HDAC-IN-4 is a selective HDAC6 and HDAC10 inhibitor (pIC50s: 7.2 and 6.8 in BRET assay) with antitumoral activity.

HDAC-IN-4-d4 is a deuterated compound of HDAC-IN-4.

HDAC/HSP90-IN-4 significantly inhibited HDAC and HSP90 activity, with compound 20 (HDACIC50= 194 nM; HSP90αIC50= 153 nM) and compound 26 ((HDACIC50= 360 nM; HSP90αIC50= 77 nM) having the strongest HDAC and HSP90α inhibition. effect. Both compounds induced HSP90 expression and down-regulated HSP90 client proteins, which play an important role in the regulation of cancer cell survival and invasion.

4-Chloro-6,7-bis(2-methoxyethoxy)quinazoline is a building block and synthetic intermediate.1,2,3,4,5It has been used as a precursor in the synthesis of receptor tyrosine kinase (RTK) inhibitors, dual RTK and histone deacetylase (HDAC) inhibitors, and anticancer compounds.1,2,3It is also a synthetic intermediate in the synthesis of EGFR inhibitors, including erlotinib , with antiproliferative activity.4,5

HDAC4 CHDI Degrader 11 is a potent, selective degrader of HDAC4 (PROTAC) with DC_50 values of 4 nM and 6 nM in Jurkat E6-1 and Jurkat cells, respectively. This compound integrates the class IIa HDAC inhibitor trifluoromethyloxadiazole with a ligand for the Von Hippel-Lindau (VHL) protein through a linker. Demonstrating significant efficacy, HDAC4 CHDI Degrader 11 achieves a DC_50 value of 1 nM in a mouse cell model of Huntington's disease. For enhanced degradation in neuroblastoma cell lines, it can be administered alongside the P-glycoprotein inhibitor, Elacridar.

CDK/HDAC-IN-1 exhibits potent inhibitory activity towards CDK2/4/6 and HDAC6, with IC50 values of 60.9 ± 2.9 nM, 276 ± 22.3 nM, 27.2 ± 4.2 nM, and 128.6 ± 0.4 nM, respectively.

Givinostat (ITF-2357) is a HDAC inhibitor with an IC50 of 198 and 157 nM for HDAC1 and HDAC3, respectively. Givinostat (ITF2357) suppresses total LPS-induced IL-1β production robustly compared with the reduction by ITF3056. At 25, 50, and 100 nM, Givinostat reduced IL-1β secretion more than 70%. Givinostat (ITF-2357) suppresses the production of IL-6 in PBMCs stimulated with TLR agonists as well as the combination of IL-12 plus IL-18. IL-6 secretion decreases to 50% at 50 nM Givinostat, but at 100 and 200 nM, there is no reduction[1]. As shown by the CCK-8 assay, Givinostat (ITF-2357) inhibits JS-1 cell proliferation in a concentration-dependent manner. Treatment with Givinostat ≥500 nM is associated with significant inhibition of JS-1 cell proliferation (P<0.01). Also, the cell inhibition rate significantly differs between the group cotreated with Givinostat ≥250 nM plus LPS and the group without LPS treatment (same Givinostat concentration) (P<0.05)[2]. Givinostat (ITF2357) at 10 mg/kg is used as a positive control and, as expected, reduced serum TNFα by 60%. Strikingly, pretreatment of ITF3056 starting at 0.1 mg/kg significantly reduces the circulating TNFα by nearly 90%. To achieve a significant increase in serum IL-1β production, a higher dose of LPS is injected (10 mg/kg), and blood is collected after 4 h. Similarly, when pretreated with lower doses of Givinostat (ITF-2357) (1 or 5 mg/kg), there is a 22% reduction for 1 mg/kg and 40% for 5 mg/kg[1]. [1]. Li S, et al. Specific inhibition of histone deacetylase 8 reduces gene expression and production of proinflammatory cytokines in vitro and in vivo. J Biol Chem. 2015 Jan 23;290(4):2368-78. [2]. Wang YG, et al. Givinostat inhibition of hepatic stellate cell proliferation and protein acetylation. World J Gastroenterol. 2015 Jul 21;21(27):8326-39. [3]. Leoni F, et al. The histone deacetylase inhibitor ITF2357 reduces production of pro-inflammatory cytokines in vitro and systemic inflammation in vivo. Mol Med. 2005 Jan-Dec;11(1-12):1-15.

CHDI-390576 is a CNS-permeable, selective and potent dibenzoyl isohydroxamic acid class IIa histone deacetylase (HDAC) inhibitor that inhibits class IIa HDAC 4, HDAC 5, HDAC 7, HDAC 9, and can be used in cancer research.

JAK/HDAC-IN-2, a potent 2-amino-4-phenylaminopyrimidine dual-target inhibitor, effectively suppresses JAK1/2 and HDAC3/6 at nanomolar concentrations. This compound exhibits proapoptotic properties, inhibits histone deacetylation, and impedes STAT3 phosphorylation, demonstrating notable antiproliferative activity against various hematological malignancies and solid tumors [1].

TW9 is a dual inhibitor of bromodomain 2 (BD2) in bromodomain-containing protein 4 (BRD4) and histone deacetylase 1 (HDAC1; IC50s = 0.074 and 0.29 μM, respectively).1It is selective for BD2 over BD1 in BRD4 (IC50= 0.72 μM) and for HDAC1 over HDAC2 (IC50= 2.5 μM). TW9 (50 nM) induces apoptosis in, and inhibits proliferation of, MIA PaCa-2 pancreatic cancer cells. It induces cell cycle arrest at the G1phase in HPAC pancreatic cancer cells when used at a concentration of 2 μM. TW9 acts synergistically with gemcitabine to reduce the viability of HPAC cells. 1.Zhang, X., Zegar, T., Weiser, T., et al.Characterization of a dual BET/HDAC inhibitor for treatment of pancreatic ductal adenocarcinomaInt. J. Cancer147(10)2847-2861(2020)

Quisinostat dihydrochloride (JNJ26854165(Quisinostat) 2HCl) is a novel second-generation HDAC inhibitor with highest potency for HDAC1 with IC50 of 0.11 nM in a cell-free assay, modest potent to HDACs 2, 4, 10, and 11; greater than 30-fold selectivity against HDACs 3, 5, 8, and 9 and lowest potency to HDACs 6 and 7. Phase 2.