Talabostat (PT100, Val-boroPro) is a potent, nonselective and orally available dipeptidyl peptidase IV (DPP-IV) inhibitor with a Ki of 0.18 nM. Talabostat is a nonselective DPP-IV inhibitor, inhibiting DPP8 9, FAP, DPP2 and some other DASH family enzymes essentially as potently as it inhibits DPP-IV[1]. Talabostat stimulates the immune system by triggering a proinflammatory form of cell death in monocytes and macrophages known as pyroptosis. The inhibition of two serine proteases, DPP8 and DPP9, activates the proprotein form of caspase-1 independent of the inflammasome adaptor ASC[2]. Talabostat competitively inhibits the dipeptidyl peptidase (DPP) activity of FAP and CD26 DPP-IV, and there is a high-affinity interaction with the catalytic site due to the formation of a complex between Ser630 624 and the boron of talabostat[3]. Talabostat can stimulate immune responses against tumors involving both the innate and adaptive branches of the immune system. In WEHI 164 fibrosarcoma and EL4 and A20 2J lymphoma models, PT-100 causes regression and rejection of tumors. The antitumor effect appears to involve tumor-specific CTL and protective immunological memory. Talabostat treatment of WEHI 164-inoculated mice increases mRNA expression of cytokines and chemokines known to promote T-cell priming and chemoattraction of T cells and innate effector cells[3]. Talabostat treated mice show significant less fibrosis and FAP expression is reduced. Upon PT100 treatment, significant differences in the MMP-12, MIP-1α, and MCP-3 mRNA expression levels in the lungs are also observed. Treatment with PT100 in this murine model of pulmonary fibrosis has an anti-fibro-proliferative effect and increases macrophage activation[4]. [1]. Connolly BA, et al. Dipeptide boronic acid inhibitors of dipeptidyl peptidase IV: determinants of potencyand in vivo efficacy and safety. J Med Chem. 2008 Oct 9;51(19):6005-13. [2]. Okondo MC, et al. DPP8 and DPP9 inhibition induces pro-caspase-1-dependent monocyte and macrophage pyroptosis. Nat Chem Biol. 2017 Jan;13(1):46-53. [3]. Adams S, et al. PT-100, a small molecule dipeptidyl peptidase inhibitor, has potent antitumor effects and augments antibody-mediated cytotoxicity via a novel immune mechanism. Cancer Res. 2004 Aug 1;64(15):5471-80. [4]. Egger C, et al. Effects of the fibroblast activation protein inhibitor, PT100, in a murine model of pulmonary fibrosis. Eur J Pharmacol. 2017 Aug 15;809:64-72.
4′-Hydroxy-2′-methylacetophenone, an aroma compound of red wines, is isolated from cv. Bobal grape variety. 4′-Hydroxy-2′-methylacetophenone has ciliate toxicity. 4′-Hydroxy-2′-methylacetophenone inhibits the growth of T. pyriformis, with an IC50 of 0.65 mM[1][2]. [1]. GómezGarcía-Carpintero E, et, al. Aroma characterization of red wines from cv. Bobal grape variety grown in La Mancha region. Food Research International. 2011 Jan; 44(1): 61-70. [2]. Schüürmann G, et, al. Stepwise discrimination between four modes of toxic action of phenols in the Tetrahymena pyriformis assay. Chem Res Toxicol. 2003 Aug;16(8):974-87.
FI-700 is a novel and potent FLT3 inhibitor with promising antileukemia activity. FI-700 showed a potent IC(50) value against FLT3 kinase at 20 nmol L in an in vitro kinase assay. FI-700 showed selective growth inhibition against mutant FLT3-expressing leukemia cell lines and primary acute myeloid leukemia cells, whereas it did not affect the FLT3 ligand (FL)-driven growth of Wt-FLT3-expressing cells. Oral administration of FI-700 induced the regression of tumors in a s.c. tumor xenograft model and increased the survival of mice in an i.v. transplanted model. Furthermore, FI-700 treatment eradicated FLT3 ITD-expressing leukemia cells, both in the peripheral blood and in the bone marrow. (Source: Clin Cancer Res. 2007 Aug 1;13(15 Pt 1):4575-82.)
Ki23057 is a a FGFR2 inhibitor, which enhances the chemosensitivity of drug-resistant gastric cancer cell lines when used in combination with chemotherapeutic drugs. Ki23057 might be therapeutically promising for treating drug-resistant gastric cancer cells, especially when used in combination with SN38, PTX, or VP16. The apoptosis process might be the main mechanism underlying the synergistic effect of these combinations. The ERCC1 and p53 genes may play an integral role in the synergism between Ki23057 and chemotherapeutic agents in drug-resistant cell lines. (source: Cancer Lett. 2011 Aug 1;307(1):47-52).
S.pombe lumazine synthase-IN-1 is an inhibitor of lumazine synthases with Ki values of 243 μM and 9.6 μM for Schizosaccharomyces pombe and Mycobacterium tuberculosis lumazine synthases, respectively[1]. [1]. Arindam Talukdar, et al. Discovery and Development of a Small Molecule Library With Lumazine Synthase Inhibitory Activity. J Org Chem. 2009 Aug 7;74(15):5123-34.
Ru360, an oxygen-bridged dinuclear ruthenium amine complex, is a selective mitochondrial calcium uptake inhibitor. Ru360 potently inhibits Ca2+ uptake into mitochondria with an IC50 of 0.184 nM. Ru360 binds to mitochondria with high affinity (Kd of 0.34 nM). Ru360 has antiarrhythmic and cardioprotective effects[1][2]. Ru360 permeates slowly into the cell, and specifically inhibits mitochondrial calcium uptake in intact cardiomyocytes and in isolated heart. 1 μm Ru360 is taken up by myocardial cells and accumulated in the cytosol in a biphasic manner[1]. During pelleting hypoxia, Ru360 (10 µM) significantly improves cell viability in wild type cardiomyocytes[3]. Ru360 (15-50 nmol/kg) treatment abolishes the incidence of arrhythmias and haemodynamic dysfunction elicited by reperfusion in a whole rat model. Ru360 administration partially inhibits calcium uptake, preventing mitochondria from depolarization by the opening of the mitochondrial permeability transition pore (mPTP)[1]. [1]. G de J García-Rivas, et al. Ru360, a Specific Mitochondrial Calcium Uptake Inhibitor, Improves Cardiac Post-Ischaemic Functional Recovery in Rats in Vivo. Br J Pharmacol. 2006 Dec;149(7):829-37. [2]. M A Matlib, et al. Oxygen-bridged Dinuclear Ruthenium Amine Complex Specifically Inhibits Ca2+ Uptake Into Mitochondria in Vitro and in Situ in Single Cardiac Myocytes. J Biol Chem. 1998 Apr 24;273(17):10223-31. [3]. Lukas J Motloch, et al. UCP2 Modulates Cardioprotective Effects of Ru360 in Isolated Cardiomyocytes During Ischemia. Pharmaceuticals (Basel). 2015 Aug 4;8(3):474-82.
CC-90005 is a potent, selective and orally active inhibitor of protein kinase C-θ (PKC-θ), with an IC50 of 8 nM. CC-90005 shows selectivity for PKC-θ over PKC-δ (IC50=4440 nM). CC-90005 can inhibit T cell activation by IL-2 expression[1]. CC-90005 shows the exquisite selectivity of CC-90005, with IC50s for all other family members of >3 μM[1].CC-90005 is a moderate inhibitor of both CYP2C9 (IC50=8 μM) and CYP2C19 (IC50=5.9 μM) in human liver microsomes[1].CC-90005 inhibits IL-2 expression in LRS_WBC human PBMCs, with an IC50 of 0.15 μM[1].CC-90005 (1-10 μM; 24 h) inhibits T cell proliferation in PBMCs by 51% at 1 μM and 88% at 3 μM[1]. CC-90005 (3-30 mg kg; p.o. twice daily for 4 days) significantly reduces the popliteal lymph node (PLN) size in a model of chronic T cell activation[1].CC-90005 (100 mg kg; a single p.o.) significantly inhibits plasma and spleen IL-2 release by 51 and 54%, respectively[1].CC-90005 exhibits reasonable oral bioavailability (66 and 46%) and Cmax (1.18 and 1.2 μM) following oral administration (10 and 3 mg kg) in rat and dog, respectively[1].CC-90005 exhibits the mean residence time (0.52 and 2.0 h), CL (69.1 and 20.5 mL min kg) and Vss (2.11 and 2.44 L kg) following intravenous administration (2 and 1 mg kg) in rat and dog, respectively[1]. [1]. Papa P, et, al. Discovery of the Selective Protein Kinase C-θ Kinase Inhibitor, CC-90005. J Med Chem. 2021 Aug 26;64(16):11886-11903.
Afatinib impurity 11 is an impurity of Afatinib. Afatinib is an irreversible EGFR family inhibitor with IC50s of 0.5 nM, 0.4 nM, 10 nM and 14 nM for EGFRwt, EGFRL858R, EGFRL858R T790M and HER2, respectively[1]. [1]. Li D, et al. BIBW2992, an irreversible EGFR HER2 inhibitor highly effective in preclinical lung cancer models. Oncogene. 2008 Aug 7;27(34):4702-11.