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Publikationen - Natur- und Wirkstoffchemie

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Publikation

Thuy, T. T.; Franke, K.; Wessjohann, L.; Sung, T. V.; Characterisation of alkaloids from Stephania rotunda Adv. Nat. Sci. (Vietnam) 6, 299-312, (2005)

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Publikation

Teichert, A.; Lübken, T.; Schmidt, J.; Porzel, A.; Arnold, N.; Wessjohann, L.; Unusual Bioactive 4-Oxo-2-alkenoic Fatty Acids from Hygrophorus eburneus Z. Naturforsch. B 60, 25-32, (2005) DOI: 10.1515/znb-2005-0105

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.
Publikation

Teichert, A.; Lübken, T.; Kummer, M.; Besl, H.; Haslberger, H.; Arnold, N.; Bioaktive Sekundärmetaboliten aus der Gattung Hygrophorus (Basidiomycetes) Z. Mykol. 71, 53-61, (2005)

Die fungizide Wirkung von verschiedenen Rohextrakten von 23 Arten der Gattung Hygrophorus gegen Cladosporium cucumerinum wird gezeigt. Als Wirkprinzip konnten ungewöhnliche Fettsäuren und die Hygrophorone A-G identifiziert werden.
Publikation

Schmidt, J.; Raith, K.; Boettcher, C.; Zenk, M. H.; Analysis of Benzylisoquinoline-Type Alkaloids by Electrospray Tandem Mass Spectrometry and Atmospheric Pressure Photoionization Eur. J. Mass Spectrom. 11, 325-333, (2005) DOI: 10.1255/ejms.745

Benzylisoquinoline alkaloids found in the Papaveraceae family play a major role in pharmaceutical biology. This is the first systematic study dealing with electrospray tandem mass spectrometry (ESI-MS/MS) of all benzylisoquinolines found as biogenetic precursors of morphinan alkaloids. Tandem mass spectral data are presented for norlaudanosoline, laudanosoline, 4′-O-methyl-norlaudanosoline, 6-O-methyl-norlaudanosoline, norcoclaurine, coclaurine, N-methylcoclaurine, N-methyl-3′-hydroxycoclaurine, N-methyl-3′-O-methylcoclaurine, norreticuline and reticuline. This study compares results obtained using an ion trap mass spectrometer with those obtained using a triple quadrupole one. The results highlight the differences between the tandem-in-time versus the tandem-in-space principle, often hampering the development of ESI-MS/MS libraries. In addition, the use of the atmospheric pressure photoionisation technique for the analysis of such substances is discussed.
Publikation

Ruijter, E.; Schültingkemper, H.; Wessjohann, L. A.; Highly Substituted Tetrahydropyrones from Hetero-Diels−Alder Reactions of 2-Alkenals with Stereochemical Induction from Chiral Dienes J. Org. Chem. 70, 2820-2823, (2005) DOI: 10.1021/jo0488311

A new method for the stereoselective synthesis of libraries of 2,3,5-trisubstituted tetrahydro-γ-pyrones and the corresponding tetrahydropyran-4-ols is reported. Dienes with a chiral moiety at position 5 were synthesized starting from (triphenylphosphoranylidene)acetone. In hetero-Diels−Alder (HDA) reactions, especially with α,β-unsaturated aldehydes, they induce diastereomeric ratios from 4:1 to 14:1. Through selective epimerization and reduction, further building blocks are available. These constitute ideal starting points for their use in the total synthesis of complex polyketide macrocycles, especially with the vinyl group available for metathetic coupling.
Publikation

Ödman, P.; Wessjohann, L. A.; Bornscheuer, U. T.; Chemoenzymatic Dynamic Kinetic Resolution of Acyloins J. Org. Chem. 70, 9551-9555, (2005) DOI: 10.1021/jo051661n

Acyloins (α-hydroxy ketones) are important building blocks in organic synthesis, e.g., for the total synthesis of epothilones. Optically pure acyloins can be obtained by lipase-catalyzed kinetic resolution (KR) of the racemate with, for example, Burkholderia cepacia lipase, but this process suffers from a yield limitation of 50%. To devise a dynamic kinetic resolution (DKR), we studied the racemization of two different acyloins and corresponding esters with various amine bases and ion exchangers. No combination of base and solvent was found that could selectively racemize the acyloin or corresponding ester under the conditions needed for a DKR. In contrast to bases, acidic resins (ARs) were found to racemize the acyloins selectively in n-hexane and in water. Unfortunately, the AR deactivated the lipase, preventing a one-pot DKR. Minor side reactions involving the AR, the substrate acyloin, and the vinyl ester acyl donor were also observed. However, an efficient DKR was made possible by the spatial separation of lipase and ion exchanger, with enzymatic transesterification and AR-catalyzed racemization taking place simultaneously in two compartments connected by a pump loop. The conversion of substrate alcohol was 91%, the selectivity toward the product butyrate ester 90%, and the enantiomeric excess of the (S)-product 93% ee.
Publikation

Nguyen, T. H. V.; Nguyen, T. H. A.; Tran, V. S.; Franke, K.; Wessjohann, L.; Three phthalide derivatives from Angelica sinensis Rhizomes Vietnam J. Chem. 43, 119-122, (2005)

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Publikation

Nguyen, T. H. V.; Nguyen, T. H. A.; Tran, V. S.; Franke, K.; Wessjohann, L.; Studies on chemical composition of Angelica sinensis. Part VI - Angelicolide and three other compounds Vietnam J. Chem. 43, 749-752, (2005)

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Publikation

Nguyen, T. H. V.; Nguyen, T. H. A.; Tran, V. S.; Franke, K.; Wessjohann, L.; Studies on chemical composition of Angelica sinensis's. V - The nitrogen-containing compounds Vietnam J. Chem. 43, 605-609, (2005)

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Publikation

Nguyen, T. H. V.; Nguyen, T. H. A.; Tran, V. S.; Franke, K.; Wessjohann, L.; Four phthalides from the roots of Angelica sinensis Vietnam J. Chem. 43, 228-231, (2005)

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  • Die Leibniz-Gemeinschaft
  • Digitalisierung in der Landwirtschaft
  • Martin-Luther Universität Halle
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