A potent, covalent, orally active ALDH1A2 inhibitor with IC50 of 0.3 uM.

Alda-1 is an ALDH2 agonist, cell-permeable activator of both the wild-type ALDH2*1 and the asian E487K mutant ALDH2*2 forms of mitochondrial aldehyde dehydrogenase 2 (mtALDH2).

ALDH3A1 inhibitor EN40 is a potent and selective, covalent, in vivo-active inhibitor of ALDH3A1 with IC50 of 2 uM, demonstrates no activity against ALDH1A3 and ALDH6A1 at 30 uM.

CVT-10216 is a potent and selective, reversible inhibitor of aldehyde dehydrogenase 2 (ALDH2) (IC50 values are 29 and 1300 nM for ALDH2 and ALDH1, respectively).

DKM 3-42 is a selective, covalent, in vivo-active ALDH3A1 inhibitor with IC50 of 50 uM against purified human ALDH3A1, targets ALDH3A1 catalytic cysteine, impairs both in situ and in vivo lung cancer pathogenicity.

NCT-501 is a potent and selective inhibitor of Aldehyde Dehydrogenase 1A1 (ALDH1A1) with IC50 of 40 nM.

NCT-505 is a potent and selective aldehyde dehydrogenase (ALDH1A1) inhibitor, with an IC50 of 7 nM, and weakly inhibits hALDH1A2, hALDH1A3, hALDH2, hALDH3A1 (IC50s, >57, 22.8, 20.1, >57 μM).

4-Hydroxynonenal (4-HNE) is an α,β unsaturated hydroxyalkenal and an oxidative/nitrosative stress biomarker. 4-Hydroxynonenal is a substrate and an inhibitor of acetaldehyde dehydrogenase 2 (ALDH2). 4-Hydroxynonenal can modulate a number of signaling processes mainly through forming covalent adducts with nucleophilic functional groups in proteins, nucleic acids, and membrane lipids. 4-Hydroxynonenal plays an important role in cancer through mitochondria.

4-Diethylaminobenzaldehyde is a reversible aldehyde dehydrogenases (ALDHs) inhibitor, with a Ki of 4 nM for ALDH1. 4-Diethylaminobenzaldehyde displays potent anti-androgenic effect (IC50= 1.71μM).

NCT-507 (NCT507) is a potent, selective, orally available ALDH1A1 inhibitor with IC50 of 7 nM (hALDH1A1), exhibits high specificity over other ALDH isozymes and unrelated dehydrogenases; also exhibits IC50 of 53 nM in MIA PaCa-2 Aldefluor cell-based assays; demonstrates target engagement in CETSA asssays, inhibits the formation of 3D spheroid cultures of OV-90 cancer cells, and potentiates the cytotoxicity of Paclitaxel in SKOV-3-TR, a Paclitaxel resistant ovarian cancer cell line.

BODIPY aminoacetaldehyde (BAAA) is a fluorescent substrate for both murine and human aldehyde dehydrogenase (ALDH). BODIPY aminoacetaldehyde consists of an aminoacetaldehyde moiety bonded to the BODIPY fluorochrome and can be used to label stem cells.

NCT-501 hydrochloride is a potent and selective theophylline-based inhibitor of aldehyde dehydrogenase 1A1 (ALDH1A1), inhibits hALDH1A1 with IC50 of 40 nM, typically shows better selectivity over other ALDH isozymes and other dehydrogenases (hALDH1B1, hALDH3A1, and hALDH2, IC50 >57 μM).

MeDTC (S-Methyl-N,N-diethylthiocarbamate Sulfone), a Disulfiram metabolite, is a potent, irreversible aldehyde dehydrogenase (ALDH) inhibitor.

ALDH1A1-IN-2 is a potent inhibitor of aldehyde dehydrogenase 1a1 (aldh1a1). Aldehyde dehydrogenases (ALDH) constitute a family of enzymes that play a critical role in oxidizing various cytotoxic xenogenic and biogenic aldehydes. ALDH1A1-IN-2 has the potential for the research of cancer, inflammation, or obesity (extracted from patent WO2019089626A1, compound 295).

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.

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.

MCI-INI-3 is a potent, selective, competitive inhibitor of ALDH1A3 (Ki=0.55 uM), shows poor inhibitory effect on the structurally related isoform ALDH1A1 (>140-fold selectivity).MCI-INI-3 also displays on inhibition against six isoforms of ALDH (ALDH16A1, ALDH7A1, ALDH9A1, ALDH2, ALDH1B1, ALDH18A1).MCI-INI-3 demonstrates selective binding to ALDH1A3 in glioma stem cell lysates, inhibits ALDH activity and affects RA synthesis in cells.

KS106 is a potent ALDH inhibitor with IC50s of 334, 2137, 360 nM for ALDH1A1, ALDH2, and ALDH3A1, respectively. KS106 shows antiproliferative and anticancer effects with low low toxic.KS106 significantly increases ROS activity, lipid peroxidation and toxic aldehyde accumulation. KS106 induces apoptosis and cell cycle arrest at the G2/M phase.

STL5-T-0057 (compound 68) is an selective ALDH1 B1 inhibitor with an IC50 value of 30 nM. STL5-T-0057 inhibits cell growth of SW480 cells in adherent and spheroid conditions with IC50 values of 2.46 and 0.39 μM, respectively. STL5-T-0057 can be used for the research of cancer.

AD-5591 (AD5591) is a potent, selective, new generation small molecule ALDH2 activator, has the improved biological activities and pharmacological properties compared to Alda-1. AD-5591 (100  μM) significantly increases the enzymatic activity of recombinant WT and mutant human ALDH2 proteins. AD-5591 is the active form of AD-9308.

AD-9308 is a water-soluble, orally bioavailable, potent, and highly selective ALDH2 activator, AD-9308 is a valine ester prodrug of a potent and selective small molecule ALDH2 activator AD-5591.

ER-001135935 is a potent selective inhibitor of aldehyde dehydrogenase family 1 member A3 (ALDH1A3) with IC50 of 64 nM, Ki value of 106 nM.

KOTX1 is a potent, selective and reversible ALDH1A3 inhibitor with IC50 of 5.14 nM by Aldefluor assay in A375 cells.

LEI-945 (LEI 945) is a first-in-class probe that enables profiling retinaldehyde dehydrogenases (ALDHs) in cancer cells.

NCT-507 (NCT507) is a potent, selective, orally available ALDH1A1 inhibitor with IC50 of 7 nM (hALDH1A1), exhibits high specificity over other ALDH isozymes and unrelated dehydrogenases.

STA-55 is a broad-spectrum activity-based probe of aldehyde dehydrogenase family, can be used to identify therapy resistance biomarkers in cancer and to validate target engagement of ALDH drug candidates.