Refine
Document Type
- Article (29) (remove)
Language
- English (29)
Has Fulltext
- yes (29)
Keywords
- Digitaler Zwilling (3)
- HIV (3)
- Heterogeneous Catalysis (3)
- Process Analytical Technology (PAT) (3)
- Virus-like Particles (VLPs) (3)
- Advanced Process Control (APC) (2)
- Cumene Hydroperoxide (2)
- Digital Twin (DT) (2)
- Gene Therapy (2)
- Heterogene Katalyse (2)
- Human Immunodeficiency Virus (HIV) (2)
- Murine Leukemia Virus (MLV) (2)
- Quality-by-Design (QbD) (2)
- Real-Time-Release Testing (RTRT) (2)
- Retroviral Vector (2)
- Sleeping Beauty Transposon (2)
- Stirred-Tank Bioreactor (2)
- Suspension Cell (2)
- Virus-like particles (2)
- mRNA Transfection (2)
- 4-dihydroisocoumarin (1)
- Aldol Reaction (1)
- Amino Acids (1)
- Aminosäuren (1)
- Antimicrobial Activity (1)
- Antiretroviral Therapy (ART) (1)
- Antiretrovirale Substanz (1)
- Apfelsaft (1)
- Apple Juice (1)
- Apple Pomace (1)
- Arzneimittelresistenz (1)
- Asymmetric Catalysis (1)
- Base-Catalyzed (1)
- Bio-Based Surfactants (1)
- Biosurfactants (1)
- Biotensid (1)
- Breast cancer resistance protein (1)
- Brustkrebs (1)
- CNT Dispersion (1)
- Cancer chemotherapy (1)
- Carbon nanotubes (1)
- Catalase (1)
- Catalysis (1)
- Catalyst Deactivation (1)
- Cationic Cyclization (1)
- Cellulose Acetate (1)
- Celluloseacetat (1)
- Ceramics, Glass, Composites, Natural Materials (1)
- Chemotherapie (1)
- Chitin Deacetylase (1)
- Closed-Loop (1)
- Cobalt Catalysis (1)
- Cyproconazole (1)
- Delf-Condensation (1)
- Dense phase carbon dioxide (1)
- Digital Twin (1)
- Diterpene (1)
- Diterpenes (1)
- Drop Tower (1)
- Drug Resistance (1)
- Electrolyte Recovery (1)
- Electrophysiology (1)
- Electroplating (1)
- Elektrophoretisches Beschichten (1)
- Emulgator (1)
- Emulsifiers (1)
- Enzyme Cascade (1)
- Experimental Characterization (1)
- Extra-Framework Aluminum (1)
- F. oxysporum (1)
- Fatty alcohols (1)
- Fettalkohole (1)
- Gas Separation (1)
- Gas permeability (1)
- Gaspermeation (1)
- Glioblastom (1)
- Glioblastoma (1)
- Glycosides (1)
- Glykoside (1)
- Green Chemistry (1)
- HIV Vaccines (1)
- HPODE (1)
- Hock Cleavage (1)
- Hock cleavage (1)
- Human Embryonic Kidney 293 (HEK293) (1)
- Human Embryonic Kidney 293 Cells (HEK293) (1)
- Human Induced Pluripotent Stem Cell (hiPSC)-Derived Neurons (1)
- Hydroperoxides (1)
- Hydrovinylation (1)
- Hymexazol (1)
- Hypergravity (1)
- In-Situ Oxygen Generation (1)
- Industrial Chemistry (1)
- Ion Exchange Resin (1)
- Isophorone (1)
- Katalase (1)
- Katalyse (1)
- Kinetics (1)
- LOX (1)
- Linoleic Acid (1)
- Linolsäure (1)
- Lipase (1)
- Lipasen (1)
- Lipoxygenase (1)
- Mammalian Cells (1)
- Manufacturing, Machines, Tools, Processes (1)
- Marine Natural Products (1)
- Mechanical effects (1)
- Mechanical properties (1)
- Mehrwandige Kohlenstoff-Nanoröhre (1)
- Membran (1)
- Membrane Formation (1)
- Menthol (1)
- Microgravity (1)
- Mixed Matrix Membranes (MMMs) (1)
- Mixed matrix membranes (1)
- Modeling and Simulation (1)
- Multi-Electrode Array (MEA) (1)
- Multidrug resistance (1)
- Multidrug-Resistenz (1)
- Neural Network (1)
- Neuronales Netz (1)
- Non‐thermal microbial inactivation (1)
- Oberflächenspannung (1)
- P-Glykoprotein (1)
- P-glycoprotein (1)
- P. Infestans (1)
- PX-12 (1)
- Pasteurization (1)
- Pdr5 (1)
- Pectin (1)
- Pektine (1)
- Pellet (1)
- Pellets (1)
- Phase Inversion (1)
- Plasma Treatment (1)
- Polyimide (1)
- Polymer nanocomposite materials (1)
- Polyole (1)
- Polyurethane (1)
- Porous Polymer Membranes (1)
- Process Optimization (1)
- Protein Production (1)
- Prozessoptimierung (1)
- Reaktionskinetik (1)
- Retroviren (1)
- Retroviruses (1)
- Reverse Osmosis (1)
- Rotor-Stator System (RS) (1)
- Scetone (1)
- Schleuderbeschichten (1)
- Shear stress (1)
- Sophorolipids (1)
- Spin Coating (1)
- Supported Thin Films (1)
- Surface Tension (1)
- Synergie (1)
- Synergism (1)
- TXNIP (1)
- Tacrolimus (1)
- Teterogeneous Catalysis (1)
- Thermal properties (1)
- Thioredoxin (1)
- Thioredoxine (1)
- Three-Roll-Mill (TRM) (1)
- Transposon Vector (1)
- Umgekehrte Osmose (1)
- Verstärkung (1)
- Virus Replication (1)
- Virus-like Particles (1)
- Vitamins (1)
- Wastewater Treatment (1)
- Wood Science & Technology (1)
- Zeolites (1)
- Zeolith (1)
- bio-based (1)
- human immunodeficiency virus (HIV) (1)
- hydroxyl fatty acid based polyols (1)
- iNGN (1)
- mRNA Splicing (1)
- platform chemicals (1)
- polyol (1)
- polyurethane (1)
- sophorolipid-based polyols (1)
- {2-(3-R-1 (1)
Faculty
- Angewandte Naturwissenschaften (F11) (29) (remove)
Stable recombinant mammalian cells are of growing importance in pharmaceutical biotechnology production scenarios for biologics such as monoclonal antibodies, growth and blood factors, cytokines and subunit vaccines. However, the establishment of recombinant producer cells using classical stable transfection of plasmid DNA is hampered by low stable gene transfer efficiencies. Consequently, subsequent selection of transgenic cells and the screening of clonal cell populations are time- and thus cost-intensive. To overcome these limitations, expression cassettes were embedded into transposon-derived donor vectors. Upon the co-transfection with transposase-encoding constructs, elevated vector copy numbers stably integrated into the genomes of the host cells are readily achieved facilitating under stringent selection pressure the establishment of cell pools characterized by sustained and high-yield recombinant protein production. Here, we discuss some aspects of transposon vector technologies, which render these vectors promising candidates for their further utilization in the production of biologics.
Despite intensive research over the last three decades, it has not yet been possible to bring an effective vaccine against human immunodeficiency virus (HIV) and the resulting acquired immunodeficiency syndrome (AIDS) to market. Virus-like particles (VLP) are a promising approach for efficient and effective vaccination and could play an important role in the fight against HIV. For example, HEK293 (human embryo kidney) cells can be used to produce virus-like particles. In this context, given the quality-by-design (QbD) concept for manufacturing, a digital twin is of great importance for the production of HIV-Gag-formed VLPs. In this work, a dynamic metabolic model for the production of HIV-Gag VLPs was developed and validated. The model can represent the VLP production as well as the consumption or formation of all important substrates and metabolites. Thus, in combination with already described process analytical technology (PAT) methods, the final step towards the implementation of a digital twin for process development and design, as well as process automation, was completed.
Abstract
Due to their pronounced bioactivity and limited availability from natural resources, metabolites of the soft coral Pseudopterogorgia elisabethae, such as erogorgiaene and the pseudopterosines, represent important target molecules for chemical synthesis. We have now developed a particularly short and efficient route towards these marine diterpenes exploiting an operationally convenient enantioselective cobalt‐catalyzed hydrovinylation as the chirogenic step. Other noteworthy C−C bond forming transformations include diastereoselective Lewis acid‐mediated cyclizations, a Suzuki coupling and a carbonyl ene reaction. Starting from 4‐methyl‐styrene the anti‐tubercular agent (+)‐erogorgiaene (>98 % ee) was prepared in only 7 steps with 46 % overall yield. In addition, the synthesis of the pseudopterosin A aglycone was achieved in 12 steps with 30 % overall yield and, surprisingly, was found to exhibit a similar anti‐inflammatory activity (inhibition of LPS‐induced NF‐κB activation) as a natural mixture of pseudopterosins A−D or iso‐pseudopterosin A, prepared by β‐D‐xylosylation of the synthetic aglycone.
Thioredoxin (Trx) overexpression is known to be a cause of chemotherapy resistance in various tumor entities. However, Trx effects on resistance are complex and depend strictly on tissue type. In the present study, we analyzed the impact of the Trx system on intrinsic chemoresistance of human glioblastoma multiforme (GBM) cells to cytostatic drugs. Resistance of GBM cell lines and primary cells to drugs and signaling inhibitors was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Impact of Trx inhibition on apoptosis was investigated by proteome profiling of a subset of proteins and annexin V apoptosis assays. Trx-interacting protein (TXNIP) was overexpressed by transfection and protein expression was determined by immunoblotting. Pharmacological inhibition of Trx by 1-methyl-2-imidazolyl-disulfide (PX-12) reduced viability of three GBM cell lines, induced expression of active caspase-3, and reduced phosphorylation of AKT-kinase and expression of β-catenin. Sensitivity to cisplatin could be restored by both PX-12 and recombinant expression of the upstream Trx inhibitor TXNIP, respectively.
In addition, PX-12 also sensitized primary human GBM cells to temozolomide. Combined inhibition of Trx and the phosphatidylinositide 3-kinase (PI3K) pathway resulted in massive cell death. We conclude that the Trx system and the PI3K pathway act as a sequential cascade and could potentially present a new drug target.
AbstractThis paper discusses the comparison of two methods to achieve thermal comfort utilising air conditioning (AC) system in a small indoor space – adaptive control and fuzzy control. Thermal comfort indoors is performed to provide comfortability individually or for a group of people. Due to the small indoor space which usually a bit cramped, crowded and less airy, the ambience can be very uncomfortable either for doing sedentary or active work, thus the AC system can be very useful to provide thermal comfort. Both methods can be utilised depending on how thermal comfort is viewed and how the level of thermal comfort is decided. Every method has its own advantage and limitations, and will be covered in this paper as well.
The Production of Isophorone
(2023)
Isophorone is a technically important compound used as a high-boiling-point solvent for coatings, adhesives, etc., and it is used as a starting material for various valuable compounds, including isophorone diisocyanate, a precursor for polyurethanes. For over 80 years, isophorone has been synthesized via base-catalyzed self-condensation of acetone. This reaction has a complex reaction mechanism with numerous possible reaction steps including the formation of isophorone, triacetone dialcohol, and ketonic resins. This review provides an overview of the different production processes of isophorone in liquid- and vapor-phase and reviews the literature-reported selectivity toward isophorone achieved using different reaction parameters and catalysts.
In this work, supported cellulose acetate (CA) mixed matrix membranes (MMMs) were prepared and studied concerning their gas separation behaviors. The dispersion of carbon nanotube fillers were studied as a factor of polymer and filler concentrations using the mixing methods of the rotor–stator system (RS) and the three-roll-mill system (TRM). Compared to the dispersion quality achieved by RS, samples prepared using the TRM seem to have slightly bigger, but fewer and more homogenously distributed, agglomerates. The green γ-butyrolactone (GBL) was chosen as a polyimide (PI) polymer-solvent, whereas diacetone alcohol (DAA) was used for preparing the CA solutions. The coating of the thin CA separation layer was applied using a spin coater. For coating on the PP carriers, a short parameter study was conducted regarding the plasma treatment to affect the wettability, the coating speed, and the volume of dispersion that was applied to the carrier. As predicted by the parameter study, the amount of dispersion that remained on the carriers decreased with an increasing rotational speed during the spin coating process. The dry separation layer thickness was varied between about 1.4 and 4.7 μm. Electrically conductive additives in a non-conductive matrix showed a steeply increasing electrical conductivity after passing the so-called percolation threshold. This was used to evaluate the agglomeration behavior in suspension and in the applied layer. Gas permeation tests were performed using a constant volume apparatus at feed pressures of 5, 10, and 15 bar. The highest calculated CO2/N2 selectivity (ideal), 21, was achieved for the CA membrane and corresponded to a CO2 permeability of 49.6 Barrer.
This study explores the potential of robust, strongly basic type I ion exchange resins—specifically, Amberlyst® A26 OH and Lewatit® K 6465—as catalysts for the aldol condensation of citral and acetone, yielding pseudoionone. Emphasis is placed on their long-term stability and commendable performance in continuous operational settings. The aldol reaction, which traditionally is carried out using aqueous sodium hydroxide as the catalyst, holds the potential for enhanced sustainability and reduced waste production through the use of basic ion exchange resins in heterogeneous catalysis. Density Functional Theory (DFT) calculations are employed to investigate catalyst deactivation mechanisms. The result of these calculations indicates that the active sites of Amberlyst® A26 OH are cleaved more easily than the active sites of Lewatit® K 6465. However, the experimental data show a gradual decline in catalytic activity for both resins. Batch experiments reveal Amberlyst® A26 OH’s active sites diminishing, while Lewatit® K 6465 maintains relative consistency. This points to distinct deactivation processes for each catalyst. The constant count of basic sites in Lewatit® K 6465 during the reaction suggests additional factors due to its unique polymer structure. This intriguing observation also highlights an exceptional temperature stability for Lewatit® K 6465 compared to Amberlyst® A26 OH, effectively surmounting one of the prominent challenges associated with the utilization of ion exchange resins in catalytic applications.
Linoleic acid hydroperoxides are versatile intermediates for the production of green note aroma compounds and bifunctional ω-oxo-acids. An enzyme cascade consisting of lipoxygenase, lipase and catalase was developed for one-pot synthesis of 13-hydroperoxyoctadecadienoic acid starting from safflower oil. Reaction conditions were optimized for hydroperoxidation using lipoxygenase 1 from Glycine max (LOX-1) in a solvent-free system. The addition of green surfactant Triton CG-110 improved the reaction more than two-fold and yields of >50% were obtained at linoleic acid concentrations up to 100 mM. To combine hydroperoxidation and oil hydrolysis, 12 lipases were screened for safflower oil hydrolysis under the reaction conditions optimized for LOX-1. Lipases from Candida rugosa and Pseudomonas fluorescens were able to hydrolyze safflower oil to >75% within 5 h at a pH of 8.0. In contrast to C. rugosa lipase, the enzyme from P. fluorescens did not exhibit a lag phase. Combination of P. fluorescens lipase and LOX-1 worked well upon LOX-1 dosage and a synergistic effect was observed leading to >80% of hydroperoxides. Catalase from Micrococcus lysodeikticus was used for in-situ oxygen production with continuous H2O2 dosage in the LOX-1/lipase reaction system. Foam generation was significantly reduced in the 3-enzyme cascade in comparison to the aerated reaction system. Safflower oil concentration was increased up to 300 mM linoleic acid equivalent and 13-hydroperoxides could be produced in a yield of 70 g/L and a regioselectivity of 90% within 7 h.
Abstract
(−)‐Menthol is one of the most popular aroma compounds worldwide. While in the past mostly extracted from mint plants, today (−)‐menthol synthesis from other raw materials is becoming more relevant. Common starting materials for menthol synthesis are m‐cresol, citral and myrcene, but also substrates like menthone, mono‐ and bicyclic terpenes and terpenoids have been used for this purpose in the past. As for many applications (−)‐menthol of high purity is required, asymmetric syntheses and enantiomeric resolution of obtained raw products are applied for menthol production. This review gives an overview on the most important synthetic menthol production processes of the companies Symrise, Takasago and BASF and relevant literature in the field of menthol synthesis with a focus on the last 20 years.