Synthesis and Anti-Proliferative Effects of Mono- and Bis-Purinomimetics Targeting Kinases

Green solvent-free synthesis of new N-heterocycle-L-ascorbic acid hybrids and their antiproliferative evaluation

Aim: The authors' aim was to improve the application of copper-catalyzed azide-alkyne cycloaddition in the synthesis of hybrids containing biologically significant nucleobases and L-ascorbic acid scaffolds by introducing an environmentally friendly and waste-free ball mill. Results: Two series of hybrids with a purine, pyrrolo[2,3- d]pyrimidine or 5-substituted pyrimidine attached to 2,3-dibenzyl-L-ascorbic acid via a hydroxyethyl- (15a–23a) or ethylidene-1,2,3-triazolyl (15b–23b) bridge were prepared by ball milling and conventional synthesis. The unsaturated 6-chloroadenine L-ascorbic acid derivative 16b can be highlighted as a lead compound and showed strong antiproliferative activity against HepG2 (hepatocellular carcinoma) and SW620 (colorectal adenocarcinoma) cells. Conclusion: Mechanochemical synthesis was superior in terms of sustainability, reaction rate and yield, highlighting the advantageous applications of ball milling over classical reactions.

Amidine- and Amidoxime-Substituted Heterocycles: Synthesis, Antiproliferative Evaluations and DNA Binding

The novel 1,2,3-triazolyl-appended N- and O-heterocycles containing amidine 4–11 and amidoxime 12–22 moiety were prepared and evaluated for their antiproliferative activities in vitro. Among the series of amidine-substituted heterocycles, aromatic diamidine 5 and coumarine amidine 11 had the most potent growth-inhibitory effect on cervical carcinoma (HeLa), hepatocellular carcinoma (HepG2) and colorectal adenocarcinoma (SW620), with IC₅₀ values in the nM range. Although compound 5 was toxic to non-tumor HFF cells, compound 11 showed certain selectivity. From the amidoxime series, quinoline amidoximes 18 and 20 showed antiproliferative effects on lung adenocarcinoma (A549), HeLa and SW620 cells emphasizing compound 20 that exhibited no cytostatic effect on normal HFF fibroblasts. Results of CD titrations and thermal melting experiments indicated that compounds 5 and 10 most likely bind inside the minor groove of AT-DNA and intercalate into AU-RNA. Compounds 6, 9 and 11 bind to AT-DNA with mixed binding mode, most probably minor groove binding accompanied with aggregate binding along the DNA backbone.

Novel Bis- and Mono-Pyrrolo[2,3-d]pyrimidine and Purine Derivatives: Synthesis, Computational Analysis and Antiproliferative Evaluation

Novel symmetrical bis-pyrrolo[2,3-d]pyrimidines and bis-purines and their monomers were synthesized and evaluated for their antiproliferative activity in human lung adenocarcinoma (A549), cervical carcinoma (HeLa), ductal pancreatic adenocarcinoma (CFPAC-1) and metastatic colorectal adenocarcinoma (SW620) cells. The use of ultrasound irradiation as alternative energy input in Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) shortened the reaction time, increased the reaction efficiency and led to the formation of exclusively symmetric bis-heterocycles. DFT calculations showed that triazole formation is exceedingly exergonic and confirmed that the presence of Cu(I) ions is required to overcome high kinetic requirements and allow the reaction to proceed. The influence of various linkers and 6-substituted purine and regioisomeric 7-deazapurine on their cytostatic activity was revealed. Among all the evaluated compounds, the 4-chloropyrrolo[2,3-d]pyrimidine monomer 5f with 4,4′-bis(oxymethylene)biphenyl had the most pronounced, although not selective, growth-inhibitory effect on pancreatic adenocarcinoma (CFPAC-1) cells (IC₅₀ = 0.79 µM). Annexin V assay results revealed that its strong growth inhibitory activity against CFPAC-1 cells could be associated with induction of apoptosis and primary necrosis. Further structural optimization of bis-chloropyrrolo[2,3-d]pyrimidine with aromatic linker is required to develop novel efficient and non-toxic agent against pancreatic cancer.

Purine and Purine Isostere Derivatives of Ferrocene: An Evaluation of ADME, Antitumor and Electrochemical Properties

Novel purine and purine isosteres containing a ferrocene motif and 4,1-disubstituted (11a-11c, 12a-12c, 13a-13c, 14a-14c, 15a-15c, 16a, 23a-23c, 24a-24c, 25a-25c) and 1,4-disubstituted (34a-34c and 35a-35c) 1,2,3-triazole rings were synthesized. The most potent cytotoxic effect on colorectal adenocarcinoma (SW620) was exerted by the 6-chloro-7-deazapurine 11c (IC₅₀ = 9.07 µM), 6-chloropurine 13a (IC₅₀ = 14.38 µM) and 15b (IC₅₀ = 15.50 µM) ferrocenylalkyl derivatives. The N-9 isomer of 6-chloropurine 13a containing ferrocenylmethylene unit showed a favourable in vitro physicochemical and ADME properties including high solubility, moderate permeability and good metabolic stability in human liver microsomes.

Discovery of a Novel Benzenesulfonamide Analogue That Inhibits Proliferation and Metastasis Against Ovarian Cancer OVCAR-8 Cells

BACKGROUND

Ovarian cancer has been a salient public health concern in the world. It is necessary to develop novel antitumor drugs to treat ovarian cancer.

PURPOSE

This study investigated the synthesis, antiproliferation ability, antitumor mechanisms in vitro and in vivo of a novel benzenesulfonamide derivative.

METHODS

The novel benzenesulfonamide-1,2,3-triazole hybrid 7c was synthesized from 4-fluorobenzenesulfonyl chloride, prop-2-yn-1-amine and 1-(azidomethyl)-3-phenoxybenzene. The structure of this benzenesulfonamide-1,2,3-triazole hybrid 7c was confirmed by 13C NMR, and 1H NMR. Compound 7c was evaluated for its antitumor effects in vitro and in vivo against ovarian cancer OVCAR-8 cells.

RESULTS

We discovered that the benzenesulfonamide hybrid 7c potently inhibited cell proliferation against ovarian cancer. Especially, it inhibited cell proliferation with an IC50 value of 0.54μM against OVCAR-8 cells. It could inhibit migration and invasion against OVCAR-8 cells in a concentration-dependent and time-dependent manner. In addition, compound 7c affected the Wnt/β-catenin/GSK3β pathway against ovarian cancer OVCAR-8 cells. In vivo study suggested that compound 7c inhibited tumor growth remarkably without obvious toxicity.

CONCLUSION

In conclusion, benzenesulfonamide hybrid 7c could be a lead compound for further antitumor drug discovery to treat ovarian cancer.