1353853-23-2Relevant academic research and scientific papers
Synthesis of Thymoquinone-Artemisinin Hybrids: New Potent Antileukemia, Antiviral, and Antimalarial Agents
Fr?hlich, Tony,Reiter, Christoph,Saeed, Mohamed E. M.,Hutterer, Corina,Hahn, Friedrich,Leidenberger, Maria,Friedrich, Oliver,Kappes, Barbara,Marschall, Manfred,Efferth, Thomas,Tsogoeva, Svetlana B.
, p. 534 - 539 (2018)
A series of hybrid compounds based on the natural products artemisinin and thymoquinone was synthesized and investigated for their biological activity against the malaria parasite Plasmodium falciparum 3D7 strain, human cytomegalovirus (HCMV), and two leukemia cell lines (drug-sensitive CCRF-CEM and multidrug-resistant subline CEM/ADR5000). An unprecedented one-pot method of selective formation of C-10α-acetate 14 starting from a 1:1 mixture of C-10α- to C-10β-dihydroartemisinin was developed. The key step of this facile method is a mild decarboxylative activation of malonic acid mediated by DCC/DMAP. Ether-linked thymoquinone-artemisinin hybrids 6a/b stood out as the most active compounds in all categories, while showing no toxic side effects toward healthy human foreskin fibroblasts and thus being selective. They exhibited EC50 values of 0.2 μM against the doxorubicin-sensitive as well as the multidrug-resistant leukemia cells and therefore can be regarded as superior to doxorubicin. Moreover, they showed to be five times more active than the standard drug ganciclovir and nearly eight times more active than artesunic acid against HCMV. In addition, hybrids 6a/b possessed excellent antimalarial activity (EC50 = 5.9/3.7 nM), which was better than that of artesunic acid (EC50 = 8.2 nM) and chloroquine (EC50 = 9.8 nM). Overall, most of the presented thymoquinone-artemisinin-based hybrids exhibit an excellent and broad variety of biological activities (anticancer, antimalarial, and antiviral) combined with a low toxicity/high selectivity profile.
Synthesis of Novel Hybrids of Thymoquinone and Artemisinin with High Activity and Selectivity Against Colon Cancer
Fr?hlich, Tony,Ndreshkjana, Benardina,Muenzner, Julienne K.,Reiter, Christoph,Hofmeister, Elisabeth,Mederer, Sandra,Fatfat, Maamoun,El-Baba, Chirine,Gali-Muhtasib, Hala,Schneider-Stock, Regine,Tsogoeva, Svetlana B.
, p. 226 - 234 (2017)
Colorectal cancer causes 0.5 million deaths each year. To combat this type of cancer the development of new specific drug candidates is urgently needed. In the present work seven novel thymoquinone–artemisinin hybrids with different linkers were synthesized and tested for their in vitro anticancer activity against a panel of various tumor cell lines. The thymoquinone–artesunic acid hybrid 7 a, in which both subunits are connected via an ester bond, was found to be the most active compound and selectively decreased the viability of colorectal cancer cells with an IC50value of 2.4 μm (HCT116) and 2.8 μm (HT29). Remarkably, hybrid 7 a was up to 20-fold more active than its parent compounds (thymoquinone and artesunic acid), while not affecting nonmalignant colon epithelial HCEC cells (IC50>100 μm). Moreover, the activity of hybrid 7 a was superior to that of various 1:1 mixtures of thymoquinone and artesunic acid. Furthermore, hybrid 7 a was even more potent against both colon cancer cell lines than the clinically used drug 5-fluorouracil. These results are another excellent proof of the hybridization concept and confirm that the type and length of the linker play a crucial role for the biological activity of a hybrid drug. Besides an increase in reactive oxygen species (ROS), elevated levels of the DNA-damage marker γ-H2AX were observed. Both effects seem to be involved in the molecular mechanism of action for hybrid 7 a in colorectal cancer cells.
Terpene conjugates of the Nigella sativa seed-oil constituent thymoquinone with enhanced efficacy in cancer cells
Effenberger, Katharina,Breyer, Sandra,Schobert, Rainer
experimental part, p. 129 - 139 (2010/04/23)
Thymoquinone (TQ; 1) is a weak anticancer constituent of black seed oil. Derivatives bearing terpene-terminated 6-alkyl residues were tested in cells of human HL-60 leukemia, 518A2 melanoma, multidrug-resistant KB-V1/Vbl cervix, and MCF-7/Topo breast carcinomas, as well as in non-malignant human foreskin fibroblasts. Derivatives with a short four-atom spacer between quinone and cyclic monoterpene moieties were more antiproliferative than analogues with longer spacers. 6-(Menthoxybutyryl) thymoquinone (3a) exhibited single-digit micromolar IC50 (72 h) values in all four cell lines. It was seven times more active than TQ (1) in 518A2 melanoma cells and four times in KB-V1/Vbl cervix carcinoma cells, while only half as toxic in the fibroblasts. Compound 3a was also not a substrate for the Pgp and BCRP drug transporters of the resistant cancer cells. The caryophyllyl and germacryl conjugates 3e and 3f specifically inhibited the growth of the resistant MCF-7 breast carcinoma cells. Conjugation of TQ with the triterpene betulinic acid via the OH group as in 3g led to a loss in activity, while conjugation via the carboxylic acid afforded compound 4 with nanomolar IC50 (72 h) activity against HL-60 cells. All anticancer-active derivatives of TQ (1) induced apoptosis associated with DNA laddering, a decrease in mitochondrial membrane potential and a slight increase in reactive oxygen species.
