Yafei Xie

Discovery of Flexible Naphthyltriazolylmethane-based Thioacetic Acids as Highly Active Uric Acid Transporter 1 (URAT1) Inhibitors for the Treatment of Hyperuricemia of Gout.

BACKGROUND Gout is the most common inflammatory arthritis, which, if left untreated or inadequately treated, will lead to joint destruction, bone erosion and disability due to the crystal deposition. Uric acid transporter 1 (URAT1) was the promising therapeutic target for urate-lowering therapy. OBJECTIVE The goal of this work is to understand the structure-activity relationship (SAR) of a potent lesinurad-based hit, sodium 2-((5-bromo-4-((4-cyclopropyl-naphth-1-yl)methyl)-4H-1,2,4-triazol-3- yl)thio)acetate (1c), and based on that discover a more potent URAT1 inhibitor. METHODS The SAR of 1c was systematically explored and the in vitro URAT1 inhibitory activity of synthesized compounds 1a-1t was determined by the inhibition of URAT1-mediated [8-14C]uric acid uptake by human embryonic kidney 293 (HEK293) cells stably expressing human URAT1. RESULTS Twenty compounds 1a-1t were synthesized. SAR analysis was performed. Two highly active URAT1 inhibitors, sodium 2-((5-bromo-4-((4-n-propylnaphth-1-yl)methyl)-4H-1,2,4-triazol-3- yl)thio)acetate (1j) and sodium 2-((5-bromo-4-((4-bromonaphth-1-yl)methyl)-4H-1,2,4-triazol-3- yl)thio)acetate (1m), were identified, which were 78- and 76-fold more active than parent lesinurad in in vitro URAT1 inhibitory assay, respectively (IC50 values for 1j and 1m were 0.092 μM and 0.094 μM, respectively, against human URAT1 vs 7.18 μM for lesinurad). CONCLUSION Two highly active URAT1 inhibitors were discovered. The SAR exploration also identified more flexible naphthyltriazolylmethane as a novel molecular skeleton that will be valuable for the design of URAT1 inhibitors, as indicated by the observation that many of the synthesized naphthyltriazolylmethane- bearing derivatives (1b-1d, 1g, 1j and 1m) showed significantly improved UART1 inhibitory activity (sub-micromolar IC50 values) as compared with lesinurad which has the rigid naphthyltriazole skeleton.

Design, synthesis and biological activity of tetrazole-bearing uric acid transporter 1 inhibitors

Systematic structure-activity relationship(SAR) exploration of a moderately active tetrazole-bearing lesinurad-based hit 1f led to the discovery of a potent uric acid transporter 1(URAT1) inhibitor 1i, which possessed a novel molecular skeleton and was 11-fold more potent than the parent lesinurad against human URAT1 in-vitro (IC50=0.66 μmol/L for 1i vs. 7.18 μmol/L for lesinurad).

Discovery of a Flexible Triazolylbutanoic Acid as a Highly Potent Uric Acid Transporter 1 (URAT1) Inhibitor

In order to systematically explore and understand the structure–activity relationship (SAR) of a lesinurad-based hit (1c) derived from the replacement of the S atom in lesinurad with CH2, 18 compounds (1a–1r) were designed, synthesized and subjected to in vitro URAT1 inhibitory assay. The SAR exploration led to the discovery of a highly potent flexible URAT1 inhibitor, 1q, which was 31-fold more potent than parent lesinurad (IC50 = 0.23 μM against human URAT1 for 1q vs 7.18 μM for lesinurad). The present study discovered a flexible molecular scaffold, as represented by 1q, which might serve as a promising prototype scaffold for further development of potent URAT1 inhibitors, and also demonstrated that the S atom in lesinurad was not indispensable for its URAT1 inhibitory activity.

Systematic Structure-Activity Relationship (SAR) Exploration of Diarylmethane Backbone and Discovery of A Highly Potent Novel Uric Acid Transporter 1 (URAT1) Inhibitor

In order to systematically explore and better understand the structure-activity relationship (SAR) of a diarylmethane backbone in the design of potent uric acid transporter 1 (URAT1) inhibitors, 33 compounds (1a–1x and 1ha–1hi) were designed and synthesized, and their in vitro URAT1 inhibitory activities (IC50) were determined. The three-round systematic SAR exploration led to the discovery of a highly potent novel URAT1 inhibitor, 1h, which was 200- and 8-fold more potent than parent lesinurad and benzbromarone, respectively (IC50 = 0.035 μM against human URAT1 for 1h vs. 7.18 μM and 0.28 μM for lesinurad and benzbromarone, respectively). Compound 1h is the most potent URAT1 inhibitor discovered in our laboratories so far and also comparable to the most potent ones currently under development in clinical trials. The present study demonstrates that the diarylmethane backbone represents a very promising molecular scaffold for the design of potent URAT1 inhibitors.

Facile synthetic approaches to 1-thiocyclopropanecarboxylates

GRAPHICAL ABSTRACT ABSTRACT Two facile synthetic approaches to the novel biologically interesting 1-thiocyclopropanecarboxylates starting from corresponding thiols were developed. Approach A involved five steps with the key steps being the SN2 reactions of thiols and α-bromobutyrolactone and cyclopropane formation via t-BuOK-mediated intramolecular SN2 cyclization. It had advantages such as inexpensive reagents and simplicity of operation but was associated with limitations such as relatively more reaction steps and incompatibility with thiols exhibiting acidic and alkaline functional groups. Approach B involved two steps with the key step being LDA-mediated cyclopropane formation at the α-position of carboxylate groups by use of 1,3,2-dioxathiolane-2,2-dioxide. It showed advantages such as fewer reaction steps and simplicity of operation but was associated with limitations such as relatively expensive reagents and incompatibility with thiols exhibiting acidic functional groups. The two approaches are complementary in many respects, allowing for flexible choices according to specific requirements for the characteristics of synthetic methods.

A Facile Convergent Synthetic Procedure for 3-Deoxydapagliflozin as SGLT2 Inhibitor

3-Deoxydapagliflzoin (1) is a highly selective, potent sodium-dependent glucose transporter 2 (SGLT2) inhibitor discovered earlier. A facile convergent synthetic procedure for 3-deoxydapagliflzoin (1) was developed in 13 steps and in 38% overall yield starting from inexpensive methyl α-D-glucopyranoside 2. Regioselective protection of 2-OH and 3-OH in the key intermediate methyl 4,6-O-benzylidene-α-D-glucopyranoside 3 was systematically studied; the regioisomers thus obtained were distinguished from each other with nuclear overhauser effect (NOE) and their ratios and relative polarities were rationally explained. The strategy for deoxygenation of the sterically hindered 3-OH in another key intermediate 4,6-O-benzylidene-2-O-t-butyldiphenylsilyl-α-D-glucopyranoside (4) was also systematically studied. The facile synthetic route is characterized by convergence characteristics and inexpensive starting material, also representing an alternative general synthetic approach to phenyl 3-deoxy-C-glucosides.

3-Oxodapagliflozin as a potent and highly selective SGLT2 inhibitor for the treatment of type 2 diabetes

Structural modifications of 3-OH in the glucose moiety of dapagliflozin(1), an approved potent sodium-dependent glucose transporter 2(SGLT2) inhibitor, led to 3-oxodapagliflozin(16), a highly potent and more selective SGLT2 inhibitor[IC50(hSGLT1)/IC50(hSGLT2)=2851 for compound 16vs. 843 for compound 1]. 3-Oxodapagliflozin(16) exhibited in vitro(IC50=1.0 nmol/L against hSGLT2 for compound 16vs. 1.3 nmol/L for compound 1) and in vivo activities comparable to those of dapagliflozin(1). The bioactivities of 3-oxodapagliflozin (16) warrant its further evaluation as a promising SGLT2 inhibitor for the treatment of type 2 diabetes.