Design and synthesis of biotinylated dimethylation of alkannin oxime derivatives

DMAKO-05,a novel dimethylation of alkannin oxime derivative,exhibits remarkable anticancer activity as well as excellent cellular selectivity and thus has been considered as a promising antineoplastic agent for colorectal carcinoma and melanoma.However,its potent cytotoxicity is not closely associated with reactive oxygen species（ROS） and bioreductive alkylation.Its specific antitumor target（s） has still remained elusive.To recognize the molecular target（s） of DMAKO-05 and its analogs,four biotinylated DMAKO derivatives were designed and prepared.The biotin moiety was successfully introduced in the molecule through a modified Mitsunobu reaction,which kept its anticancer activity.Moreover,the cellbased investigation demonstrated that replacement of the linker C4 chain with another alkyl chain（C6 or C8） gave rise to the enhancement of cytotoxicity.Among these biotinyl derivatives,both compound 16 and 8c exhibited more potent anticancer activity than DMAKO-05 against MCF-7 cells and were comparatively effective to alkannin toward HCT-15 cells.As expected,they might be thought as ideal chemical probes.Collectively,our present work could provide an available approach for the identification of the potential antineoplastic target（s） of DMAKO derivatives.

Design and synthesis of new 7,8-dimethoxy-α-naphthoflavones as CYP1A1 inhibitors

The flavonoids as inhibitors of CYP1A1 exhibit chemopreventive effects against certain procarcinogens and have been considered as the promising cancer preventive agents. A series of novel 7,8-dimethoxy-a- naphthoflavones as the substrate analogs were designed and prepared, The enzyme assay suggested that all of these new flavones were stronger inhibitors of CYP1A1 than the lead compound a-naphthoflavone, Among the tested ones, 3h showed the most potent inhibitory effects,

Cerium(Ⅳ)ammonium nitrate(CAN)-mediated regioselective synthesis and anticancer activity of 6-substituted 5,8-dimethoxy-1,4-naphthoquinone

6-Substituted 5,8-O-dimethyl-1,4-naphthoquinones（6-DMNQ）,the promising anticancer scaffolds,were selectively generated by oxidative demethylation of 2-substituted 1,4,5,8-tetramethoxynaphthalenes with CAN in EtOAc/H2O in comparatively high yields.An interesting finding was that apart from the reported electron-withdrawing effects of substituents on position 2 of naphthalene ring,regioselective synthesis of 6-DMNQ was largely dependent on the steric effects in CAN-mediated oxidation.The selective cytotoxicities of 6-DMNQ from the in vitro cell-based assays were exhibited between the cancer cells and normal cells.Moreover,most of sulfur-containing 6-DMNQ derivatives displayed better anticancer activities than the corresponding oxygen-containing ones,which could provide an available strategy for the design of 6-DMNQ derivatives as potential anticancer agents.