Unser 10. Leibniz Plant Biochemistry Symposium am 7. und 8. Mai war ein großer Erfolg. Thematisch ging es in diesem Jahr um neue Methoden und Forschungsansätze der Naturstoffchemie. Die exzellenten Vorträge über Wirkstoffe…
Omanische Heilpflanze im Fokus der Phytochemie IPB-Wissenschaftler und Partner aus Dhofar haben jüngst die omanische Heilpflanze Terminalia dhofarica unter die phytochemische Lupe genommen. Die Pflanze ist reich an…
Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Farag, M. A.; El Senousy, A. S.; El-Ahmady, S. H.; Porzel, A.; Wessjohann, L. A.;Comparative metabolome-based classification of Senna drugs: a prospect for phyto-equivalency of its different commercial productsMetabolomics1580(2019)DOI: 10.1007/s11306-019-1538-x
IntroductionThe demand to develop efficient and reliable analytical methods for the quality control of nutraceuticals is on the rise, together with an increase in the legal requirements for safe and consistent levels of its active principles.ObjectiveTo establish a reliable model for the quality control of widely used Senna preparations used as laxatives and assess its phyto-equivalency.MethodsA comparative metabolomics approach via NMR and MS analyses was employed for the comprehensive measurement of metabolites and analyzed using chemometrics.ResultsUnder optimized conditions, 30 metabolites were simultaneously identified and quantified including anthraquinones, bianthrones, acetophenones, flavonoid conjugates, naphthalenes, phenolics, and fatty acids. Principal component analysis (PCA) was used to define relative metabolite differences among Senna preparations. Furthermore, quantitative 1H NMR (qHNMR) was employed to assess absolute metabolites levels in preparations. Results revealed that 6-hydroxy musizin or tinnevellin were correlated with active metabolites levels, suggesting the use of either of these naphthalene glycosides as markers for official Senna drugs authentication.ConclusionThis study provides the first comparative metabolomics approach utilizing NMR and UPLC–MS to reveal for secondary metabolite compositional differences in Senna preparations that could readily be applied as a reliable quality control model for its analysis.
Publikation
Farag, M. A.; Maamoun, A. A.; Meyer, A.; Wessjohann, L. A.;Salicylic acid and its derivatives elicit the production of diterpenes and sterols in corals and their algal symbionts: a metabolomics approach to elicitor SARMetabolomics14127(2018)DOI: 10.1007/s11306-018-1416-y
IntroductionThe production of marine drugs in its normal habitats is often low and depends greatly on ecological conditions. Chemical synthesis of marine drugs is not economically feasible owing to their complex structures. Biotechnology application via elicitation represents a promising tool to enhance metabolites yield that has yet to be explored in soft corals.ObjectivesStudy the elicitation impact of salicylic acid (SA) and six analogues in addition to a systemic acquired resistance inducer on secondary metabolites accumulation in the soft coral Sarcophyton ehrenbergi along with the symbiont zooxanthellae and if SA elicitation effect is extended to other coral species S. glaucum and Lobophyton pauciliforum.MethodsPost elicitation in the three corals and zooxanthella, metabolites were extracted and analyzed via UHPLC-MS coupled with chemometric tools.ResultsMultivariate data analysis of the UHPLC-MS data set revealed clear segregation of SA, amino-SA, and acetyl-SA elicited samples. An increased level ca. 6- and 8-fold of the diterpenes viz., sarcophytonolide I, sarcophine and a C28-sterol, was observed in SA and amino-SA groups, respectively. Post elicitation, the level of diepoxy-cembratriene increased 1.5-fold and 2.4-fold in 1 mM SA, and acetyl-SA (aspirin) treatment groups, respectively. S. glaucum and Lobophyton pauciliforum showed a 2-fold increase of diepoxy-cembratriene levels.ConclusionThese results suggest that SA could function as a general and somewhat selective diterpene inducing signaling molecule in soft corals. Structural consideration reveals initial structure–activity relationship (SAR) in SA derivatives that seem important for efficient diterpene and sterol elicitation.
Publikation
Farag, M. A.; Mahrous, E. A.; Lübken, T.; Porzel, A.; Wessjohann, L.;Classification of commercial cultivars of Humulus lupulus L. (hop) by chemometric pixel analysis of two dimensional nuclear magnetic resonance spectraMetabolomics1021-32(2014)DOI: 10.1007/s11306-013-0547-4
The development of fast and effective spectroscopic methods that can detect most compounds in an untargeted manner is of increasing interest in plant extracts fingerprinting or profiling projects. Metabolite fingerprinting by nuclear magnetic resonance (NMR) is a fast growing field which is increasingly applied for quality control of herbal products, mostly via 1D 1H NMR coupled to multivariate data analysis. Nevertheless, signal overlap is a common problem in 1H NMR profiles that hinders metabolites identification and results in incomplete data interpretation. Herein, we introduce a novel approach in coupling 2D NMR datasets with principal component analysis (PCA) exemplified for hop resin classification. Heteronuclear multiple bond correlation (HMBC) profile maps of hop resins (Humulus lupulus) were generated for a comparative study of 13 hop cultivars. The method described herein combines reproducible metabolite fingerprints with a minimal sample preparation effort and an experimental time of ca. 28 min per sample, comparable to that of a standard HPLC run. Moreover, HMBC spectra provide not only unequivocal assignment of hop major secondary metabolites, but also allow to identify several isomerization and degradation products of hop bitter acids including the sedative principal of hop (2-methylbut-3-en-2-ol). We do believe that combining 2D NMR datasets to chemometrics, i.e. PCA, has great potential for application in other plant metabolome projects of (commercially relevant) nutraceuticals and or herbal drugs.
Publikation
Porzel, A.; Farag, M. A.; Mülbradt, J.; Wessjohann, L. A.;Metabolite profiling and fingerprinting of Hypericum species: a comparison of MS and NMR metabolomicsMetabolomics10574-588(2014)DOI: 10.1007/s11306-013-0609-7
Hypericum perforatum, commonly known as St. John’s wort, is a popular herbal supplement used for the treatment of mild to moderate depression. The major secondary metabolites of St. John’s wort extracts include phenylpropanoids, flavonoids, xanthones, phloroglucinols, and naphthodianthrones. There are over 400 species in the genus Hypericum world-wide, most of which are little or not characterized in terms of phytochemical or pharmacological properties. Metabolomics techniques were used to investigate the natural product diversity within the genus Hypericum (Hypericaceae) and its correlation to bioactivity, exemplified by cytotoxic properties. Utilizing nuclear magnetic resonance (NMR) fingerprinting and mass spectrometry (MS) metabolic profiling techniques, MS and NMR spectra of extracts from H. perforatum, H. polyphyllum, H. tetrapterum, H. androsaemum, H. inodorum, H. undulatum and H. kouytchense were evaluated and submitted to statistical multivariate analyses. Although comparable score plots in principal component analysis were derived from both MS and NMR datasets, loading plots reveal, that different set of metabolites contribute for species segregation in each dataset. Major peaks in 1H NMR and MS spectra contributing to species discrimination were assigned as those of hyperforins, lipids, chlorogenic and shikimic acid. Shikimic acid and its downstream phenylpropanoids were more enriched in H. perforatum, H. androsaemum, H. kouytchense and H. inodorum extracts; whereas a novel hyperforin was found exclusively in H. polyphyllum. Next to H. perforatum, H. polyphyllum and H. tetrapterum show the highest levels of hypericins, and H. perforatum and H. polyphyllum are highest in phloroglucinols, suggesting that the latter species might be used as an alternative to St. John’s wort. However, the major hyperforin-type compound in H. polyphyllum possesses a novel constitution of yet unknown bioactivity. Anti-cancer in vitro assays to evaluate the ability of extracts from Hypericum species in inhibiting prostate and colon cancer growth suggest that such bioactivity might be predicted by gross metabolic profiling.