@article{FayezBruhnFeineisetal.2022, author = {Fayez, Shaimaa and Bruhn, Torsten and Feineis, Doris and Assi, Laurent Ak{\´e} and Kushwaha, Prem Prakash and Kumar, Shashank and Bringmann, Gerhard}, title = {Naphthylisoindolinone alkaloids: the first ring-contracted naphthylisoquinolines, from the tropical liana Ancistrocladus abbreviatus, with cytotoxic activity}, series = {RSC Advances}, volume = {12}, journal = {RSC Advances}, number = {45}, doi = {10.1039/d2ra05758a}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300766}, pages = {28916-28928}, year = {2022}, abstract = {The West African liana Ancistrocladus abbreviatus is a rich source of structurally most diverse naphthylisoquinoline alkaloids. From its roots, a series of four novel representatives, named ancistrobrevolines A-D (14-17) have now been isolated, displaying an unprecedented heterocyclic ring system, where the usual isoquinoline entity is replaced by a ring-contracted isoindolinone part. Their constitutions were elucidated by 1D and 2D NMR and HR-ESI-MS. The absolute configurations at the chiral axis and at the stereogenic center were assigned by using experimental and computational electronic circular dichroism (ECD) investigations and a ruthenium-mediated oxidative degradation, respectively. For the biosynthetic origin of the isoindolinones from 'normal' naphthyltetrahydroisoquinolines, a hypothetic pathway is presented. It involves oxidative decarboxylation steps leading to a ring contraction by a benzilic acid rearrangement. Ancistrobrevolines A (14) and B (15) were found to display moderate cytotoxic effects (up to 72\%) against MCF-7 breast and A549 lung cancer cells and to reduce the formation of spheroids (mammospheres) in the breast cancer cell line.}, language = {en} } @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{AbdelhameedHabibEltahawyetal.2020, author = {Abdelhameed, Reda F. A. and Habib, Eman S. and Eltahawy, Nermeen A. and Hassanean, Hashim A. and Ibrahim, Amany K. and Mohammed, Anber F. and Fayez, Shaimaa and Hayallah, Alaa M. and Yamada, Koji and Behery, Fathy A. and Al-Sanea, Mohammad M. and Alzarea, Sami I. and Bringmann, Gerhard and Ahmed, Safwat A. and Abdelmohsen, Usama Ramadan}, title = {New cytotoxic natural products from the Red Sea sponge Stylissa carteri}, series = {Marine Drugs}, volume = {18}, journal = {Marine Drugs}, number = {5}, issn = {1660-3397}, doi = {10.3390/md18050241}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-205795}, year = {2020}, abstract = {Bioactivity-guided isolation supported by LC-HRESIMS metabolic profiling led to the isolation of two new compounds, a ceramide, stylissamide A (1), and a cerebroside, stylissoside A (2), from the methanol extract of the Red Sea sponge Stylissa carteri. Structure elucidation was achieved using spectroscopic techniques, including 1D and 2D NMR and HRMS. The bioactive extract's metabolomic profiling showed the existence of various secondary metabolites, mainly oleanane-type saponins, phenolic diterpenes, and lupane triterpenes. The in vitro cytotoxic activity of the isolated compounds was tested against two human cancer cell lines, MCF-7 and HepG2. Both compounds, 1 and 2, displayed strong cytotoxicity against the MCF-7 cell line, with IC\(_{50}\) values at 21.1 ± 0.17 µM and 27.5 ± 0.18 µM, respectively. They likewise showed a promising activity against HepG2 with IC\(_{50}\) at 36.8 ± 0.16 µM for 1 and IC\(_{50}\) 30.5 ± 0.23 µM for 2 compared to the standard drug cisplatin. Molecular docking experiments showed that 1 and 2 displayed high affinity to the SET protein and to inhibitor 2 of protein phosphatase 2A (I2PP2A), which could be a possible mechanism for their cytotoxic activity. This paper spreads light on the role of these metabolites in holding fouling organisms away from the outer surface of the sponge, and the potential use of these defensive molecules in the production of novel anticancer agents.}, language = {en} } @article{EltamanyAbdelmohsenHaletal.2021, author = {Eltamany, Enas E. and Abdelmohsen, Usama Ramadan and Hal, Dina M. and Ibrahim, Amany K. and Hassanean, Hashim A. and Abdelhameed, Reda F. A. and Temraz, Tarek A. and Hajjar, Dina and Makki, Arwa A. and Hendawy, Omnia Magdy and AboulMagd, Asmaa M. and Youssif, Khayrya A. and Bringmann, Gerhard and Ahmed, Safwat A.}, title = {Holospiniferoside: A New Antitumor Cerebroside from The Red Sea Cucumber Holothuria spinifera: In Vitro and In Silico Studies}, series = {Molecules}, volume = {26}, journal = {Molecules}, number = {6}, issn = {1420-3049}, doi = {10.3390/molecules26061555}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234058}, year = {2021}, abstract = {Chemical investigation of the methanolic extract of the Red Sea cucumber Holothuria spinifera led to the isolation of a new cerebroside, holospiniferoside (1), together with thymidine (2), methyl-α-d-glucopyranoside (3), a new triacylglycerol (4), and cholesterol (5). Their chemical structures were established by NMR and mass spectrometric analysis, including gas chromatography-mass spectrometry (GC-MS) and high-resolution mass spectrometry (HRMS). All the isolated compounds are reported in this species for the first time. Moreover, compound 1 exhibited promising in vitro antiproliferative effect on the human breast cancer cell line (MCF-7) with IC\(_{50}\) of 20.6 µM compared to the IC50 of 15.3 µM for the drug cisplatin. To predict the possible mechanism underlying the cytotoxicity of compound 1, a docking study was performed to elucidate its binding interactions with the active site of the protein Mdm2-p53. Compound 1 displayed an apoptotic activity via strong interaction with the active site of the target protein. This study highlights the importance of marine natural products in the design of new anticancer agents.}, language = {en} } @article{HofmannFayezScheineretal.2020, author = {Hofmann, Julian and Fayez, Shaimaa and Scheiner, Matthias and Hoffmann, Matthias and Oerter, Sabrina and Appelt-Menzel, Antje and Maher, Pamela and Maurice, Tangui and Bringmann, Gerhard and Decker, Michael}, title = {Sterubin: Enantioresolution and Configurational Stability, Enantiomeric Purity in Nature, and Neuroprotective Activity in Vitro and in Vivo}, series = {Chemistry - A European Journal}, volume = {26}, journal = {Chemistry - A European Journal}, number = {32}, doi = {10.1002/chem.202001264}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-215993}, pages = {7299 -- 7308}, year = {2020}, abstract = {Alzheimer′s disease (AD) is a neurological disorder with still no preventive or curative treatment. Flavonoids are phytochemicals with potential therapeutic value. Previous studies described the flavanone sterubin isolated from the Californian plant Eriodictyon californicum as a potent neuroprotectant in several in vitro assays. Herein, the resolution of synthetic racemic sterubin (1) into its two enantiomers, (R)-1 and (S)-1, is described, which has been performed on a chiral chromatographic phase, and their stereochemical assignment online by HPLC-ECD coupling. (R)-1 and (S)-1 showed comparable neuroprotection in vitro with no significant differences. While the pure stereoisomers were configurationally stable in methanol, fast racemization was observed in the presence of culture medium. We also established the occurrence of extracted sterubin as its pure (S)-enantiomer. Moreover, the activity of sterubin (1) was investigated for the first time in vivo, in an AD mouse model. Sterubin (1) showed a significant positive impact on short- and long-term memory at low dosages.}, language = {en} } @article{AbdelhameedHabibGodaetal.2020, author = {Abdelhameed, Reda F. A. and Habib, Eman S. and Goda, Marwa S. and Fahim, John Refaat and Hassanean, Hashem A. and Eltamany, Enas E. and Ibrahim, Amany K. and AboulMagd, Asmaa M. and Fayez, Shaimaa and Abd El-kader, Adel M. and Al-Warhi, Tarfah and Bringmann, Gerhard and Ahmed, Safwat A. and Abdelmohsen, Usama Ramadan}, title = {Thalassosterol, a New Cytotoxic Aromatase Inhibitor Ergosterol Derivative from the Red Sea Seagrass Thalassodendron ciliatum}, series = {Marine Drugs}, volume = {18}, journal = {Marine Drugs}, number = {7}, doi = {10.3390/md18070354}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236085}, year = {2020}, abstract = {Thalassodendron ciliatum (Forssk.) Den Hartog is a seagrass belonging to the plant family Cymodoceaceae with ubiquitous phytoconstituents and important pharmacological potential, including antioxidant, antiviral, and cytotoxic activities. In this work, a new ergosterol derivative named thalassosterol (1) was isolated from the methanolic extract of T. ciliatum growing in the Red Sea, along with two known first-reported sterols, namely ergosterol (2) and stigmasterol (3), using different chromatographic techniques. The structure of the new compound was established based on 1D and 2D NMR spectroscopy and high-resolution mass spectrometry (HR-MS) and by comparison with the literature data. The new ergosterol derivative showed significant in vitro antiproliferative potential against the human cervical cancer cell line (HeLa) and human breast cancer (MCF-7) cell lines, with IC\(_{50}\) values of 8.12 and 14.24 µM, respectively. In addition, docking studies on the new sterol 1 explained the possible binding interactions with an aromatase enzyme; this inhibition is beneficial in both cervical and breast cancer therapy. A metabolic analysis of the crude extract of T. ciliatum using liquid chromatography combined with high-resolution electrospray ionization mass spectrometry (LC-ESI-HR-MS) revealed the presence of an array of phenolic compounds, sterols and ceramides, as well as di- and triglycerides.}, language = {en} } @article{AbdelhameedEltamanyHaletal.2020, author = {Abdelhameed, Reda F. A. and Eltamany, Enas E. and Hal, Dina M. and Ibrahim, Amany K. and AboulMagd, Asmaa M. and Al-Warhi, Tarfah and Youssif, Khayrya A. and Abd El-kader, Adel M. and Hassanean, Hashim A. and Fayez, Shaimaa and Bringmann, Gerhard and Ahmed, Safwat A. and Abdelmohsen, Usama Ramadan}, title = {New cytotoxic cerebrosides from the Red Sea cucumber Holothuria spinifera supported by in-silico studies}, series = {Marine Drugs}, volume = {18}, journal = {Marine Drugs}, number = {8}, issn = {1660-3397}, doi = {10.3390/md18080405}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211089}, year = {2020}, abstract = {Bioactivity-guided fractionation of a methanolic extract of the Red Sea cucumber Holothuria spinifera and LC-HRESIMS-assisted dereplication resulted in the isolation of four compounds, three new cerebrosides, spiniferosides A (1), B (2), and C (3), and cholesterol sulfate (4). The chemical structures of the isolated compounds were established on the basis of their 1D NMR and HRMS spectral data. Metabolic profiling of the H. spinifera extract indicated the presence of diverse secondary metabolites, mostly hydroxy fatty acids, diterpenes, triterpenes, and cerebrosides. The isolated compounds were tested for their in vitro cytotoxicities against the breast adenocarcinoma MCF-7 cell line. Compounds 1, 2, 3, and 4 displayed promising cytotoxic activities against MCF-7 cells, with IC\(_{50}\) values of 13.83, 8.13, 8.27, and 35.56 µM, respectively, compared to that of the standard drug doxorubicin (IC\(_{50}\) 8.64 µM). Additionally, docking studies were performed for compounds 1, 2, 3, and 4 to elucidate their binding interactions with the active site of the SET protein, an inhibitor of protein phosphatase 2A (PP2A), which could explain their cytotoxic activity. This study highlights the important role of these metabolites in the defense mechanism of the sea cucumber against fouling organisms and the potential uses of these active molecules in the design of new anticancer agents.}, language = {en} } @article{ZahranAlbohyKhaliletal.2020, author = {Zahran, Eman Maher and Albohy, Amgad and Khalil, Amira and Ibrahim, Alyaa Hatem and Ahmed, Heba Ali and El-Hossary, Ebaa M. and Bringmann, Gerhard and Abdelmohsen, Usama Ramadan}, title = {Bioactivity Potential of Marine Natural Products from Scleractinia-Associated Microbes and In Silico Anti-SARS-COV-2 Evaluation}, series = {Marine Drugs}, volume = {18}, journal = {Marine Drugs}, number = {12}, issn = {1660-3397}, doi = {10.3390/md18120645}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-220041}, year = {2020}, abstract = {Marine organisms and their associated microbes are rich in diverse chemical leads. With the development of marine biotechnology, a considerable number of research activities are focused on marine bacteria and fungi-derived bioactive compounds. Marine bacteria and fungi are ranked on the top of the hierarchy of all organisms, as they are responsible for producing a wide range of bioactive secondary metabolites with possible pharmaceutical applications. Thus, they have the potential to provide future drugs against challenging diseases, such as cancer, a range of viral diseases, malaria, and inflammation. This review aims at describing the literature on secondary metabolites that have been obtained from Scleractinian-associated organisms including bacteria, fungi, and zooxanthellae, with full coverage of the period from 1982 to 2020, as well as illustrating their biological activities and structure activity relationship (SAR). Moreover, all these compounds were filtered based on ADME analysis to determine their physicochemical properties, and 15 compounds were selected. The selected compounds were virtually investigated for potential inhibition for SARS-CoV-2 targets using molecular docking studies. Promising potential results against SARS-CoV-2 RNA dependent RNA polymerase (RdRp) and methyltransferase (nsp16) are presented.}, language = {en} } @article{FayezFeineisMudogoetal.2017, author = {Fayez, Shaimaa and Feineis, Doris and Mudogo, Virima and Awale, Suresh and Bringmann, Gerhard}, title = {Ancistrolikokines E-H and related 5,8\('\)-coupled naphthylisoquinoline alkaloids from the Congolese liana \(Ancistrocladus\) \(likoko\) with antiausterity activities against PANC-1 human pancreatic cancer cells}, series = {RSC Advances}, volume = {7}, journal = {RSC Advances}, number = {85}, doi = {10.1039/c7ra11200a}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172008}, pages = {53740-53751}, year = {2017}, abstract = {A striking feature of the metabolite profile of \(Ancistrocladus\) \(likoko\) (Ancistrocladaceae) is the exclusive production of 5,8\('\)-linked naphthylisoquinoline alkaloids varying in their OMe/OH substitution patterns and in the hydrogenation degree in their isoquinoline portions. Here we present nine new compounds of this coupling type isolated from the twigs of this remarkable Central African liana. Three of them, the ancistrolikokines E (9), E\(_2\) (10), and F (11), are the first 5,8\('\)-linked naphthyldihydroisoquinolines found in nature with \(R\)-configuration at C-3. The fourth new metabolite, ancistrolikokine G (12), is so far the only representative of the 5,8\('\)-coupling type that belongs to the very rare group of alkaloids with a fully dehydrogenated isoquinoline portion. Moreover, five new \(N\)-methylated naphthyltetrahydroisoquinolines, named ancistrolikokines A\(_2\) (13), A\(_3\) (14), C\(_2\) (5), H (15), and H\(_2\) (16) are presented, along with six known 5,8\('\)-linked alkaloids, previously identified in related African \(Ancistrocladus\) species, now found for the first time in \(A.\) \(likoko\). The structural elucidation was achieved by spectroscopic analysis (HRESIMS, 1D and 2D NMR) and by chemical (oxidative degradation) and chiroptical (electronic circular dichroism) methods. The new ancistrolikokines showed moderate to good preferential cytotoxic activities towards pancreatic PANC-1 cells in nutrient-deprived medium (NDM), without causing toxicity under normal, nutrient-rich conditions, with ancistrolikokine H\(_2\) (16) being the most potent compound.}, language = {en} } @article{FayezFeineisAkeAssietal.2019, author = {Fayez, Shaimaa and Feineis, Doris and Ak{\´e} Assi, Laurent and Seo, Ean-Jeong and Efferth, Thomas and Bringmann, Gerhard}, title = {Ancistrobreveines A-D and related dehydrogenated naphthylisoquinoline alkaloids with antiproliferative activities against leukemia cells, from the West African liana Ancistrocladus abbreviatus}, series = {RSC Advances}, volume = {9}, journal = {RSC Advances}, number = {28}, doi = {10.1039/C9RA03105G}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201686}, pages = {15738-15748}, year = {2019}, abstract = {A unique series of six biaryl natural products displaying four different coupling types (5,10 , 7,10 , 7,80 , and 5,80) were isolated from the roots of the West African liana Ancistrocladus abbreviatus (Ancistrocladaceae). Although at first sight structurally diverse, these secondary metabolites all have in common that they belong to the rare group of naphthylisoquinoline alkaloids with a fully dehydrogenated isoquinoline portion. Among the African Ancistrocladus species, A. abbreviatus is so far only the second one that was found to produce compounds with such a molecular entity. Here, we report on four new representatives, named ancistrobreveines A-D (12-14, and 6). They were identified along with the two known alkaloids 6-O-methylhamateine (4) and entdioncophylleine A (10). The two latter naphthylisoquinolines had so far only been detected in Ancistrocladus species from Southeast Asia. All of these fully dehydrogenated alkaloids have in common being optically active despite the absence of stereogenic centers, due to the presence of the rotationally hindered biaryl axis as the only element of chirality. Except for ent-dioncophylleine A (10), which lacks an oxygen function at C-6, the ancistrobreveines A-D (12-14, and 6) and 6-O-methylhamateine (4) are 6-oxygenated alkaloids, and are, thus, typical 'Ancistrocladaceae-type' compounds. Ancistrobreveine C (14), is the first - and so far only - example of a 7,80-linked fully dehydrogenated naphthylisoquinoline discovered in nature that is configurationally stable at the biaryl axis. The stereostructures of the new alkaloids were established by spectroscopic (in particular HRESIMS, 1D and 2D NMR) and chiroptical (electronic circular dichroism) methods. Ancistrobreveine C (14) and 6-O-methylhamateine (4) exhibited strong antiproliferative activities against drug-sensitive acute lymphoblastic CCRF-CEM leukemia cells and their multidrugresistant subline, CEM/ADR5000.}, language = {en} }