Quantitative Metabolomics Using Isotope Residue Outlier Analysis (IROA®) with Internal Standards

The treatment of pain after thoracic surgery is a challenge and takes place in the individual clinics mostly according to clinic internal standards. It exists no currently valid S3 guideline for the treatment of acute perioperative and posttraumatic pain. For an effective pain treatment as well individual pain experience as the pain intensity of the various thoracic surgical procedures must be considered. Regular pain assessment with appropriate methods and their documentation form the basis for adequate and adapted pain therapy.There are a number of different pain therapy methods, non-medicamentous and drug-based methods, whose effectiveness is described in the literature partially different. For the treatment of acute postoperative pain after thoracic surgery, mainly drug-related procedures are used, except for physiotherapy as a non-medicamentous method. Increasingly, alternative procedures for the peridural catheter as a therapeutic gold standard in the treatment of pain after thoracic surgery are used. Their application can be integrated into a therapeutic algorithm.

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Quantitative metabolomics of Iranian saffron based on their HPLC-DAD and MALDI-TOF-MS

10.1055/s-0039-3399774 ◽

2019 ◽

Author(s):

M Hooshyari ◽

H Rezadoost ◽

P Ghezellou ◽

A Ghassempour

Keyword(s):

Maldi Tof Ms ◽

Quantitative Metabolomics ◽

Maldi Tof ◽

Tof Ms

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Development of 96 Multiple Injection-GC-MS Technique and Its Application in Protein Engineering of Natural and Non-Natural Enzymatic Reactions

10.26434/chemrxiv.10314239 ◽

2019 ◽

Author(s):

Anja Knorrscheidt ◽

Pascal Püllmann ◽

Eugen Schell ◽

Dominik Homann ◽

Erik Freier ◽

...

Keyword(s):

Microtiter Plate ◽

Axial Ligand ◽

Cell System ◽

Enzymatic Reactions ◽

The Novel ◽

Internal Standards ◽

E Coli ◽

Enzyme Screening ◽

Plate Analysis ◽

Microtiter Plate Analysis

Directed evolution requires the screening of enzyme libraries in biological matrices. Available assays are mostly substrate or enzyme specific. Chromatographic techniques like LC and GC overcome this limitation, but require long analysis times. The herein developed multiple injections in a single experimental run (MISER) using GC coupled to MS allows the injection of samples every 33 s resulting in 96-well microtiter plate analysis within 50 min. This technique is implementable in any GC-MS system with autosampling. Since the GC-MS is far less prone to ion suppression than LCMS, no chromatographic separation is required. This allows the utilisation of an internal standards and the detection of main and side-product. To prove the feasibility of the system in enzyme screening, two libraries were assessed: i) YfeX library in an E. coli whole cell system for the carbene-transfer reaction on indole revealing the novel axial ligand tryptophan, ii) a library of 616 chimeras of fungal unspecific peroxygenase (UPO) in S. cerevisiae supernatant for hydroxylation of tetralin resulting in novel constructs. The data quality and representation are automatically assessed by a new R-script.

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