the most lipophilic haloperidol. The degradation products were identified using UPLC/MS/MS method.

Simultaneous Determination of Acetylsalicylic Acid, Hydrochlorothiazide, Enalapril, and Atorvastatin in a Polypill-Based Quaternary Mixture by TLC

A new chromatographic-densitometric method has been developed for the qualitative and quantitative determination of the active ingredients in a simulated mixture corresponding to the PolyIran polypill, composed of acetylsalicylic acid, hydrochlorothiazide (HCT), enalapril (ENA), and atorvastatin (ATR), whose efficacy in the treatment and prevention of cardiovascular disease has been documented in clinical trials. Chromatographic separation was performed using TLC silica gel 60 plates with fluorescent indicator F254 as the stationary phase and a mixture of n-hexane-ethyl acetate-methanol-water-acetic acid (8.4 + 8 + 3 + 0.4 + 0.2, v/v/v/v/v) as the mobile phase. Densitometric measurements were carried out at λ = 210 nm when determining ENA and at λ = 265 nm in the case of the other drugs. Peaks of examined substances were well separated in the recorded chromatograms, enabling the evaluation of the results in terms of both qualitative and quantitative analysis. The method was specific for the analyzed components and was characterized by high sensitivity. The LOD was between 0.043 and 0.331 μg/spot, and LOQ was between 0.100 and 0.942 μg/spot. Recovery was in the range of 97.02-101.34%. The linearity range was broad and ranged from 0.600 to 6.000 μg/spot for acetylsalicylic acid, from 0.058 to 1.102 μg/spot for HCT, from 0.505 to 6.560 μg/spot for ENA, and from 0.100 to 1.000 μg/spot for ATR. The method was characterized by good precision, with RSD values that ranged from 0.10 to 2.26%.

In Vitro Culture of Boletus badius as a Source of Indole Compounds and Zinc Released in Artificial Digestive Juices

The objective of this study was to obtain the in vitro cultures of Boletus badius under controlled conditions and investigate the release of indole compounds and zinc from the mycelium of B. badius to artificial digestive juices under conditions similar to those in the human gastrointestinal tract. Biomass was obtained from cultures grown using both only the Oddoux medium as well as the same medium with added zinc hydroaspartate and zinc sulfate. The release of 5-hydroxy-L-tryptophan, L-tryptophan, and serotonin from the B. badius biomass extracts to the artificial digestive juices was determined. Differential pulse anodic stripping voltammetry was used to demonstrate that zinc is released from each of the extracted materials. The total amount of zinc in the materials under study was estimated to be between 7.12 and 44.15 mg/100 g dry weight. It was demonstrated that in vitro cultures of B. badius grown using appropriately selected media may supplement zinc and indole compounds.