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MedKoo CAT#: 561075

CAS#: 5466-89-7

Description: U-0521 is a catechol-O-methyltransferase (COMT) inhibitor. U-0521 enhances the availability and utilization of levodopa in the brain.

Price and Availability

Size Price Shipping out time Quantity
20mg USD 165 2 Weeks
100mg USD 550 2 Weeks
Inquire bulk and customized quantity

Pricing updated 2020-09-23. Prices are subject to change without notice.

U-0521, purity > 98%, is in stock. Current shipping out time is about 2 weeks after order is received. CoA, QC data and MSDS documents are available in one week after order is received.

Chemical Structure


Theoretical Analysis

MedKoo Cat#: 561075
Name: U-0521
CAS#: 5466-89-7
Chemical Formula: C10H12O3
Exact Mass: 180.0786
Molecular Weight: 180.203
Elemental Analysis: C, 66.65; H, 6.71; O, 26.63

Synonym: U-0521, U0521, U 0521

IUPAC/Chemical Name: 3',4'-Dihydroxy-2-methylpropiophenone


InChi Code: InChI=1S/C10H12O3/c1-6(2)10(13)7-3-4-8(11)9(12)5-7/h3-6,11-12H,1-2H3

SMILES Code: CC(C)C(C1=CC=C(O)C(O)=C1)=O

Technical Data

White to off-white solid powder

>98% (or refer to the Certificate of Analysis)

Shipping Condition:
Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition:
Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Soluble in DMSO

Shelf Life:
>2 years if stored properly

Drug Formulation:
This drug may be formulated in DMSO

Stock Solution Storage:
0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code:


1: Cumming P, Boyes BE, Martin WR, Adam M, Ruth TJ, McGeer EG. Altered metabolism of [18F]-6-fluorodopa in the hooded rat following inhibition of catechol-O-methyltransferase with U-0521. Biochem Pharmacol. 1987 Aug 1;36(15):2527-31. PubMed PMID: 3111485.

2: Lloyd T, Waldman CD. The antihypertensive effect of U-0521 (3',4'-dihydroxy-2-methylpropiophenone). Life Sci. 1982 Nov 8;31(19):2121-7. PubMed PMID: 7176811.

3: Reches A, Jiang D, Fahn S. Catechol-O-methyltransferase inhibition by U-0521 increases striatal utilization of levodopa. Naunyn Schmiedebergs Arch Pharmacol. 1982 Jul;320(1):34-7. PubMed PMID: 7121609.

4: Henseling M. Accumulation of 3H-(-)noradrenaline in the rabbit aorta not related to uptake1 and uptake2, but sensitive to 3,4-dihydroxy-2-methylpropiophenone (U-0521) and oxytetracycline. Naunyn Schmiedebergs Arch Pharmacol. 1983 Jun;323(2):121-7. PubMed PMID: 6888566.

5: Rice PJ, Abraham ST, Huang NY, Doman RJ. Extraneuronal uptake inhibitor U-0521 decreases contractile responses in rat vas deferens. Gen Pharmacol. 1997 Sep;29(3):437-9. PubMed PMID: 9378252.

6: Bryan LJ, O'Donnell SR. Comparison of the effects of tropolone, beta-thujaplicin and U-0521 on the extraneuronal accumulation of isoprenaline in guinea-pig trachealis smooth muscle cells. A quantitative fluorescence histochemical study. Naunyn Schmiedebergs Arch Pharmacol. 1979 Jul;307(3):235-41. PubMed PMID: 492345.

7: Lloyd T, Boyd B, Walega MA, Ebersole BJ, Weisz J. A comparison of 2-hydroxyestradiol and U-0521 (3'4'-dihydroxy-2-methylpropiophenone, Upjohn) as in situ and in vitro inhibitors of tyrosine hydroxylase. J Neurochem. 1982 Apr;38(4):948-54. PubMed PMID: 6121005.

8: Fahn S, Comi R, Snider SR, Prasad AL. Effect of a catechol-O-methyl transferase inhibitor, U-0521, with levodopa administration. Biochem Pharmacol. 1979 Apr 1;28(7):1221-5. PubMed PMID: 444281.

9: Reches A, Jiang D, Fahn S. Effect of 3',4'-dihydroxy-2-methyl-propriophenone (U-0521) on catechol-O-methyltransferase activity and on DOPA accumulation in rat red blood cells and corpus striatum. Biochem Pharmacol. 1982 Nov 1;31(21):3415-8. PubMed PMID: 7150363.

10: Bryan LJ, Fleig H, Trendelenburg U. A comparative study of the properties of the catechol-O-methyltransferase inhibitors, U-0521 and tropolone acetamide, in rat perfused heart. Naunyn Schmiedebergs Arch Pharmacol. 1983 Feb;322(1):6-19. PubMed PMID: 6843690.

11: Paiva MQ, Guimarães S. The oil immersion technique for studying the disposition of drugs inducing relaxation; influence of U-0521 and hydrocortisone on the disposition of isoprenaline. J Pharm Pharmacol. 1980 Dec;32(12):868-9. PubMed PMID: 6110758.

12: Giles RE, Miller JW. Studies on the potentiation of the inotropic actions of certain catecholamines by U-0521 (3',4'-dihydroxy-alpha-methyl propiophenone). J Pharmacol Exp Ther. 1967 Jul;157(1):55-61. PubMed PMID: 6029491.

13: Sterin-Borda L, Gimeno MF, Borda ES, Gimeno AL. A positive influence of frequency on the inotrophic response of isolated rat atria to certain adrenergic amines. Effects of cocaine and U-0521 (3',4'-dihydroxy-2-methyl propiophenone. Proc Soc Exp Biol Med. 1977 Nov;156(2):315-20. PubMed PMID: 928402.

14: Gimeno AL, Gimeno MF, Sterin-Borda L, Cossio PM, Sterin-Speziale N, Diez C, Seara SM, Arana RM. Altered inotropic and chronotropic effects of noradrenaline on isolated rat atria exposed to chagasic sera. Influences of cocaine, normetanephrine and U-0521 (3'-4'-dihydroxy-2-methyl propiophenone. Cardiovasc Res. 1979 Dec;13(12):723-31. PubMed PMID: 119577.

15: Giles RE, Miller JW. The catechol-O-methyl transferase activity and endogenous catecholamine content of various tissues in the rat and the effect of administration of U-0521 (3',4'-dihydroxy-2-methyl propiophenone). J Pharmacol Exp Ther. 1967 Nov;158(2):189-94. PubMed PMID: 5625691.

16: Kaumann AJ, Wittmann R, Birnbaumer L, Hoppe BH. Activation of myocardial beta-adrenoceptors by the nitrogen-free low affinity ligand 3',4'-dihydroxy-alpha-methylpropiophenone (U-0521). Naunyn Schmiedebergs Arch Pharmacol. 1977 Feb;296(3):217-28. PubMed PMID: 14306.

17: Branco D, Osswald W. The fate of isoprenaline after inhibition of O-methylation and of extraneuronal uptake. Eur J Pharmacol. 1980 Oct 17;67(2-3):247-53. PubMed PMID: 7461032.

18: Barone S, Panek D, Bennett L, Stitzel RE, Head RJ. The influence of oestrogen and oestrogen metabolites on the sensitivity of the isolated rabbit aorta to catecholamines. Naunyn Schmiedebergs Arch Pharmacol. 1987 May;335(5):513-20. PubMed PMID: 3614387.

19: Percy E, Kaye DM, Lambert GW, Gruskin S, Esler MD, Du XJ. Catechol-O-methyltransferase activity in CHO cells expressing norepinephrine transporter. Br J Pharmacol. 1999 Oct;128(3):774-80. PubMed PMID: 10516661; PubMed Central PMCID: PMC1571673.

20: Nuutila J, Kaakkola S, Männistö PT. Potentiation of central effects of L-dopa by an inhibitor of catechol-O-methyltransferase. J Neural Transm. 1987;70(3-4):233-40. PubMed PMID: 2960778.