Synthesis of Distorted Nitrogen-Doped Nanographenes by Partially Oxidative Cyclodehydrogenation Reaction.

A series of partially fused N-doped nanographenes (2-4) are synthesized via the oxidative cyclodehydrogenation of oligoaryl-substituted dibenzo[e,l]pyrene (1), and five, six, and seven new C-C bonds are formed, respectively, implying stepwise C-C bond fusion and extended π-conjugation. Single-crystal X-ray diffraction analysis of compound 4 a revealed that the presence of sterically demanding groups hindered the formation of planar and fully fused nanographene in the oxidative cyclodehydrogenation reaction step. Optical study of compounds 2 to 4 showed that extended π-conjugation leads to a regular stepwise bathochromic shift in the absorption and emission spectra. Furthermore, the HOMO-LUMO gaps of these compounds exhibit a decrease as C-C bond formation proceeds. Thus, the optoelectronic properties of nanographenes are highly dependent on the formation of new C-C bonds in the molecular skeleton.

JS­K induces G2/M phase cell cycle arrest and apoptosis in A549 and H460 cells via the p53/p21WAF1/CIP1 and p27KIP1 pathways.

Lung cancer is one of the most common malignancies worldwide, with high mortality and morbidity rates. O2­â€‹(2,4­â€‹dinitrophenyl)­1­â€‹[(4­ethoxycarbonyl)piperazin­1­yl]diazen­1­ium­1,2­diolate (JS­K) is a potent anticancer agent that acts against a subset of human non­small cell lung cancer (NSCLC) cell lines; however, the underlying mechanisms of JS­K in NSCLC remain unclear. The present study aimed to evaluate the anticancer effect of JS­K and investigate its underlying mechanisms in A549 and H460 cells. In the present study, A549 and H460 cells were treated with JS­K, and then evaluated by cell viability assay, flow cytometry and western blot analysis. JS­K markedly induced cell cycle arrest at the G2/M phase in a concentration and time­dependent manner in both cell lines. This was associated with increased expression levels of p53, and the cell cycle inhibitors p21WAF1/CIP1 and p27KIP1, which, in turn, inhibited the expression of Cdc2, cyclin B1 and cyclin­dependent kinase 2. In addition, JS­K­induced inhibition of proliferation was revealed to be partially modulated by the upregulation of p53 and p21WAF1, the ratio of Bax/Bcl­2, and the activation of both the intrinsic and extrinsic apoptotic pathways in A549 and H460 cells. These results demonstrated that JS­K could trigger cell cycle arrest at the G2/M phase and apoptosis in A549 and H460 cells, which was likely mediated via the p53/p21WAF1/CIP1 and p27KIP1 pathways. Overall, the results indicated that JS­K may be used as an anticancer agent for the treatment of NSCLC.