Search results for "naphthoquinone"

Theileria parasites secrete a prolyl isomerase to maintain host leukocyte transformation

2015

Infectious agents develop intricate mechanisms to interact with host cell pathways and hijack their genetic and epigenetic machinery to change host cell phenotypic states. Among the Apicomplexa phylum of obligate intracellular parasites, which cause veterinary and human diseases, Theileria is the only genus that transforms its mammalian host cells. Theileria infection of bovine leukocytes induces proliferative and invasive phenotypes associated with activated signalling pathways, notably JNK and AP-1 (ref. 2). The transformed phenotypes are reversed by treatment with the theilericidal drug buparvaquone. We used comparative genomics to identify a homologue of the peptidyl-prolyl isomerase PI…

Shikonin promotes intestinal wound healing in vitro via induction of TGF-β release in IEC-18 cells

2013

The intestinal barrier is a complex system with a dynamic structure that is designed for the maintenance of homeostasis in healthy individuals. Ulcerative colitis, one of the main manifestations of inflammatory bowel disease, is characterized by an inadequate and delayed wound healing. Shikonin, the active principle in the root of Lithospermum erythrorhizon, has demonstrated its ability to attenuate dextran sulfate sodium-induced ulcerative colitis in mice. Moreover, the root of L. erythrorhizon has been used in traditional Chinese medicine for treatment of burns, anal ulcers, hemorrhoids and skin wounds. However, the effect of shikonin on intestinal wound healing is unknown. Using an in vi…

Inhibition of the mutagenicity of 2-nitrofluorene, 3-nitrofluoranthene and 1-nitropyrene by flavonoids, coumarins, quinones and other phenolic compou…

1997

When 56 flavonoids, 32 coumarins, five naphthoquinones, 12 anthraquinones and five structurally-related compounds were tested for their antimutagenic potencies with respect to mutagenicities induced by 2-nitrofluorene (2-NF), 3-nitrofluoranthene (3-NFA) and 1-nitropyrene (1-NP) in Salmonella typhimurium TA98 distinct structure-activity relationships were detected. First, the tetracyclic nitroarenes 3-NFA and 1-NP were in general more effectively antagonized by potent antimutagenic flavonoids and coumarins than the tricyclic 2-NF, while there were only minor differences with quinones. Secondly, antimutagenicity of natural compounds of plant origin correlated with the aglyconic nature 10 of a…

CCDC 945346: Experimental Crystal Structure Determination

2013

Related Article: Sonja Schwolow, Horst Kunz, Joachim Rheinheimer, Till Opatz|2013|Eur.J.Org.Chem.|2013|6519|doi:10.1002/ejoc.201301088

CCDC 945345: Experimental Crystal Structure Determination

2013

Related Article: Sonja Schwolow, Horst Kunz, Joachim Rheinheimer, Till Opatz|2013|Eur.J.Org.Chem.|2013|6519|doi:10.1002/ejoc.201301088

Synthesis and cytotoxicity of 6,11-Dihydro-pyrido- and 6,11-Dihydro-benzo[2,3-b]phenazine-6,11-dione derivatives

2003

6,11-Dihydro-pyrido[2,3-b]phenazine-6,11-diones and 6,11-dihydro-benzo[2,3-b]phenazine-6,11-diones were synthesized from 6,7-dichloro-5,8-quinolinedione and 2,3-dichloro-1,4-naphthoquinone. The study on the cytotoxicity on these products revealed that the pyridophenazinediones, tetracyclic heteroquinone analogues with three nitrogen atoms exhibited a high cytotoxicity on several human tumor cell lines. Compound 9c and 9e showed in vitro antitumor activity comparable or superior to doxorubicin against the human ovarian tumor cells (SK-OV-3) and the human CNS cells (XF 498). The IC(50) value for compound 9e was 0.06 microM against the human CNS cells (XF 498), which was 2.6 times higher than …

Crystal structure of 4-[(adamantan-1-yl)amino]­naphthalene-1,2-dione

2019

The title compound, an example of a stable 1,2-naphtho­quinone, illustrates steric buttressing of the adamantanyl group.

Paclitaxel and beta-lapachone synergistically induce apoptosis in human retinoblastoma Y79 cells by downregulating the levels of phospho-Akt.

2009

Paclitaxel (PTX) and beta-lapachone (LPC) are naturally occurring compounds that have shown a large spectrum of anticancer activity. In this article we show for the first time that PTX/LPC combination induces potent synergistic apoptotic effects in human retinoblastoma Y79 cells. Combination of suboptimal doses of PTX (0.3 nM) and LPC (1.5 microM) caused biochemical and morphological signs of apoptosis at 48 h of treatment. These effects were accompanied by potent lowering in inhibitor of apoptosis proteins and by activation of Bid and caspases 3 and 6 with lamin B and PARP breakdown. PTX/LPC combination acted by favoring p53 stabilization through a lowering in p-Akt levels and in ps166-MDM…

1,4-Naphthoquinones as inducers of oxidative damage and stress signaling in HaCaT human keratinocytes.

2010

Selected biological effects of 1,4-naphthoquinone, menadione (2-methyl-1,4-naphthoquinone) and structurally related quinones from natural sources--the 5-hydroxy-naphthoquinones juglone, plumbagin and the 2-hydroxy-naphthoquinones lawsone and lapachol--were studied in human keratinocytes (HaCaT). 1,4-naphthoquinone and menadione as well as juglone and plumbagin were highly cytotoxic, strongly induced reactive oxygen species (ROS) formation and depleted cellular glutathione. Moreover, they induced oxidative DNA base damage and accumulation of DNA strand breaks, as demonstrated in an alkaline DNA unwinding assay. Neither lawsone nor lapachol (up to 100 microM) were active in any of these assay…

2020

The facile synthesis and detailed investigation of a class of highly potent protease inhibitors based on 1,4-naphthoquinones with a dipeptidic recognition motif (HN-l-Phe-l-Leu-OR) in the 2-position and an electron-withdrawing group (EWG) in the 3-position is presented. One of the compound representatives, namely the acid with EWG = CN and with R = H proved to be a highly potent rhodesain inhibitor with nanomolar affinity. The respective benzyl ester (R = Bn) was found to be hydrolyzed by the target enzyme itself yielding the free acid. Detailed kinetic and mass spectrometry studies revealed a reversible covalent binding mode. Theoretical calculations with different density functionals (DFT…