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Article ; Online: Natural Products for Drug Discovery in the 21st Century

Ericsson Coy-Barrera / Ifedayo Victor Ogungbe / Thomas J. Schmidt

Molecules, Vol 28, Iss 3690, p

Innovations for Novel Therapeutics

2023 Volume 3690

Abstract: Natural products (NPs) from plants, fungi, animals, and microorganisms have historically played important roles in drug discovery [.] ...

Abstract	Natural products (NPs) from plants, fungi, animals, and microorganisms have historically played important roles in drug discovery [.]
Keywords	n/a ; Organic chemistry ; QD241-441
Language	English
Publishing date	2023-04-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Investigation of the Variability of Alkaloids in Buxus sempervirens L. Using Multivariate Data Analysis of LC/MS Profiles

Lara U. Szabó / Thomas J. Schmidt

Molecules, Vol 27, Iss 82, p

2022 Volume 82

Abstract: Buxus sempervirens L. is a common ornamental plant in southern and central Europe, and has been used ethopharmacologically against a wide variety of diseases due to it containing nor -triterpene alkaloids of the nor -cycloartane type. Recently, we ... ...

Abstract	Buxus sempervirens L. is a common ornamental plant in southern and central Europe, and has been used ethopharmacologically against a wide variety of diseases due to it containing nor -triterpene alkaloids of the nor -cycloartane type. Recently, we demonstrated the interesting antiprotozoal potential of some of these compounds. To characterize the temporal variability in the alkaloid profile of two different varieties and their leaves and twigs, 30 different extracts of B . sempervirens were evaluated by Ultra High Performance Liquid Chromatography/positive Mode-Electrospray Ionization Quadrupole Time-of-Flight-Tandem Mass Spectrometry (UHPLC/+ESI-QqTOF-MS/MS). The analytical profiles were thoroughly investigated by various methods of multivariate data analysis (MVDA). A principal component analysis (PCA) model elucidates the seasonal variation in the phytochemical composition of B . sempervirens var. arborescens and suffruticosa along with differences between the varieties. Analysis of a volcano plot illustrated the differences between the two organs, the leaf and twig. Eighteen compounds were highlighted by the models as constituents of the plant characteristic for a season, variety or organ. These compounds were dereplicated based on their chromatographic and +ESI-QqTOF-MS and –MS/MS data. In addition, mass spectral fragmentation pathways for already known alkaloids as well as new natural products could be postulated for the first time. In conclusion, the MVDA models give detailed information on the temporal variability in the alkaloid profile of two different varieties and their organs (leaf vs. twig) of B . sempervirens . Thus, the results of this study allow, e.g., the identification of characteristic compounds for the different varieties, plant organs, seasons, and the optimal harvesting time for the isolation of particular Buxus -alkaloids of interest for subsequent studies.
Keywords	Buxus sempervirens L ; nor -cycloartane alkaloids ; seasonal variability ; optimal harvesting time ; multivariate data analysis ; principal component analysis ; Organic chemistry ; QD241-441
Subject code	540
Language	English
Publishing date	2022-12-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Natural Products with Antitumor Potential Targeting the MYB-C/EBPβ-p300 Transcription Module

Thomas J. Schmidt / Karl-Heinz Klempnauer

Molecules, Vol 27, Iss 2077, p

2022 Volume 2077

Abstract: The transcription factor MYB is expressed predominantly in hematopoietic progenitor cells, where it plays an essential role in the development of most lineages of the hematopoietic system. In the myeloid lineage, MYB is known to cooperate with members of ...

Abstract	The transcription factor MYB is expressed predominantly in hematopoietic progenitor cells, where it plays an essential role in the development of most lineages of the hematopoietic system. In the myeloid lineage, MYB is known to cooperate with members of the CCAAT box/enhancer binding protein (C/EBP) family of transcription factors. MYB and C/EBPs interact with the co-activator p300 or its paralog CREB-binding protein (CBP), to form a transcriptional module involved in myeloid-specific gene expression. Recent work has demonstrated that MYB is involved in the development of human leukemia, especially in acute T-cell leukemia (T-ALL) and acute myeloid leukemia (AML). Chemical entities that inhibit the transcriptional activity of the MYB-C/EBPβ-p300 transcription module may therefore be of use as potential anti-tumour drugs. In searching for small molecule inhibitors, studies from our group over the last 10 years have identified natural products belonging to different structural classes, including various sesquiterpene lactones, a steroid lactone, quinone methide triterpenes and naphthoquinones that interfere with the activity of this transcriptional module in different ways. This review gives a comprehensive overview on the various classes of inhibitors and the inhibitory mechanisms by which they affect the MYB-C/EBPβ-p300 transcriptional module as a potential anti-tumor target. We also focus on the current knowledge on structure-activity relationships underlying these biological effects and on the potential of these compounds for further development.
Keywords	transcription factor ; MYB ; C/EBPβ ; p300 ; cancer ; leukemia ; Organic chemistry ; QD241-441
Subject code	570
Language	English
Publishing date	2022-03-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: How, where, and when to charge electric vehicles – net-zero energy system implications and policy recommendations

Sandro Luh / Ramachandran Kannan / Russell McKenna / Thomas J Schmidt / Tom Kober

Environmental Research Communications, Vol 5, Iss 9, p

2023 Volume 095004

Abstract: A coordinated Charging Infrastructure (CI) strategy could accelerate the adoption of Battery Electric Vehicles (BEVs). Policymakers need to understand the tradeoffs between several types of CI developments. To support decision-makers, we apply the Swiss ... ...

Abstract	A coordinated Charging Infrastructure (CI) strategy could accelerate the adoption of Battery Electric Vehicles (BEVs). Policymakers need to understand the tradeoffs between several types of CI developments. To support decision-makers, we apply the Swiss TIMES Energy system Model, which we extended with heterogeneous consumer segments with four trip types and several CI options. The novelty of this work lies in the interplay of such method advancements, representing BEV charging options with various CI types that can be accessed based on their location type at an hourly intraday temporal resolution. In explorative scenario analyses, we evaluate the effects of CI on car fleet deployment and their energy system implications in achieving net-zero CO _2 emissions in Switzerland by 2050. Our analysis shows that the BEV share makes up 39%–77% of the fleet by 2050, and each BEV needs about 5 kW total charging capacity, split into 1.6–2.6 BEVs per private charger and 18–25 BEVs per public charger. Providing overnight charging access through private home chargers or public chargers in residential areas facilitates a 12%–20% increased BEV penetration compared to the reference scenario. For consumers without private home charging, improved public CI in non-residential areas increases BEV uptake by 24%. While low-power slow CI is cost-effective at home, high-power fast CI in commercial areas supports integration of solar PV. We highlight the need for coordinated CI policies and provide a variety of policy options based on our analysis and international insights.
Keywords	energy system model ; battery electric vehicles ; charging infrastructure ; mobility ; optimization ; decarbonization ; Environmental sciences ; GE1-350 ; Meteorology. Climatology ; QC851-999
Subject code	380
Language	English
Publishing date	2023-01-01T00:00:00Z
Publisher	IOP Publishing
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Target-Guided Isolation of O -tigloylcyclovirobuxeine -B from Buxus sempervirens L. by Centrifugal Partition Chromatography

Lara U. Szabó / Thomas J. Schmidt

Molecules, Vol 25, Iss 4804, p

2020 Volume 4804

Abstract: The increasing drug resistance of malaria parasites challenges the treatment of this life-threatening disease. Consequently, the development of innovative and effective antimalarial drugs is inevitable. O -tigloylcyclovirobuxeine-B, a nor -cycloartane ... ...

Abstract	The increasing drug resistance of malaria parasites challenges the treatment of this life-threatening disease. Consequently, the development of innovative and effective antimalarial drugs is inevitable. O -tigloylcyclovirobuxeine-B, a nor -cycloartane alkaloid from Buxus sempervirens L., has shown promising and selective in vitro activity in previous studies against Plasmodium falciparum ( Pf ), causative agent of Malaria tropica. For further investigations, it is indispensable to develop an advanced and efficient isolation procedure of this valuable natural product. Accordingly, we used liquid–liquid chromatography including centrifugal partition chromatography (CPC) to obtain the pure alkaloid on a semi-preparative scale. Identification and characterization of the target compound was accomplished by UHPLC/+ESI-QqTOF-MS/MS, 1 H NMR and 13 C NMR. In conclusion, this work provides a new and efficient method to obtain O -tigloylcyclovirobuxeine-B, a valuable natural product, as a promising antiplasmodial lead structure for the development of innovative and safe medicinal agents.
Keywords	Buxus sempervirens L ; nor -cycloartane alkaloids ; O -tigloylcyclovirobuxeine-B ; antimalarial activity ; target-guided isolation ; centrifugal partition chromatography ; Organic chemistry ; QD241-441
Language	English
Publishing date	2020-10-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Salvia officinalis L.

Núria Llurba Montesino / Marcel Kaiser / Pascal Mäser / Thomas J. Schmidt

Molecules, Vol 26, Iss 3226, p

Antitrypanosomal Activity and Active Constituents against Trypanosoma brucei rhodesiense

2021 Volume 3226

Abstract: As part of our studies on antiprotozoal activity of approved herbal medicinal products, we previously found that a commercial tincture from Salvia officinalis L. (common Sage, Lamiaceae) possesses high activity against Trypanosoma brucei rhodesiense (Tbr) ...

Abstract	As part of our studies on antiprotozoal activity of approved herbal medicinal products, we previously found that a commercial tincture from Salvia officinalis L. (common Sage, Lamiaceae) possesses high activity against Trypanosoma brucei rhodesiense (Tbr) , causative agent of East African Human Trypanosomiasis. We have now investigated in detail the antitrypanosomal constituents of this preparation. A variety of fractions were tested for antitrypanosomal activity and analyzed by UHPLC/+ESI QqTOF MS. The resulting data were used to generate a partial least squares (PLS) regression model that highlighted eight particular constituents that were likely to account for the major part of the bioactivity. These compounds were then purified and identified and their activity against the pathogen tested. All identified compounds (one flavonoid and eight diterpenes) displayed significant activity against Tbr , in some cases higher than that of the total tincture. From the overall results, it can be concluded that the antitrypanosomal activity of S. officinalis L. is, for the major part, caused by abietane-type diterpenes of the rosmanol/rosmaquinone group.
Keywords	Salvia officinalis L ; Trypanosoma brucei rhodesiense ; antitrypanosomal activity ; diterpene ; abietane ; rosmanol derivative ; Organic chemistry ; QD241-441
Subject code	500
Language	English
Publishing date	2021-05-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Boswellic Acids Show In Vitro Activity against Leishmania donovani

Hippolyt L. Greve / Marcel Kaiser / Pascal Mäser / Thomas J. Schmidt

Molecules, Vol 26, Iss 3651, p

2021 Volume 3651

Abstract: In continuation of our search for leads from medicinal plants against protozoal pathogens, we detected antileishmanial activity in polar fractions of a dichloromethane extract from Boswellia serrata resin. 11-keto-β-boswellic acid (KBA) could be isolated ...

Abstract	In continuation of our search for leads from medicinal plants against protozoal pathogens, we detected antileishmanial activity in polar fractions of a dichloromethane extract from Boswellia serrata resin. 11-keto-β-boswellic acid (KBA) could be isolated from these fractions and was tested in vitro against Leishmania donovani axenic amastigotes along with five further boswellic acid derivatives. 3- O -acetyl-11-keto-β-boswellic acid (AKBA) showed the strongest activity with an IC 50 value of 0.88 µM against axenic amastigotes but was inactive against intracellular amastigotes in murine macrophages
Keywords	Boswellia serrata ; frankincense ; Burseraceae ; Leishmania donovani ; antiprotozoal activity ; boswellic acids ; Organic chemistry ; QD241-441
Language	English
Publishing date	2021-06-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Identification of Antiprotozoal Compounds from Buxus sempervirens L. by PLS-Prediction

Lara U. Szabó / Marcel Kaiser / Pascal Mäser / Thomas J. Schmidt

Molecules, Vol 26, Iss 6181, p

2021 Volume 6181

Abstract: Various nor -triterpene alkaloids of Buxus ( B. ) sempervirens L. have shown remarkable in vitro activity against the causative agents of tropical malaria and East African sleeping sickness. To identify further antiprotozoal compounds of this plant, 20 ... ...

Abstract	Various nor -triterpene alkaloids of Buxus ( B. ) sempervirens L. have shown remarkable in vitro activity against the causative agents of tropical malaria and East African sleeping sickness. To identify further antiprotozoal compounds of this plant, 20 different fractions of B . sempervirens L., exhibiting a wide range of in vitro bioactivity, were analyzed by UHPLC/+ESI-QqTOF-MS/MS. The analytical profiles were investigated by partial least squares regression (PLS) for correlations between the intensity of LC/MS signals, bioactivity and cytotoxicity. The resulting models highlighted several compounds as mainly responsible for the antiprotozoal activity and thus, worthwhile for subsequent isolation. These compounds were dereplicated based on their mass spectra in comparison with isolated compounds recently reported by us and with literature data. Moreover, an estimation of the cytotoxicity of the highlighted compounds was derived from an additional PLS model in order to identify plant constituents with strong selectivity. In conclusion, high levels of antitrypanosomal and antiplasmodial activity were predicted for eight and four compounds, respectively. These include three hitherto unknown constituents of B . sempervirens L., presumably new natural products.
Keywords	Buxus sempervirens L ; nor -cycloartane alkaloids ; antiprotozoal activity ; multivariate data analysis ; partial least squares regression ; mass spectrometry ; Organic chemistry ; QD241-441
Subject code	540
Language	English
Publishing date	2021-10-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Sesquiterpene Lactones with Dual Inhibitory Activity against the Trypanosoma brucei Pteridine Reductase 1 and Dihydrofolate Reductase

Katharina Possart / Fabian C. Herrmann / Joachim Jose / Maria P. Costi / Thomas J. Schmidt

Molecules, Vol 27, Iss 149, p

2022 Volume 149

Abstract: The parasite Trypanosoma brucei ( T . brucei ) is responsible for human African trypanosomiasis (HAT) and the cattle disease “Nagana” which to this day cause severe medical and socio-economic issues for the affected areas in Africa. So far, most of the ... ...

Abstract	The parasite Trypanosoma brucei ( T . brucei ) is responsible for human African trypanosomiasis (HAT) and the cattle disease “Nagana” which to this day cause severe medical and socio-economic issues for the affected areas in Africa. So far, most of the available treatment options are accompanied by harmful side effects and are constantly challenged by newly emerging drug resistances. Since trypanosomatids are auxotrophic for folate, their pteridine metabolism provides a promising target for an innovative chemotherapeutic treatment. They are equipped with a unique corresponding enzyme system consisting of the bifunctional dihydrofolate reductase-thymidylate synthase ( Tb DHFR-TS) and the pteridine reductase 1 ( Tb PTR1). Previously, gene knockout experiments with PTR1 null mutants have underlined the importance of these enzymes for parasite survival. In a search for new chemical entities with a dual inhibitory activity against the Tb PTR1 and Tb DHFR, a multi-step in silico procedure was employed to pre-select promising candidates against the targeted enzymes from a natural product database. Among others, the sesquiterpene lactones (STLs) cynaropicrin and cnicin were identified as in silico hits. Consequently, an in-house database of 118 STLs was submitted to an in silico screening yielding 29 further virtual hits. Ten STLs were subsequently tested against the target enzymes in vitro in a spectrophotometric inhibition assay. Five compounds displayed an inhibition over 50% against Tb PTR1 as well as three compounds against Tb DHFR. Cynaropicrin turned out to be the most interesting hit since it inhibited both Tb PTR1 and Tb DHFR, reaching IC 50 values of 12.4 µM and 7.1 µM, respectively.
Keywords	Trypanosoma brucei ; human African trypanosomiasis ; pteridine reductase 1 inhibitor ; dihydrofolate reductase inhibitor ; sesquiterpene lactones ; natural products ; Organic chemistry ; QD241-441
Subject code	540 ; 572
Language	English
Publishing date	2022-12-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Estimation of activity coefficients for aqueous organic redox flow batteries

Gaël Mourouga / Déborah Chery / Emmanuel Baudrin / Hyacinthe Randriamahazaka / Thomas J. Schmidt / Juergen O. Schumacher

iScience, Vol 25, Iss 9, Pp 104901- (2022)

Theoretical basis and equations

2022

Abstract: Summary: The field of aqueous organic redox flow batteries (AORFBs) has been developing fast in recent years, and many chemistries are starting to emerge as serious contenders for grid-scale storage. The industrial development of these systems would ... ...

Abstract	Summary: The field of aqueous organic redox flow batteries (AORFBs) has been developing fast in recent years, and many chemistries are starting to emerge as serious contenders for grid-scale storage. The industrial development of these systems would greatly benefit from accurate physics-based models, allowing to optimize battery operation and design. Many authors in the field of flow battery modeling have brought evidence that the dilute solution hypothesis (the assumption that aqueous electrolytes behave ideally) does not hold for these systems and that calculating cell voltage or chemical potentials through concentrations rather than activities, while serviceable, may become insufficient when greater accuracy is required. This article aims to provide the theoretical basis for calculating activity coefficients of aqueous organic electrolytes used in AORFBs to provide tools to predict the concentrated behavior of aqueous electrolytes, thereby improving the accuracy of physics-based models for flow batteries.
Keywords	Chemistry ; Electrochemistry ; Electrochemical energy storage ; Computational chemistry ; Science ; Q
Language	English
Publishing date	2022-09-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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