TY - JOUR A1 - Luisier, Raphaëlle A1 - Lempiäinen, Harri A1 - Scherbichler, Nina A1 - Braeuning, Albert A1 - Geissler, Miriam A1 - Dubost, Valerie A1 - Müller, Arne A1 - Scheer, Nico A1 - Chibout, Salah-Dine A1 - Hara, Hisanori A1 - Picard, Frank A1 - Theil, Diethilde A1 - Couttet, Philippe A1 - Vitobello, Antonio A1 - Grenet, Olivier A1 - Grasl-Kraupp, Bettina A1 - Ellinger-Ziegelbauer, Heidrung A1 - Thomson, John P. A1 - Meehan, Richard R. A1 - Elcombe, Clifford R. A1 - Henderson, Colin J. A1 - Wolf, C. Roland A1 - Schwarz, Michael A1 - Moulin, Pierre A1 - Terranova, Remi A1 - Moggs, Jonathan G. T1 - Phenobarbital Induces Cell Cycle Transcriptional Responses in Mouse Liver Humanized for Constitutive Androstane and Pregnane X Receptors JF - Toxicological Sciences N2 - The constitutive androstane receptor (CAR) and the pregnane X receptor (PXR) are closely related nuclear receptors involved in drug metabolism and play important roles in the mechanism of phenobarbital (PB)-induced rodent nongenotoxic hepatocarcinogenesis. Here, we have used a humanized CAR/PXR mouse model to examine potential species differences in receptor-dependent mechanisms underlying liver tissue molecular responses to PB. Early and late transcriptomic responses to sustained PB exposure were investigated in liver tissue from double knock-out CAR and PXR (CARᴷᴼ-PXRᴷᴼ), double humanized CAR and PXR (CARʰ-PXRʰ), and wild-type C57BL/6 mice. Wild-type and CARʰ-PXRʰ mouse livers exhibited temporally and quantitatively similar transcriptional responses during 91 days of PB exposure including the sustained induction of the xenobiotic response gene Cyp2b10, the Wnt signaling inhibitor Wisp1, and noncoding RNA biomarkers from the Dlk1-Dio3 locus. Transient induction of DNA replication (Hells, Mcm6, and Esco2) and mitotic genes (Ccnb2, Cdc20, and Cdk1) and the proliferation-related nuclear antigen Mki67 were observed with peak expression occurring between 1 and 7 days PB exposure. All these transcriptional responses were absent in CARᴷᴼ-PXRᴷᴼ mouse livers and largely reversible in wild-type and CARʰ-PXRʰ mouse livers following 91 days of PB exposure and a subsequent 4-week recovery period. Furthermore, PB-mediated upregulation of the noncoding RNA Meg3, which has recently been associated with cellular pluripotency, exhibited a similar dose response and perivenous hepatocyte-specific localization in both wild-type and CARʰ-PXRʰ mice. Thus, mouse livers coexpressing human CAR and PXR support both the xenobiotic metabolizing and the proliferative transcriptional responses following exposure to PB. Y1 - 2014 U6 - https://doi.org/https://doi.org/10.1093/toxsci/kfu038 SN - 1094-2025 VL - 139 IS - 2 SP - 501 EP - 511 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Scheer, Nico A1 - Mclaughlin, Lesley A. A1 - Rode, Anja A1 - MacLeod, Alastair Kenneth A1 - Henderson, Colin J. A1 - Wolf, Roland C. T1 - Deletion of thirty murine cytochrome P450 genes results in viable mice with compromised drug metabolism JF - Drug Metabolism and Disposition N2 - In humans, 75% of all drugs are metabolized by the cytochrome P450-dependent monooxygenase system. Enzymes encoded by the CYP2C, CYP2D, and CYP3A gene clusters account for ∼80% of this activity. There are profound species differences in the multiplicity of cytochrome P450 enzymes, and the use of mouse models to predict pathways of drug metabolism is further complicated by overlapping substrate specificity between enzymes from different gene families. To establish the role of the hepatic and extrahepatic P450 system in drug and foreign chemical disposition, drug efficacy, and toxicity, we created a unique mouse model in which 30 cytochrome P450 genes from the Cyp2c, Cyp2d, and Cyp3a gene clusters have been deleted. Remarkably, despite a wide range of putative important endogenous functions, Cyp2c/2d/3a KO mice were viable and fertile, demonstrating that these genes have evolved primarily as detoxification enzymes. Although there was no overt phenotype, detailed examination showed Cyp2c/2d/3a KO mice had a smaller body size (15%) and larger livers (20%). Changes in hepatic morphology and a decreased blood glucose (30%) were also noted. A five-drug cocktail of cytochrome P450 isozyme probe substrates were used to evaluate changes in drug pharmacokinetics; marked changes were observed in either the pharmacokinetics or metabolites formed from Cyp2c, Cyp2d, and Cyp3a substrates, whereas the metabolism of the Cyp1a substrate caffeine was unchanged. Thus, Cyp2c/2d/3a KO mice provide a powerful model to study the in vivo role of the P450 system in drug metabolism and efficacy, as well as in chemical toxicity. Y1 - 2014 U6 - https://doi.org/10.1124/dmd.114.057885 SN - 1521-009X VL - 42 IS - 6 SP - 1022 EP - 1030 PB - ASPET CY - Bethesda, Md. ER - TY - JOUR A1 - Scheer, Nico A1 - Henderson, Colin James A1 - Kapelyukh, Yury A1 - Rode, Anja A1 - Mclaren, Aileen W. A1 - MacLeod, Alastair Kenneth A1 - Lin, De A1 - Wright, Jayne A1 - Stanley, Lesley A1 - Wolf, C. Roland T1 - An extensively humanised mouse model to predict pathways of drug disposition, drug/drug interactions, and to facilitate the design of clinical trials JF - Drug Metabolism and Disposition Y1 - 2019 U6 - https://doi.org/10.1124/dmd.119.086397 IS - Early view ER - TY - JOUR A1 - Wilson, Ian D. A1 - Wilson, Claire E. A1 - Scheer, Nico A1 - Dickie, A.P. A1 - Schreiter, K. A1 - Wilson, E. M. A1 - Riley, R. J. A1 - Wehr, R. A1 - Bial, J. T1 - The Pharmacokinetics and Metabolism of Lumiracoxib in Chimeric Humanized and Murinized FRG Mice JF - Biochemical pharmacology Y1 - 2017 U6 - https://doi.org/10.1016/j.bcp.2017.03.015 SN - 1873-2968 VL - Volume 135 SP - 139 EP - 150 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hough, Lindsay B. A1 - Nalwalk, Julia W. A1 - Ding, Xinxin A1 - Scheer, Nico T1 - Opioid Analgesia in P450 Gene Cluster Knockout Mice: A Search for Analgesia-Relevant Isoforms JF - Drug Metabolism and Disposition Y1 - 2015 U6 - https://doi.org/10.1124/dmd.115.065490 SN - 1521-009x VL - 43 IS - 9 SP - 1326 EP - 1330 ER - TY - JOUR A1 - Mues genannt Koers, Lucas A1 - McNeil, S. W. A1 - Radchenko, V. A1 - Paulßen, Elisabeth A1 - Hoehr, Cornelia T1 - Production of Co-58m in a siphon-style liquid target on a medical cyclotron N2 - We present the production of 58mCo on a small, 13 MeV medical cyclotron utilizing a siphon style liquid target system. Different concentrated iron(III)-nitrate solutions of natural isotopic distribution were irradiated at varying initial pressures and subsequently separated by solid phase extraction chromatography. The radio cobalt (58m/gCo and 56Co) was successfully produced with saturation activities of (0.35 ± 0.03) MBq μA−1 for 58mCo with a separation recovery of (75 ± 2) % of cobalt after one separation step utilizing LN-resin. Y1 - 2023 U6 - https://doi.org/10.1016/j.apradiso.2023.110734 SN - 0969-8043 VL - 195 IS - Art. 110734 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hafidi, Youssef A1 - El Hatka, Hicham A1 - Schmitz, Dominik A1 - Krauss, Manuel A1 - Pettrak, Jürgen A1 - Biel, Markus A1 - Ittobane, Najim T1 - Sustainable soil additives for water and micronutrient supply: swelling and chelating properties of polyaspartic acid hydrogels utilizing newly developed crosslinkers JF - Gels N2 - Drought and water shortage are serious problems in many arid and semi-arid regions. This problem is getting worse and even continues in temperate climatic regions due to climate change. To address this problem, the use of biodegradable hydrogels is increasingly important for the application as water-retaining additives in soil. Furthermore, efficient (micro-)nutrient supply can be provided by the use of tailored hydrogels. Biodegradable polyaspartic acid (PASP) hydrogels with different available (1,6-hexamethylene diamine (HMD) and L-lysine (LYS)) and newly developed crosslinkers based on diesters of glycine (GLY) and (di-)ethylene glycol (DEG and EG, respectively) were synthesized and characterized using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) and regarding their swelling properties (kinetic, absorbency under load (AUL)) as well as biodegradability of PASP hydrogel. Copper (II) and zinc (II), respectively, were loaded as micronutrients in two different approaches: in situ with crosslinking and subsequent loading of prepared hydrogels. The results showed successful syntheses of di-glycine-ester-based crosslinkers. Hydrogels with good water-absorbing properties were formed. Moreover, the developed crosslinking agents in combination with the specific reaction conditions resulted in higher water absorbency with increased crosslinker content used in synthesis (10% vs. 20%). The prepared hydrogels are candidates for water-storing soil additives due to the biodegradability of PASP, which is shown in an exemple. The incorporation of Cu(II) and Zn(II) ions can provide these micronutrients for plant growth. KW - micronutrients KW - swelling properties KW - biodegradable polymers KW - hydrogels KW - superabsorbent polymers KW - glycine KW - polyaspartic acid Y1 - 2024 U6 - https://doi.org/10.3390/gels10030170 SN - 2310-2861 VL - 10 IS - 3 SP - Artikel 170 PB - MDPI CY - Basel ER - TY - JOUR A1 - Berndt, Heinz A1 - Zahn, Helmut T1 - Peptide, 99 : Monomere cyclische Cystinpeptidderivate, III ; Synthese der Schafinsulin-A-Kettensequenzen A2–21 und A1–21 als monomere cyclische Dicystinpeptidderivate JF - Justus Liebigs Annalen der Chemie N2 - Die Synthese der Sequenzen A2—21 (13) und A1—21 (15) der Schafinsulin-A-Kette als monomere cyclische Dicystinpeptidderivate wird beschrieben. Die intrachenaren Cystinbrücken A6—7 und A 11 —20 vermitteln die Löslichkeit dieser Derivate in Dimethylformamid und ermöglichen erstmalig die Reindarstellung vollgeschützter Insulin-A-Kettenderivate. Die während der Synthese eingesetzten Schutzgruppen lassen sich mittels Trifluoressigsäure und 2-Mercaptoäthanol quantitativ entfernen. Y1 - 1975 U6 - https://doi.org/10.1002/jlac.197519750908 SN - 1099-0690 VL - 1975 IS - 9 SP - 1601 EP - 1612 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Mang, Thomas A1 - Roosen, C. A1 - Ansorge, Marion A1 - Leitner, W. T1 - Gaining pH-control in water/carbon dioxide biphasic systems / Abstract No. 1038 / Roosen, Ch. ; Ansorge, M. ; Mang, Thomas ; Leitner, W. ; Greiner, L. JF - Green solvents for processes : Lake Constance, Friedrichshafen, Germany, 8 - 11 October 2006 ; book of abstracts / DECHEMA e.V. Y1 - 2006 N1 - DECHEMA, Gesellschaft für Chemische Technik und Biotechnologie ; [Conference] ; ((Friedrichshafen) : 2006.10.08-11) PB - DECHEMA CY - Frankfurt am Main ER - TY - JOUR A1 - Zientz, Evelyn A1 - Bongaerts, Johannes A1 - Unden, Gottfried T1 - Fumarate regulation of gene expression in Escherichia coli by the DcuSR (dcuSR genes) two-component regulatory system JF - Journal of bacteriology Y1 - 1998 SN - 1098-5530 (E-Journal); 0021-9193 (Print) VL - Vol. 180 IS - No. 20 SP - 5421 EP - 5425 ER - TY - JOUR A1 - Wiesen, Sebastian A1 - Tippkötter, Nils A1 - Muffler, Kai A1 - Suck, Kirstin A1 - Sohling, Ulrich A1 - Ruf, Nils A1 - Ulber, Roland T1 - Adsorptive Vorbehandlung von Rohglycerin für die 1,3-Propandiol Fermentation mit Clostridium diolis JF - Chemie Ingenieur Technik N2 - Bei der Gewinnung von Fettsäuren aus Pflanzenölen, z. B. zur Herstellung von Biopolymeren, oder bei der Biodiesel- und Seifenproduktion, fällt Glycerin als Nebenprodukt an. Bei der Biokonversion dieses Rohstoffes zu 1,3-Propandiol wird der Produktionsorganismus Clostridium diolis durch Verunreinigungen im Rohglycerin gehemmt. Als inhibierende Substanzen konnten freie Fettsäuren identifiziert werden. Mithilfe eines adsorptiven Aufarbeitungsverfahrens ist es gelungen, die Fettsäuren zu entfernen und die Konversionseffizienz zu 1,3-Propandiol zu erhöhen. Y1 - 2014 U6 - https://doi.org/10.1002/cite.201300080 N1 - Englischer Titel: Adsorptive Pretreatment of Crude Glycerol Prior to Fermentation to 1,3-Propanediole by Clostridium Diolis VL - 86 IS - 1-2 SP - 129 EP - 135 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Roth, Jasmine A1 - Tippkötter, Nils T1 - Evaluation of lignocellulosic material for butanol production using enzymatic hydrolysate medium JF - Cellulose Chemistry and Technology N2 - Butanol is a promising gasoline additive and platform chemical that can be readily produced via acetone-butanolethanol (ABE) fermentation from pretreated lignocellulosic materials. This article examines lignocellulosic material from beech wood for ABE fermentation, using Clostridium acetobutylicum. First, the utilization of both C₅₋ (xylose) and C₆₋ (glucose) sugars as sole carbon source was investigated in static cultivation, using serum bottles and synthetic medium. The utilization of pentose sugar resulted in a solvent yield of 0.231 g·g_sugar⁻¹, compared to 0.262 g·g_sugar⁻¹ using hexose. Then, the Organosolv pretreated crude cellulose fibers (CF) were enzymatically decomposed, and the resulting hydrolysate medium was analyzed for inhibiting compounds (furans, organic acids, phenolics) and treated with ionexchangers for detoxification. Batch fermentation in a bioreactor using CF hydrolysate medium resulted in a total solvent yield of 0.20 gABE·g_sugar⁻¹. Y1 - 2016 VL - 50 IS - 3-4 SP - 405 EP - 410 PB - Editura Academiei Romane CY - Bukarest ER - TY - JOUR A1 - Becht, Alexander A1 - Schollmayer, Curd A1 - Monakhova, Yulia A1 - Holzgrabe, Ulrike T1 - Tracing the origin of paracetamol tablets by near-infrared, mid-infrared, and nuclear magnetic resonance spectroscopy using principal component analysis and linear discriminant analysis JF - Analytical and Bioanalytical Chemistry N2 - Most drugs are no longer produced in their own countries by the pharmaceutical companies, but by contract manufacturers or at manufacturing sites in countries that can produce more cheaply. This not only makes it difficult to trace them back but also leaves room for criminal organizations to fake them unnoticed. For these reasons, it is becoming increasingly difficult to determine the exact origin of drugs. The goal of this work was to investigate how exactly this is possible by using different spectroscopic methods like nuclear magnetic resonance and near- and mid-infrared spectroscopy in combination with multivariate data analysis. As an example, 56 out of 64 different paracetamol preparations, collected from 19 countries around the world, were chosen to investigate whether it is possible to determine the pharmaceutical company, manufacturing site, or country of origin. By means of suitable pre-processing of the spectra and the different information contained in each method, principal component analysis was able to evaluate manufacturing relationships between individual companies and to differentiate between production sites or formulations. Linear discriminant analysis showed different results depending on the spectral method and purpose. For all spectroscopic methods, it was found that the classification of the preparations to their manufacturer achieves better results than the classification to their pharmaceutical company. The best results were obtained with nuclear magnetic resonance and near-infrared data, with 94.6%/99.6% and 98.7/100% of the spectra of the preparations correctly assigned to their pharmaceutical company or manufacturer. KW - IR KW - Manufacturer KW - Linear discriminant analysis KW - Principal component analysis Y1 - 2021 U6 - https://doi.org/10.1007/s00216-021-03249-z SN - 1618-2650 VL - 413 SP - 3107 EP - 3118 PB - Springer Nature ER - TY - JOUR A1 - Lindner, Simon A1 - Burger, René A1 - Rutledge, Douglas N. A1 - Do, Xuan Tung A1 - Rumpf, Jessica A1 - Diehl, Bernd W. K. A1 - Schulze, Margit A1 - Monakhova, Yulia T1 - Is the calibration transfer of multivariate calibration models between high- and low-field NMR instruments possible? A case study of lignin molecular weight JF - Analytical chemistry N2 - Although several successful applications of benchtop nuclear magnetic resonance (NMR) spectroscopy in quantitative mixture analysis exist, the possibility of calibration transfer remains mostly unexplored, especially between high- and low-field NMR. This study investigates for the first time the calibration transfer of partial least squares regressions [weight average molecular weight (Mw) of lignin] between high-field (600 MHz) NMR and benchtop NMR devices (43 and 60 MHz). For the transfer, piecewise direct standardization, calibration transfer based on canonical correlation analysis, and transfer via the extreme learning machine auto-encoder method are employed. Despite the immense resolution difference between high-field and low-field NMR instruments, the results demonstrate that the calibration transfer from high- to low-field is feasible in the case of a physical property, namely, the molecular weight, achieving validation errors close to the original calibration (down to only 1.2 times higher root mean square errors). These results introduce new perspectives for applications of benchtop NMR, in which existing calibrations from expensive high-field instruments can be transferred to cheaper benchtop instruments to economize. Y1 - 2022 SN - 1520-6882 U6 - https://doi.org/10.1021/acs.analchem.1c05125 VL - 94 IS - 9 SP - 3997 EP - 4004 PB - ACS Publications CY - Washington, DC ER - TY - JOUR A1 - Aboulnaga, El-Hussiny A1 - Pinkenburg, Olaf A1 - Schiffels, Johannes A1 - El-Refai, Ahmed A1 - Buckel, Wolfgang A1 - Selmer, Thorsten T1 - Butyrate production in Escherichia coli: Exploitation of an oxygen tolerant bifurcating butyryl-CoA dehydrogenase/electron transferring flavoprotein complex from Clostridium difficile JF - Journal of bacteriology. June 14, 2013 Y1 - 2013 SN - 1098-5530 (E-Journal) ; 0021-9193 (Print) SP - Epub ahead of print ER - TY - JOUR A1 - Aboulnaga, Elhussiny A. A1 - Zou, Huibin A1 - Selmer, Thorsten A1 - Xian, Mo T1 - Development of a plasmid-based, tunable, tolC-derived expression system for application in Cupriavidus necator H16 JF - Journal of Biotechnology N2 - Cupriavidus necator H16 gains increasing attention in microbial research and biotechnological application due to its diverse metabolic features. Here we present a tightly controlled gene expression system for C. necator including the pBBR1-vector that contains hybrid promoters originating from C. necator native tolC-promoter in combination with a synthetic tetO-operator. The expression of the reporter gene from these plasmids relies on the addition of the exogenous inducer doxycycline (dc). The novel expression system offers a combination of advantageous features as; (i) high and dose-dependent recombinant protein production, (ii) tight control with a high dynamic range (On/Off ratio), which makes it applicable for harmful pathways or for toxic protein production, (iii) comparable cheap inducer (doxycycline, dc), (iv) effective at low inducer concentration, that makes it useful for large scale application, (v) rapid, diffusion controlled induction, and (vi) the inducer does not interfere within the cell metabolism. As applications of the expression system in C. necator H16, the growth ability on glycerol was enhanced by constitutively expressing the E. coli glpk gene-encoding for glycerol kinase. Likewise, we used the system to overcome the expression toxicity of mevalonate pathway in C. necator H16. With this system, the mevalonate-genes were successfully introduced in the host and the recombinant strains could produce about 200 mg/l mevalonate. Y1 - 2018 U6 - https://doi.org/10.1016/j.jbiotec.2018.03.007 SN - 0168-1656 VL - 274 SP - 15 EP - 27 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Aggarwal, Pranav A1 - Dhiman, Shashi K. A1 - Kumar, G. A1 - Scherer, Ulrich W. A1 - Singla, M. L. A1 - Srivastava, Alok T1 - Optical study of poly(ethyleneterephthalate) modified by different ionizing radiation dose JF - Indian Journal of Pure and Applied Physics N2 - Thin films of poly(ethyleneterephthalate) [PET]were exposed to radiation dose ranging from 10 to 30 kGy by using gamma rays in the range 12.8-177.8 MGy using swift light ions of hydrogen. There was no effect of the radiation dose on the optical behaviour of PET as a result of exposure to radiation dose up to 30 kGy brought about by gamma rays but a significant decrease in the optical band gap values was observed when PET was exposed to swift light ions of hydrogen. The data obtained are discussed in terms of optical studies carried out on PET using swift heavy ions. Y1 - 2012 SN - 0019-5596 VL - 50 IS - 2 SP - 129 EP - 132 ER - TY - JOUR A1 - Srivastava, Alok A1 - Singh, Virendra A1 - Aggarwal, Pranav A1 - Schneeweiss, F. A1 - Scherer, Ulrich W. A1 - Friedrich, W. T1 - Optical studies of insulating polymers for radiation dose monitoring JF - Indian Journal of Pure & Applied Physics Y1 - 2010 SN - 0019-5596 N1 - Special Issue: SI VL - 48 IS - 11 SP - 782 EP - 786 ER - TY - JOUR A1 - Berndt, Heinz A1 - Gattner, Hans-Gregor A1 - Zahn, Helmut T1 - Semisynthetisches Des-A1-glycin-Schafinsulin JF - Biological Chemistry Y1 - 1975 U6 - https://doi.org/10.1515/bchm2.1975.356.2.1455 SN - 1437-4315 VL - 356 IS - 2 SP - 1469 EP - 1472 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Gielen, Hans-Günther A1 - Wolf, Günter A1 - Berndt, Heinz A1 - Zahn, Helmut T1 - Synthese der Fragmente A1–8, A9–15 und A16–21 der Schafinsulin-A-Kette unter Verwendung des S-tert-Butylmercaptorestes als Thiolschutzgruppe JF - Hoppe-Seyler's Zeitschrift für physiologische Chemie Y1 - 1979 U6 - https://doi.org/10.1515/bchm2.1979.360.2.1535 SN - 1437-4315 SN - 0018-4888 VL - 360 IS - 2 SP - 1535 EP - 1548 ER - TY - JOUR A1 - Wolf, Wilhelm A1 - Berndt, Heinz A1 - Brandenburg, Dietrich T1 - Synthese von Fragmenten einer [LysA13] Rinder-Insulin-A-Kette unter Verwendung des S-tert-Butylmercaptorestes als Thiolschutz JF - Hoppe-Seyler's Zeitschrift für physiologische Chemie Y1 - 1979 U6 - https://doi.org/10.1515/bchm2.1979.360.2.1549 SN - 1437-4315 SN - 0018-4888 VL - 360 IS - 2 SP - 1549 EP - 1558 ER - TY - JOUR A1 - Wilhelm, Wolff A1 - Berndt, Heinz A1 - Brandenburg, Dietrich T1 - Zur Synthese der Hühnerinsulin-A-Kette, I : Darstellung der Fragmente A1–8, A9–15, A1–7 und A8–15 JF - Hoppe-Seyler's Zeitschrift für physiologische Chemie Y1 - 1979 U6 - https://doi.org/10.1515/bchm2.1979.360.2.1559 SN - 1437-4315 SN - 0018-4888 VL - 360 IS - 2 SP - 1559 EP - 1568 ER - TY - JOUR A1 - Berndt, Heinz T1 - Synthese der Sequenz 71—86 des Humanproinsulins, III : Synthese über die Fragmente 71—78 und 79—86 JF - Hoppe-Seyler's Zeitschrift für physiologische Chemie Y1 - 1979 U6 - https://doi.org/10.1515/bchm2.1979.360.1.765 SN - 1437-4315 SN - 0018-4888 VL - 360 IS - 1 SP - 765 EP - 772 ER - TY - JOUR A1 - Oehlenschläger, Katharina A1 - Volkmar, Marianne A1 - Stiefelmaier, Judith A1 - Langsdorf, Alexander A1 - Holtmann, Dirk A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - New insights into the influence of pre-culture on robust solvent production of C. acetobutylicum JF - Applied Microbiology and Biotechnology N2 - Clostridia are known for their solvent production, especially the production of butanol. Concerning the projected depletion of fossil fuels, this is of great interest. The cultivation of clostridia is known to be challenging, and it is difficult to achieve reproducible results and robust processes. However, existing publications usually concentrate on the cultivation conditions of the main culture. In this paper, the influence of cryo-conservation and pre-culture on growth and solvent production in the resulting main cultivation are examined. A protocol was developed that leads to reproducible cultivations of Clostridium acetobutylicum. Detailed investigation of the cell conservation in cryo-cultures ensured reliable cell growth in the pre-culture. Moreover, a reason for the acid crash in the main culture was found, based on the cultivation conditions of the pre-culture. The critical parameter to avoid the acid crash and accomplish the shift to the solventogenesis of clostridia is the metabolic phase in which the cells of the pre-culture were at the time of inoculation of the main culture; this depends on the cultivation time of the pre-culture. Using cells from the exponential growth phase to inoculate the main culture leads to an acid crash. To achieve the solventogenic phase with butanol production, the inoculum should consist of older cells which are in the stationary growth phase. Considering these parameters, which affect the entire cultivation process, reproducible results and reliable solvent production are ensured. KW - Pre-culture KW - Metabolic shift KW - Acid crash KW - C. acetobutylicum KW - ABE KW - Butanol Y1 - 2024 U6 - https://doi.org/10.1007/s00253-023-12981-8 SN - 1432-0614 VL - 108 PB - Springer CY - Berlin, Heidelberg ER - TY - JOUR A1 - Krüger, Götz A1 - Grötzinger, Joachim A1 - Berndt, Heinz T1 - Enantiomeric resolution of amino acid derivatives on chiral stationary phases by high-performance liquid chromatography JF - Journal of Chromatography A Y1 - 1987 U6 - https://doi.org/10.1016/S0021-9673(01)85005-6 SN - 0021-9673 VL - 1987 IS - 397 SP - 223 EP - 232 ER - TY - JOUR A1 - Nokihara, Kiyoshi A1 - Berndt, Heinz T1 - Synthesis of hapten–polypeptide conjugates as antigen models for the N-terminal region of the α-2-chain of rabbit skin collagen JF - Journal of the Royal Society of Chemistry: Perkin Transactions 1 N2 - Synthesis of derivatives of the peptide sequence L-pyroglutamyl-L-phenylalanyl-L-aspartyl-glycyl-L-lysyl-glycyl-glycyl-glycine as the antigenic determinant representing the N-terminal non-helical region of the α-2-chain of rabbit skin collagen, and conjugation to two different polypeptide carriers, are described. Y1 - 1978 U6 - https://doi.org/10.1039/P19780000260 SN - 1364-5463 SN - 0300-922X SN - 1470-4358 VL - 1978 IS - 3 SP - 260 EP - 263 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Scheer, Nico A1 - Kapelyukh, Yury A1 - Rode, Anja A1 - Buechel, Sandra A1 - Wolf, C. Roland T1 - Generation and characterization of novel cytochrome P450 Cyp2c gene cluster knockout and CYP2C9 humanized mouse lines JF - Molecular Pharmacology N2 - Compared with rodents and many other animal species, the human cytochrome P450 (P450) Cyp2c gene cluster varies significantly in the multiplicity of functional genes and in the substrate specificity of its enzymes. As a consequence, the use of wild-type animal models to predict the role of human CYP2C enzymes in drug metabolism and drug-drug interactions is limited. Within the human CYP2C cluster CYP2C9 is of particular importance, because it is one of the most abundant P450 enzymes in human liver, and it is involved in the metabolism of a wide variety of important drugs and environmental chemicals. To investigate the in vivo functions of cytochrome P450 Cyp2c genes and to establish a model for studying the functions of CYP2C9 in vivo, we have generated a mouse model with a deletion of the murine Cyp2c gene cluster and a corresponding humanized model expressing CYP2C9 specifically in the liver. Despite the high number of functional genes in the mouse Cyp2c cluster and the reported roles of some of these proteins in different biological processes, mice deleted for Cyp2c genes were viable and fertile but showed certain phenotypic alterations in the liver. The expression of CYP2C9 in the liver also resulted in viable animals active in the metabolism and disposition of a number of CYP2C9 substrates. These mouse lines provide a powerful tool for studying the role of Cyp2c genes and of CYP2C9 in particular in drug disposition and as a factor in drug-drug interaction. Y1 - 2012 U6 - https://doi.org/10.1124/mol.112.080036 SN - 1521-0111 VL - 82 IS - 6 SP - 1022 EP - 1029 PB - ASPET CY - Bethesda, Md. ER - TY - JOUR A1 - Berndt, Heinz T1 - Zur Reaktion von Iminodithiocarbonaten mit Carbonsäuren. I : Synthese des Modellpeptid-Derivates Z-(L)-Ala-(L/D)-Phe-(L)-Val-OMe JF - Tetrahedron letters Y1 - 1980 U6 - https://doi.org/10.1016/S0040-4039(00)78663-1 SN - 0040-4039 VL - 21 IS - 34 SP - 3265 EP - 3268 ER - TY - JOUR A1 - Berndt, Heinz A1 - Krüger, Götz T1 - Resolution of enantiomeric amino acid derivatives by high-performance liquid chromatography on chiral stationary phases JF - Journal of chromatography A Y1 - 1985 U6 - https://doi.org/10.1016/S0021-9673(01)92461-6 SN - 0021-9673 VL - 1985 IS - 348 SP - 275 EP - 279 ER - TY - JOUR A1 - Meyer-Stork, L. Sebastian A1 - Kalbe, Jochen A1 - Kuropka, Rolf A1 - Sauter, S. L. A1 - Höcker, Hartwig A1 - Berndt, Heinz T1 - Eindeutige Provenienzanalyse von Wolle und feinen Tierhaaren mit Hilfe der Erbsubstanz (DNS) JF - Textilveredlung : schweizerische Zeitschrift für Textilchemie, Textilveredlung und deren Randgebiete Y1 - 1988 SN - 0040-5310 VL - 23 IS - 9 SP - 304 EP - 307 ER - TY - JOUR A1 - Schnabel, Eugen A1 - Schnabel, Henning A1 - Berndt, Heinz T1 - Zur selektiven acidolytischen Abspaltbarkeit der tert.-Butyloxycarbonyl-Gruppe JF - Justus Liebigs Annalen der Chemie N2 - Die tert.-Butyloxycarbonyl-Gruppe (Boc) läßt sich mittels reiner Trifluoressigsäure nicht selektiv neben dem Benzyloxycarbonyl-Rest (Z) abspalten. Das gelingt auch nicht mit Lösungen von Trifluoressigsäure bzw. Chlorwasserstoff in organischen Lösungsmitteln. Kern-substituierte Z-Gruppen wie Z(pCl), Z(mCl) oder Z(pNO₂) sind zwar stabiler, werden aber von den obengenannten Reagenzien ebenfalls angegriffen bzw. sind nicht mehr acidolytisch abspaltbar. – Mit 70proz. wäßriger Trifluoressigsäure gelingt die Abspaltung von Boc neben Z dagegen fast selektiv; dabei werden aber Benzylester, besonders Glutaminsäure-γ-benzylester, teilweise hydrolysiert, während Methyl- sowie Äthylester nahezu beständig sind. Die Brauchbarkeit des Abspaltungsverfahrens wird anhand der schrittweise durchgeführten Synthese zweier Heptapeptid-Derivate gezeigt. – Ähnlich spezifisch gelingt die Abspaltung von Boc mit Bortrifluorid-ätherat in Eisessig; Benzylester sind gegenüber diesem Reagenz stabiler als gegen wäßrige Trifluoressigsäure. Das Bortrifluorid-Verfahren eignet sich besonders für die Abspaltung von Boc-Gruppen neben säurelabilen Thiol-Schutzgruppen (Tetrahydropyranyl- bzw. Trityl-Rest) sowie neben dem Cyclocystinyl-Rest. Die Leistungsfähigkeit der Methode wird durch die Synthese zweier Peptid-Derivate mit S-Trityl-Schutzgruppen belegt. Als Nebenreaktion ist die Acetylierung von aliphatischen Hydroxylgruppen möglich. Sie läßt sich vermeiden, wenn man die Spaltung in anderen Lösungsmitteln durchführt. Die als Modellverbindungen für Stabilitätsuntersuchungen verwendeten Nε-acylierten Lysin-Derivate werden mit dem Aminosäureanalysator quantitativ neben Lysin bestimmt. Y1 - 1971 U6 - https://doi.org/10.1002/jlac.19717490111 SN - 1099-0690 VL - 749 IS - 1 SP - 90 EP - 108 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Kuropka, Rolf A1 - Müller, Bettina A1 - Höcker, Hartwig A1 - Berndt, Heinz T1 - Chiral stationary phases via hydrosilylation reaction of N-acryloylamino acids : I. Stationary phase with one chiral centre for high-performance liquid chromatography and development of a new derivatization pattern for amino acid enantiomers JF - Journal of chromatography A Y1 - 1989 SN - 0021-9673 IS - 481 SP - 380 EP - 386 ER - TY - JOUR A1 - Nokihara, Kiyoshi A1 - Berndt, Heinz T1 - Studies on sulfur-containing peptides : tert-butyloxycarbonylsulfenyl and benzyloxycarbonylsulfenyl derivatives as protecting groups for cysteine JF - The journal of organic chemistry Y1 - 1978 U6 - https://doi.org/10.1021/jo00419a046 SN - 0022-3263 VL - 43 IS - 25 SP - 4893 EP - 4895 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Kalbe, Jochen A1 - Höcker, Hartwig A1 - Berndt, Heinz T1 - Design of enzyme reactors as chromatographic columns for racemic resolution of amino acid esters JF - Chromatographia Y1 - 1989 SN - 0009-5893 U6 - https://doi.org/10.1007/BF02319646 VL - 28 IS - 3-4 SP - 193 EP - 196 ER - TY - JOUR A1 - Turck, Christoph W. A1 - Berndt, Heinz T1 - Synthese definierter Peptid-Derivate durch Aminolyse von 3-(Nα-Acyl-peptidyloxy)-2-hydroxy-N-alkylbenzamiden bei erhöhten Temperaturen, I : Synthese des Modellpeptid-Derivates Z-Ala-Phe-Gly-N(Et)2 JF - Hoppe-Seyler´s Zeitschrift für physiologische Chemie Y1 - 1981 U6 - https://doi.org/10.1515/bchm2.1981.362.1.821 SN - 1437-4315 SN - 0018-4888 VL - 362 IS - 1 SP - 821 EP - 828 ER - TY - JOUR A1 - Danho, Waleed A1 - Naithani, Vinod K. A1 - Sasaki, André N. A1 - Föhles, Joseph A1 - Berndt, Heinz A1 - Büllesbach, Erika E. A1 - Zahn, H. T1 - Human proinsulin, VII : synthesis of two protected peptides corresponding to the sequences 1—45 and 46—86 of the prohormone JF - Hoppe-Seyler's Zeitschrift für physiologische Chemie Y1 - 1980 U6 - https://doi.org/10.1515/bchm2.1980.361.1.857 SN - 1437-4315 SN - 0018-4888 VL - 361 IS - 1 SP - 857 EP - 863 ER - TY - JOUR A1 - Kalbe, Jochen A1 - Kuropka, Rolf A1 - Meyer-Stork, L. Sebastian A1 - Berndt, Heinz A1 - Sauter, Sybille L. A1 - Loss, Peter A1 - Hendo, Karsten A1 - Riesner, Detlev A1 - Höcker, Hartwig T1 - Isolation and characterization of high-molecular mass DNA from hair shafts JF - Biological chemistry Y1 - 1988 SN - 0177-3593 U6 - https://doi.org/10.1515/bchm3.1988.369.1.413 VL - 369 IS - 1 SP - 413 EP - 416 ER - TY - JOUR A1 - Baumann, Marcus A1 - Tillmann, Urban A1 - Aletsee, Ludwig T1 - Distribution of Carbon Among Photosynthetic End Products in the Bloom-Forming Arctic Diatom Thalassiosira antarctica COMBER / Tillmann, U. ; Baumann, M.E.M. ; Aletsee, L. JF - Polar Biology. 10 (1989), H. 3 Y1 - 1989 SN - 0722-4060 SP - 231 EP - 238 ER -