Clonogenicity assay == PC-3 cells were seeded in a 6-well plate and incubated to get 24 h, then the mass media were replaced with fresh mass media containing diverse concentrations of compound8i. bioactive isoflavone found in red clover plant and widespread in the Leguminosae family members, was reported to have many potent pharmacological activities, including antioxidant, antiviral, antitumor, antihypertensive, antibacterial, antiangiogenic effects Anle138b and so on [26]. In recent years, many formononetin analogues were designed as antitumor agents and explored their particular biological mechanism against diverse human malignancy cell lines [79]. Its 7-phosphoramidate derivative2significantly induced early apoptosis in HepG-2 cells [10]. Formononetin nitrogen mustard derivative3could stimulate cell routine arrest at G2/M phase and cell apoptosis [11], with an IC50value of 3. eight M against HCT-116 cells (Fig. 1). == Fig. 1 . == Formononetin derivatives with anticancer activity. Dithiocarbamate, a privileged scaffold in drug finding with a wide array of biological activities, including antifungal, antibacterial, antitumor, inhibition of carbonic anhydrase activities and so on [1217]. Besides, the dithiocarbamate has always been used as a linkage to Rabbit Polyclonal to ZNF387 combine diverse antiproliferative energetic scaffolds to design new chemical entities. Our group possess reported three series of dithiocarbamates derivatives because potential antitumor agents: the butenolide-containing dithiocarbamate4displayed an excellent activity against Hela cells with an IC50value of 0. 77 M [18]; the book dithiocarbamate-chalcone analogue5could change the manifestation of Anle138b apoptosis-related proteins and arrest the cell routine at G0/G1 phase against SK-N-SH cells [19]; triazole-dithiocarbamate centered selective lysine specific demethylase 1 inactivator6inhibited gastric malignancy cell growth, invasion, and migration (Fig. 2) [20]. == Fig. 2 . == Dithiocarbamate derivatives with anticancer activity. Molecular hybridization is a useful strategy of rational design of new ligands based on the recognition of pharmacophoric subunits in the molecular structure of two or more known bioactive derivatives [21]. These above interesting findings and our continuous quest to determine more potent anticancer agents, led to the molecular hybridization of formononetin and dithiocarbamate to integrate them in one molecular platform to generate a new cross with a great antiproliferative activity (Fig. 3). == Fig. 3. == Rational molecular hybridization strategy for target antiproliferative derivatives. Because shown inFig. 3, a molecular hybridization strategy based on the structures of a organic formononetin1and a bioactive dithiocarbamate analogue6yielded a scaffold which has four parts: (i) a dithiocarbamate group with drug-like properties, (ii) a natural formononetin scaffold because an antitumor pharmacophore fragment (iii) a medium-chain alkoxyl group to get lipophilicity, and (IV) various aliphatic amine units attached with dithiocarbamate fragment. To the best of our knowledge, there have been no books reports regarding formononetin-dithiocarbamate hybrids so far. These findings possess encouraged us to investigate the potential synergistic effect of dithiocarbamate and formononetin scaffolds. == 2 . Results and discussion == == 2 . 1 . Chemistry == The synthetic path were demonstrated inScheme 1 . Commercially available formononetin1was subjected to etherification reaction with 1, 2-dibromoethane, 1, 3-dibromopropane, 1, Anle138b 4-dibromobutane, or 1, 5-dibromopentane to afford7adin the presence of potassium carbonate. The target analogues were very easily obtained in high yields with the older reaction conditions developed by our group [22]. == Scheme 1 . == Reagents and conditions: (a) 1, 2-dibromoethane, 1, 3-dibromopropane, 1, 4-dibromobutane, or 1, 5-dibromopentane, K2CO3, THF, reflux, 7083% yield; (b) CS2, substituted amine, Na3PO412H2O, acetone, rt, 7885% yield. == 2 . 2 . Antiproliferative activity == In continuation with our attempts toward the identification of novel derivatives with anticancer potential, we evaluated the antiproliferative activity of formononetin analogues7adand formononetin-dithiocarbamate hybrids8ajagainst several malignancy cell lines (PC-3, MGC-803 and EC-109) using the MTT assay. Due to potentially comparable mode of action between reported dithiocarbamate derivatives and well-known 5-fluorouracil (5-FU), 5-Fu was used because the research drug in the MTT assay [23]. Besides, formononetin1also was a positive control. The antiproliferative activity results against all three malignancy cells to get the candidate compounds were shown inTable 1 . The replacement of the bromine atom by the dithiocarbamate scaffold led to a powerful improvement of activity for formononetin-dithiocarbamate derivatives in contrast to the corresponding formononetin analogues (7ad). Especially, compound8ishowed the inhibitory effect.