NSC321039, also known as hMAO-B-IN-4, is a selective, reversible, BBB (blood-brain barrier)-penetrating inhibitor of human monoamine oxidase-B (hMAO-B) with IC50 of 0.067 μM. This compound has been reported in Scientific Reports (2022), 12(1), 22404 NSC321039, and is a reversible inhibitor of hMAO-B. PAMPA assay shows that NSC321039 has significant permeability and CNS bioavailability, with a Pe value higher than 4.0 x 10-6 cm/s. NSC321039 are stabilized in protein-ligand complexes via π-π stacking, which allows them to bind very efficiently to the active site of hMAO-B enzymes.

Physicochemical Properties

Molecular Formula	C20H16O2S
Molecular Weight	320.404844284058
Exact Mass	320.09
Elemental Analysis	C, 74.97; H, 5.03; O, 9.99; S, 10.01
CAS #	1666119-75-0
PubChem CID	5344692
Appearance	White to off-white solid powder
LogP	5.2
Hydrogen Bond Donor Count	0
Hydrogen Bond Acceptor Count	3
Rotatable Bond Count	6
Heavy Atom Count	23
Complexity	392
Defined Atom Stereocenter Count	0
SMILES	C(C1SC=CC=1)(=O)/C=C/C1=CC=C(OCC2=CC=CC=C2)C=C1
InChi Key	MKSMRBDQELHEBO-JLHYYAGUSA-N
InChi Code	InChI=1S/C20H16O2S/c21-19(20-7-4-14-23-20)13-10-16-8-11-18(12-9-16)22-15-17-5-2-1-3-6-17/h1-14H,15H2/b13-10+
Chemical Name	2-Propen-1-one, 3-[4-(phenylmethoxy)phenyl]-1-(2-thienyl)-, (2E)-
Synonyms	NSC321039; NSC-321039; NSC 321039; hMAO-B-IN-4;
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	hMAO-B-IN-4 (0-40 μM), which has a SI value of 504.791[1], exhibits higher selectivity for hMAO-B than hMAO-A. With IC50 values of 33.821 and 0.067 μM, respectively, hMAO-B-IN-4 (0-40 μM) inhibits hMAO-A and hMAO-B.
References	[1]. Introduction of benzyloxy pharmacophore into aryl/heteroaryl chalcone motifs as a new class of monoamine oxidase B inhibitors. Sci Rep. 2022 Dec 27;12(1):22404.

Solubility Data

Solubility (In Vitro)

DMSO : ~50 mg/mL (~156.05 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.80 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.1211 mL	15.6055 mL	31.2110 mL
	5 mM	0.6242 mL	3.1211 mL	6.2422 mL
	10 mM	0.3121 mL	1.5605 mL	3.1211 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.