TY - JOUR A1 - Abdelhameed, Reda F. A. A1 - Eltamany, Enas E. A1 - Hal, Dina M. A1 - Ibrahim, Amany K. A1 - AboulMagd, Asmaa M. A1 - Al-Warhi, Tarfah A1 - Youssif, Khayrya A. A1 - Abd El-kader, Adel M. A1 - Hassanean, Hashim A. A1 - Fayez, Shaimaa A1 - Bringmann, Gerhard A1 - Ahmed, Safwat A. A1 - Abdelmohsen, Usama Ramadan T1 - New cytotoxic cerebrosides from the Red Sea cucumber Holothuria spinifera supported by in-silico studies JF - Marine Drugs N2 - 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. KW - LC-HRESIMS KW - Holothuria spinifera KW - cerebrosides KW - molecular docking KW - cytotoxicity Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-211089 SN - 1660-3397 VL - 18 IS - 8 ER - TY - JOUR A1 - Eltamany, Enas E. A1 - Abdelmohsen, Usama Ramadan A1 - Hal, Dina M. A1 - Ibrahim, Amany K. A1 - Hassanean, Hashim A. A1 - Abdelhameed, Reda F. A. A1 - Temraz, Tarek A. A1 - Hajjar, Dina A1 - Makki, Arwa A. A1 - Hendawy, Omnia Magdy A1 - AboulMagd, Asmaa M. A1 - Youssif, Khayrya A. A1 - Bringmann, Gerhard A1 - Ahmed, Safwat A. T1 - Holospiniferoside: A New Antitumor Cerebroside from The Red Sea Cucumber Holothuria spinifera: In Vitro and In Silico Studies JF - Molecules N2 - 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. KW - Holothuria spinifera KW - HRMS KW - cerebrosides KW - molecular docking KW - cytotoxicity Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234058 SN - 1420-3049 VL - 26 IS - 6 ER - TY - JOUR A1 - Abdelhameed, Reda F. A. A1 - Habib, Eman S. A1 - Goda, Marwa S. A1 - Fahim, John Refaat A1 - Hassanean, Hashem A. A1 - Eltamany, Enas E. A1 - Ibrahim, Amany K. A1 - AboulMagd, Asmaa M. A1 - Fayez, Shaimaa A1 - Abd El-kader, Adel M. A1 - Al-Warhi, Tarfah A1 - Bringmann, Gerhard A1 - Ahmed, Safwat A. A1 - Abdelmohsen, Usama Ramadan T1 - Thalassosterol, a New Cytotoxic Aromatase Inhibitor Ergosterol Derivative from the Red Sea Seagrass Thalassodendron ciliatum JF - Marine Drugs N2 - 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. KW - cytotoxic activity KW - ergosterol derivative KW - metabolic analysis KW - docking studies KW - seagrass KW - Thalassodendron ciliatum Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236085 VL - 18 IS - 7 ER -