Axel Teichert

Publications (11)15.46 Total impact

• Source

  Available from: Nasser Ali

  Article: Chemical composition, antimicrobial, antiradical and anticholinesterase activity of the essential oil of Pulicaria stephanocarpa from Soqotra.

  Nasser A Awadh Ali, Rebecca A Crouch, Mohamed A Al-Fatimi, Norbert Arnold, Axel Teichert, William N Setzer, Ludger Wessjohann
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  ABSTRACT: The chemical composition of the hydrodistilled leaf essential oil from Pulicaria stephanocarpa Balf. Fil was determined by GC-MS analysis, and its antimicrobial, antioxidant and anticholinesterase (AChE) activities were evaluated. Eighty-three compounds were identified representing 97.2% of the total oil. (E)-Caryophyllene 13.4%, (E)-nerolidol 8.5%, caryophyllene oxide 8.5%, alpha-cadinol 8.2% spathulenol 6.8% and tau-cadinol 4.7%, were the main components. Antimicrobial activity of the oil, evaluated using the disc diffusion and broth dilution methods, demonstrated the highest susceptibility on Gram-positive bacteria and Candida albicans. The free radical scavenging ability of the oil was assessed by the DPPH assay to show antiradical activity with IC50 of 330 microg/mL. Moreover, the oil revealed an AChE inhibitory activity of 47% at a concentration of 200 microg/mL using Ellman's method.
  Natural product communications 01/2012; 7(1):113-6. · 1.24 Impact Factor
• Source

  Available from: Nasser Ali

  Article: Anticholinesterase activity of endemic plant extracts from Soqotra.

  Hussein Bakthira, Nasser A Awadh Ali, Norbert Arnold, Axel Teichert, Ludger Wessjohann
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  ABSTRACT: A total of 30 chloroform and methanol extracts from the following endemic Soqotran plants Acridocarpus socotranus Olive, Boswellia socotranao Balf.fil, Boswellia elongata Balf. fil., Caralluma socotrana N. Br, Cephalocroton socotranus Balf.f, Croton socotranus Balf. fil.., Dendrosicycos socotrana Balf.f., Dorstenia gigas Schweinf. ex Balf. fil., Eureiandra balfourii Cogn. & Balf. fil., Kalanchoe farinaceae Balf.f, Limonium sokotranum (Vierh) Radcl. Sm), Oldenlandia pulvinata, Pulicaria diversifolia (Balf. and Pulicaria stephanocarpa Balf. were screened for their acetylcholinesterase inhibitory activity by using in vitro Ellman method at 50 and 200 µg/ml concentrations. Chloroform extracts of Croton socotranus, Boswellia socotrana, Dorstenia gigas, and Pulicaria stephanocarpa as well as methanol extracts of Eureiandra balfourii exhibited inhibitory activities higher than 50 % at concentration of 200 µg. At a concentrations of 50 µg, the chloroform extract of Croton socotranus exhibited an inhibition of 40.6 %.
  African Journal of Traditional, Complementary and Alternative Medicines 01/2011; 8(3):296-9. · 0.71 Impact Factor
• Article: Antioomycete activity of gamma-oxocrotonate fatty acids against P. infestans.

  Lennart Eschen-Lippold, Tobias Draeger, Axel Teichert, Ludger Wessjohann, Bernhard Westermann, Sabine Rosahl, Norbert Arnold
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  ABSTRACT: Infections with Phytophthora infestans, the causal agent of potato and tomato late blight disease, are difficult to control and can lead to considerable agricultural losses. Thus, the development of new effective agents against the pathogen is of great interest. In previous work, (E)-4-oxohexadec-2-enoic acid (3) was isolated from Hygrophorus eburneus, which exhibited fungicidal activity against Cladosporium cucumerinum. Here, the inhibitory effect of 3 on P. infestans spore germination and mycelium growth in vitro is demonstrated. The in vivo effect on infections of whole potato plants was investigated by spraying plants with the sodium salt of 3, sodium (2E)-4-oxohexadec-2-enoic acid (4), prior to P. infestans inoculation. Additionally, the influence of 3 on mycelium growth of Colletotrichum coccodes, the causal agent of potato black dot disease, was analyzed. In all approaches, a significant inhibition of pathogen development was achieved. Importantly, the unsaturated fatty acid exerted no toxic effect when sprayed on plants, a prerequisite for its commercial use.
  Journal of Agricultural and Food Chemistry 09/2009; 57(20):9607-12. · 2.82 Impact Factor
• Article: Determination of beta-carboline alkaloids in fruiting bodies of Hygrophorus spp. by liquid chromatography/electrospray ionisation tandem mass spectrometry.

  Axel Teichert, Tilo Lübken, Jürgen Schmidt, Christine Kuhnt, Manfred Huth, Andrea Porzel, Ludger Wessjohann, Norbert Arnold
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  ABSTRACT: The beta-carboline alkaloids harmane (1) and norharmane (2) were isolated from fruiting bodies of Hygrophorus eburneus (Bull.) Fr. as well as brunnein A (3) from Hygrophorus hyacinthinus Quél. (Tricholomataceae, Agaricales) for the first time. Their occurrence within the genus was investigated using liquid chromatography/electrospray ionisation tandem mass spectrometric methods, especially by selected reaction monitoring. Based on these results their chemotaxonomical relevance is discussed.
  Phytochemical Analysis 08/2008; 19(4):335-41. · 2.63 Impact Factor
• Article: (Iso)-quinoline alkaloids from fungal fruiting bodies of Cortinarius subtortus.

  Axel Teichert, Jürgen Schmidt, Andrea Porzel, Norbert Arnold, Ludger Wessjohann
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  ABSTRACT: Chemical analysis of the fruiting bodies of the agaricoid fungus Cortinarius subtortus yielded three new natural products, two quinoline and one isocarbostyryl alkaloid. The structures of compounds 1- 3 were determined by analysis of NMR and MS data. Compound 1 exhibited inhibitory effects against the phytopathogenic fungus Colletotrichum coccodes. All three compounds displayed moderate antioxidant activity in a DPPH free radical scavenging bioassay.
  Journal of Natural Products 07/2008; 71(6):1092-4. · 3.13 Impact Factor
• Article: N-glucosyl-1H-indole derivatives from Cortinarius brunneus (Basidiomycetes).

  Axel Teichert, Jürgen Schmidt, Andrea Porzel, Norbert Arnold, Ludger Wessjohann
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  ABSTRACT: Two new N-glucosylated indole alkaloids were isolated from fruiting bodies of the basidiomycete Cortinarius brunneus (Pers.) Fr. The structures were elucidated by means of the spectroscopic data. Additionally, the very recently reported compounds N-1-beta-glucopyranosyl-3-(carboxymethyl)-1H-indole (3) and N-1-beta-glucopyranosyl-3-(2-methoxy-2-oxoethyl)-1H-indole (4) could be detected. Compound 3 is the N-glucoside of the plant-growth regulator 1H-indole-3-acetic acid (IAA), but, in contrast, it does not exhibit auxin-like activity in an Arabidopsis thaliana tap root elongation assay.
  Chemistry & Biodiversity 05/2008; 5(4):664-9. · 1.80 Impact Factor
• Article: Chemical Composition and Biological Activities of Essential Oils from the Oleogum Resins of Three EndemicSoqotraen Boswellia Species

  Nasser A. Awadh Ali, Martina Wurster, Norbert Arnold, Axel Teichert, Jürgen Schmidt, Ulrike Lindequist, Ludger Wessjohann
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  ABSTRACT: The chemical composition, antioxidant and anticholinesterase activity of three essential oils (EOs) obtained from the oleogum resin of three endemic Sqotraen Boswellia species, Boswellia socotrana Balf. f, Boswellia ameero Balf. f, and Boswellia elongata Balf. f were determined. GC-MS technique was used for the analysis of the oils. Oils of B. socotrana and B. ameero were characterized by a high content of monoterpenes.The main constituens of B. socotrana and B. ameero were (E)-2,3-epoxycarene (51.8%), 1,5-isopropyl-2- methylbicyclo[3.1.0]hex-3-en-2-ol (31.3%), and a-cymene (7.1%); (3E,5E)-2,6-dimethyl-1,3,5,7-octatetraene (34.9%), 1-(2,4-Dimethylphenyl)ethanol (20.3%), 3,4-dimethylstyrene (17.3%), a-campholenal (13.4%) and a- terpineol (12.4%) respectively. The composition of B. elongata oil was dominated by the diterpene verticiol (52.4%), the sesquiterpene caryophellene (39.1%) and methylcycloundecanecarboxylate (7.8%). The oils were screened for their antioxidant activity by using the DPPH free radical scavenger assay and theiranticholinesterase activity on acetylcholinesterase enzyme by using in vitro Ellman method. The antioxidantactivity of EOs from B. socotrana (IC50 =121.4 μg/mL) appeared to be more potent than that of B. elongata (IC50=211.2 μg/mL) and B. ameero (IC50 =175.2 μg/mL). EO of B. socotrana showed the higher AChE inhibitory activity with 59.3% at concentration of 200 μg/mL in comparison to EOs of B. elongata and B. ameero (29.6, 41.6 enzyme inhibition) respectively.
  Rec. Nat. Prod. 01/2008; 2:6-12.
• Article: Brunneins A-C, beta-carboline alkaloids from Cortinarius brunneus.

  Axel Teichert, Jürgen Schmidt, Andrea Porzel, Norbert Arnold, Ludger Wessjohann
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  ABSTRACT: Four beta-carboline alkaloids, brunneins A-C (1-3) and 3-(7-hydroxy-9H-beta-carboline-1-yl)propanoic acid (4), were isolated from fruiting bodies of the agaricoid fungus Cortinarius brunneus. The structures of 1-3 were determined by analysis of NMR and MS data, and the structure of compound 4 was determined by comparison with published data. Brunnein A (1) exhibited very low cholinesterase inhibitory effects and no cytotoxicity.
  Journal of Natural Products 10/2007; 70(9):1529-31. · 3.13 Impact Factor
• Article: Unusual Bioactive 4-Oxo-2-alkenoic Fatty Acids from Hygrophorus eburneus

  Axel Teichert, Tilo Lübken, Jürgen Schmidt, Andrea Porzel, Norbert Arnold, Ludger Wessjohann
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  ABSTRACT: From fruit bodies of the basidiomycete Hygrophorus eburneus (Bull.: Fr.) Fr. (Tricholomataceae) eight fatty acids (C16, C18) with γ-oxocrotonate partial structure could be isolated. Initial tests demonstrate their bactericidal and fungicidal activity. The structures of (2E,9E)-4-oxooctadeca-2,9,17-trienoic acid (1), (2E,11Z)-4-oxooctadeca-2,11,17-trienoic acid (2), (E)-4-oxohexadeca-2,15-dienoic acid (3), (E)-4-oxooctadeca-2,17-dienoic acid (4), (2E,9E)-4-oxooctadeca-2,9-dienoic acid (5), (2E,11Z)-4-oxooctadeca-2,11-dienoic acid (6), (E)-4-oxohexadec-2-enoic acid (7), and (E)-4-oxooctadec-2-enoic acid (8) were elucidated on the basis of their spectroscopic data.
  Zeitschrift für Naturforscher. 01/2005; 60b(1):25-32.
• Article: Bioaktive Sekundärmetaboliten aus der Gattung Hygrophorus (Basidiomycetes)

  Axel Teichert, Tilo Lübken, Monika Kummer, Helmut Besl, Herbert Haslberger, Norbert Arnold
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  ABSTRACT: The fungicidal activity of different crude extracts from fruiting bodies of 23 species of the genus Hygrophorus was tested in a bioassay against the phytopathogenic fungus Cladosporium cucumerinum. Responsible for the demonstrated activity are unusual fatty acids and the hygrophorones A-G.
  Zeitschrift für Mykologie. 01/2005; 71(1):53-61.
• Article: Bioaktive Sekundärmetaboliten aus der Gattung Hygrophorus (Basidiomycetes)

  Axel Teichert, Tilo Lübken, Monika Kummer, Helmut Besl, H. Haslberger, Norbert Arnold
  Zeitschrift für Mykologie. 01/2005; 1(71):53-61.