PTG-0861 is a highly specific inhibitor of histone deacetylase 6 (HDAC6), demonstrating an impressive IC50 value of 5.92 nm. This compound effectively triggers apoptosis and holds potential for research pertaining to acute myeloid leukemia, multiple myeloma, and other hematological cancers [1].

PTG-0861 (compound 54) (0.1-5 μM, 6 hours) stimulates the expression of acetylated a-tubulin and has inhibitory activity against HDAC6 with the IC 50 value of 0.59 μM [1]. PTG-0861 (compound 54) (0-4 μM, 18 hours) can induce apoptosis in a dose-dependent manner and has some cytotoxic effect [1]. Western Blot Analysis [1] Cell Line: MV4-11 cells Concentration: 0.1-5 μM Incubation Time: 6 hours Result: Induced the accumulation of acetylated a-tubulin expression at 500 nM. Immunofluorescence [1] Cell Line: HeLa cells Concentration: 0-2 μM Incubation Time: 6 hours Result: Increased levels of acetylated a-tubulin at 0.1 μM. Apoptosis Analysis [1] Cell Line: MV4-11 cells Concentration: 0-4 μM Incubation Time: 18 hours Result: Induced about 18% cells late apoptosis at 4 μM while at low dose 0.25 μM only about 5%. Cell Cytotoxicity Assay [1] Cell Line: Hematological cancer cell lines MV4-11, MM.1S, and RPMI 8226 Concentration: 1.24-4.94 μM Incubation Time: 72 hours Result: Showed cytotoxic effects on MV4-11, MM.1S, and RPMI 8226 with the IC 50 value of 1.85 μM，1.9 μM，4.94 μM, respectively. Cell Line: Concentration: Incubation Time: Result: Result: The pharmacokinetic parameters of PTG-0861 in vitro Parameter PTG-0861 Percent Remaining (%) 0 min 100.00 Percent Remaining (%) 30 min 96.41 Percent Remaining (%) 60 min 97.98 Percent Remaining (%) 120 min 97.08 T1/2 (min) ∞ T1/2 (min) 50.85 ± 3.37 CLint (mL/min/106 cells) 27.32 ± 1.81 -Log Pe 5.66 ± 0.02 Papp (A-B) (10 6, cm/s) 1.33 ± 0.03 Papp (B-A) (10 6, cm/s) 0.94 ± 0.13 Efflux Ratio 0.71 ± 0.08

PTG-0861 (compound 54) (oral administration, 20 mg/kg, everyday, 5 days) has no effect on weight and no obvious toxicity in CD1 mice [1]. Animal Model: CD1 mice [1] Dosage: 20 mg/kg Administration: Oral administration; everyday; 5 days Result: No weight loss in mice and no obvious toxicity. Animal Model: Male CD1 mice [1] Dosage: 20 mg/kg Administration: Intraperitoneal injection; once Result: The pharmacokinetic parameters of PTG-0861 in vivo Parameter PTG-0861 half-life 0.25 h C max 526 ng/mL AUC last 190 h ng/mL AUC inf 219 h ng/mL AUC Extr(%) 0.324 MRT(h) 0.350 AUC/D(h mg/mL) 9.5