Design, Synthesis, and Anticancer Activity of Cinnamoylated Barbituric Acid Derivatives.

This work deals with the design and synthesis of 18 barbituric acid derivatives bearing 1,3-dimethylbarbituric acid and cinnamic acid scaffolds to find potent anticancer agents. The target molecules were obtained through Knoevenagel condensation and acylation reaction. The cytotoxicity was assessed by the MTT assay. Flowcytometry was performed to determine the cell cycle arrest, apoptosis, ROS levels and the loss of MMP. The ratios of GSH/GSSG and the MDA levels were determined by using UV spectrophotometry. The results revealed that introducing substitutions (CF3 , OCF3 , F) on the meta- of the benzyl ring of barbituric acid derivatives led to a considerable increase in the antiproliferative activities compared with that of corresponding ortho- and para-substituted barbituric acid derivatives. Mechanism investigation implied that the 1c could increase the ROS and MDA level, decrease the ratio of GSH/GSSG and MMP, and lead to cell cycle arrest. Further research is needed for structural optimization to enhance hydrophilicity, thereby improve the biological activity of these compounds.

Piperlongumine Analogs Promote A549 Cell Apoptosis through Enhancing ROS Generation.

Chemotherapeutic agents, which contain the Michael acceptor, are potent anticancer molecules by promoting intracellular reactive oxygen species (ROS) generation. In this study, we synthesized a panel of PL (piperlongumine) analogs with chlorine attaching at C2 and an electron-withdrawing/electron-donating group attaching to the aromatic ring. The results displayed that the strong electrophilicity group at the C2-C3 double bond of PL analogs plays an important role in the cytotoxicity whereas the electric effect of substituents, which attached to the aromatic ring, partly contributed to the anticancer activity. Moreover, the protein containing sulfydryl or seleno, such as TrxR, could be irreversibly inhibited by the C2-C3 double bond of PL analogs, and boost intracellular ROS generation. Then, the ROS accumulation could disrupt the redox balance, induce lipid peroxidation, lead to the loss of MMP (Mitochondrial Membrane Potential), and ultimately result in cell cycle arrest and A549 cell line death. In conclusion, PL analogs could induce in vitro cancer apoptosis through the inhibition of TrxR and ROS accumulation.

Synthesis and biological evaluation of ß-ionone oriented proapoptosis agents by enhancing the ROS generation.

ß-ionone, a cyclic terpenoid compound present in many fruits, has been showed a broad spectrum of biological activities. In this paper, we synthesized a panel of ß-ionone derivatives and tested their anti-proliferation activity on cancer cell by the MTT assay. The results showed that most of the ß-ionone derivatives were more active than ß-ionone and curcumin. Particularly, the ß-ionone derivatives (1a, 1d and 1g) with ortho-substituents on the aromatic ring exhibited much stronger cytotoxicity than their corresponding meta- and para-substituted compounds. Importantly, the cytotoxicity of the ß-ionone derivatives (1a, 1d and 1g) were relationship with their reactive oxygen species (ROS)-generation abilities, which could lead to the redox imbalance, lipid peroxidation, the loss of mitochondrial membrane potential (MMP), the activation of Bax and Caspase 3, followed by cell apoptosis. This work suggest that the "ortho effect", the ROS-generation ability and drawing fluorine atom into drugs may play a potent role in enhancing the anticancer activity of ß-ionone derivatives.

Synthesis and evaluation of the anticancer activity of bischalcone analogs in human lung carcinoma (A549) cell line.

Bischalcone has gained much attention because of its wide range of application in pharmaceutical chemistry. This work aims to evaluate the antiproliferation effects and explore the anticancer mechanism of bischalcone analogs on human lung cancer A549 cells. In this study, we synthesized a series of bischalcone analogs via Aldol condensation reaction; MTT method was used to evaluate the antiproliferation effects; the 2',7'-dichlorofluorescein fluorescence assay was used to determine the intracellular reactive oxygen species levels; the glutathione reductase-DTNB recycling assay was used to detect the redox imbalance; determination of thiobarbituric acid-reactive substance was used to evaluate the lipid peroxidation; Rhodamine 123 was used to test the mitochondrial membrane potential (MMP); the FITC/PI kit was used to detect the apoptosis; Western blotting was used to detect the expression of Bax and Caspase 3. After treatment with curcumin and bischalcone analogs, compounds 1d and 1g, the more stabilities compounds than curcumin, exhibited much higher potency in A549 cells than curcumin and other bischalcone analogs. Further mechanism of action studies revealed that 1d and 1g exhibited more stronger reactive oxygen species production abilities than curcumin and accompanied by the redox imbalance, lipid peroxidation, the loss of MMP, the activition of Bax and Caspase 3, and ultimately resulted in apoptosis of A549 cell. These data suggest that enhancing the reactive oxygen species generation ability of bischalcone analogs may be a promising strategy for the treatment of human lung cancer.

The potential role of the 5,6-dihydropyridin-2(1H)-one unit of piperlongumine on the anticancer activity.

Piperlongumine (PL), a potent anticancer agent from the plant long pepper (Piper longum), contains the 5,6-dihydropyridin-2(1H)-one heterocyclic scaffold and cinnamoyl unit. In this paper, we synthesized a series of PL analogs and evaluated their cytotoxicity against cancer cells for the sake of exploring which pharmacophore plays a more potent role in enhancing the anticancer activities of PL. These results illustrated that the position effect, not the electronic effect, of substituents plays a certain role in the cytotoxicity of PL and its analogs. More important, the 5,6-dihydropyridin-2(1H)-one unit, a potent pharmacophore in enhancing the antiproliferative activities of PL, could react with cysteamine and lead to ROS generation, and then bring about the occurrence of ROS-induced downstream events, followed by cell cycle arrest and apoptosis. This work suggests that introducing a lactam unit containing Michael acceptors may be a potent strategy to enhancing the anticancer activity of drugs.