Lingyun Yang

Discovery of imidazopyridine derivatives as novel c-Met kinase inhibitors: Synthesis, SAR study, and biological activity

Receptor tyrosine kinase c-Met acts as an alternative angiogenic pathway in the process and contents of cancers. A series of imidazopyridine derivatives were designed and synthesized according to the established docking studies as possible c-Met inhibitors. Most of these imidazopyridine derivatives displayed nanomolar potency against c-Met in both biochemical enzymatic screens and cellular pharmacology studies. Especially, compound 7g exhibited the most inhibitory activity against c-Met with IC50 of 53.4nM and 253nM in enzymatic and cellular level, respectively. Following that, the compound 7g was docked into the protein of c-Met and the structure-activity relationship was analyzed in detail. These findings indicated that the novel imidazopyridine derivative compound 7g was a potential c-Met inhibitor deserving further investigation for cancer treatment.

Protective effects of hepatocyte-specific glycyrrhetic derivatives against carbon tetrachloride-induced liver damage in mice

Glycyrrhetic acid (GA), the main hydrolysate of glycyrrhizic acid extracted from the roots of the Chinese herb Glycyrrhiza glabra, was reported to be accumulated in hepatocytes due to the extensive distribution of GA receptors in liver. A series of hepatocyte-specific derivatives on the basis of anetholtrithione and glycyrrhizic were designed and synthesized. The potential beneficial effect was evaluated in carbon tetrachloride (CCl4)-induced liver injury model. In addition, the hepatoprotective activity of these derivatives was assessed by measuring levels of serum marker enzymes, including serum glutamate oxaloacetate transaminase (GOT), serum glutamate pyruvate transaminase (GPT), alkaline phosphatase (AKP), lactate dehydrogenase (LDH) and the ratio of GSH to GSSG. Gratifyingly, compounds 5a-c (100mg/kg, p.o.) markedly prevented CCl4-induced elevation of levels of serum GPT, GOT. A comparative histopathological study of liver exhibited almost a normal liver lobular architecture and cell structure of the livers, as compared to CCl4-treated group. These findings were confirmed with the histopathological observations, where hepatocyte-specific glycyrrhetic acid derivatives 5a-c were capable of reversing the toxic effects of CCl4 on hepatocytes.

Design, synthesis and biological evaluation of dihydroquinoxalinone derivatives as BRD4 inhibitors

BRD4 plays a key role in transcriptional regulation. Recent biological and pharmacological studies have demonstrated that bromodomain-containing protein 4 (BRD4) is a viable drug target for cancer treatment. In this study, we synthesized a series of dihydroquinoxalinone derivatives and evaluated their BRD4 inhibitory activities, obtaining compound 5i with IC50 value of 73nM of binding activity in BRD4(1) and 258nM of cellular activity in MV-4-11 cancer cell lines. Docking studies were performed to explain the structure-activity relationship. Based on its potent biochemical and anti-proliferative activity, the novel BRD4 inhibitor compound 5i, is a promising lead compound for further investigation.

Design, synthesis and biological evaluation of 7-methylimidazo[1,5-a]pyrazin-8(7H)-one derivatives as BRD4 inhibitors

BRD4 is an attractive target for antitumor due to its important role in regulation of gene transcription. In this paper, we synthesized a series of 7-methylimidazo[1,5-a]pyrazin-8(7H)-one derivatives as potent BRD4 inhibitors and evaluated their BRD4 inhibitory activities in vitro and anti-proliferation effects on tumor cells. Gratifyingly, compound 10j exhibited robust potency of BRD4(1) and BRD4(2) inhibition with IC50 values of 130 and 76nM respectively. Docking studies were performed to explain the structure-activity relationship. Furthermore, compound 10j potently inhibited cell proliferation in BRD4-sensitive cell lines HL-60 and MV4-11 with IC50 value of 0.57 and 0.18μM respectively. Activity on BRD4-independent K562 cell was weaker than on BRD4-sensitive lines. Overall, these results suggest that compound 10j is a potential BRD4 inhibitor deserving further investigation for cancer treatment.

Design, synthesis and biological evaluation of anthranilamide derivatives as potential factor Xa (fXa) inhibitors

Factor Xa (fXa) is a crucial player in various thromboembolic disorders. Inhibition of fXa can provide safe and effective antithrombotic effects. In this study, a series of anthranilamide compounds were designed by utilizing structure-based design strategies. Optimization at P1 and P4 groups led to the discovery of compound 16g: a highly potent, selective fXa inhibitor with pronounced in vitro anticoagulant activity. Moreover, 16g also displayed excellent in vivo antithrombotic activity in the rat venous thrombosis (VT) and arteriovenous shunt (AV-SHUNT) models. The bleeding risk evaluation showed that 16g had a safer profile than that of betrixaban at 1 mg/kg and 5 mg/kg dose. Additionally, 16g also exhibited satisfactory PK profiles. Eventually, 16g was selected to investigate its effect on hypoxia-reoxygenation- induced H9C2 cell viability. MTT results showed that H9C2 cell viability can be remarkably alleviated by 16g.