Discovery of potential anticancer multi-targeted ligustrazine based cyclohexanone and oxime analogs overcoming the cancer multidrug resistance

Synthesis and biological evaluation of new tetramethylpyrazine-based chalcone derivatives as potential anti-Alzheimer agents

In the current study, a series of new ligustrazine-based chalcones was synthesized. For insertion of tetramethylpyrazine (TMP, also designated as ligustrazine) in chemical backbone of chalcone, a new ligustrazine-based aldehyde was prepared. New ketones were synthesized for inclusion of quinazolin-4-yl amino and pyrazin-2-yl amino moieties. The newly synthesized compounds were screened for acetylcholinesterase, butyrylcholinesterase, and monoamine oxidases (MAO) inhibitory activities and also for in vitro cytotoxicity on PC12 cells. The effect of these compounds against amyloid β-induced cytotoxicity and aggregation was also investigated. The synthesized compounds effectively inhibited the related enzymes and also exhibited neuroprotective effects. Most of the compounds displayed better inhibitory potencies against Aβ aggregation than reference compounds. Some compounds such as 11e and 16b showed very potent effects on multiple targets exhibiting behavior as multifunctional anti-Alzheimer agents.

Recent progress in the structural modification and pharmacological activities of ligustrazine derivatives

Ligustrazine is a main active fraction of the traditional medicine known as Ligusticum chuanxiong hort, which has been used as clinical medication for cerebral thrombosis, coronary heart disease and stenocardia recently. The rapid metabolism and short half-life of ligustrazine seriously limits its application in clinical practice. Therefore, derivatives of ligustrazine are designed and synthesized in our and other labs, including piperazine, cinnamic acid, styrene, acylguanidine, amides, curcumin and triterpenes derivatives of ligustrazine. Most of these compounds present better pharmacodynamics activities and more favorable pharmacokinetic properties compared to the parent compound. Besides, some new biological activities of these compounds are discovered. Hence, this review continues the previous review of our group as well as aims to highlight recent prominent advances in this field in the past ten years.

Novel 1,2,4-triazole derivatives as potential anticancer agents: Design, synthesis, molecular docking and mechanistic studies

A series of novel compounds carrying 1,2,4-triazole scaffold was synthesized and evaluated for their anticancer activity against a panel of cancer cell lines using MTT assay. Compounds 8a, 8b, 8c, 8d, 10b, 10e, and 10 g showed remarkable antiproliferative activity against the tested cell lines. Compounds 8a, 8b, 8c, 8d, 10b, 10e, and 10 g with the least IC₅₀ values in MTT assay were tested against three known anticancer targets including EGFR, BRAF and Tubulin. The results revealed that compounds 8c and 8d showed almost same BRAF inhibitory activity and were discovered to be potent inhibitors of cancer cell proliferation and were also observed to be strong Tubulin inhibitors. Moreover, 8c also showed the best EGFR inhibition with IC₅₀ = 3.6 μM. Finally molecular modeling studies were performed to explore the binding mode of the most active compounds to the target enzymes.

DMXAA-pyranoxanthone hybrids enhance inhibition activities against human cancer cells with multi-target functions

Four 5,6-dimethylxanthone-4-acetic acid (D) and pyranoxanthone (P) hybrids (D-P-n) were design-synthesized based on multi-target-addressed strategy. D-P-4 was confirmed as the most active agent against HepG-2 cell line growth with an IC₅₀ of 0.216 ± 0.031 μM. Apoptosis analysis indicated different contributions of early/late apoptosis/necrosis to cell death for both monomers, the combination (D + P in 1:1 mol ratio) and D-P-4. They all arrested more cells on S phase. Western Blot implied that D-P-4 regulated p53/MDM2 to a better healthy state. Moreover, it improved Bax/Bcl-2 signaling pathway to increase cancer cell apoptosis. In all cases studied, D-P-4 showed the best activity and synergistic effect. All the evidences support that D-P-4 is a better anti-cancer therapy with multi-target functions.

Novel diphenylthiazole derivatives with multi-target mechanism: Synthesis, docking study, anticancer and anti-inflammatory activities

Over the last few decades, a growing body of studies addressed the anticancer activity of NSAIDs, particularly selective COX-2 inhibitors. However, their exact molecular mechanism is still unclear and is not fully investigated. In this regard, a novel series of compounds bearing a COXs privilege scaffold, diphenyl thiazole, was synthesized and evaluated for their anticancer activity against a panel of cancer cell lines. The most active compounds 10b, 14a,b, 16a, 17a,b and 18b were evaluated in vitro for COX-1/COX-2 inhibitory activity. These compounds were suggested to exert their anticancer activity through a multi-target mechanism based on their structural features. Thus, compounds 10b and 17b with the least IC₅₀ values in MTT assay were tested against three known anticancer targets; EGFR, BRAF and tubulin. Compounds 10b and 17b showed remarkable activity against EGFR with IC₅₀ values of 0.4 and 0.2μM, respectively and good activity against BRAF with IC₅₀ values of 1.3 and 1.7μM, respectively. In contrast, they showed weak activity in tubulin polymerization assay. The in vivo anti-inflammatory potential was assessed and interestingly, compound 17b was the most potent compound. Together, this study offers some important insights into the correlation between COXs inhibition and cancer treatment. Additionally, the results demonstrated the promising activity of these compounds with a multi-target mechanism as good candidates for further development into potential anticancer agents.

Novel Gomisin B analogues as potential cytotoxic agents: Design, synthesis, biological evaluation and docking studies

As part of pharmacological-phytochemical integrated studies on medicinal flora, Gomisin B (1) was isolated as major phytochemical lead from schisandra grandiflora, a plant traditionally used in different Asian systems of medicine. A series of 1,2,3-triazoles derivatives were synthesized at the C-7' position of the gomisin B core through diastereoselective Michael addition followed by regioselective Huisgen 1,3-dipolar cycloaddition reactions. All these triazolyl derivatives (5a-5q) were well characterized using modern spectroscopic techniques and evaluated for their anti-cancer activity against a panel of five human cancerous cell-lines. Among them, compound 5b exhibited the best cytotoxicity against SIHA cell (IC₅₀ 0.24 μM) which was more than the standard drug doxorubicin, while the other derivatives were exhibited moderate to low activities in tested cell lines. The cell cycle analysis indicated that compound 5b stalled HeLa cells at G2/M phase. 5b promoted tubulin polymerization and this was supported by the docking studies, wherein 5b showed significant binding affinity at the colchicine binding pocket of tubulin. Overall, we identified a novel small molecule that demonstrated anticancer activity by promoting in vitro tubulin assembly.