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Recently, submicron particles have been discussed as a means to increase the bioavailability of poorly water-soluble drugs. Separation of these small particles is done with both fibre and membrane filters, as well as electrostatic precipitators. A major disadvantage of an electrostatic precipitator (ESP) is the agglomerate formation on the precipitation electrode. These agglomerates frequently show low bioavailability, due to the decreased specific surface area and poor wettability. In this w...
Understanding and quantification of cosolvent influences on enzyme-catalyzed reactions are driven by a twofold interest. On the one hand, cosolvents can simulate the cellular environment for deeper understanding of in cellulo reaction conditions. On the other hand, cosolvents are applied in biotechnology to tune yield and kinetics of reactions. Further, cosolvents are even present inherently, for example, for reactions with cofactor regeneration or for enzymes that need cosolvents in a functi...
Aqueous Two-Phase Extraction is known to be a gentle separation technique for biochemical molecules where product partitioning is fast. However, the reason for the high mass transfer rates has not been investigated, yet. Many researchers claim that the low interfacial tension facilitates the formation of very small droplets and with it a large interfacial area causing a fast partitioning. However, an experimental evidence for this hypothesis has not been published yet. In this study, the mass...
Biosurfactants offer environmental as well as health benefits over traditionally used chemical surfactants and heterologous production from engineered microorganisms has been demonstrated, offering containable as well as scalable production of these alternative chemicals. Low product titers and cost intensive downstream processing are the main hurdles for economical biosurfactant production at industrial scales. Increased biosurfactant concentrations are found in the liquid fraction of the fo...
Micelle-like polymer particles have been applied in aqueous multiphasic hydroformylation reactions of long chain alkenes. These colloids act as phase transfer agents for the nonpolar substrates and as carriers for the catalyst bearing sulfonated ligands by electrostatic attraction. The catalyst performance and the phase separation were optimized with special focus on the conversion, selectivity and catalyst recovery, as those are key points in multiphasic systems to achieve a feasible industr...
Tropane alkaloids (TA) are valuable secondary plant metabolites which are mostly found in high concentrations in the Solanaceae and Erythroxylaceae families. The TAs, which are characterized by their unique bicyclic tropane ring system, can be divided into three major groups: hyoscyamine and scopolamine, cocaine and calystegines. Although all TAs have the same basic structure, they differ immensely in their biological, chemical and pharmacological properties. Scopolamine, also known as hyosci...
The glycolytic pathway is one of the most studied metabolic pathways to date. This work focuses on determining the standard Gibbs energy of reaction (ΔRg0) of the first adenosine triphosphate-yielding reaction step of glycolysis, namely, the 3-phosphoglycerate kinase (PGK) reaction. Trustworthy values of ΔRg0 are required for thermodynamic approaches to determine single reaction conversions or even fluxes of metabolic reactions. In literature, the observed ΔRg0,obs values are usually determin...
The liverwort Radula marginata belongs to the bryophyte division of land plants and is a prospective alternate source of cannabinoid-like compounds. However, mechanistic insights into the molecular pathways directing the synthesis of these cannabinoid-like compounds have been hindered due to the lack of genetic information. This prompted us to deep sequencing, de novo assembly and annotation of R. marginata transcriptome, which resulted in the identification and validation of the genes for ca...
The properties of melting are required for the prediction of solubility of solid compounds. Unfortunately, direct determination of the enthalpy of fusion and melting temperature by using conventional DSC or adiabatic calorimetry is often not possible for biological compounds due to decomposition during the measurement. To overcome this, fast scanning calorimetry (FSC) with scanning rates up to 2 × 104 K s−1 was used in this work to measure the melting parameters for L-alanine and glycine. The...
Cell-free protein synthesis (CFPS) has become an established tool for rapid protein synthesis in order to accelerate the discovery of new enzymes and the development of proteins with improved characteristics. Over the past years, progress in CFPS system preparation has been made towards simplification, and many applications have been developed with regard to tailor-made solutions for specific purposes. In this review, various preparation methods of CFPS systems are compared and the significan...
The myxochelins were first mentioned in the literature nearly 30 years ago and described as catechol-type siderophores produced by myxobacteria. Since then, totally eight members of this compound class have been discovered, namely myxochelins A, B, C, D, as well as the structurally related hyalachelins A, B, C, and the recently isolated pseudochelin A. Current studies show that myxochelin biosynthesis is not restricted to myxobacteria, as assumed for a long time, but occurs in phylogeneticall...
Aromatic prenyltransferases catalyze the prenylation of an electron-rich aromatic compound by a prenyl diphosphate by transfer a prenyl residue to carbon, nitrogen or an oxygen atom of the aromatic acceptor molecule. The bioactivity of the resulting products is often increased, compared to the non-prenylated substrates. Prenylation of aromatic compounds is important for the diversification of secondary metabolites like phytocannabinoids. The membrane-bound cannabigerolic acid synthase from Ca...
In this work, two reactions are studied as a mean to deal with the current CO2 conundrum. The first reaction is the high-temperature pyrolysis of methane. This reaction serves as a way to avoid the stoichiometric production of CO2 when producing hydrogen, which could either be used for energy production or as a base chemical. The second reaction is the reverse Water-Gas Shift (rWGS) reaction. By means of this reaction, CO2 that is unavoidably produced and has been captured, can be activa...
Platinhaltige Zytostatika, wie z. B. Cisplatin, werden in vivo durch eine Reihe von (bio-) chemischen Reaktionen verändert und metabolisiert. Die wichtigsten Prozesse dabei sind die intrazelluläre Hydrolyse und die Reaktion mit kleineren Nukleophilen oder Proteinen. Bezüglich des Verhaltens von Platinkomplexen im Cytosol sind einige Fragen weiterhin nur unbefriedigend geklärt, insbesondere hinsichtlich der Art und Bedeutung von Addukten des Platins mit intrazellulären Bindungspartnern. Im Ra...
Reactions catalysed by oxidoreductases are indispensable for chemical synthesis. However, despite obvious advantages like mild reaction conditions and regio-, chemo-, and stereoselectivity, which simplifies product work-up, their implementation in the chemical industry is lacking. Therefore, an integrated approach involving catalyst and reaction engineering and proper reactor design is necessary for commercialising oxidoreductases for organic synthesis. Rational reaction design linking kineti...
Cannabinoids are secondary natural products predominantly found in the oil compartments of trichomes of the plant Cannabis sativa L. Up to now more than 100 cannabinoids have been isolated, the most prominent being the psychoactive Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). As THC-derived products are already available for medical use and CBD is currently investigated for its application in several disease treatments, the demand of cannabinoid-based products is expected to further r...
Zur Prozessintensivierung chemischer Synthesen wird unter anderem eine Erhöhung der Effizienz zur Minimierung des Ressourceneinsatzes angestrebt. Verbesserungen im Reaktionsschritt wirken sich oftmals auch vorteilhaft auf konsekutive Separationsverfahren aus, weshalb eine Optimierung der Reaktortechnologie abseits der häufig durch den Syntheseweg bestimmten Chemie erstrebenswert ist. Bei Reaktionen zwischen Gasen und Flüssigkeiten auf heterogenen Katalysatoren besteht die reaktionstechnische ...
In Zeiten sich schnell ausbreitender Infektionskrankheiten und resistenter Bakterien existiert ein wachsender Bedarf an neuen Antibiotika. Die Formulierung und Derivatisierung von bekannten Antibiotika ist eine viel versprechende Alternative zur Entwicklung neuer antimikrobieller Verbindungen. Dabei rückt vor allem die Kombination mit Makromolekülen in den Fokus der Wissenschaft. Daher war das Ziel dieser Arbeit die kovalente Verknüpfung von Ciprofloxacin und Penicillin mit dem Polymer Poly(2...