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Muttenz, Switzerland

Adhami H.-R.,University of Vienna | Scherer U.,Northwestern University | Kaehlig H.,University of Vienna | Hettich T.,Northwestern University | And 3 more authors.
Phytochemical Analysis | Year: 2013

Introduction In the search for new natural compounds with acetylcholinesterase (AChE) inhibitory activity this study focused on galbanum, the oleo gum-resin from Ferula gummosa Boiss., which had shown AChE inhibitory activity in a screening. Objective The isolation of bioactive compounds from plant extracts usually is laborious and time consuming. In an approach to accelerate the characterisation of compounds with AChE inhibitory activity, the potential of a combination of HPTLC bioautography with HPTLC-MS/NMR for the fast identification of active compounds in galbanum was studied. Method Pre-fractionation of the dichloromethane extract was performed by vacuum liquid chromatography. The resulting fractions were separated by HPTLC and active zones determined by bioautography. A TLC-MS interface was used to elute the single zones from the plates directly into a mass spectrometer. The interface was also used to extract the two major active zones from HPTLC plates for off-line one- and two-dimensional NMR and quadrupole time of flight (QTOF) MS. Results The isolated compounds were identified as 7-{[(2E)-3,7-dimethylocta-2,6-dien-1-yl] oxy}-2H-chromen-2-one (auraptene) and 7-{[(1R,4aR,6S,8aS)-6-hydroxy-5,5,8a- trimethyl-2-methylenedecahydronaphthalen-1-yl]methoxy}-2H-chromen-2-one (farnesiferol A). This is the first report of these substances in F. gummosa. Their median inhibitory concentration (IC50) values for AChE inhibition were determined as 47 and 17 μg/mL in comparison with physostigmine as a positive control (IC50: 0.8 μg/mL) and their concentrations in galbanum were quantified by HPLC as 3.5% and 7.9%, respectively. Conclusion The study showed that HPTLC-MS/NMR can be considered as a fast and high-confidence method for dereplication of natural compounds. From the correlation of the concentration of the elucidated compounds and their IC50 values for AChE inhibition it can be concluded that auraptene and farnesiferol A are contributing to this activity of galbanum. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd. Source


Rueda D.C.,University of Basel | Zaugg J.,University of Basel | Quitschau M.,University of Basel | Reich E.,CAMAG Laboratory | And 2 more authors.
Planta Medica | Year: 2012

In a twomicroelectrode voltage clamp assay using Xenopus laevis oocytes, a petroleum ether extract prepared from a commercial sample of the traditional Chinese herbal drug labelled as Chaihu (Bupleurum chinense DC. roots) enhanced the Iby 156% ±22% when tested at 100μg/mL. By means of HPLC-based activity profiling combined with high-resolution LC-MS and microprobe NMR, the germacranolide aristolactone (1) was identified as one of the main active compounds (EC56.02μM±5.09μM). However, aristolactone has been previously reported only from the genus Aristolochia (Aristolochiaceae), suggesting a possible adulteration. With the aid of a validated HPTLC protocol for detection of aristolochic acids and with reference samples, the commercial sample was confirmed to be a mixture of Aristolochia manshuriensis root and Bupleurum chinense root. This finding was corroborated by macroscopic inspection of the drug. This case of adulteration with a highly nephrotoxic drug raises concerns about adequate quality control of TCM drugs commercialized in Europe. © Georg Thieme Verlag KG Stuttgart - New York. Source


Kaale E.,Muhimbili University of Health and Allied Sciences | Risha P.,Muhimbili University of Health and Allied Sciences | Reich E.,CAMAG Laboratory | Layloff T.P.,Management science for Health
Journal of AOAC International | Year: 2010

Two laboratories extensively investigated the use of HPTLC to perform assays on lamivudine-zidovudine, metronidazole, nevirapine, and quinine composite samples. To minimize the effects of differences in analysts' technique, the laboratories conducted the study with automatic sample application devices in conjunction with variable-wavelength scanning densitometers to evaluate the plates. The HPTLC procedures used relatively innocuous, inexpensive, and readily available chromatography solvents used in the Kenyon or the Global Pharma Health Fund Minilabs® TLC methods. The use of automatic sample applications in conjunction with variable- wavelength scanning densitometry demonstrated an average repeatability or within-laboratory RSD of 1.90%, with 73% less than 2% and 97% at 2.60% or less, and an average reproducibility or among-laboratory RSD of 2.74%. Source


Agnaniet H.,Universite des Sciences et Techniques de Masuku | Mbot E.J.,Universite des Sciences et Techniques de Masuku | Keita O.,ISA University | Fehrentz J.-A.,Montpellier University | And 7 more authors.
BMC Complementary and Alternative Medicine | Year: 2016

Background: Diabetes mellitus is a metabolic disorder which is rising globally in rich and developing countries. In the African region this rate is the highest, with 20 million diagnosed diabetics. Despite a noticeable progress in the treatment of diabetes mellitus by synthetic drugs, the search for new natural anti-diabetic agents is going on. Nauclea diderrichii (De Wild.) Merr. (ND) and Sarcocephalus pobeguinii Hua ex Pellegr. (SP) are used as traditional medicines in Gabon for the treatment of different diseases, especially in the case of diabetes. The aim of this study was to evaluate the antidiabetic potential of these two medicinal plants traditionally used in Gabon. Methods: Pharmacological (inhibitory action on α and β-glucosidases) and toxicological (effect on human T cell proliferation) studies were conducted on aqueous extracts of ND (leaves and bark) and SP (bark) collected in Gabon. All raw extracts were analyzed by HPTLC and their content in phenolic compounds was determined by using standard method. The most active extracts were submitted to preparative HPLC in order to evidence the most efficient subfractions by biological evaluation. Results: The results showed that two extracts from ND were potent α-glucosidase inhibitors, the leaf extract being more active that the bark extract: the first one was more than 60 fold more active than Acarbose, which is an oral medication used to treat type 2 diabetes; the extract from SP bark was less efficient. The HPLC subfractions of the extracts of ND leaves and SP bark were tested in the same experimental conditions. In each case, the most active subfractions still show very potent inhibitory effect on α-glucosidase (80-90 % inhibition at 0.1 mg/mL). The most efficient extract, from ND leaves, was also characterized by the highest percentage of phenolic compounds, which suggests a relationship between its inhibitory potential on α-glucosidase and its content in phenolic compounds. Conversely, only a moderate inhibitory activity of the three extracts was observed on β-glucosidase. Conclusion: These results clearly indicated that active compounds present in N. diderrichii and S. pobeguinii leaves or/and bark were selective and highly potent inhibitors of α-glucosidase and validate their popular use for the treatment of diabetes. © 2016 Agnaniet et al. Source


Al-Harrasi A.,The University of Nizwa | Ali L.,The University of Nizwa | Ceniviva E.,CAMAG Laboratory | Al-Rawahi A.,The University of Nizwa | And 6 more authors.
Tropical Journal of Pharmaceutical Research | Year: 2013

Purpose: To evaluate antiglycation and antioxidant activities as undertake HPTLC analysis of Boswellia sacra resin. Methods: Sub-fractionation of the crude methanol extract of Hougari regular (HR) grade resin of Boswellia sacra was carried out by vacuum liquid chromatography. Free radical scavenging and antiglycation activities of sub-fractions were characterized in order to assess their anti-aging properties. Furthermore, high performance thin layer chromatography (HPTLC) analysis of Boswellia sacra resins was also carried out. Results: Polar fractions of the extract obtained exhibited the highest antiglycation activity while nonpolar fractions showed more than 50 % inhibition in superoxide anion scavenging assay. Scavenging activity of reactive oxygen species results indicate that non-polar sub-fractions showed > 50 % inhibition, except Shabi frankincense (SF) oil which showed 33 % inhibition. Dichloromethane (CH2Cl2) fraction, 40 % dichloromethane (CH2Cl2)/n-hexane sub-fraction, and SF oil showed moderate activity in di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH) assay. Furthermore, HPTLC analysis indicates the presence of 11-keto-β-boswellic acid (KBA) and 3-O-acetyl-11-keto-β-boswellic acid (AKBA) along with some other terpenoids. Conclusion: Various sub-fractions of Boswellia sacra exert effective antiglycation and antioxidant activities. The extracts should be studied further for possible formulation into pharmaceutical products. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. Source

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