15455-20-6Relevant articles and documents
Electron Transfer in Linked Viologen-Quinone Molecules: Rate Constant Enhancement with Increased Chain Length
Brun, A. M.,Hubig, S. M.,Rodgers, M. A. J.,Wade, W. H.
, p. 710 - 715 (1992)
We synthesized a homologous series of molecules (MVnn'Q) where a methylviologen (MV) and a aminochloronaphthoquinone (Q) are linked to each other via a flexible chain.Using the electron pulse radiolysis technique, we have measured time-resolved spectra and rate constants for intra- and intermolecular electron transfer between donor and acceptor site of the MVnn'Q molecules in water and in SDS micellar solution.For comparison, we also irradiated a solution containing a 1:1 mixture of methylviologen and aminochloronaphthoquinone and measured spectra and intermolecular ET reactions between the separated electron donor and acceptor molecules.The intramolecular electron transfer rate constants of all MVnn'Q molecules were surprisingly low both in water and in aqueous SDS micellar suspensions.The intramolecular rate constants measured in water increase with increasing number of intervening bonds, leading to the conclusion that electron transfer occurs by a through-space rather than through-bond mechanism.The intramolecular rate constants virtually lose their chain length dependence in SDS suspensions where because of an extended configuration of the micelled MVnn'Q molecules through-space interaction is not favored.
A simple synthesis of 3,4-dihydrobenzo[f]quinoxalin-6(2H)-one derivatives substituted in the ring B
Castro-Castillo, Vicente,Suárez-Rozas, Cristian,Simpson, Sebastián,Barriga-González, Andrés
, p. 553 - 559 (2017/08/30)
[Figure not available: see fulltext.] We followed a simple, inexpensive, and efficient route to synthesize a series of 3,4-dihydrobenzo[f]quinoxalin-6(2H)-one derivatives substituted in the ring B, with the expectation that this scaffold might exhibit antineoplastic activity. 5-Chlorobenzo[f]quinoxalin-6-ylacetate and 4-benzylbenzo[f]quinoxalin-6(4H)-one were obtained for the first time.
Antiproliferative, DNA intercalation and redox cycling activities of dioxonaphtho[2,3-d]imidazolium analogs of YM155: A structure-activity relationship study
Ho, Si-Han Sherman,Sim, Mei-Yi,Yee, Wei-Loong Sherman,Yang, Tianming,Yuen, Shyi-Peng John,Go, Mei-Lin
supporting information, p. 42 - 56 (2015/10/19)
The anticancer agent YM155 is widely investigated as a specific survivin suppressant. More recently, YM155 was found to induce DNA damage and this has raised doubts as to whether survivin is its primary target. In an effort to assess the contribution of DNA damage to the anticancer activity of YM155, several analogs were prepared and evaluated for antiproliferative activity on malignant cells, participation in DNA intercalation and free radical generation by redox cycling. The intact positively charged scaffold was found to be essential for antiproliferative activity and intercalation but was less critical for redox cycling where the minimal requirement was a pared down bicyclic quinone. Side chain requirements at the N1 and N3 positions of the scaffold were more alike for redox cycling and intercalation than antiproliferative activity, underscoring yet again, the limited structural overlaps for these activities. Furthermore, antiproliferative activities were poorly correlated to DNA intercalation and redox cycling. Potent antiproliferative activity (IC50 9-23 nM), exceeding that of YM155, was found for a minimally substituted methyl analog AB7. Like YM155 and other dioxonaphthoimidazoliums, AB7 was a modest DNA intercalator but with weak redox cycling activity. Thus, the capacity of this scaffold to inflict direct DNA damage leading to cell death may not be significant and YM155 should not be routinely classified as a DNA damaging agent.
