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1.
Food Chem ; 175: 366-73, 2015 May 15.
Article in English | MEDLINE | ID: mdl-25577093

ABSTRACT

Infusions and decoctions of three chemotypes of Lippia alba (Mill.) N. E. Brown (Verbenaceae) were investigated for their quantitative profiles by HPLC-DAD-ESI-MS analyses. An RP-HPLC method was developed which permitted the quality control of the preparations. The correct choice of the column allowed the detailed characterization of the constituents in a total analysis time of 35 min. The HPLC method was accordingly validated for linearity range, LOD, LOQ, accuracy and precision. For the quantitative analysis the three major phytochemical groups were taken into consideration, namely iridoids, phenylpropanoids and flavonoids. Comparative quantitative analyses revealed significant differences among the chemotypes that should be taken into account in the uses of the herbal teas. The developed HPLC-UV assay proved to be an efficient and alternative method for the discrimination of the three chemotypes. This is the first report of detailed analysis of the chemical composition of the constituents of L. alba chemotypes' teas.


Subject(s)
Beverages/analysis , Chromatography, High Pressure Liquid/methods , Lippia/chemistry , Brazil , Flavonoids/analysis
2.
Complement Ther Clin Pract ; 20(4): 280-4, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25047603

ABSTRACT

This study focused on herbalists, herbal shops and people currently using traditional Arabic medicine. Informants were asked to list plants and methods for obtaining plant herbal extracts used to manage a range of illnesses. A total of 109 plants were identified, of these, principle plant elements included, leaves (47.3%), fruits (18.5%) and seeds (18.0%) were most commonly utilized. Extraction methods included decoction (boiling) 51%, and infusion 17% and prepared as creams, powders, syrups, food or cooked. Many plant species are used by herbalists for treating a range of ailments. This study suggests that a lack of methodological standardization during herbal extraction could compromise herbal stability. There is also a need to monitor for potential adverse drug interactions when used concurrently with prescribed medications.


Subject(s)
Phytotherapy/methods , Phytotherapy/statistics & numerical data , Plant Extracts/classification , Plant Extracts/therapeutic use , Plants, Medicinal , Cross-Sectional Studies , Fruit/chemistry , Health Personnel/statistics & numerical data , Humans , Medicine, Traditional , Middle East , Plant Leaves/chemistry , Seeds/chemistry , Surveys and Questionnaires
3.
J Pharm Pharmacol ; 63(4): 594-601, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21401613

ABSTRACT

OBJECTIVES: This study reports on the rapid isolation of verbascoside from Lippia citriodora H.B.K. (Verbenaceae), an inexpensive and widespread source, and the evaluation of its antihyperalgesic activity. METHODS: Isolation of verbascoside was achieved by size exclusion chromatography with Sephadex LH-20 eluting with 50% EtOH, which is proposed as a fast and efficient method of separation. KEY FINDINGS: The antihyperalgesic activity of verbascoside was tested by in-vivo assay using the paw-pressure test in two animal models of neuropathic pain: a peripheral mononeuropathy produced either by a chronic constriction injury of the sciatic nerve (CCI) or by an intra-articular injection of sodium monoiodoacetate (MIA). CONCLUSIONS: Verbascoside administered intraperitoneally at a dose of 100 mg/kg reverted the mechanical hyperalgesia in both CCI and MIA treated rats, as evaluated in the paw-pressure test. Verbascoside was also effective against mechanical hyperalgesia after oral administration at doses of 300 and 600 mg/kg.


Subject(s)
Analgesics/therapeutic use , Drugs, Chinese Herbal/therapeutic use , Glucosides/therapeutic use , Hyperalgesia/drug therapy , Neuralgia/drug therapy , Phenols/therapeutic use , Phytotherapy , Administration, Oral , Analgesics/administration & dosage , Analgesics/isolation & purification , Animals , Disease Models, Animal , Drugs, Chinese Herbal/administration & dosage , Drugs, Chinese Herbal/isolation & purification , Glucosides/administration & dosage , Glucosides/isolation & purification , Hyperalgesia/chemically induced , Hyperalgesia/complications , Injections, Intraperitoneal , Iodoacetates , Lippia/chemistry , Male , Neuralgia/chemically induced , Neuralgia/complications , Phenols/administration & dosage , Phenols/isolation & purification , Rats , Rats, Sprague-Dawley , Rotarod Performance Test/methods , Sciatic Nerve/injuries
4.
Nat Prod Commun ; 6(1): 79-84, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21366051

ABSTRACT

The use of Traditional Arabic Medicine (TAM) for various diseases has been popular but scarcely studied in Syria. In the present study, we carried out ethnobotanical and ethnopharmacological research on the plants traditionally used to cure various diseases in northern Syria. The information was collected from the city and villages of the Aleppo governorate "Mohaafazah" in the north of Syria, collecting data directly on the basis of a detailed survey of inhabitants and herbalists. In this survey, we found that hundreds of plant species are still in use in TAM for the treatment of various diseases. We selected the most common 100 species, used in the treatment of more than 25 diseases. Among these plants, 53 are used for treating gastrointestinal disorders, 38 for respiratory system diseases, including asthma, bronchitis and cough, 34 for skin diseases, 21 for diabetes, 17 for kidney and urinary disorders, 16 for cardiac disorders, 14 for infertility and sexual impotency, 13 for treating liver diseases, 13 for several types of cancer, 9 for enhancing breast milk excretion, 8 for weight loss, 5 for reducing cholesterol, and three for weight gain. Plants were collected and identified: scientific Latin names, local names, the used parts of the plant, the herbal preparations and the local medical uses are described. Scientific literature concerning the activity of the investigated species is also reported and discussed according to their traditional uses.


Subject(s)
Medicine, Arabic , Syria
5.
J Pharm Biomed Anal ; 55(3): 479-86, 2011 Jun 01.
Article in English | MEDLINE | ID: mdl-21420820

ABSTRACT

In the present study two methods based on liquid chromatography with diode array detection (HPLC-DAD) coupled to an electrospray ionisation (ESI-MS) interface were developed for the determination of constituents in the tinctures (60%, v/v, DER 1:5) of turmeric (Curcuma longa L.) and Devil's claw (Harpagophytum procumbens L.). The developed simple and effective assays permitted the quality control of both tinctures. The aim of this work was to assess the qualitative and quantitative profile of the constituents of two widely marketed commercial preparations and to evaluate chemical stability of their marker constituents during accelerated thermal stability test by HPLC analysis. Characteristic constituents of C. longa rhizomes are the curcuminoids, whereas characteristic constituents of H. procumbens are acylated iridoid glycosides and phenylethylalcohols. Constituents of Devil's claw tincture (mainly iridoids) were more stable than curcuminoids of turmeric.


Subject(s)
Curcuma/chemistry , Harpagophytum/chemistry , Plant Extracts/analysis , Calibration , Chromatography, High Pressure Liquid , Drug Stability , Magnetic Resonance Spectroscopy , Molecular Structure , Plant Extracts/chemistry , Plant Extracts/standards , Plant Roots/chemistry , Quality Control , Reference Standards , Reproducibility of Results , Spectrometry, Mass, Electrospray Ionization
6.
Anal Bioanal Chem ; 399(4): 1715-23, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21153584

ABSTRACT

In the present study, a method based on liquid chromatography with diode array detection (HPLC-DAD) coupled to an electrospray ionisation (ESI) interface was developed for the determination of the constituents in the aqueous preparations of Viola odorata L. flowering tops. The developed assay was fast, simple and effective and permitted the quality control of the preparations. The aim of this work was to assess the qualitative and quantitative profile of the investigated preparations, which find until today wide applications in food and cosmetic industry, and to propose a validated method for their quality control. Characteristic constituents of V. odorata flowers are considered to be the anthocyanins; however, a detailed literature research showed that data concerning their chemical content are scarce. HPLC-DAD-ESI-MS analyses supported by extensive preparative chromatographic investigations and 2D NMR analyses revealed the predominance of complex flavonol glycosides and permitted the complete characterisation of the content of V. odorata preparations. This is the first report of detailed analysis of the chemical composition of V. odorata flowers.


Subject(s)
Flowers/chemistry , Viola/chemistry , Chromatography, High Pressure Liquid , Quality Control , Spectrometry, Mass, Electrospray Ionization , Water/chemistry
7.
J Pharm Biomed Anal ; 53(1): 15-23, 2010 Sep 21.
Article in English | MEDLINE | ID: mdl-20347244

ABSTRACT

In the present study a method based on liquid chromatography with diode array detection (HPLC/DAD) coupled to an electrospray ionization (ESI) interface for the simultaneous determination of phenolic constituents in three aqueous preparations of the herbal medicinal drug Stachys recta. The developed assay was simple and effective and permitted the quality control of S. recta decoctions and infusion. Overall, 30 constituents were detected and identified, belonging mainly to three classes of compounds: caffeoylquinic acids, phenylethanol glycosides and flavonoids. 15 of them were quantified having a lower limit not less than 0.02% of the lyophilized extracts. Only seven of them were previously reported in this species, while 23 were identified for the first time as constituents of S. recta. HPLC-DAD-ESI-MS analysis provided evidence for the certain identification of the main constituents and in some cases of their isomers. Eight constituents were isolated and their structure elucidated by HPLC-ESI-MS and 1D- and 2D-NMR spectroscopy. Among the investigated preparations, the infusion seems to be the best method to extract the native constituents of the plant, while decoction is a more aggressive treatment and causes partial degradation of some acylated flavonoids.


Subject(s)
Beverages/analysis , Chromatography, High Pressure Liquid/methods , Plant Components, Aerial/chemistry , Spectrometry, Mass, Electrospray Ionization/methods , Stachys/chemistry , Chromatography, High Pressure Liquid/instrumentation , Drug Compounding/methods , Flavonoids/chemistry , Glycosides/chemistry , Molecular Structure , Phenylethyl Alcohol/chemistry , Quinic Acid/analogs & derivatives , Quinic Acid/chemistry , Reproducibility of Results , Spectrometry, Mass, Electrospray Ionization/instrumentation
8.
Biochem Pharmacol ; 79(9): 1327-36, 2010 May 01.
Article in English | MEDLINE | ID: mdl-20045676

ABSTRACT

Current pharmacological treatments for neuropathic pain have limited efficacy and severe side-effect limitations. St. John's Wort (SJW) is a medicinal plant, mainly used as antidepressant, with a favourable side-effect profile. We here demonstrate the ability of SJW to relieve neuropathic pain in rat models. The antihyperalgesic profile and mechanism of action of SJW and its main components were studied in two rat models of neuropathic pain: the chronic constriction injury and the repeated administration of oxaliplatin. SJW, acutely administered at low doses (30-60 mg kg(-1) p.o.), reversed mechanical hyperalgesia with a prolonged effect, being effective up to 180 min after injection. Further examinations of the SJW main components revealed that hyperforin and hypericin were responsible for the antihyperalgesic properties whereas flavonoids were ineffective. The effect of SJW on the PKC expression and activation was investigated in the periaqueductal grey (PAG) area by immunoblotting experiments. Mechanistic studies showed a robust over-expression and hyperphosphorylation of the PKCgamma (227.0+/-15.0% of control) and PKCepsilon (213.9+/-17.0) isoforms in the rat PAG area. A single oral administration of SJW produced a significant decrease of the PKCgamma (131.8+/-10.0) and PKCepsilon (105.2+/-12.0) phosphorylation in the PAG area due to the presence of hypericin. Furthermore, SJW showed a dual mechanism of action since hyperforin antinociception involves an opioid-dependent pathway. Rats undergoing treatment with SJW and purified components did not show any behavioural side effects or signs of altered locomotor activity. Our results indicate SJW as a prolonged antihyperalgesic treatment through inhibition of PKC isoforms and their phosphorylation.


Subject(s)
Hypericum , Pain/drug therapy , Perylene/analogs & derivatives , Protein Kinase C-epsilon/antagonists & inhibitors , Protein Kinase C/antagonists & inhibitors , Analgesics/pharmacology , Animals , Anthracenes , Male , Perylene/pharmacology , Phytotherapy , Plant Extracts/chemistry , Plant Extracts/therapeutic use , Rats , Rats, Sprague-Dawley
9.
Nat Prod Commun ; 4(12): 1761-76, 2009 Dec.
Article in English | MEDLINE | ID: mdl-20120121

ABSTRACT

Studies on stability of active ingredients are fundamental and critical for the rational development of Traditional Chinese Medicine (TCM) in view of its modernization and worldwide use. The stability of both active and marker constituents of plants used in TCM is reviewed for the first time. More than 100 papers, mostly written in Chinese, have been reviewed. Studies concerning plant constituents were analyzed according to their chemical classification of active ingredients. In addition, several crude drugs of animal origin are also reported. Stability of active ingredients is summarized during extraction and/or storage of the herbal drug preparations, and under stress conditions (pH, temperature, solvents, light, and humidity) and in the presence of preservatives, antioxidants, and metals.


Subject(s)
Drugs, Chinese Herbal/chemistry , Medicine, Chinese Traditional , Alkaloids/chemistry , Alkaloids/standards , Animals , China , Drug Stability , Drugs, Chinese Herbal/standards , Flavonoids/chemistry , Flavonoids/standards , Government Agencies , Humans , Legislation, Drug , Medicine, Chinese Traditional/standards , Phenols/chemistry , Phenols/standards , Polyphenols , Terpenes/chemistry , Terpenes/standards
10.
Food Chem Toxicol ; 46(11): 3383-8, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18768153

ABSTRACT

BACKGROUND: A number of scientific reports have investigated the possible implications of refined seed oils in allergic reactions, resulting in conflicting points of view. Also the total amount of residual proteins after refinement is still a matter of debate. Nevertheless, seed oils are now blamed as possible cause of allergic reactions. OBJECTIVE: To determine the true amount of proteins after oil refinement and to shed new lights on allergenic properties of refined seed oils. METHODS: We optimized a protein extraction procedure on several commercial refined seed oils. Both colorimetric and amino acid analysis were used to measure residual protein content. SDS-PAGE was also used for characterizations of protein band patterns. Sensitized child patients sera were tested by Western blot on PAGE-resolved proteins. RESULTS: Our extraction method proved to be effective and reproducible. Amino acid analysis resulted more accurate in determining the protein content with respect to colorimetric methods, indicating a higher protein content than that previously reported. IgE responsive residual proteins were found in peanut oil extracts. CONCLUSIONS: Our preliminary data suggest that fully refined seed oils should be taken into account in the context of allergic reactions and would benefit of further toxicological studies.


Subject(s)
Food Handling/methods , Food Hypersensitivity/etiology , Plant Oils/adverse effects , Plant Proteins/analysis , Plant Proteins/immunology , Allergens/analysis , Allergens/immunology , Amino Acids/analysis , Amino Acids/immunology , Arachis/immunology , Blotting, Western , Colorimetry/methods , Corn Oil/analysis , Corn Oil/immunology , Electrophoresis, Polyacrylamide Gel , Humans , Immunoglobulin E/blood , Peanut Oil , Plant Oils/analysis , Soybean Oil/immunology , Sunflower Oil
11.
J Sep Sci ; 31(12): 2206-10, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18563742

ABSTRACT

First baseline HPLC enantioseparation of kavain is described. Complete enantiodiscrimination was achieved on the immobilised-type Chiralpak IA chiral stationary phase (CSP) using pure methanol and simple methanol-water and ethanol-water mixtures as eluents. A water-dependent enantioselectivity was clearly demonstrated. Performance of the Chiralpak IA CSP in polar organic and RP conditions was compared with that of five coated polysaccharide-derived CSPs used in normal-phase mode.


Subject(s)
Chromatography, High Pressure Liquid/methods , Pyrones/isolation & purification , Amylose/analogs & derivatives , Ethanol , Methanol , Polysaccharides/chemistry , Pyrones/chemistry , Solvents , Stereoisomerism , Water
12.
Plant Physiol Biochem ; 46(4): 414-20, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18243002

ABSTRACT

The present paper reports on the production of anthocyanins and xanthones in different in vitro systems of Hypericum perforatum var. angustifolium (sin. Fröhlich) Borkh. Undifferentiated calli and regenerated shoots at different developmental stages were analyzed by applying an extractive and an analytical procedure capable of detecting and quantifying anthocyanins. The findings revealed, for the first time, the co-presence of hypericins and anthocyanins in shoots at initial and more developed stages of H. perforatum var. angustifolium L. Moreover, a high production of xanthones was found in the undifferentiated calli.


Subject(s)
Anthocyanins/biosynthesis , Hypericum/metabolism , Plant Shoots/metabolism , Xanthones/metabolism , Anthocyanins/analysis , Hypericum/cytology , Plant Shoots/cytology , Regeneration/physiology , Xanthones/analysis
13.
Bioorg Med Chem Lett ; 17(21): 5744-8, 2007 Nov 01.
Article in English | MEDLINE | ID: mdl-17855090

ABSTRACT

The interactions of some natural flavonols with alpha, beta- and gamma-Cds have been investigated. Guest molecules were galangin, kaempferol and quercetin. Inclusion complexes were prepared by kneading and freeze-drying. The complexes were characterized using different physico-chemical methods based on differential scanning calorimetry (DSC), infrared spectroscopy (IR) and NMR spectroscopy. In the proton and carbon spectra the effects of complexation on the chemical shifts of the internal and external protons of Cds in the presence of each flavonoid were observed. Moreover, the water-solubility of the flavonols in the presence of Cds was also evaluated. The increased solubility of quercetin and kaempferol in the presence of beta-Cd was evidenced. For all three guests, multidimensional NMR experiments in DMSO and water are consistent with dynamic binding processes, dominated by insertion of the B ring into the wider rim of the Cd cavity.


Subject(s)
Cyclodextrins/chemistry , Flavonols/chemistry , Calorimetry, Differential Scanning , Chromatography, High Pressure Liquid , Hydrogen Bonding , Spectrum Analysis/methods
14.
J Agric Food Chem ; 55(16): 6596-602, 2007 Aug 08.
Article in English | MEDLINE | ID: mdl-17622155

ABSTRACT

The aim of the present work was to develop a quali-quantitative investigation, using HPLC/DAD and HPLC/ESI/MS techniques, of the phenolic composition of berries collected from wild Tuscan plants of Juniperus communis L. and grown in three different geographical zones. The applied chromatographic elution method made it possible to well separate up to 16 different compounds belonging to flavonoids, such as isoscutellarein and 8-hydroxyluteolin or hypolaetin glycosides, and six biflavonoids, among them amentoflavone, hynokiflavone, cupressoflavone, and methyl-biflavones. To the best of the authors' knowledge this is the first report on the presence of these compounds in juniper berries. The flavonoidic content in the analyzed berries ranged between 1.46 and 3.79 mg/g of fresh pulp, whereas the amount of the biflavonoids was always lower, varying between 0.14 and 1.38 mg/g of fresh weight.


Subject(s)
Biflavonoids/analysis , Flavonoids/analysis , Fruit/chemistry , Juniperus/chemistry , Chromatography, High Pressure Liquid , Italy , Spectrometry, Mass, Electrospray Ionization
15.
J Pharm Biomed Anal ; 44(1): 70-8, 2007 May 09.
Article in English | MEDLINE | ID: mdl-17331690

ABSTRACT

As a part of our investigations on the content and stability of herbal drug preparations, we evaluated the content and stability of tinctures and mother tinctures of Hawthorn leaves and flowers and Hawkweed. Hawthorn preparations are mainly used by patients with cardiac diseases; Hawkweed is employed for the treatment of cellulitis and obesity due to its diuretic properties. Both tinctures (DER 1:5) and mother tinctures (DER 1:10) are herbal preparations reported in the European Pharmacopoeia. The first preparation is obtained using dried herbal drugs; the latter is a homoeopathic preparation obtained with fresh plant material, often used in substitution of tinctures. The aim of this work was to assess the qualitative and quantitative profile of the constituents of the investigated preparations and the chemical stability of their marker constituents from long-term testing using HPLC assays. Characteristic constituents of Hawthorn leaves and flowers are flavonoids such as vitexin-2''-O-rhamnoside and hyperoside and oligomeric procyanidins. Characteristic constituents of Hawkweed are caffeoyl-quinic acid derivatives, flavonoids and a coumarin:umbelliferone. Our investigation showed that Hawthorn mother tincture had a higher concentration of procyanidins with respect to the tincture but the stability of these constituents were very low in both preparations. Total flavonoidic content was 3.33 mg/ml, about 1.5 times more than the content of mother tincture and the shelf-life t(90) was about 7 months for both preparations. For Hawkweed preparations a content of caffeoyl-quinic acid derivatives (ca. 4 mg/ml) was found, but their stability was good only in the tincture. The concentrations of flavonoids and umbelliferone were two times as much in the tincture with respect to the mother tincture. Stability of these two classes of constituents was good for both preparations over a 9-month period.


Subject(s)
Asteraceae/chemistry , Crataegus/chemistry , Drug Stability , Plant Extracts/chemistry , Plants, Medicinal/chemistry , Asteraceae/classification , Chromatography, High Pressure Liquid , Crataegus/classification , Flowers/chemistry , Hot Temperature , Mass Spectrometry , Molecular Structure , Plant Leaves/chemistry , Plants, Medicinal/classification , Structure-Activity Relationship , Time Factors
16.
Rapid Commun Mass Spectrom ; 20(13): 2013-22, 2006.
Article in English | MEDLINE | ID: mdl-16755600

ABSTRACT

This work is focused on the recovery and structural characterisation of bioactive compounds from SOR (solid olive residue), a low cost and widely available by-product in the Mediterranean basin. In the light of the interesting biological activities attributed both to secoiridoid and phenylpropanoids, the aim of this work was to carry out a systematic tandem mass spectrometric study for the identification and characterisation of these two class of compounds extracted from SOR derived from Coratina, a cultivar widely diffused in the south of Italy. Five phenylpropanoids, in addition to verbascoside, and two new secoiridoids were identified.


Subject(s)
Iridoids/chemistry , Iridoids/isolation & purification , Olea/chemistry , Spectrometry, Mass, Electrospray Ionization/methods , Chromatography, High Pressure Liquid/methods , Glucosides/chemistry , Glucosides/isolation & purification , Italy , Molecular Structure , Phenols/chemistry , Phenols/isolation & purification , Tandem Mass Spectrometry/methods
17.
J Pharm Biomed Anal ; 41(2): 449-54, 2006 May 03.
Article in English | MEDLINE | ID: mdl-16457981

ABSTRACT

Conventional herbal drug preparations (HDP) based on Arnica montana L. have a low content of the active principles, sesquiterpene lactones, which show poor stability and low physical compatibility in semisolid formulations. Recently, an innovative supercritical carbon dioxide (CO2) extract with high sesquiterpene content has been marketed. Development of six semisolid preparations (cetomacrogol, polysorbate 60, polawax, anphyphil, natrosol and sepigel) based on this innovative CO2 extract is discussed. Stability of these preparations was investigated according to ICH guidelines. The evaluation of in vitro release of active constituents was performed using the cell method reported in the European Pharmacopoeia. Preliminary data on in vivo permeation of three selected formulations is demonstrated using the "skin stripping" test, according to the FDA, in healthy subjects. Analysis of sesquiterpene lactones within the extract and in vitro and in vivo studies was performed by RP-HPLC-DAD-MS method. The cetomacrogol showed the best release profile in the in vitro test, while in the in vivo test the best preparation resulted polysorbate 60 and polawax.


Subject(s)
Arnica , Plant Extracts/administration & dosage , Plant Extracts/chemistry , Administration, Cutaneous , Adult , Arnica/chemistry , Cetomacrogol/administration & dosage , Cetomacrogol/chemistry , Chromatography, Supercritical Fluid , Drug Stability , Emulsions , Excipients/administration & dosage , Excipients/chemistry , Female , Humans , Permeability , Polysorbates/administration & dosage , Polysorbates/chemistry , Sesquiterpenes/analysis , Sesquiterpenes/chemistry , Sesquiterpenes, Guaiane , Skin Absorption , Surface-Active Agents/administration & dosage , Surface-Active Agents/chemistry
18.
Bioorg Med Chem ; 14(9): 2972-7, 2006 May 01.
Article in English | MEDLINE | ID: mdl-16412643

ABSTRACT

The reactions with hemoglobin of artemisinin and of its parent compounds, sodium artesunate and dihydroartemisinin, were investigated by visible absorption spectroscopy under standard solution conditions (50 mM phosphate buffer, pH 7, 37 degrees C). Notably, these antimalarial drugs were found to react with hemoglobin (i.e., ferrous heme), but not with methemoglobin (i.e., ferric heme). The reaction selectively occurs at the heme sites and consists of the progressive, slow decay of the Soret band, as a consequence of heme alkylation and subsequent loss of pi electron delocalization. For the various tested compounds the process reaches completion within approximately 30-70 h. Additional experiments were carried out upon adopting the solution conditions described by Meunier et al. and by Kannan et al. in their recent studies. Some reactivity of artemisinin with methemoglobin was indeed detected after addition of 50% v/v acetonitrile, most likely as a consequence of extensive protein unfolding. A unified description for the reactions of artemisinins with hemoglobin is given.


Subject(s)
Artemisinins/chemistry , Hemoglobins/chemistry , Sesquiterpenes/chemistry , Acetates , Acetonitriles , Buffers , Humans , Hydrogen-Ion Concentration , Iron/chemistry , Molecular Structure , Protoporphyrins/chemistry , Spectrum Analysis
19.
Bioorg Med Chem Lett ; 13(22): 4055-7, 2003 Nov 17.
Article in English | MEDLINE | ID: mdl-14592507

ABSTRACT

The reaction of hemin with three well known artemisinin analogues, namely dihydroartemisinin, artemether and artesunate, was independently analysed by visible spectrophotometry and by ESI-MS/HPLC. A very similar reaction pathway emerges for all these compounds that matches closely the reaction profile previously described for artemisinin. In the course of the reaction characteristic isomeric 1:1 drug-hemin adducts are formed as in the case of artemisinin; eventual disruption of the porphyrin ring takes place in all cases, most likely through oxidative degradation.


Subject(s)
Artemisinins/chemistry , Hemin/chemistry , Sesquiterpenes/chemistry , Artemisinins/chemical synthesis , Chromatography, High Pressure Liquid , Molecular Structure , Sesquiterpenes/chemical synthesis , Spectrometry, Mass, Electrospray Ionization/methods , Spectrophotometry , Structure-Activity Relationship
20.
J Pharm Biomed Anal ; 30(3): 613-24, 2002 Oct 15.
Article in English | MEDLINE | ID: mdl-12367686

ABSTRACT

As a part of our investigations on the stability of tinctures, we evaluated 40 and 60% v/v tinctures of Calendula flower, Milk-thistle fruit and Passionflower. These preparations are widely employed in phytotherapy, thus Calendula is used externally for anti-inflammatory properties, Milk-thistle and Passionflower are employed for hepatic injuries and in tenseness with difficulty in falling asleep, respectively. Aim of this work was to assess the chemical stability of their active or marker constituents from accelerated and long-term testing by using HPLC. For Calendula flower and Passionflower active constituents are not known, however, flavonoids seem to have a crucial importance for the activity, and thus are considered the markers of Calendula and of Passionflower. Active constituents of Milk-thistle are represented by silymarin that is a phytocomplex mainly constituted by three flavolignans: silybin, silychristin and silydianin. Our investigation showed a very low thermal stability of the constituents from accelerated and long-term testing and determined by HPLC-DAD and -MS analyses and was related both to the class of flavonoids and water content of the investigated tinctures. Thus, shelf-lives at 25 degrees C of the most stable tincture (Passionflower 60% v/v) was about 6 months and only about 3 months the stability of Milk-thistle tinctures.


Subject(s)
Calendula/chemistry , Passiflora/chemistry , Silybum marianum/chemistry , Chemistry, Pharmaceutical , Chromatography, Liquid/methods , Drug Stability , Fruit/chemistry , Mass Spectrometry/methods , Plant Components, Aerial/chemistry , Plant Extracts/chemistry , Plant Extracts/isolation & purification
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