Synthesis and biological evaluation of novel 5,6,7-trimethoxy flavonoid salicylate derivatives as potential anti-tumor agents

Design, synthesis and anticancer evaluation of polymethoxy aurones as potential cell cycle inhibitors

Background

Cancer is the most fatal disease in humans and the aberrant activity of various cell cycle proteins results in uncontrolled tumor cell proliferation, thus, regulating the cell cycle is an attractive target in cancer therapy.

Objectives

Aurone is a naturally occurring active compound with a wide range of biological activities, of which 3, 4, 5-trimethoxyphenyl (TMP) is an important microtubule targeting pharmacophore. Based on the pharmacophore combination principle, we incorporate the TMP pharmacophore into the aurone structure and design a novel polymethoxy derivative that is expected to inhibit tumor cell proliferation through regulating the cell cycle.

Methods

By introducing different substituents on C-4' and C-3', a series of new 4, 5, 6-trimethoxy aurone derivatives have been designed and synthesized. DU145, MCF-7 and H1299 cell lines were selected to evaluate their anticancer activity. The compound with the best cytotoxicity was then selected and the anticancer mechanisms were investigated by network pharmacology, flow cytometry, Western blot, and cell heat transfer assay. ADMET prediction evaluated the draggability of aurone derivatives.

Results

Aurones 1b and 1c have selective anti-proliferative activity against DU145 cells. Among them, the compound 1c have better cytotoxicity against DU145. Compound 1c could bind the active cavity of CyclinB1/CDK1/CKS complex protein and induced G2/M phase arrest of DU145 cells by regulating the expression of CyclinB1 and p21. Compound 1c satisfies the Lipinski rule, is suitable for the absorption and metabolism index, and has a lower risk of cardiac toxicity.

Conclusions

Polymethoxy aurones 1c might function as a CyclinB1/CDK1 inhibitor that deserved to be further developed for the treatment of prostate cancer.

Synthesis and anti-hepatocellular carcinoma evaluation of salicylic acid-modified indole trimethoxy flavonoid derivatives

Simultaneous inhibition of tumor vasculature and the glycolysis pathway may be a targeted anti-tumor strategy to inhibit tumor nutrient supply. Flavonoids are natural products with strong biological activity, which inhibit hypoxia induction factor 1α (HIF-1α) regulating glycolysis and tumor angiogenesis, while salicylic acid can reduce the glycolysis level of tumor cells by inhibiting related rate-limiting enzymes. A series of salicylic acid-modified indole trimethoxy-flavone derivatives were designed and synthesized by introducing benzotrimethoxy-structure commonly used in blood vessel blockers, and their anti-tumor activities were evaluated. Among them, compound 8f exhibited significant anti-proliferative activity against two hepatoma cells, HepG-2 and SMMC-7721, with IC50 values of 4.63 ± 1.13 μM and 3.11 ± 0.35 μM, respectively. Colony formation experiments also further verified its excellent in vitro anti-tumor activity. In addition, compound 8f showed the ability to induce apoptosis in SMMC-7721 cells in a concentration-dependent manner. After treatment with compound 8f, the expressions of the rate-limiting enzymes PKM2, PFKM, HK2 and tumor angiogenesis-related vascular endothelial growth factor of the glycolytic pathway were all down-regulated, and the lactate level in the hepatoma cell SMMC-7721 was significantly reduced. The morphology of the nucleus and tubulin was also observed to disperse gradually with the increase of compound 8f concentration. And compound 8f showed strong binding ability to tubulin. Our results suggest that the strategy of synthesizing the salicylic acid-modified indole flavone derivative 8f is a way to obtain active anti-tumor candidate compounds that may be further developed as targeted agents to inhibit tumor vasculature and glycolytic pathways.

Recent Development of Flavonoids with Various Activities

Flavonoids, a series of compounds with C6-C3-C6 structure, mostly originate from plant metabolism. Flavonoids have shown beneficial effects on many aspects of human physiology and health. Recently, many flavonoids with various activities have been discovered, which has led to more and more studies focusing on their physiological and pharmacodynamic activities. The anti-cancer and anti-viral activities especially have attracted the attention of many researchers. Therefore, the discovery and development of flavonoids as anti-disease drugs has great potential and may make significant contribution to fighting diseases. This review focus on the discovery and development of flavonoids in medicinal chemistry in recent years.

Gastric cancer: a comprehensive review of current and future treatment strategies

Gastric cancer remains a major unmet clinical problem with over 1 million new cases worldwide. It is the fourth most commonly occurring cancer in men and the seventh most commonly occurring cancer in women. A major fraction of gastric cancer has been linked to variety of pathogenic infections including but not limited to Helicobacter pylori (H. pylori) or Epstein Barr virus (EBV). Strategies are being pursued to prevent gastric cancer development such as H. pylori eradication, which has helped to prevent significant proportion of gastric cancer. Today, treatments have helped to manage this disease and the 5-year survival for stage IA and IB tumors treated with surgery are between 60 and 80%. However, patients with stage III tumors undergoing surgery have a dismal 5-year survival rate between 18 and 50% depending on the dataset. These figures indicate the need for more effective molecularly driven treatment strategies. This review discusses the molecular profile of gastric tumors, the success, and challenges with available therapeutic targets along with newer biomarkers and emerging targets.