Discovery of novel sulfonamide chromone-oxime derivatives as potent indoleamine 2,3-dioxygenase 1 inhibitors.

A series of chromone-oxime derivatives containing piperazine sulfonamide moieties were designed, synthesized and evaluated for their inhibitory activities against IDO1. These compounds displayed moderate to good inhibitory activity against IDO1 with IC50 values in low micromolar range. Among them, compound 10m bound effectively to IDO1 with good inhibitory activities (hIDO1 IC50 = 0.64 µM, HeLa IDO1 IC50 = 1.04 µM) and were selected for further investigation. Surface plasmon resonance analysis confirmed the direct interaction between compound 10m and IDO1 protein. Molecular docking study of the most active compound 10m revealed key interactions between 10m and IDO1 in which the chromone-oxime moiety coordinated to the heme iron and formed several hydrogen bonds with the porphyrin ring of heme and ALA264, consistent with the observation by UV-visible spectra that 10m induced a Soret peak shift from 403 to 421 nm. Moreover, compound 10m exhibited no cytotoxicity at its effective concentration in MTT assay. Consistently, in vivo assays results demonstrated that 10m displayed potent antitumor activity with low toxicity in CT26 tumor-bearing Balb/c mice, in comparison with 1-methyl-l-tryptophan (1-MT) and 4-amino-N-(3-chloro-4-fluorophenyl)-N'-hydroxy-1,2,5-oxadiazole-3-carboximidamide (IDO5L). In brief, the results suggested that chromone-oxime derivatives containing sulfonamide moieties might serve as IDO1 inhibitors for the development of new antitumor agents.

Design, synthesis, and antitumor evaluation of morpholine substituted bisnaphthalimides as DNA targeting agents.

A series of mono- and bisnaphthalimides derivatives containing 3-nitro and 4-morpholine moieties were designed, synthesized, and evaluated for their in vitro anticancer activities against four cancer cell lines. Some compounds exhibited relatively good antiproliferative activity on the cell lines tested, in comparison with mitonafide and amonafide. It is noteworthy that bisnaphthalimide A6 was identified as the most potent compound in anti-proliferation against MGC-803 cells, with an IC50 lowered to 0.09 µM, a far greater potency than that of mono-naphthalimide A7, mitonafide, and amonafide. A gel electrophoresis assay revealed that DNA and Topo I were the potential targets of compounds A6 and A7. The treatment of CNE-2 cells with compounds A6 and A7 resulted in an S phase cell cycle arrest, accompanied by the upregulation of the expression levels of the antioncogene p27 and the down-regulation of the expression levels of CDK2 and cyclin E. In addition, compounds A6 and A7-induced apoptosis was further confirmed by flow cytometry, ROS generation assay, and Hoechst 33,258 staining. In particular, in vivo antitumor assay results revealed that bisnaphthalimide A6 exhibited potent anticancer efficiency in an MGC-803 xenograft tumor model, in comparison with mitonafide, and had lower toxicity than mono-naphthalimide A7. In brief, the results suggested that bisnaphthalimide derivatives containing 3-nitro and 4-morpholine moieties might serve as DNA binding agents for the development of new antitumor agents.