ST13 

ST13, an ortho-hydroxyanilide, is a selective, slow- and tight-binding HDAC1 and HDAC2 inhibitor with IC₅₀s of 23 nM and 49 nM, respectively. ST13 shows a weak inhibition of HDAC3 (IC₅₀ = 4.30 μM) and HDAC6 (IC₅₀ > 10 μM). The induced fit mechanism of ST13 proceeds through a two-step process: first, the enzyme and inhibitor rapidly form a collision complex (EI), which then slowly transforms into the stable complex E*I. ST13 induces apoptosis in cancer cells. ST13 can be used for the study of melanoma and triple-negative breast^[1].

ST13 (72-120 h) exhibits time-dependent antiproliferative activity in cancer cell lines, with EC₅₀ values decreasing from 2.77 µM (72 h) to 0.311 µM (120 h) in MV-3 cells. In MDA-MB-231, EC₅₀ values decreased from 4.87 µM (72 h) to 0.087 µM (120 h)^[1].
ST13 (10 µM; 48 h) significantly induces apoptosis in MDA-MB-231 cells^[1].
ST13 (5 μM, 24-72 h) shows a substantial increase in acetylated histone H3 in MV-3 cells^[1].
In MV-3 cells, MDA-MB-231 cells, nontumorigenic cell line HEK293 and hematological cancer cell line MM.1S, ST13 (18 h) exhibits an inhibitory effect against HDACs, with EC₅₀ values of 0.311 μM, 0.577 μM, 0.333 μM and 0.637 μM, respectively^[1].
ST17 (0.040 µM, 0.072 µM; 10 min) is a light-activatable prodrug of ST13 with potent HDAC1/HDAC2 inhibition upon UV irradiation^[1].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

346.38

C₂₁H₁₈N₂O₃

1013620-98-8

CC(NC1=CC=C(C(NC2=C(O)C=CC(C3=CC=CC=C3)=C2)=O)C=C1)=O

Room temperature in continental US; may vary elsewhere.

Please store the product under the recommended conditions in the Certificate of Analysis.

• [1]. Honin I, et al. Ortho-Hydroxyanilides: Slow-Acting, Selective Histone Deacetylase 1/2 Inhibitors Suitable for Photocaging Applications. ACS Pharmacol Transl Sci. 2025;8(12):4385-4398.   [Content Brief]