PF-04827736 ((S)-PF-04677490) is a potent, selective PDE1 inhibitor with IC50 of 42, 9.1 and 38 nM for PDE1A, PDE1B and PDE1C, respectively; displays >10-fold selectivity over PDE10A1, and >45-fold selectivity over other PDE isoforms.

NRT-870-59 is a potent, reversible PTP4A3 inhibitor (IC50=86 nM) with inhibitory specificity for PTP4A3 versus both PTP4A3 A111S mutant and CDC25B.NRT-870-59 does not inhibit CDC25B and PTP4A3 A111S mutant at 1 uM, and 5- to 6-fold less potent aginst DUSP3.NRT-870-59 inhibits PTP4A1, PTP4A2, PTP4A3 mutants C49S, K144I and A106V with IC50 of 133.2, 264.4, 86.0, 332.2, 180.2 and 57.7 nM, respectively.NRT-870-59 inhibits cancer cell colony formation, which is required PTP4A3 expression.The PTP4A (phosphatase of regenerating liver/PRL) phosphatases are a unique subfamily of protein tyrosine phosphatases (PTPs) comprising three highly homologous members (PTP4A1, PTP4A2, and PTP4A3) with 80% amino acid sequence identity.PTP4A3, and to a lesser extent PTP4A1 and PTP4A2, are overexpressed in many types of cancer, promote tumor invasion and dissemination, and contribute to poor patient prognosis.

NOS31 is a potent, selective NADPH oxidase 1 (Nox1) inhibitor with IC50 of 2.0 uM.NOS31 inhibited ROS production in CaCO2 cells in a dose-dependent manner, inhibits NOXO1/NOXA1-induced ROS production.NOS31 is much less potent with other Nox enzymes Nox2, Nox3, Nox4, and Nox5 in HEK293 reconstitution systems (>15-fold selectivity).NOS31 inhibited the proliferation of several colon cancer cell lines in vitro (CaCO2, HT-29, DLD-1, RKO, and HCT-116), with no direct antioxidant activity nor cytotoxity.

NHB1109 is a potent, selective, orally active PTPRD phosphatase inhibitor with IC50 of 0.6 uM, displays selectivity over PTPRS, PTPRF, PTPRJ or PTPN1/PTP1B phosphatases.NHB1109 exhibited no substantial potency at other protein tyrosine phosphatases screened, no significant potency at any of the targets of clinically-useful drugs identified in EUROFINS screens.NHB1109 (200 mg/kg) is well tolerated by mice.NHB1109 is a good candidate to advance to in vivo studies in addiction paradigms and toward human use to reduce reward from addictive substances.

NCATS-SM5637 (NSC 791985) is a potent, selective mutant IDH1 inhibitor with IC50 of 81/72 nM for IDH1 mutant R132H/R132C, respctively.NCATS-SM5637 showed higher tumoral concentrations that corresponded to lower 2-HG concentrations in engineered mIDH1-U87-xenograft mouse model, compared with the approved drug AG-120 (ivosidenib).

MMP-13i is a potent, highly-selective inhibitor of MMP-13 catalytic activity with IC50 of 2.7 nM, no inhibitory effect against MMP1/2/8/9/14 (IC50>5,000 nM).MMP-13i potently suppressed wild-type osteoclast formation in vitro at concentrations <100 nM.MMP-13i strongly inhibited multiple myeloma viability.MMP-13i treatment delayed multiple myeloma growth in immunocompetent syngeneic mouse model of multiple myeloma, inhibited multiple myeloma promotes systemic skeletal bone disease.

LY2775240 (LY-2775240) is a highly selective, potent and orally active inhibitor of phosphodiesterase 4 (PDE4) with IC50 of 0.09/0.09/2.4/0.14 nM for PDE4A/B/C/D.LY2775240 displays >200-fold selectivity over PDE10A, and >5000-fold selectivity over other PDE isoforms (IC50>10 uM).LY2775240 potently inhibits TNFα secreted induced by Toll‐like receptor 4 agonist LPS in a human whole blood assay, inhibited LPS‐stimulated TNFα but has no effect with the media‐only control.LY2775240 is more potent than apremilast (IC50, 18 nM vs. 290 nM), also affects E‐selectin, secreted IgG, plasminogen activator inhibitor‐1, and secreted IL‐10.

Lockdown is a selective, reversible and non-competitive inhibitor of the integrin phosphatase PPM1F (IC50=16.37 uM), blocks cancer cell invasion.Lockdown acts in a dose-dependent, allosteric manner with high selectivity for PPM1F.Lockdown does not inhibit other protein phosphatases (PTP1P, PTPRJ, PP5) in vitro and does not induce additional phenotypes in PPM1F knockout cells.Lockdown fully re-capitulated the phenotype of PPM1F-deficient cells, increased phosphorylation of PPM1F substrates and corruption of integrin-dependent cellular processes in Lockdown treated glioblastoma cells.Phosphatase PPM1F is a regulator of cell adhesion by fine-tuning integrin activity and actin cytoskeleton structures. Elevated expression of this enzyme in human tumors is associated with high invasiveness, enhanced metastasis, and poor prognosis.

Lockdown Ester Prodrug (Lockdown Pro) is the ester-modified Lockdown with increased membrane permeability and prodrug-like properties, a selective small-molecule inhibitor of the integrin phosphatase PPM1F, blocks cancer cell invasion.Lockdown Ester Prodrug (Lockdown Pro) effectively block PPM1F-mediated effects on integrin β1 and PAK in cells, Lockdown Pro suppresses tissue invasion by PPM1F-overexpressing human cancer cells.

JNJ-39641160 (JNJ39641160) is a peripherally restricted, non-covalent, potent, selective, orally-available Cathepsin S (CatS) inhibitor with Ki of 38 nM (hCatS).JNJ-39641160 maintains a high selectivity against other closely related cysteine proteases including cathepsins B, C, F, V (L2), K, Z, C, or legumain and the aspartic proteases such as cathepsins E or D.JNJ-39641160 showed similar potency against human and monkey CatS enzymes, and it exhibited less, albeit significant, activity against mouse and dog CatS enzymes (Ki=160-207 nM).JNJ-39641160 is only weakly active against rat cathepsin S (Ki=9.6 uM). JNJ-39641160 induced accumulation of the p10Ii with an average IC50 of 294 ± 28 nM, showed similar potency in purified human PBMC with IC50 of 327 nM.JNJ-39641160 dose-dependently blocked the proteolysis of the invariant chain, and inhibited both T-cell activation and antibody production to a vaccine antigen in C57BL/6 mice.JNJ-39641160 fully reversed tactile allodynia in wild-type mice but was completely ineffective in the same model in CatS knockout mice.

IRAP-IN-1 is a selective insulin-regulated aminopeptidase (IRAP) inhibitor with IC50 of 32 nM, >25-fold selectivity over ERAP1 and ERAP2.IRAP-IN-1 reduces IRAP-dependent but not ERAP1-dependent cross-presentation by dendritic cells with nanomolar efficacy.

IMA-1 is a small molecule that interrupt the arachidonate 12-lipoxygenase (ALOX12)-acetyl-CoA carboxylase 1 (ACC1) interaction.IMA-1 markedly blocked diet-induced NASH progression in both male mice and Cynomolgus macaque therapeutic models.The anti-NASH efficacy of IMA-1 was comparable to ACC inhibitor in both species.IMA-1 directly binds to a pocket in ALOX12 proximal to its ACC1-interacting surface instead of inhibiting ALOX12 lipoxygenase activity.IMA-1 treatment did not elicit hyperlipidemia, a known side effect of direct inhibition of ACC enzymatic activity, in both mice and macaques.

Human C53 peptide (C53, pGC-B activator C53) is a novel potent, selective particulate guanylyl cyclase B (pGC-B) activator, activates pGC-B/cGMP signaling pathway, and enhances cGMP generating actions.C53 is highly resistant to NEP degradation and has less interaction with NPRC compared to CNP in vitro.C53 activates the protective pGC-B/cGMP signaling pathway and possesses enhanced cGMP generating actions.C53 inhibits fibroblast proliferation chronically and suppresses the differentiation of fibroblasts to myofibroblasts.

GSK2194069 is a potent and specific inhibitor of the β-ketoacyl reductase (KR) activity of human fatty acid synthase (hFAS) with IC50 of 7.7 nM (CoA release); shows an IC50 of 29 nM versus hFAS with acetoacetyl-CoA as the substrate, but shows little or no inhibition with β-hydroxybutyrylCoA and crotonyl-CoA (IC50 >1,000 nM), also does not inhibit the partial activities of the KS domain; decreases phosphatidylcholine levels in A549 cells with IC50 of 15.5 nM without effect on FAS protein levels, reduced A549 cell growth with EC50 of 15 nM.

GSK180 (GSK-180) is a potent and specific inhibitor of kynurenine-3-monooxygenase (KMO) with IC50 of 6 nM, shows negligible activity against other enzymes on the tryptophan pathway; inhibits the convertion of kynurenine to 3-hydroxykynurenine with IC50 of 2.0 uM in cell-based assays; prevents multiple organ failure in rodent models of acute pancreatitis.

GNI-50 is a potent, selective Nampt inhibitor with enzyme IC50 of 7 nM, A2780 cellular IC50 of 32 nM.GNI-50 showed excellent in vivo antitumor efficacy when dosed orally in an A2780 ovarian tumor xenograft model (TGI of 97% was observed on day 17).

Dichloro-all-trans-retinone (DAR) is an irreversible inhibitor of retinaldehyde dehydrogenase (RALDH/ALDH1A) with IC50 of 434/55/161 nM for RALDH1/RALDH2/RALDH3.Dichloro-all-trans-retinone has no activity on human mitochondrial ALDH2.Dichloro-all-trans-retinone inhibits ATRA synthesis in a RALDH2 expressing cell line with IC50 of 3 uM.The retinaldehyde dehydrogenase (RALDH, also ALDH1A) subfamily consists of three members, RALDH1 (ALDH1A1), RALDH2 (ALDH1A2), and RALDH3 (ALDH1A3), which synthesize all-trans-retinoic acid (ATRA) from retinaldehyde.

C-type natriuretic peptide (CNP, pGC-B activator) is the native particulate guanylyl cyclase B receptor (pGC-B) activator.CNP induces anti-remodeling actions in the heart and kidney through the generation of the second messenger cGMP.CNP selectively activates pGC-B and generates cGMP in vitro.CNP is abundantly expressed in the endothelium and kidneys as well as the heart, but to lesser extent than trial natriuretic peptide (ANP) and b-type natriuretic peptide (BNP).CNP is produced as a prohormone that is cleaved intracellularly by the enzyme, furin, to yield a 53-AA intermediate form (C53).

CPL500036 (CPL-500036) is a highly potent, selective and orally bioavailable PDE10A inhibitor with IC50 of 35 nM.CPL500036 is highly selective for PDE10A over other PDEs and common off-targets.CPL500036 effectively penetrates the brain where increases cAMP/cGMP levels and phosphorylates effector proteins like AMPA subunits.CPL500036 reduced sensorimotor deficits in 6-OHDA-lesioned rats.Acute and chronic CPL500036 did not reduce effects of L-DOPA in sensorimotor tests.Chronic CPL500036 treatment did not decrease L-DOPA-induced contralateral rotation.

CNBDA is a novel selective Src homology phosphotyrosine phosphatase 2 (SHP2) inhibitor with IC50 of 5 uM, 25-fold selectivity over SHP1.Treatment HER2-positive BC cells with CNBDA suppressed cell proliferation in 2D culture, anchorage-independent growth in soft agar, and mammosphere (tumorisphere) formation in suspension cultures in a concentration-dependent manner.CNBDA inhibited EGF-induced signaling and expression of HER2 by inhibiting the PTPase activity of SHP2 in BC cells.

BVQ1814 (BVQ-1814) is a highly effective fluorescent probe targeting PDE10A with highly potent affinity (IC50=0.9 nM), >1000-fold subfamily selectivity.

BI-1915 (BI 1915) is a highly potent, selective inhibitor of Cathepsin S (CatS) with IC50 of 17 nM for in vitro use, no significant inhibition on Cathepsin L/K/B (IC50>10 uM); BI-1915 effectively blocks the specific ovalbumin induced IL-2 secretion in T-cells with an EC50 value of 2.8 nM. BI-1915 shows excellent selectivity against related cathepsins with IC50 values of >10 µM (Cat K and Cat B) and >30 µM (Cat L).

BI-1124 (BI 1124) is a highly potent, selective inhibitor of Cathepsin S (CatS) with IC50 of 7 nM, >40-fold selectivity over Cathepsin L/K/B; BI-1124 had a superior PK profile and showed dose-dependent inhibition of the ovalbumin induced IL-2 secretion in a T cell receptor transgenic DO11 mouse model with an IC50 of 0.3 mg/kg.

AXKO-0046 (AXKO0046) is the first highly selective, small molecule inhibitor of human lactate dehydrogenase B (LDHB), exhibits uncompetitive LDHB inhibition with EC50 of 42 nM.AXKO-0046 selectively inhibited LDHB activity in an uncompetitive manner with respect to NADH and pyruvate, no inhibitory activity against LDHA at 300 uM.AXKO-0046 did not bind in the catalytic site of the enzyme but significantly bound to LDHB in the novel allosteric site of the tetramer.AXKO-0046 is a promising chemical probe to elucidate the role of LDHB-associated pathways in cancer metabolism.

AM9928 is a potent, covalent monoacylglycerol lipase (MAGL) inhibitor with IC50 of 8.9 nM (hMAGL).AM9928 covalently binds to and inactivates MAGL by carbamylation of the enzyme's catalytic Ser122 nucleophile.AM9928 inhibited adhesion and transmigration of breast cancer cells through human brain microvascular endothelial cells (HBMECs), inhibited TNBC's secretion of inflammatory cytokines such as IL-6 and IL-8, and the angiogenic factor VEGF-A.AM9928 inhibited in vivo changes in BBB permeability and decreased TNBC colonization in brain.MAGL inhibitor AM9928 is a novel treatment of TNBC tumor growth and TNBC-colonization in the brain.

AM6580 is a potent, covalent monoacylglycerol lipase (MAGL) inhibitor with IC50 of 3 nM (hMAGL).AM6580 covalently binds to and inactivates MAGL by carbamylation of the enzyme's catalytic Ser122 nucleophile.

ALDH inhibitor KS100 (KS100) is a novel, potent, multi-isoform ALDH inhibitor with IC50 of 207/1410/240 nM for ALDH1A1/ALDH2/ALDH3A1, respectively; KS100 was mitigated by development of a nanoliposomal formulation, called NanoKS100. NanoKS100 was 5-fold more selective for killing melanoma cells compared with normal human fibroblasts. Inhibition by KS100 significantly reduced total cellular ALDH activity to increase reactive oxygen species generation, lipid peroxidation, and accumulation of toxic aldehydes leading to apoptosis and autophagy.

ACC2 inhibitor 2e is a highly potent and selective acetyl-CoA carboxylase 2 (ACC2) inhibitor with IC50 of 1.9 nM and 1950 nM for ACC2 and ACC1, respectively.ACC2 inhibitor 2e exhibited good PK profile and in vivo antidiabetic efficacy in C57BL/6 mice.

AA6216 (AA 6216) is novel potent, selective PDE4 inhibitor with IC50 of 0.63 nM.AA6216 showed stronger inhibitory effects against PDE4 than other PDE family members. AA6216 potently inhibits cytokine production (TNF-α,IL-12p40, IL-4, and IL-13, IC50s=2.2-7.9 nM) by PBMCs stimulated with PHA.AA6216 inhibited the production of TGF-β1 by a human monocytic cell line THP-1, AA6216 dose-dependently reduced the production of TNF-α by alveolar macrophages from patients with IPF.AA6216 demonstrated anti-fibrotic potency on mouse model of bleomycin-induced lung fibrosis.

A-908292 is a highly potent and selective acetyl-CoA carboxylase 2 (ACC2) inhibitor with IC50 of 38 nM (hACC2), no activity against ACC1 (IC50>30 uM).