5,5-Difluoro- and 5-Fluoro-5-methyl-hexose-based C-Glucosides as potent and orally bioavailable SGLT1 and SGLT2 dual inhibitors

(2S,3R,4R,5S,6R)-2-Aryl-5,5-difluoro-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4-diols and (2S,3R,4R,5S,6R)-2-aryl-5-fluoro-5-methyl-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4-diols were discovered as dual inhibitors of sodium glucose co-transporter proteins (e.g. SGLT1 and SGLT2) through rational drug design, efficient synthesis, and in vitro and in vivo evaluation. Compound 6g demonstrated potent dual inhibitory activities (IC₅₀ = 96 nM for SGLT1 and IC₅₀ = 1.3 nM for SGLT2). It showed robust inhibition of blood glucose excursion in an oral glucose tolerance test (OGTT) in Sprague Dawley (SD) rats when dosed at both 1 mg/kg and 10 mg/kg orally. It also demonstrated postprandial glucose control in db/db mice when dosed orally at 10 mg/kg.     

Synthesis and biological evaluation of benzocyclobutane-C-glycosides as potent and orally active SGLT1/SGLT2 dual inhibitors

Synthesis and biological evaluation of benzocyclobutane-C-glycosides as potent and orally active SGLT1/SGLT2 dual inhibitors are described. Compound 19 showed high inhibitory potency at SGLT1 (IC₅₀?=?45?nM), and excellent potency at SGLT2 (IC₅₀?=?1?nM). It also displayed excellent PK profiles in mice, rats, dogs and monkeys (F?=?78–107%). In SD rats, compound 19 treatments significantly reduced blood glucose levels in a dose-dependent manner. In ZDF rats, compound 19 displayed anti-hyperglycemic effect up to 24?h. Therefore, compound 19 may serve as valuable pharmacological tool, and potential use as a treatment for metabolic syndrome.     

Synthesis and biological evaluation of 6-hydroxyl C-aryl glucoside derivatives as novel sodium glucose co-transporter 2 (SGLT2) inhibitors

The sodium glucose co-transporter 2 (SGLT2) was considered as an important target for the treatment of type 2 diabetes mellitus in recent years. This report describes the design and synthesis of a series of novel SGLT2 inhibitors (11a–17a) as well as their dehydrate dihydrofuran derivatives (11b–17b), which were prepared by Mitsunobu reaction. Their SGLT2 inhibitory activity was also evaluated, and 16a and 17a were found to be the most potent compounds with IC₅₀ values of 0.63 and 0.81?nM, respectively. However, all the dehydrate derivatives lose the SGLT2 inhibitory activity, with inhibition percentage no more than 66.5% at the concentration of 0.5?μM, which might because of the configuration inversion at C-2 of glucose. In conclusion, the present study improves understanding of the SAR of SGLT2 inhibitors, and provided more information that could be applied to design new molecules.     

Discovery of a potent,low-absorbable sodium-dependent glucose cotransporter 1 (SGLT1) inhibitor (TP0438836) for the treatment of type 2 diabetes

The design and synthesis of a novel class of low-absorbable SGLT1 inhibitors are described. To achieve low absorption in the new series, we performed an optimization study based on a strategy to increase TPSA. Fortunately, the optimization of an aglycon moiety and a side chain of the distal aglycon moiety led to the identification of compound 30b as a potent and low-absorbable SGLT1 inhibitor. Compound 30b showed a desirable PK profile in Sprague-Dawley (SD) rats and a favorable glucose-lowering effect in diabetic rats.     

Discovery of novel 2-(aminoheteroaryl)-thiazole-5-carboxamides as potent and orally active Src-family kinase p56(Lck) inhibitors

A series of substituted 2-(aminoheteroaryl)-thiazole-5-carboxamide analogs have been synthesized as novel, potent inhibitors of the Src-family kinase p56^Lck. Among them, compound 2 displayed superior in vitro potency and excellent in vivo efficacy.     

Design, synthesis, and biological evaluation of triazolopiperazine-based beta-amino amides as potent, orally active dipeptidyl peptidase IV (DPP-4) inhibitors

Various beta-amino amides containing triazolopiperazine heterocycles have been prepared and evaluated as potent, selective, orally active dipeptidyl peptidase IV (DPP-4) inhibitors. These compounds display excellent oral bioavailability and good overall pharmacokinetic profiles in preclinical species. Moreover, in vivo efficacy in an oral glucose tolerance test in lean mice is demonstrated.     

Novel tetrahydropyran analogs as dipeptidyl peptidase IV inhibitors: Profile of clinical candidate (2R,3S,5R)-2-(2,5-difluorophenyl)-5-[2-(methylsulfonyl)-2,6-dihydropyrrolo[3,4-c]pyrazol-5(4H)-yl]tetrahydro-2H-pyran-3-amine (23)

A series of novel tri-2,3,5-substituted tetrahydropyran analogs were synthesized and evaluated as inhibitors of dipeptidyl peptidase IV (DPP-4) for the treatment of type 2 diabetes. Optimization of the series provided inhibitors with good DPP-4 potency and selectivity over other peptidases (QPP, DPP8, and FAP). Compound 23, which is very potent, selective, efficacious in the diabetes PD model, and has an excellent pharmacokinetic profile, is selected as a clinical candidate.     

Synthesis and biological evaluation of substituted 4-(thiophen-2-ylmethyl)-2H-phthalazin-1-ones as potent PARP-1 inhibitors

We have developed a series of substituted 4-(thiophen-2-ylmethyl)-2H-phthalazin-1-ones as potent PARP-1 inhibitors. Preliminary biological evaluation indicated that most compounds possessed inhibitory potencies comparable to, or higher than AZD-2281. Among these compounds, 18q appeared to be the most notable one, which displayed an 8-fold improvement in enzymatic activity compared to AZD-2281. These efforts lay the foundation for our further investigation.     

Design, synthesis and biological evaluation of 2-(substituted phenyl)thiazolidine-4-carboxylic acid derivatives as novel tyrosinase inhibitors

Herein we describe the design, synthesis and biological activities of 2-(substituted phenyl)thiazolidine-4-carboxylic acid derivatives as novel tyrosinase inhibitors. The target compounds 2a–2j were designed and synthesized from the structural characteristics of N-phenylthiourea, tyrosinase inhibitor and tyrosine, and l-DOPA, the natural substrates of tyrosinase. Among them, (2R/S,4R)-2-(2,4-dimethoxyphenyl)thiazolidine-4-carboxylic acid (2g) caused the greatest inhibition 66.47% at 20 μM of l-DOPA oxidase activity of mushroom tyrosinase. Kinetic analysis of tyrosinase inhibition revealed that 2g is a competitive inhibitor. We predicted the tertiary structure of tyrosinase, and simulated the docking of mushroom tyrosinase with 2g. These results suggest that the binding affinity of 2g with tyrosinase is high. Also, 2g effectively inhibited tyrosinase activity and reduced melanin levels in B16 cells treated with α-MSH. These data strongly suggest that 2g can suppress the production of melanin via the inhibition of tyrosinase activity.     

Design,synthesis and biological evaluation of 4-aminopyrimidine-5-cabaldehyde oximes as dual inhibitors of c-Met and VEGFR-2

The synergistically collaboration of c-Met/HGF and VEGFR-2/VEGF leads to development of tumor angiogenesis and progression of various human cancers. Therefore, inhibiting both HGF/c-Met and VEGF/VEGFR signaling may provide a novel and effective therapeutic approach for treating patients with abroad spectrum of tumors. Toward this goal, we designed and synthesized a series of derivatives bearing 4-aminopyrimidine-5-cabaldehyde oxime scaffold as potent dual inhibitors of c-Met and VEGFR-2. The cell proliferation assay in vitro demonstrated most target compounds have inhibition potency both on c-Met and VEGFR-2 with IC₅₀ values in nanomolar range, especially compound 14i, 18a and 18b. Based on the further enzyme assay in vitro, compound 18a was considered as the most potent one, the IC₅₀s of which were 210 nM and 170 nM for c-Met and VEGFR-2, respectively. Following that, we docked the compound 10 and 18a with the proteins c-Met and VEGFR-2, and interpreted the SAR of these analogs. All the results indicate that 18a is a dual inhibitors of c-Met and VEGFR-2 that holds promising potential.     

C-aryl glucosides substituted at the 4'-position as potent and selective renal sodium-dependent glucose co-transporter 2 (SGLT2) inhibitors for the treatment of type 2 diabetes

A series of C-aryl glucosides with various substituents at the 4′-position of the distal aryl ring have been synthesized and evaluated for inhibition of hSGLT1 and hSGLT2. Introduction of alkyl or alkoxy substituents at the 4′-position was found to improve SGLT2 potency, whereas introduction of a hydrophilic group at this position was deleterious. Compounds with alkoxy-, cycloalkoxy- or cycloalkenyloxy-ethoxy scaffolds exhibited good inhibitory activity and high selectivity toward SGLT2. Selected compounds were investigated for in vivo efficacy.     

Design,synthesis, and biological evaluation of 2-amino-N-(2-methoxyphenyl)-6-((4-nitrophenyl)sulfonyl)benzamide derivatives as potent HIV-1 Vif inhibitors

Viral infectivity factor (Vif) is one of the accessory protein of human immunodeficiency virus type I (HIV-1) that inhibits host defense factor, APOBEC3G (A3G), mediated viral cDNA hypermutations. Previous work developed a novel Vif inhibitor 2-amino-N-(2-methoxyphenyl)-6-((4-nitrophenyl)thio)benzamide (1) with strong antiviral activity. Through optimizations on the two side branches, a series of compound 1 derivatives (2–18) were designed, synthesized and tested in vitro for their antiviral activities. The biological results showed that compound 5 and 16 inhibited the virus replication efficiently with EC₅₀ values of 9.81 and 4.62 μM. Meanwhile, low cytotoxicities on H9 cells were observed for the generated compounds by the MTT assay. The structure–activity relationship of compound 1 was preliminarily clarified, which gave rise to the development of more potent Vif inhibitors.     

Novel tricyclic poly (ADP-ribose) polymerase-1/2 inhibitors with potent anticancer chemopotentiating activity: Design,synthesis and biological evaluation

8,9-Dihydro-2,4,7,9a-tetraazabenzo[cd]azulen-6(7H)-ones were designed and synthesized as a new class of PARP-1/2 inhibitors. The compounds displayed a variable pattern of PARP-1/2 enzymes inhibition profile that, in part, paralleled the antiproliferative activity in cell lines. Among them, compound 9e exhibited not only the significant IC₅₀ value of 28 nM in the PARP-1 and 7.7 nM in PARP-2 enzyme assay, but also a profound synergic efficacy combined with temozolomide with PF₅₀ values of 2.6, 2.5, and 6.5 against MDA-MB-468, SW-620 and A549 and cell line, respectively.     

Design,synthesis and evaluation of new 6-substituted-5-benzyloxy-4-oxo-4H-pyran-2-carboxamides as potential Src inhibitors

Src family kinases (SFKs) are nonreceptor tyrosine kinases that are reported to be critical for cancer progression. Inhibiting the catalytic activity of these proteins has become one of the major therapeutic concepts in contemporary drug discovery. We report here the design and the synthesis of novel 6-substituted-5-benzyloxy-4-oxo-4H-pyran-2-carboxamides as potential inhibitors of Src kinase. The synthesis of these derivatives and the preliminary results of biological activity will be discussed.     

Design,synthesis and biological evaluation of novel pyrimidinedione derivatives as DPP-4 inhibitors

A series of novel pyrimidinedione derivatives were designed and evaluated for in vitro dipeptidyl peptidase-4 (DPP-4) inhibitory activity and in vivo anti-hyperglycemic efficacy. Among them, the representative compounds 11, 15 and 16 showed excellent inhibitory activity of DPP-4 with IC₅₀ values of 64.47?nM, 188.7?nM and 65.36?nM, respectively. Further studies revealed that compound 11 was potent in vivo hypoglycemic effect. The structure–activity relationships of these pyrimidinedione derivatives had been discussed, which would be useful for developing novel DPP-4 inhibitors as treating type 2 diabetes.     

Discovery of 5-(5-fluoro-1H-pyrrolo[2,3-b]pyridin-3-yl)pyrazin-2(1H)-one derivatives as new potent PB2 inhibitors

PB2 is an important subunit of influenza RNA-dependent RNA polymerase (RdRP) and has been recognized as a promising target for the treatment of influenza. We herein report the discovery of a new series of PB2 inhibitors containing the skeleton 5-(5-fluoro-1H-pyrrolo[2,3-b]pyridin-3-yl)pyrazin-2(1H)-one. Compound 12b is the most potent one, which showed K_D values of 0.11 μM and 0.19 μM in surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) assays, respectively. In antiviral activity and cellular cytotoxicity assays, compound 12b showed an EC₅₀ value of 1.025 μM and a CC₅₀ value greater than 100 μM. Molecular docking was also used to predict the binding mode of 12b with PB2. Collectively, this study provides a promising lead compound for subsequent anti-influenza drug discovery targeting PB2.     

Synthesis and biological evaluation of 5-carbamoyl-2-phenylpyrimidine derivatives as novel and potent PDE4 inhibitors

5-Carbamoyl-2-phenylpyrimidine derivative 2 has been identified as a phosphodiesterase 4 (PDE4) inhibitor with moderate PDE4B inhibitory activity (IC₅₀ = 200 nM). Modification of the carboxylic acid moiety of 2 gave N-neopentylacetamide derivative 10f, which had high in vitro PDE4B inhibitory activity (IC₅₀ = 8.3 nM) and in vivo efficacy against lipopolysaccharide (LPS)-induced pulmonary neutrophilia in mice (ID₅₀ = 16 mg/kg, ip). Furthermore, based on the X-ray crystallography of 10f bound to the human PDE4B catalytic domain, we designed 7,8-dihydro-6H-pyrido[4,3-d]pyrimidin-5-one derivative 39 which has a fused bicyclic lactam scaffold. Compound 39 exhibited excellent inhibitory activity against LPS-induced tumor necrosis factor alpha (TNF-α) production in mouse splenocytes (IC₅₀ = 0.21 nM) and in vivo anti-inflammatory activity against LPS-induced pulmonary neutrophilia in mice (41% inhibition at a dose of 1.0 mg/kg, i.t.).     

Design,synthesis and biological evaluation of 7-nitro-1H-indole-2-carboxylic acid derivatives as allosteric inhibitors of fructose-1,6-bisphosphatase

A series of novel indole derivatives was synthesized as inhibitors of fructose-1,6-bisphosphatase (FBPase). Extensive structure–activity relationships were conducted and led to a potent FBPase inhibitor 3.9 with an IC₅₀ of 0.99 μM. The binding mode of this series of indoles was predicted using CDOCKER algorithm. The results of this research will shed light on the further design and optimization of novel small molecules as FBPase inhibitors.     

A novel,potent, and orally active VLA-4 antagonist with good aqueous solubility: trans-4-[1-[[2-(5-Fluoro-2-methylphenylamino)-7-fluoro-6-benzoxazolyl]acetyl]-(5S)-[methoxy(methyl)amino]methyl-(2S)-pyrrolidinylmethoxy]cyclohexanecarboxylic acid

We have carried out the optimization of substituents at the C-3 or the C-5 position on the pyrrolidine ring of VLA-4 antagonist 3 with 2-(phenylamino)-7-fluorobenzoxazolyl moiety for the purpose of improving in vivo efficacy while maintaining good aqueous solubility. As a result, we successfully increased in vitro activity in the presence of 3% human serum albumin and achieved an exquisite lipophilic and hydrophilic balance of compounds suitable for oral administrative regimen. The modification resulted in the identification of zwitterionic compound 7n with (5S)-[methoxy(methyl)amino]methylpyrrolidine, which significantly alleviated bronchial hyper-responsiveness to acetylcholine chloride at 12.5 mg/kg, p.o. in a murine asthma model and showed favorable aqueous solubility (JP1, 89 μg/mL; JP2, 462 μg/mL). Furthermore, this compound showed good oral bioavailability (F = 54%) in monkeys.     

Design, synthesis, and biological evaluation of (E)-3-(4-methanesulfonylphenyl)-2-(aryl)acrylic acids as dual inhibitors of cyclooxygenases and lipoxygenases

A group of (E)-3-(4-methanesulfonylphenyl)acrylic acids possessing a substituted-phenyl ring (4-H, 4-Br, 3-Br, 4-F, 4-OH, 4-OMe, 4-OAc, and 4-NHAc) attached to the acrylic acid C-2 position were prepared using a stereospecific Perkin condensation reaction. A related group of compounds having 4- and 3-(4-isopropyloxyphenyl)phenyl, 4- and 3-(2,4-difluorophenyl)phenyl and 4- and 3-(4-methanesulfonylphenyl)phenyl substituents attached to the acrylic acid C-2 position were also synthesized, using a palladium-catalyzed Suzuki cross-coupling reaction, for evaluation as dual cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) inhibitors. (E)-2-(3-Bromophenyl)-3-(4-methanesulfonylphenyl)acrylic acid (9h), and compounds having 4-(4-isopropyloxyphenyl-, 2,4-difluorophenyl-, or 4-methylsulfonylphenyl)phenyl moieties at the acrylic acid C-2 position (11a,b,d), were particularly potent COX-2 inhibitors with a high COX-2 selectivity index (COX-2 IC50 approximately 0.32 microM, SI > 316) similar to the reference drug rofecoxib (COX-2 IC50 = 0.5 microM, SI > 200). Acrylic acid analogs with a C-2 4-hydoxyphenyl (9d, IC50 = 0.56 microM), or 4-acetamidophenyl (9g, IC50 = 0.11 microM), substituent were particularly potent 5-LOX inhibitors that may participate in an additional specific hydrogen-bonding interaction. A number of compounds possessing a C-2 substituted-phenyl moiety (4-Br, 4-F, and 4-OH), or a 4- or 3-(2,4-difluorophenyl)phenyl moiety, showed potent 15-LOX inhibitory activity (IC50 values in the 0.31-0.49 microM range) relative to the reference drug luteolin (IC50 = 3.2 microM). Compounds having a C-2 4-acetylaminophenyl, or 4-(2,4-difluorophenyl)phenyl, moiety exhibited anti-inflammatory activities that were equipotent to aspirin, but less than that of celecoxib. The structure-activity data acquired indicate the acrylic acid moiety constitutes a suitable scaffold (template) to design novel acyclic dual inhibitors of the COX and LOX isozymes.