Chunxia Liu

Design, synthesis and structure–activity relationship studies of novel free fatty acid receptor 1 agonists bearing amide linker

The free fatty acid receptor 1 (FFA1/GPR40) has attracted extensive attention as a novel antidiabetic target. Aiming to explore the chemical space of FFA1 agonists, a new series of lead compounds with amide linker were designed and synthesized by combining the scaffolds of NIH screened lead compound 1 and GW9508. Among them, the optimal lead compound 17 exhibited a considerable agonistic activity (45.78%) compared to the NIH screened compound 1 (15.32%). During OGTT in normal mice, the compound 17 revealed a significant glucose-lowering effect (-23.7%) at the dose of 50mg/kg, proximity to the hypoglycemic effect (-27.8%) of Metformin (200mg/kg). In addition, the compound 17 (100mg/kg) also exhibited a significant improvement in glucose tolerance with a 29.1% reduction of glucose AUC0-2h in type 2 diabetic mice. All of these results indicated that compound 17 was considered to be a promising lead structure suitable for further optimization.

Design, synthesis, and biological evaluation of deuterated phenylpropionic acid derivatives as potent and long-acting free fatty acid receptor 1 agonists

The free fatty acid receptor 1 (FFA1) is a potential target due to its function in enhancement of glucose-stimulated insulin secretion. Takedas compound 1 has robustly in vitro activity for FFA1, but it has been suffered from poor pharmacokinetic (PK) profiles because the phenylpropanoic acid is vulnerable to β-oxidation. To identify orally available agonists, we tried to interdict the metabolically labile group by incorporating two deuterium atoms at the α-position of phenylpropionic acid. Interestingly, the differences of physicochemical properties between hydrogen and deuterium are quite small, but there are many differences in the structure-activity relationship between phenylpropionic acid series and present deuterated series. Further optimizations of deuterated series led to the discovery of compound 18, which exhibited a superior balance in terms of in vitro activity, lipophilicity, and solubility. Better still, compound 18 revealed a lower clearance (CL = 0.44 L/h/kg), higher maximum concentration (Cmax = 7584.27 μg/L), and longer half-life (T1/2 = 4.16 h), resulting in a >23-fold exposure than compound 1. In subsequent in vivo pharmacodynamic studies, compound 18 showed a robustly glucose-lowering effect in rodent without the risk of hypoglycemia.

Improving metabolic stability with deuterium: The discovery of HWL-066, a potent and long-acting free fatty acid receptor 1 agonists

The free fatty acid receptor 1 (FFA1) is a potential target due to its function in enhancing of glucose‐stimulated insulin secretion. The FFA1 agonist GW9508 has great potential for the treatment of type 2 diabetes mellitus, but it has been suffering from high plasma clearance probably because the phenylpropanoic acid is vulnerable to β‐oxidation. To identify orally available analog without influence on the unique pharmacological mechanism of GW9508, we tried to interdict the metabolically labile group by incorporating two deuterium atoms at the α‐position of phenylpropionic acid affording compound 4 (HWL‐066). As expected, HWL‐066 revealed a lower clearance (CL = 0.23 L−1 hr−1 kg−1), higher maximum concentration (Cmax = 5907.47 μg/L), and longer half‐life (T1/2 = 3.50 hr), resulting in a 2.8‐fold higher exposure than GW9508. Moreover, the glucose‐lowering effect of HWL‐066 was far better than that of GW9508 and comparable with TAK‐875. Different from glibenclamide, no side‐effect of hypoglycemia was observed in mice after oral administrating HWL‐066 (80 mg/kg).

Design, synthesis and evaluation of a novel series of inhibitors reversing P-glycoprotein-mediated multidrug resistance

Multidrug resistance (MDR) is still the main barrier to attaining effective results with chemotherapy. Discovery of new chemo‐reversal agents is needed to overcome MDR. Our study focused on a better way to obtain novel drugs with triazole rings that have an MDR reversal ability through click chemistry. Among 20 developed compounds, compound 19 had a minimal cytotoxic effect compared to tariquidar and verapamil (VRP) and showed a higher reversal activity than VRP through increased accumulation in K562/A02 cells. Compound 19 also played an important role in the P‐gp efflux function of intracellular Rh123 and doxorubicin (DOX) accumulation in K562/A02 cells. Moreover, compound 19 exhibited a long lifetime of approximately 24 hr. These results indicated that compound 19 is a potential lead compound for the design of new drugs to overcome cancer MDR.

Design, synthesis and biological evaluation of novel tetrahydroisoquinoline derivatives as P-glycoprotein-mediated multidrug resistance inhibitors

Multidrug resistance (MDR) is one of the main obstacles of clinical chemotherapy. A great deal of research shows that the occurrence of drug resistance in various malignant tumors is closely related to the expression of P-glycoprotein (P-gp) on the surface of the cell membrane. In this paper, based on the structure-activity relationship of phenylethyl tetrahydroisoquinoline, we choose tariquidar as the lead compound for the design and synthesis of 17 novel tetrahydroisoquinoline P-gp inhibitors. Additionally, in vitro and in vivo cytotoxicity assays and reversed MDR activity assays were evaluated. Among them, compound 3 had a good reversal of MDR activity and the reversal mechanism study of it was carried out. All of these results demonstrated that compound 3 was considered to be a promising P-gp-mediated MDR reversal candidate.

Novel fatty acid chain modified GLP-1 derivatives with prolonged in vivo glucose-lowering ability and balanced glucoregulatory activity

Glucagon-like peptide-1 is a potent hypoglycemic hormone with beneficial properties for the treatment of diabetes. However, its half-life is short because the rapid metabolic degradation. This study aims to prolong the half-life of glucagon-like peptide-1 through conjugation with the fatty acid side chain which helps the conjugates to interact with the albumin. Firstly, we chose two optimized polypeptide chains which have tremendous hypoglycemic effect named Cys17-Gly8-GLP-1(7-36)-NH2 and Cys37-Gly8-GLP-1(7-37)-NH2, and various fatty acid chains were modified. All conjugates preserved relatively strong GLP-1R activation and I-6 behaved best in glucose-lowering ability. The prolonged antidiabetic effects of I-6 were further confirmed by hypoglycemic efficacy test in vivo. Meanwhile, once daily injection of I-6 to diabetic mice achieved long-term beneficial effects on glucose tolerance, body weight and blood chemistry. It is concluded that I-6 is a promising agent for further investigation of its potential to treat obese patients with diabetes.

Novel benzodiazepines derivatives as analgesic modulating for Transient receptor potential vanilloid 1

A new series of derivatives of 3-(7-chloro-5-(2-fluorophenyl)-2-oxo-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)propanoic acid were designed and synthesized as analgesic modulating for Transient receptor potential vanilloid 1. They were investigated for TRPV1 antagonistic activity in vitro, analgesic activity and sedative activity in vivo and aqueous solubility. Preliminary studies identified 3-(7-chloro-5-(2-fluorophenyl)-2-oxo-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)-N,N-dimethylpropanamide(Compound 11), as a potent analgesic modulating for TRPV1 with potent activity and good aqueous solubility.

Identification of highly potent and orally available free fatty acid receptor 1 agonists bearing isoxazole scaffold

The free fatty acid receptor 1 (FFA1) is being considered to be a novel anti-diabetic target based on its role in amplifying insulin secretion. We have previously identified several series of FFA1 agonists with different heterocyclic scaffolds. Herein, we describe the structural exploration of other heterocyclic scaffolds directed by drug-like physicochemical properties. Further structure-based design and chiral resolution provided the most potent compound 11 (EC50 = 7.9 nM), which exhibited improved lipophilicity (LogD7.4: 1.93), ligand efficiency (LE = 0.32) and ligand lipophilicity efficiency (LLE = 6.2). Moreover, compound 11 revealed an even better pharmacokinetic property than that of TAK-875 in terms of plasma clearance, maximum concentration, and plasma exposure. Although robust agonistic activity and PK profiles for compound 11, the glucose-lowering effects in vivo is not ideal, and the exact reason for in vitro/in vivo difference was worthy for further exploration.

Phenylquinoline transient receptor potential vanilloid 1 antagonists for the treatment of pain: Discovery of 1-(2-phenylquinoline-4-carbonyl)-N-(4-(trifluoromethyl)phenyl)pyrrolidine-3-carboxamide

Reported herein is the design, synthesis, and pharmacologic characterization of a class of TRPV1 antagonists constructed on a phenylquinoline platform that evolved from Cinchophen lead. This design composes three sections: a phenylquinoline headgroup attached to an aliphatic carboxamides, which is tethered at a phenyl tail group. Optimization of this design led to the identification of 37, comprising a pyrrolidine linker and a trifluoromethyl-phenyl tail. In the TRPV1 functional assay, using cells expressed hTRPV1, 37 antagonized capsaicin-induced Ca2+ influx, with an IC50 value of 10.2 nM. In the complete mice analgesic model, 37 exhibited better antinociceptive activity than the positive control BCTC in diverse pain models. All of these results suggested that 37 could be considered as a lead candidate for the further development of antinociceptive drugs.

Design, synthesis, and biological evaluation of thieno[2,3-d]pyrimidine derivatives as novel dual c-Met and VEGFR-2 kinase inhibitors

Both c-Met and VEGFR-2 are important targets for cancer therapies. Here we report a series of potent dual c-Met and VEGFR-2 inhibitors bearing thieno[2,3-d]pyrimidine scaffold. The cell proliferation assay in vitro demonstrated that most target compounds had inhibition potency both on c-Met and VEGFR-2 with IC50 values in nanomolar range, especially compound 12j and 12m. Based on the further enzyme assay in vitro, compound 12j was considered as the most potent one, the IC50 values of which were 25 nM and 48 nM for c-Met and VEGFR-2, respectively. Following that, we docked the compound 12j with the proteins c-Met and VEGFR-2, and interpreted the SAR of these analogues. All the results indicate that 12j is a dual inhibitors of c-Met and VEGFR-2 that holds promising potential.