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Publikation Dynemicin analogs: Syntheses, methods of preparation and use(United States Patent and Trademark Office, 04.01.1994) Smith, Adrian L.; Hwang, Chan-Kou; Wendeborn, Sebastian; Nicolaou, Kyriacos C.; Schreiner, Erwin P.; Stahl, Wilhelm; Dai, Wei-Min; Maligres, Peter E.; Suzuki, ToshioA fused ring system compound is disclosed that contains an epoxide group on one side or the fused rings and an enediyne macrocyclic ring on the other side of the fused rings. The compounds have DNA-cleaving, antimicrobial and tumor growth-inhibiting properties. Chimeric compounds having the fused ring system compound as an aglycone bounded to (i) a sugar moiety as the ogligosaccharide portion or(ii) a monoclonal antibody or antibody combining site portion thereof that immunoreacts with target tumor cells are also disclosed. Compositions containing a compound or a chimer are disclosed, as are methods or preparing a compound.12 - PatentPublikation Enantiomeric dynemicin analogs, preparation and use thereof(World Intellectual Property Organization, 25.11.1993) Smith, Adrian L.; Wendeborn, Sebastian; Nicolaou, Kyriacos; Schreiner, Erwin P.; Dai, Wei-Min; Susuki, ToshioAn enantiomer of a fused ring system compound is disclosed that contains an epoxide group on one side of the fused rings and an enediyne macrocyclic ring on the other side of the fused rings. The enantiomeric compounds have DNA-cleaving, antimicrobial and tumor growth-inhibiting properties that are enhanced over their racemates. Chimeric compounds having the enantiomeric fused ring system compound as an aglycone bonded to (i) a sugar moiety as the oligosaccharide portion or (ii) a monoclonal antibody or antibody combining site portion thereof that immunoreacts with target tumor cells are also disclosed. Compositions containing an enatiomeric compound or an enantiomeric chimer are disclosed, as are methods of preparing an enantiomeric compound.12 - PatentPublikation Liquid–liquid equilibrium and molecular toxicity of active and inert diluents of the organic mixture tri-iso-octylamine/dodecanol/dodecane as a potential liquid membrane for lactic acid removal(American Chemical Society, 2019) Pérez, Alan; Gómez, Verónica M.; Rodríguez-Barona, Sneyder; Fontalvo, JavierLactic acid can be in situ removed from a fermentation broth through reactive liquid extraction or a liquid membrane to enhance the fermentation process. The organic mixture tri-iso-octylamine (TiOA)/dodecanol/dodecane at 10 vol % of the amine is a potential organic mixture for lactic acid removal. Liquid–liquid equilibria with lactic acid aqueous solutions and molecular toxicity on the bacteria Lactobacillus casei ATCC 393 were measured with several dodecanol proportions in dodecane (0 to 90 vol %) and 10 vol % TiOA as potential solvents or membrane phases for LA removal from a fermentation broth. Effects of the organic phase on the bacteria as cell growth, biomass production, glucose consumption, productivity, and product to biomass yield are analyzed. Dodecanol increases the lactic acid chemical equilibrium constant for the liquid–liquid equilibria, while increasing the molecular toxicity on the bacteria. However, for dodecanol concentrations from 30 to 40 vol % the value of the chemical equilibrium constant is high enough for lactic acid distribution between the phases and its toxicity is low enough on the bacteria, making a proper range of dodecanol concentrations for lactic acid removal. Also, the distribution coefficient and the chemical equilibrium constant are fitted as a function of the dodecanol concentration in the organic mixture.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Liquid–Liquid equilibria for trioctylamine/1-dodecanol/lactic acid/water system at 306.1, 310.1 and 316.1 K: Experimental Data and Prediction(American Chemical Society, 2016) Pérez, Alan; Rodríguez-Barona, Sneyder; Fontalvo, JavierLiquid–liquid equilibria of aqueous solutions of lactic acid with trioctylamine diluted in 1-dodecanol was measured experimentally at three temperatures (306.1, 310.1, and 316.1 ± 0.1 K). During the transfer process, lactic acid reacts with trioctylamine to produce an amine–lactate complex. Two models were proposed to predict the liquid–liquid equilibria. The first model considered the equilibrium constant of chemical reaction and the distribution coefficient. Those parameters have been determined by fitting the experimental data. The distribution coefficients have also been experimentally measured. It was found that as temperature increases, the distribution coefficient increases and equilibrium constant decreases. The second proposed model involved the non-random two liquid activity model. Energies of binary interaction and the equilibrium constant of chemical reaction were fitted to experimental data. The equilibrium constant and partition coefficients show the same trends as the first model; however, the first model shows a better prediction as compared to the second model of the liquid–liquid equilibrium data. These two models are especially suitable at low lactic acid concentrations in the aqueous phase where the experimental standard deviation is low.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Liquid–liquid equilibria of lactic acid/water solutions in tri-iso-octylamine/dodecane/1-dodecanol at 306.1, 310.1, and 316.1 K. Experimental data and prediction(American Chemical Society, 2019) Pérez, Alan; Rodríguez-Barona, Sneyder; Fontalvo, JavierThe liquid–liquid equilibria of systems that involves lactic acid in the aqueous phase and tri-iso-octylamine with diluents as dodecane and 1-dodecanol (active or/and inert) were measured experimentally at three temperatures (306.15, 310.15, and 316.15 K). A previous liquid–liquid equilibrium model that is based on Nernst’s distribution law and mass action law equilibrium equations was extended and generalized for stoichiometric ratios (amine/acid) 1:n. The effect of the diluents and the tertiary amine on the liquid–liquid equilibrium is shown and quantified in terms of the predicted values of the distribution coefficient, chemical equilibrium constants, and temperature. The lactic acid concentration in equilibrium for the organic phase decreases as follows: water/LA/TiOA/1-dodecanol system > water/LA/TiOA/dodecane/1-dodecanol > system water/LA/TiOA/dodecane system.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Integration of a liquid membrane in Taylor flow regime with a fermentation by Lactobacillus casei ATCC 393 for in-situ lactic acid removal(Elsevier, 06/2019) Pérez, Alan; Rodríguez-Barona, Sneyder; Fontalvo, JavierA new type of liquid membranes called liquid membrane in Taylor flow was integrated to a lactic acid fermentation, using Lactobacillus casei ATCC 393, for lactic acid removal during fermentation. The performance in terms of lactic acid production of the hybrid batch system is compared to a conventional batch fermentation. Lactic acid removal rate increases proportionally with the LA concentration within the fermenter. The lactic acid, the biomass production and the LA productivity in the hybrid system increased by 41.8, 12 and 26.6%, respectively, as compared to the conventional batch fermentation. However, toxicity effects reduce LA to glucose yield in 15.9% as compared to conventional fermentation. Liquid membranes in Taylor flow results promising for enhancing batch and continuous fermentation processes by a hybrid system.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Study of overall mass transfer coefficients in a liquid membrane in Taylor flow regime: Calculation and correlation(Elsevier, 12/2018) Pérez, Alan; Van der Bruggen, Bart; Fontalvo, JavierThe use of a liquid membrane in Taylor flow regime is a recent technology, which extends and generalizes the definition of a membrane. It has been developed and tested for lactic acid removal. A challenge in understanding the technology is that the values of the overall volumetric mass transfer coefficients are not known, and it is unclear how they are related with the operational conditions. In this work, the overall volumetric mass transfer for the liquid membrane in Taylor flow was calculated from experimental results and three empirical models, two of which are from literature and one was developed in this work based on dimensional analysis. From combination of experimental results and the developed models the main variables (operational conditions) of the liquid membrane in Taylor flow that have a strong influence on the overall volumetric mass transfer coefficients (in the donor and in the membrane phase) were defined. The relative velocity results as the variable that has the largest influence on the performance of this new liquid membrane technology.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Molecular toxicity of potential liquid membranes for lactic acid removal from fermentation broths using Lactobacillus casei ATCC 393(Universidad Nacional de Colombia * Facultad Nacional de Minas, 2018) Pérez, Alan; Rodríguez-Barona, Sneyder; Fontalvo-Alzate, JavierToxic effects of extractants and carriers of specific microorganisms must be taken into account before using them with hybrid fermentation processes that are combined with liquid membranes or liquid-liquid extraction. In the current research three extractants (trioctylamine, tri-iso-octylamine and Aliquat 336), three diluents (dodecane, dodecanol, and oleyl alcohol) and two mixtures (extractant/diluent) were tested for molecular toxicity on the bacteria Lactobacillus casei ATCC 393 as potential components of a liquid membrane or a liquid-liquid extraction process for lactic acid removal in an intensified fermentation process. Glucose consumption, lactic acid production, and cell growth were used as toxicity indicators. Physical properties of extractants and diluents were related to the molecular toxicity on the microorganism. These results show that mixtures of tri-iso-octylamine/dodecane and trioctylamine/dodecane at a proportion of 1:9 v/v have great potential to be used in liquid membranes or liquid-liquid extraction processes on hybrid fermentations with Lactobacillus casei ATCC 393.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Surface water treatment by UV/H2O2 with subsequent soil aquifer treatment. Impact on micropollutants, dissolved organic matter and biological activity(Royal Society of Chemistry, 2019) Wünsch, Robin; Plattner, Julia; Cayon, David; Eugster, Fabienne; Gebhardt, Jens; Wülser, Richard; von Gunten, Urs; Wintgens, ThomasBecause organic micropollutants (MP) are frequently detected in river waters that are used as drinking water sources, combining a relatively cost-efficient natural treatment with upstream advanced oxidation processes (AOP) appears promising for their efficient abatement. Such a multi-barrier system can be integrated in drinking water production schemes to minimize risks from potentially hazardous MPs. This study investigates the impact of an UV/H2O2 AOP before soil aquifer treatment (SAT) on the abatement of selected MPs (EDTA, acesulfame, iopamidol, iomeprol, metformin, 1H-benzotriazole, iopromide), dissolved organic matter (DOM) (apparent molecular size distribution, specific UV absorbance at 254 nm – SUVA) and microbial parameters (intact cell count, cell-bound ATP). A pilot plant consisting of an AOP (0.5 m3 h−1, 4 mg L−1 H2O2, 6000 J m−2) and two parallel soil columns (filtration velocity: 1 m d−1, column height: 1 m) was continuously operated over a period of 15 months with Rhine river water pre-treated with rapid sand filtration. The investigations revealed a shift towards longer retention times of the humic substances peak in LC analysis of DOM, lower SUVA and higher biodegradability of DOM after UV/H2O2 treatment. In addition, an overall higher abatement of all investigated MPs by the combined treatment was observed (AOP with subsequent SAT) compared to either process alone. This observation could be explained by an addition of the single treatment effects. The strong primary disinfection effect of the AOP was detectable along the first meter of infiltration, but did not lead to any change in the column performance (i.e., similar abatement of dissolved organic matter).01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Biological properties of extracellular vesicles and their physiological functions(Taylor & Francis, 14.05.2015) Lipps, Georg01A - Beitrag in wissenschaftlicher Zeitschrift