@article{RushdiAbdelRahmanAttiaetal.2022, author = {Rushdi, Mohammed I. and Abdel-Rahman, Iman A. M. and Attia, Eman Zekry and Saber, Hani and Saber, Abdullah A. and Bringmann, Gerhard and Abdelmohsen, Usama Ramadan}, title = {The biodiversity of the genus Dictyota: phytochemical and pharmacological natural products prospectives}, series = {Molecules}, volume = {27}, journal = {Molecules}, number = {3}, issn = {1420-3049}, doi = {10.3390/molecules27030672}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-302428}, year = {2022}, abstract = {Although a broad variety of classes of bioactive compounds have already been isolated from seaweeds of the genus Dictyota, most different species are still chemically and biologically unexplored. Dictyota species are well-known brown seaweeds belonging to the Dictyotaceae (Phaeophyta). The phytochemical composition within the genus Dictyota has recently received considerable interest, and a vast array of components, including diterpenes, sesquiterepenes, sterols, amino acids, as well as saturated and polyunsaturated fatty acids, have been characterized. The contribution of these valued metabolites to the biological potential, which includes anti-proliferative, anti-microbial, antiviral, antioxidant, anti-inflammatory, and anti-hyperpigmentation activities, of the genus Dictyota has also been explored. Therefore, this is the most comprehensive review, focusing on the published literature relevant to the chemically and pharmacologically diverse biopharmaceuticals isolated from different species of the genus Dictyota during the period from 1976 to now.}, language = {en} } @article{HofmannGinexEspargaroetal.2021, author = {Hofmann, Julian and Ginex, Tiziana and Espargar{\´o}, Alba and Scheiner, Matthias and Gunesch, Sandra and Arag{\´o}, Marc and Stigloher, Christian and Sabat{\´e}, Raimon and Luque, F. Javier and Decker, Michael}, title = {Azobioisosteres of Curcumin with Pronounced Activity against Amyloid Aggregation, Intracellular Oxidative Stress, and Neuroinflammation}, series = {Chemistry - A European Journal}, volume = {27}, journal = {Chemistry - A European Journal}, number = {19}, doi = {10.1002/chem.202005263}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238988}, pages = {6015 -- 6027}, year = {2021}, abstract = {Many (poly-)phenolic natural products, for example, curcumin and taxifolin, have been studied for their activity against specific hallmarks of neurodegeneration, such as amyloid-β 42 (Aβ42) aggregation and neuroinflammation. Due to their drawbacks, arising from poor pharmacokinetics, rapid metabolism, and even instability in aqueous medium, the biological activity of azobenzene compounds carrying a pharmacophoric catechol group, which have been designed as bioisoteres of curcumin has been examined. Molecular simulations reveal the ability of these compounds to form a hydrophobic cluster with Aβ42, which adopts different folds, affecting the propensity to populate fibril-like conformations. Furthermore, the curcumin bioisosteres exceeded the parent compound in activity against Aβ42 aggregation inhibition, glutamate-induced intracellular oxidative stress in HT22 cells, and neuroinflammation in microglial BV-2 cells. The most active compound prevented apoptosis of HT22 cells at a concentration of 2.5 μm (83 \% cell survival), whereas curcumin only showed very low protection at 10 μm (21 \% cell survival).}, language = {en} } @article{SawatzkyDrakopoulosRoelzetal.2016, author = {Sawatzky, Edgar and Drakopoulos, Antonios and R{\"o}lz, Martin and Sotriffer, Christoph and Engels, Bernd and Decker, Michael}, title = {Experimental and theoretical investigations into the stability of cyclic aminals}, series = {Beilstein Journal of Organic Chemistry}, volume = {12}, journal = {Beilstein Journal of Organic Chemistry}, doi = {10.3762/bjoc.12.221}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-160976}, pages = {2280-2292}, year = {2016}, abstract = {Background: Cyclic aminals are core features of natural products, drug molecules and important synthetic intermediates. Despite their relevance, systematic investigations into their stability towards hydrolysis depending on the pH value are lacking. Results: A set of cyclic aminals was synthesized and their stability quantified by kinetic measurements. Steric and electronic effects were investigated by choosing appropriate groups. Both molecular mechanics (MM) and density functional theory (DFT) based studies were applied to support and explain the results obtained. Rapid decomposition is observed in acidic aqueous media for all cyclic aminals which occurs as a reversible reaction. Electronic effects do not seem relevant with regard to stability, but the magnitude of the conformational energy of the ring system and pK a values of the N-3 nitrogen atom. Conclusion: Cyclic aminals are stable compounds when not exposed to acidic media and their stability is mainly dependent on the conformational energy of the ring system. Therefore, for the preparation and work-up of these valuable synthetic intermediates and natural products, appropriate conditions have to be chosen and for application as drug molecules their sensitivity towards hydrolysis has to be taken into account.}, language = {en} } @phdthesis{Glaser2015, author = {Glaser, Jan}, title = {Antileishmanial compounds from Nature - Elucidation of the active principles of an extract from Valeriana wallichii rhizomes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129140}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2015}, abstract = {This study is dealing with the bioactivity-guided fractionation of a chloroform extract from pulverized rhizomes of Valeriana wallichii with focus on isolation and structure elucidation of the antileishmanial active principles.}, subject = {Leishmaniose}, language = {en} } @article{DashtiGrkovicAbdelmohsenetal.2014, author = {Dashti, Yousef and Grkovic, Tanja and Abdelmohsen, Usama Ramadan and Hentschel, Ute and Quinn, Ronald J.}, title = {Production of Induced Secondary Metabolites by a Co-Culture of Sponge-Associated Actinomycetes, Actinokineospora sp EG49 and Nocardiopsis sp RV163}, series = {MARINE DRUGS}, volume = {12}, journal = {MARINE DRUGS}, number = {5}, issn = {1660-3397}, doi = {10.3390/md12053046}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-116547}, pages = {3046-3059}, year = {2014}, abstract = {Two sponge-derived actinomycetes, Actinokineospora sp. EG49 and Nocardiopsis sp. RV163, were grown in co-culture and the presence of induced metabolites monitored by H-1 NMR. Ten known compounds, including angucycline, diketopiperazine and beta-carboline derivatives 1-10, were isolated from the EtOAc extracts of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163. Co-cultivation of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163 induced the biosynthesis of three natural products that were not detected in the single culture of either microorganism, namely N-(2-hydroxyphenyl)-acetamide (11), 1,6-dihydroxyphenazine (12) and 5a, 6,11a, 12-tetrahydro-5a, 11a-dimethyl[1,4]benzoxazino[3,2-b][1,4]benzoxazine (13a). When tested for biological activity against a range of bacteria and parasites, only the phenazine 12 was active against Bacillus sp. P25, Trypanosoma brucei and interestingly, against Actinokineospora sp. EG49. These findings highlight the co-cultivation approach as an effective strategy to access the bioactive secondary metabolites hidden in the genomes of marine actinomycetes.}, language = {en} } @phdthesis{Rummey2002, author = {Rummey, Christian}, title = {3D-QSAR-Untersuchungen an antimalaria-aktiven Naphthylisochinolin-Alkaloiden}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-4599}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2002}, abstract = {Aufbauend auf einen Datensatz von etwa 70 antimalaria-aktiven Verbindungen wurde mit Hilfe des CoMSIA-Verfahrens ein QSAR(Qantitative Structure Activity Relationship)-Modell erstellt, das in der Lage ist antiplasmodiale Aktivit{\"a}ten von Verbindungen aus der Substanzklasse der Naphthylisochinolin-Alkaloide vorherzusagen. Da die behandelten Strukturen ein sehr kompliziertes konformatives Verhalten aufweisen, mussten f{\"u}r ein m{\"o}glichst flexibles Alignment (unter Verwendung von FLEXS und GASP) eigene Abl{\"a}ufe entwickelt werden, die schließlich weitestgehend automatisiert werden konnten. Das erstellte Modell erlaubte es dar{\"u}ber hinaus, die f{\"u}r die Aktivit{\"a}t verantwortlichen strukturellen Merkmale zu identifizieren und so entscheidende Anregungen zur Vereinfachung des relativ komplizierten Grundger{\"u}sts zu geben. Die Vorschl{\"a}ge wurden zu einem großen Teil bereits synthetisch verwirklicht, wobei die anschließend experimentell gefundenen Aktivit{\"a}ten die vorher berechneten sehr gut best{\"a}tigten. Die neu entwickelten Substanzen befinden sich derzeit im Patentpr{\"u}fungsverfahren.}, subject = {Malaria}, language = {de} }