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Zeitschriftendaten
Format
Zeitschrift
eISSN
1846-9558
Erstveröffentlichung
28 Feb 2007
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

Volumen 64 (2014): Heft 4 (December 2014)

Zeitschriftendaten
Format
Zeitschrift
eISSN
1846-9558
Erstveröffentlichung
28 Feb 2007
Erscheinungsweise
4 Hefte pro Jahr
Sprachen
Englisch

Suche

10 Artikel
Uneingeschränkter Zugang

Therapeutic drug monitoring of atypical antipsychotic drugs

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 387 - 401

Zusammenfassung

Abstract

Schizophrenia is a severe psychiatric disorder often associated with cognitive impairment and affective, mainly depressive, symptoms. Antipsychotic medication is the primary intervention for stabilization of acute psychotic episodes and prevention of recurrences and relapses in patients with schizophrenia. Typical antipsychotics, the older class of antipsychotic agents, are currently used much less frequently than newer atypical antipsychotics. Therapeutic drug monitoring (TDM) of antipsychotic drugs is the specific method of clinical pharmacology, which involves measurement of drug serum concentrations followed by interpretation and good cooperation with the clinician. TDM is a powerful tool that allows tailor-made treatment for the specific needs of individual patients. It can help in monitoring adherence, dose adjustment, minimizing the risk of toxicity and in cost-effectiveness in the treatment of psychiatric disorders. The review provides complex knowledge indispensable to clinical pharmacologists, pharmacists and clinicians for interpretation of TDM results.

Keywords

  • therapeutic drug monitoring
  • antipsychotic drugs
  • therapeutic reference ranges
Uneingeschränkter Zugang

Influence of different formulations and process parameters during the preparation of drug-loaded PLGA microspheres evaluated by multivariate data analysis

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 403 - 417

Zusammenfassung

Abstract

The main objective of this study was to evaluate the influence of the formulation and process parameters on PLGA microparticles containing a practically insoluble model drug (ibuprofen) prepared by the o/w solvent evaporation method. Multivariate data analysis was used. The effects of altered stirring speed of a mechanical stirrer (600, 1000 rpm), emulsifier concentrations (PVA concentration 0.1 %, 1 %) and solvent selection (dichloromethane, ethyl acetate) on microparticle characteristics (encapsulation efficiency, drug loading, burst effect) were observed. It was found that with increased stirring speed, the PVA concentration or the use of ethyl acetate had a significantly negative effect on encapsulation efficiency. In addition, ethyl acetate had an adverse effect on the burst effect, while increased stirring speed had the opposite effect. Drug load was not affected by any particular variable, but rather by the interactions of evaluated variables.

Schlüsselwörter

  • solvent evaporation
  • encapsulation
  • PLGA
  • controlled release
  • burst effect
Uneingeschränkter Zugang

Novel thiophene derivatives with sulfonamide, isoxazole, benzothiazole, quinoline and anthracene moieties as potential anticancer agents

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 419 - 431

Zusammenfassung

Abstract

A novel series of thiophenes having biologically active sulfonamide 2-11, 3-methylisoxazole 12, 4-methoxybenzo[d] thiazole 13, quinoline 14, 15, benzoylphenylamino 16, and anthracene-9,10-dione 17 moieties were prepared. Structures of the newly synthesized compounds were established by elemental analysis and spectral data. All newly synthesized compounds were evaluated for their in vitro anticancer activity against human breast cancer cell line (MCF7). Most of the screened compounds showed cytotoxic activities compared to doxorubicin as a positive control. Compounds 6, 7, 9 and 13 (IC50 values 10.25, 9.70, 9.55 and 9.39 μmol L-1) revealed higher cytotoxic activities than that of doxorubicin (IC50 = 32.00 μmol L-1). Also, compounds 5, 8 and 10 were found nearly as active as doxorubicin (IC50 28.85, 23.48 and 27.51 μmol L-1).

Schlüsselwörter

  • thiophenes
  • sulfonamides
  • isoxazole
  • benzothiazole
  • quinoline
  • anthracene
  • anticancer activity
Uneingeschränkter Zugang

High-performance liquid chromatography and derivative spectrophotometry for simultaneous determination of pravastatin and fenofibrate in the dosage form

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 433 - 446

Zusammenfassung

Abstract

High performance liquid chromatography (HPLC) and second-order derivative spectrophotometry have been used for simultaneous determination of pravastatin (PS) and fenofibrate (FF) in pharmaceutical formulations. HPLC separation was performed on a phenyl HYPERSIL C18 column (125 mm × 4.6 mm i.d., 5 μm particle diameter) in the isocratic mode using a mobile phase acetonitrile/0.1 % diethyl amine (50:50, V/V, pH 4.5) pumped at a flow rate of 1.0 mL min-1. Measurement was made at 240 nm. Both drugs were well resolved on the stationary phase, with retention times of 2.15 and 5.79 min for PS and FF, respectively. Calibration curves were linear (R = 0.999 for PS and 0.996 for FF) in the concentration range of 5-50 and 20-200 µg mL-1 for PS and FF, respectively. Pravastatin and fenofibrate were quantitated in combined preparations also using the second-order derivative response at 237.6 and 295.1 nm for PS and FF, respectively. Calibration curves were linear, with the correlation coefficient R = 0.999 for pravastatin and fenofibrate, in the concentration range of 5-20 and 3-20 µg mL-1 for PS and FF, respectively. Both methods were fully validated and compared, the results confirmed that they were highly suitable for their intended purpose.

Schlüsselwörter

  • pravastatin
  • fenofibrate
  • spectrophotometry
  • HPLC
  • dosage form
Uneingeschränkter Zugang

Attitudes of physicians, nurses and pharmacists concerning the development of clinical pharmacy activities in a university hospital

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 447 - 461

Zusammenfassung

Abstract

It is essential to identify the expectations of physicians and nurses regarding clinical pharmacy (CP) services before its introduction in a hospital, because it is known that their expectations can substantially differ from the pharmacists’ point of view. Agreement of leading physicians, nurses and clinical pharmacists about the importance of CP activities in the hospital was evaluated using five point Likert scale questionnaire. Two groups of CP activities were set; the activities related to the hospital system (first group) and the activities connected with an individual patient (second group). Total mean score of agreement of physicians with the first and second group of CP activities is 4.28 and 3.73, respectively, while these scores are lower for nurses (3.87 and 3.38 for the first and second group, respectively). Pharmacists’ total mean scores are highest, 4.57 and 4.23 for the first and second group, respectively.

Schlüsselwörter

  • clinical pharmacist
  • activities
  • physicians
  • nurses
Uneingeschränkter Zugang

Use of compounded dispersing media for extemporaneous pediatric syrups with candesartan cilexetil and valsartan

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 463 - 474

Zusammenfassung

Abstract

Available tablets or capsules for adults are often used to prepare extemporaneously formulated medicines appropriate for children. The most acceptable drug forms in pediatric population are oral liquids and pharmacists use commercial dispersing media to compound syrups from an active substance or from tablets available on the market. In many countries ready-to-use dispersing media are not available or refunded, but pharmacists can use other compounded media, providing their compatibility and stability are proven. The aim of this study was to formulate and evaluate the stability of syrups with candesartan cilexetil (1 mg mL-1) and valsartan (4 mg mL-1) extemporaneously prepared using commercial tablets (Diovan® and Atacand®). The following three different suspending media, which could be easily made in a pharmacy, were investigated: V1 - with xanthan gum (0.5 %), V2 - the USP/NF vehicle for oral solution and V3 - the medium based on a simple sucrose syrup. The stability of preparations was studied during 35 days of storage in a dark place at controlled temperature of 25 and 4 °C. During the study, microscopic observation was carried out and pH, viscosity, and concentration of candesartan cilexetil and valsartan were analyzed. Syrups with valsartan prepared with V2 and V3 media were stable for 3 or 4 weeks when stored at 25 °C, while syrups with candesartan were stable for as long as 35 days. For syrups prepared using V1 medium, the 14-day expiry date was not achieved because of microbial deterioration.

Schlüsselwörter

  • extemporaneous formulation
  • pediatric syrups
  • candesartan cilexetil
  • valsartan
  • stability
Uneingeschränkter Zugang

Evaluation of anti-Bothrops asper venom activity of ethanolic extract of Brownea rosademonte leaves

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 475 - 483

Zusammenfassung

Abstract

Significant inhibition of the coagulant and hemorrhagic effects of Bothrops asper venom was demonstrated by ethanolic extract prepared from the leaves of Brownea rosademonte. In vitro experiments preincubating 5.5 mg of extract kg-1 b.m. for 30 min with a minimum hemorrhagic dose of venom (273.8 ± 16.1 μg of venom kg-1 b.m.) lowered the hemorrhagic activity of the venom alone in CD-1 mice by 51.5 ± 2.6 %. Additionally, 1.7 mg extract L-1 plasma prolonged 5.1 times the plasma coagulation time. Fractionation of the extract led to the isolation of two compounds: ononitol (1) and quercetrin (2). The structure of compounds 1 and 2 was established by spectroscopic analyses, including APCI-HRMS and NMR (1H, 13C, HSQC, HMBC and COSY). A quercetrin concentration of 0.11 μmol L-1 prolonged the plasma coagulation time 2.6 times demonstrating that this compound was one of the active constituents of the Brownea rosademonte extract.

Schlüsselwörter

  • Bothrops asper (Viperidae) venom
  • Brownea rosademonte (Caesalpinaceae)
  • quercetrin
  • anticoagulant
  • antihemorrhagic
  • antiproteolytic
  • antihemolytic
Uneingeschränkter Zugang

Preparation and in vitro characterization of non-effervescent floating drug delivery system of poorly soluble drug, carvedilol phosphate

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 485 - 494

Zusammenfassung

Abstract

The objective of the study was to enhance the solubility of carvedilol phosphate and to formulate it into non-effervescent floating tablets using swellable polymers. Solid dispersions (SD) of carvedilol were prepared with hydrophilic carriers such as polyvinylpyrrolidone and poloxamer to enhance solubility. Non-effervescent floating tablets were prepared with a combination of optimized solid dispersions and release retarding polymers/swellable polymers such as xanthan gum and polyethylene oxide. Tablets were evaluated for physicochemical properties such as hardness, thickness and buoyancy. SD prepared with the drug to poloxamer ratio of 1:4 by melt granulation showed a higher dissolution rate than all other dispersions. Formulations containing 40 mg of polyethylene oxide (C-P40) and 50 mg xanthan gum (C-X50) were found to be best, with the drug retardation up to 12 hours. Optimized formulations were characterized using FTIR and DSC and no drug and excipient interactions were detected.

Schlüsselwörter

  • carvedilol phosphate
  • solid dispersion
  • non-effervescent
  • floating tablets
Uneingeschränkter Zugang

Seasonal phytochemical study and antimicrobial potential of Vetiveria zizanioides roots

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 495 - 501

Zusammenfassung

Abstract

This paper describes the seasonal phytochemical variation and the antimicrobial potential of V. zizanioides roots collected in Brazil. Considering the high levels of chemical constituents and their biological activity in dichloromethane fraction, the plants were grown in different seasons and the respective dichloromethane fractions were analyzed by gas chromatography-mass spectrometry. The antimicrobial activity was evaluated against several pathogenic microorganisms by determining the minimum inhibitory concentration (MIC) using the agar dilution method. Yields of dichloromethane fractions from plants collected in the autumn and spring occurred in a higher proportion than in other seasons. Khusimol (2) was isolated by column chromatography and identified by NMR and CG-MS, along with other sesquiterpenes, including β-vetivenene (1), vetiselinenol (3), isovalencenol (4), vetivenic acid (5), α-vetivone (6) and β-vetivone (7). Some extracts showed promising antimicrobial effects, with MICs ranging from 31.25 to 500 μg mL-1. Kushimol was slightly active against the tested microorganisms.

Schlüsselwörter

  • Vetiveria zizanioides (Poaceae)
  • seasonality
  • sesquiterpenes
  • khusimol
  • antimicrobial activity
Uneingeschränkter Zugang

TLC densitometric method for screening of lycopsamine in comfrey root (Symphytum officinale L.) extracts using retrorsine as a reference compound

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 503 - 508

Zusammenfassung

Abstract

Due to severe toxicity of pyrrolizidine alkaloids, their quantification in medicinal products is very important. The idea of this research was to use retrorsine as a surrogate reference compound instead of lycopsamine reference or lycopsamine isolated from comfrey. A method for the analysis of lycopsamine in extracts of comfrey roots was developed and validated, employing thin layer chromatography, derivatisation with Dann-Mattocks reagent followed by densitometric analysis. The new method showed linearity within 0.70 to 7.0 μg of lycopsamine per application of 10 μL of a solution. It has also been proven to be specific and precise (repeatability RSD 2-4 % within the plate). The method was successfully employed for quantification of lycopsamine in comfrey root and comfrey root medicinal products such as ointments.

Schlüsselwörter

  • comfrey
  • lycopsamine
  • retrorsine
  • TLC
  • densitometry
10 Artikel
Uneingeschränkter Zugang

Therapeutic drug monitoring of atypical antipsychotic drugs

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 387 - 401

Zusammenfassung

Abstract

Schizophrenia is a severe psychiatric disorder often associated with cognitive impairment and affective, mainly depressive, symptoms. Antipsychotic medication is the primary intervention for stabilization of acute psychotic episodes and prevention of recurrences and relapses in patients with schizophrenia. Typical antipsychotics, the older class of antipsychotic agents, are currently used much less frequently than newer atypical antipsychotics. Therapeutic drug monitoring (TDM) of antipsychotic drugs is the specific method of clinical pharmacology, which involves measurement of drug serum concentrations followed by interpretation and good cooperation with the clinician. TDM is a powerful tool that allows tailor-made treatment for the specific needs of individual patients. It can help in monitoring adherence, dose adjustment, minimizing the risk of toxicity and in cost-effectiveness in the treatment of psychiatric disorders. The review provides complex knowledge indispensable to clinical pharmacologists, pharmacists and clinicians for interpretation of TDM results.

Keywords

  • therapeutic drug monitoring
  • antipsychotic drugs
  • therapeutic reference ranges
Uneingeschränkter Zugang

Influence of different formulations and process parameters during the preparation of drug-loaded PLGA microspheres evaluated by multivariate data analysis

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 403 - 417

Zusammenfassung

Abstract

The main objective of this study was to evaluate the influence of the formulation and process parameters on PLGA microparticles containing a practically insoluble model drug (ibuprofen) prepared by the o/w solvent evaporation method. Multivariate data analysis was used. The effects of altered stirring speed of a mechanical stirrer (600, 1000 rpm), emulsifier concentrations (PVA concentration 0.1 %, 1 %) and solvent selection (dichloromethane, ethyl acetate) on microparticle characteristics (encapsulation efficiency, drug loading, burst effect) were observed. It was found that with increased stirring speed, the PVA concentration or the use of ethyl acetate had a significantly negative effect on encapsulation efficiency. In addition, ethyl acetate had an adverse effect on the burst effect, while increased stirring speed had the opposite effect. Drug load was not affected by any particular variable, but rather by the interactions of evaluated variables.

Schlüsselwörter

  • solvent evaporation
  • encapsulation
  • PLGA
  • controlled release
  • burst effect
Uneingeschränkter Zugang

Novel thiophene derivatives with sulfonamide, isoxazole, benzothiazole, quinoline and anthracene moieties as potential anticancer agents

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 419 - 431

Zusammenfassung

Abstract

A novel series of thiophenes having biologically active sulfonamide 2-11, 3-methylisoxazole 12, 4-methoxybenzo[d] thiazole 13, quinoline 14, 15, benzoylphenylamino 16, and anthracene-9,10-dione 17 moieties were prepared. Structures of the newly synthesized compounds were established by elemental analysis and spectral data. All newly synthesized compounds were evaluated for their in vitro anticancer activity against human breast cancer cell line (MCF7). Most of the screened compounds showed cytotoxic activities compared to doxorubicin as a positive control. Compounds 6, 7, 9 and 13 (IC50 values 10.25, 9.70, 9.55 and 9.39 μmol L-1) revealed higher cytotoxic activities than that of doxorubicin (IC50 = 32.00 μmol L-1). Also, compounds 5, 8 and 10 were found nearly as active as doxorubicin (IC50 28.85, 23.48 and 27.51 μmol L-1).

Schlüsselwörter

  • thiophenes
  • sulfonamides
  • isoxazole
  • benzothiazole
  • quinoline
  • anthracene
  • anticancer activity
Uneingeschränkter Zugang

High-performance liquid chromatography and derivative spectrophotometry for simultaneous determination of pravastatin and fenofibrate in the dosage form

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 433 - 446

Zusammenfassung

Abstract

High performance liquid chromatography (HPLC) and second-order derivative spectrophotometry have been used for simultaneous determination of pravastatin (PS) and fenofibrate (FF) in pharmaceutical formulations. HPLC separation was performed on a phenyl HYPERSIL C18 column (125 mm × 4.6 mm i.d., 5 μm particle diameter) in the isocratic mode using a mobile phase acetonitrile/0.1 % diethyl amine (50:50, V/V, pH 4.5) pumped at a flow rate of 1.0 mL min-1. Measurement was made at 240 nm. Both drugs were well resolved on the stationary phase, with retention times of 2.15 and 5.79 min for PS and FF, respectively. Calibration curves were linear (R = 0.999 for PS and 0.996 for FF) in the concentration range of 5-50 and 20-200 µg mL-1 for PS and FF, respectively. Pravastatin and fenofibrate were quantitated in combined preparations also using the second-order derivative response at 237.6 and 295.1 nm for PS and FF, respectively. Calibration curves were linear, with the correlation coefficient R = 0.999 for pravastatin and fenofibrate, in the concentration range of 5-20 and 3-20 µg mL-1 for PS and FF, respectively. Both methods were fully validated and compared, the results confirmed that they were highly suitable for their intended purpose.

Schlüsselwörter

  • pravastatin
  • fenofibrate
  • spectrophotometry
  • HPLC
  • dosage form
Uneingeschränkter Zugang

Attitudes of physicians, nurses and pharmacists concerning the development of clinical pharmacy activities in a university hospital

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 447 - 461

Zusammenfassung

Abstract

It is essential to identify the expectations of physicians and nurses regarding clinical pharmacy (CP) services before its introduction in a hospital, because it is known that their expectations can substantially differ from the pharmacists’ point of view. Agreement of leading physicians, nurses and clinical pharmacists about the importance of CP activities in the hospital was evaluated using five point Likert scale questionnaire. Two groups of CP activities were set; the activities related to the hospital system (first group) and the activities connected with an individual patient (second group). Total mean score of agreement of physicians with the first and second group of CP activities is 4.28 and 3.73, respectively, while these scores are lower for nurses (3.87 and 3.38 for the first and second group, respectively). Pharmacists’ total mean scores are highest, 4.57 and 4.23 for the first and second group, respectively.

Schlüsselwörter

  • clinical pharmacist
  • activities
  • physicians
  • nurses
Uneingeschränkter Zugang

Use of compounded dispersing media for extemporaneous pediatric syrups with candesartan cilexetil and valsartan

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 463 - 474

Zusammenfassung

Abstract

Available tablets or capsules for adults are often used to prepare extemporaneously formulated medicines appropriate for children. The most acceptable drug forms in pediatric population are oral liquids and pharmacists use commercial dispersing media to compound syrups from an active substance or from tablets available on the market. In many countries ready-to-use dispersing media are not available or refunded, but pharmacists can use other compounded media, providing their compatibility and stability are proven. The aim of this study was to formulate and evaluate the stability of syrups with candesartan cilexetil (1 mg mL-1) and valsartan (4 mg mL-1) extemporaneously prepared using commercial tablets (Diovan® and Atacand®). The following three different suspending media, which could be easily made in a pharmacy, were investigated: V1 - with xanthan gum (0.5 %), V2 - the USP/NF vehicle for oral solution and V3 - the medium based on a simple sucrose syrup. The stability of preparations was studied during 35 days of storage in a dark place at controlled temperature of 25 and 4 °C. During the study, microscopic observation was carried out and pH, viscosity, and concentration of candesartan cilexetil and valsartan were analyzed. Syrups with valsartan prepared with V2 and V3 media were stable for 3 or 4 weeks when stored at 25 °C, while syrups with candesartan were stable for as long as 35 days. For syrups prepared using V1 medium, the 14-day expiry date was not achieved because of microbial deterioration.

Schlüsselwörter

  • extemporaneous formulation
  • pediatric syrups
  • candesartan cilexetil
  • valsartan
  • stability
Uneingeschränkter Zugang

Evaluation of anti-Bothrops asper venom activity of ethanolic extract of Brownea rosademonte leaves

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 475 - 483

Zusammenfassung

Abstract

Significant inhibition of the coagulant and hemorrhagic effects of Bothrops asper venom was demonstrated by ethanolic extract prepared from the leaves of Brownea rosademonte. In vitro experiments preincubating 5.5 mg of extract kg-1 b.m. for 30 min with a minimum hemorrhagic dose of venom (273.8 ± 16.1 μg of venom kg-1 b.m.) lowered the hemorrhagic activity of the venom alone in CD-1 mice by 51.5 ± 2.6 %. Additionally, 1.7 mg extract L-1 plasma prolonged 5.1 times the plasma coagulation time. Fractionation of the extract led to the isolation of two compounds: ononitol (1) and quercetrin (2). The structure of compounds 1 and 2 was established by spectroscopic analyses, including APCI-HRMS and NMR (1H, 13C, HSQC, HMBC and COSY). A quercetrin concentration of 0.11 μmol L-1 prolonged the plasma coagulation time 2.6 times demonstrating that this compound was one of the active constituents of the Brownea rosademonte extract.

Schlüsselwörter

  • Bothrops asper (Viperidae) venom
  • Brownea rosademonte (Caesalpinaceae)
  • quercetrin
  • anticoagulant
  • antihemorrhagic
  • antiproteolytic
  • antihemolytic
Uneingeschränkter Zugang

Preparation and in vitro characterization of non-effervescent floating drug delivery system of poorly soluble drug, carvedilol phosphate

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 485 - 494

Zusammenfassung

Abstract

The objective of the study was to enhance the solubility of carvedilol phosphate and to formulate it into non-effervescent floating tablets using swellable polymers. Solid dispersions (SD) of carvedilol were prepared with hydrophilic carriers such as polyvinylpyrrolidone and poloxamer to enhance solubility. Non-effervescent floating tablets were prepared with a combination of optimized solid dispersions and release retarding polymers/swellable polymers such as xanthan gum and polyethylene oxide. Tablets were evaluated for physicochemical properties such as hardness, thickness and buoyancy. SD prepared with the drug to poloxamer ratio of 1:4 by melt granulation showed a higher dissolution rate than all other dispersions. Formulations containing 40 mg of polyethylene oxide (C-P40) and 50 mg xanthan gum (C-X50) were found to be best, with the drug retardation up to 12 hours. Optimized formulations were characterized using FTIR and DSC and no drug and excipient interactions were detected.

Schlüsselwörter

  • carvedilol phosphate
  • solid dispersion
  • non-effervescent
  • floating tablets
Uneingeschränkter Zugang

Seasonal phytochemical study and antimicrobial potential of Vetiveria zizanioides roots

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 495 - 501

Zusammenfassung

Abstract

This paper describes the seasonal phytochemical variation and the antimicrobial potential of V. zizanioides roots collected in Brazil. Considering the high levels of chemical constituents and their biological activity in dichloromethane fraction, the plants were grown in different seasons and the respective dichloromethane fractions were analyzed by gas chromatography-mass spectrometry. The antimicrobial activity was evaluated against several pathogenic microorganisms by determining the minimum inhibitory concentration (MIC) using the agar dilution method. Yields of dichloromethane fractions from plants collected in the autumn and spring occurred in a higher proportion than in other seasons. Khusimol (2) was isolated by column chromatography and identified by NMR and CG-MS, along with other sesquiterpenes, including β-vetivenene (1), vetiselinenol (3), isovalencenol (4), vetivenic acid (5), α-vetivone (6) and β-vetivone (7). Some extracts showed promising antimicrobial effects, with MICs ranging from 31.25 to 500 μg mL-1. Kushimol was slightly active against the tested microorganisms.

Schlüsselwörter

  • Vetiveria zizanioides (Poaceae)
  • seasonality
  • sesquiterpenes
  • khusimol
  • antimicrobial activity
Uneingeschränkter Zugang

TLC densitometric method for screening of lycopsamine in comfrey root (Symphytum officinale L.) extracts using retrorsine as a reference compound

Online veröffentlicht: 20 Dec 2014
Seitenbereich: 503 - 508

Zusammenfassung

Abstract

Due to severe toxicity of pyrrolizidine alkaloids, their quantification in medicinal products is very important. The idea of this research was to use retrorsine as a surrogate reference compound instead of lycopsamine reference or lycopsamine isolated from comfrey. A method for the analysis of lycopsamine in extracts of comfrey roots was developed and validated, employing thin layer chromatography, derivatisation with Dann-Mattocks reagent followed by densitometric analysis. The new method showed linearity within 0.70 to 7.0 μg of lycopsamine per application of 10 μL of a solution. It has also been proven to be specific and precise (repeatability RSD 2-4 % within the plate). The method was successfully employed for quantification of lycopsamine in comfrey root and comfrey root medicinal products such as ointments.

Schlüsselwörter

  • comfrey
  • lycopsamine
  • retrorsine
  • TLC
  • densitometry

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