Systematic isolation of microbial metabolites for natural products depository (NPDepo)

2011 ◽  
Vol 84 (6) ◽  
pp. 1407-1420 ◽  
Author(s):  
Hiroyuki Osada ◽  
Toshihiko Nogawa
Keyword(s):  
Mass Spectrometry ◽  
Natural Products ◽  
Biological Activity ◽  
Microbial Metabolites ◽  
Liquid Chromatography Mass Spectrometry ◽  
Chromatographic Techniques ◽  
New Type ◽  
Metabolite Database ◽  
Microbial Products ◽  
Microbial Sources

A microbial fraction library has been constructed as a part of RIKEN Natural Products Depository (NPDepo) to discover and isolate novel metabolites with unique biological activity from microbial sources efficiently and rapidly. The fraction library was made by a systematic separation method based on basic chromatographic techniques. Each fraction in the library was analyzed by liquid chromatography/mass spectrometry (LC/MS) to reveal physicochemical properties of each metabolite within the fraction, and the results were applied to construct a database for rapid discovery of novel and structurally unique compounds. We developed a new type of metabolite database called MP (microbial products) plot to visualize each metabolite on a 2D area. The combination of the fraction library and the database led to the discovery and isolation of novel metabolites, verticilactam, which was a 16-membered macrolactam with an unprecedented β-keto-amide moiety, and spirotoamides A and B, which had a highly substituted 6,6-spiroaccetal moiety and a carboxamide moiety. Moreover, based on the utilization of the MP plot, the new capacity of a streptomycete to produce specific metabolites was discovered.

Combined liquid chromatography - mass spectrometry of pesticides and natural products

1982 ◽  
Vol 19 (5) ◽  
pp. 253 ◽  
Author(s):  
D. E. Games ◽  
C. Eckers ◽  
M. S. Lant ◽  
E. Lewis ◽  
N. C. A. Weerasinghe ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Natural Products ◽  
Liquid Chromatography ◽  
Liquid Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry

scholarly journals Mass Spectrometry and Its Importance for the Analysis and Discovery of Active Molecules in Natural Products

2021 ◽  
Author(s):  
Paco Noriega ◽  
Gabriela Gortaire ◽  
Edison Osorio
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Quality Control ◽  
Natural Products ◽  
Atomic Mass ◽  
Mass Analyzer ◽  
Chromatographic Techniques ◽  
Positive Ions ◽  
Ionization Processes ◽  
Ion Analysis

Mass spectrometry is one of the best techniques for analyzing the structure of a molecule. It usually provides information about the molecular weight of a substance, and it can present atomic mass units and up to ten thousandths of atomic mass units depending on the accuracy of the mass analyzer. In addition, it provides information on the positive ions formed in the ionization process, which is linked to the chemical structure of the molecule and the nature of the bonds. This technique is widely used for analyzing compounds from natural products. The development of the technique combined with the use of software and databases has been remarkable in recent years, improving the ionization processes and the ion analysis. Since natural products generally constitute a mixture of a complex quantity of components, mechanisms have been developed for coupling to chromatographic techniques of various kinds. This review aims to show how mass spectrometry has contributed to the qualitative quality control in natural products, as well as in the finding of new metabolites of industrial interest.

scholarly journals Quantification of the Emetic Toxin Cereulide in Food Products by Liquid Chromatography-Mass Spectrometry Using Synthetic Cereulide as a Standard

2010 ◽  
Vol 76 (22) ◽  
pp. 7466-7472 ◽  
Author(s):  
Elisabeth G. Biesta-Peters ◽  
Martine W. Reij ◽  
Richard H. Blaauw ◽  
Paul H. in ′t Veld ◽  
Andreja Rajkovic ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Biological Activity ◽  
Liquid Chromatography ◽  
Transmembrane Potential ◽  
Food Products ◽  
Accurate Method ◽  
Food Samples ◽  
High Yield ◽  
Liquid Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry

ABSTRACT Bacillus cereus produces the emetic toxin cereulide, a cyclic dodecadepsipeptide that can act as a K+ ionophore, dissipating the transmembrane potential in mitochondria of eukaryotic cells. Because pure cereulide has not been commercially available, cereulide content in food samples has been expressed in valinomycin equivalents, a highly similar cyclic potassium ionophore that is commercially available. This research tested the biological activity of synthetic cereulide and validated its use as a standard in the quantification of cereulide contents in food samples. The synthesis route consists of 10 steps that result in a high yield of synthetic cereulide that showed biological activity in the HEp-2 cell assay and the boar sperm motility assay. The activity is different in both methods, which may be attributed to differences in K+ content of the test media used. Using cereulide or valinomycin as a standard to quantify cereulide based on liquid chromatography-mass spectrometry (LC-MS), the concentration determined with cereulide as a standard was on average 89.9% of the concentration determined using valinomycin as a standard. The recovery experiments using cereulide-spiked food products and acetonitrile as extraction solute showed that the LC-MS method with cereulide as a standard is a reliable and accurate method to quantify cereulide in food, because the recovery rate was close to 100% over a wide concentration range.

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