WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 598979

CAS#: 1634-78-2

Description: Malaoxon, also known as Malathion impurity B, is an insecticide.

Chemical Structure

CAS# 1634-78-2

Theoretical Analysis

MedKoo Cat#: 598979
Name: Malaoxon
CAS#: 1634-78-2
Chemical Formula: C10H19O7PS
Exact Mass: 314.06
Molecular Weight: 314.280
Elemental Analysis: C, 38.22; H, 6.09; O, 35.63; P, 9.86; S, 10.20

Price and Availability

Size Price Availability Quantity
100mg USD 350 3-4 Weeks
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Synonym: Malaoxon; NCI-C08628; NCI C08628; NCIC08628; DL-Malaoxon; Liromat; Malaoxan; Malaoxon; Malaoxone; Malathion oxon; Malathion-O-analog; Maloxon; Oxycarbophos; Malathion impurity B

IUPAC/Chemical Name: diethyl 2-((dimethoxyphosphoryl)thio)succinate


InChi Code: InChI=1S/C10H19O7PS/c1-5-16-9(11)7-8(10(12)17-6-2)19-18(13,14-3)15-4/h8H,5-7H2,1-4H3


Appearance: Liquid

Purity: >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).

Solubility: Soluble in DMSO

Shelf Life: >3 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: 2934.99.9001

More Info:

Biological target:
In vitro activity:
In vivo activity:

Preparing Stock Solutions

The following data is based on the product molecular weight 314.28 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL
Formulation protocol:
In vitro protocol:
In vivo protocol:

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1: Angelini DJ, Moyer RA, Cole S, Willis KL, Oyler J, Dorsey RM, Salem H. The Pesticide Metabolites Paraoxon and Malaoxon Induce Cellular Death by Different Mechanisms in Cultured Human Pulmonary Cells. Int J Toxicol. 2015 Sep-Oct;34(5):433-41. doi: 10.1177/1091581815593933. Epub 2015 Jul 14. PubMed PMID: 26173615.

2: Zhang A, Lai W, Sun J, Hu G, Liu W. Probing the chiral separation mechanism and the absolute configuration of malathion, malaoxon and isomalathion enantiomers by chiral high performance liquid chromatography coupled with chiral detector-binding energy computations. J Chromatogr A. 2013 Mar 15;1281:26-31. doi: 10.1016/j.chroma.2013.01.016. Epub 2013 Jan 18. PubMed PMID: 23398995.

3: Galántai R, Emody-Kiss B, Somosy Z, Bognár G, Horváth G, Forgács Z, Gachályi A, Szilasi M. Does malaoxon play a role in the geno- and cytotoxic effects of malathion on human choriocarcinoma cells? J Environ Sci Health B. 2011;46(8):773-9. doi: 10.1080/03601234.2012.597703. PubMed PMID: 21902555.

4: dos Santos AA, dos Santos DB, Dafre AL, de Bem AF, Souza DO, da Rocha JB, Kuca K, Farina M. In vitro reactivating effects of standard and newly developed oximes on malaoxon-inhibited mouse brain acetylcholinesterase. Basic Clin Pharmacol Toxicol. 2010 Sep;107(3):768-73. doi: 10.1111/j.1742-7843.2010.00576.x. Epub 2010 Apr 12. PubMed PMID: 20406208.

5: Samimi A, Last JA. Inhibition of lysyl hydroxylase by malathion and malaoxon. Toxicol Appl Pharmacol. 2001 May 1;172(3):203-9. PubMed PMID: 11312648.

6: Gbaye OA, Holloway GJ, Callaghan A. Variation in the sensitivity of Callosobruchus (Coleoptera: Bruchidae) acetylcholinesterase to the organophosphate insecticide malaoxon: effect of species, geographical strain and food type. Pest Manag Sci. 2012 Sep;68(9):1265-71. doi: 10.1002/ps.3293. Epub 2012 May 17. PubMed PMID: 22605686.

7: Savolainen KM, Hirvonen MR. Effects of malaoxon on phosphatidylinositol signaling in convulsing and non-convulsing non-pregnant and pregnant female rats and their offspring. Neurotoxicology. 1992 Spring;13(1):295-9. PubMed PMID: 1508433.

8: Berkman CE, Quinn DA, Thompson CM. Interaction of acetylcholinesterase with the enantiomers of malaoxon and isomalathion. Chem Res Toxicol. 1993 Sep-Oct;6(5):724-30. PubMed PMID: 8292752.

9: Aker WG, Hu X, Wang P, Hwang HM. Comparing the relative toxicity of malathion and malaoxon in blue catfish Ictalurus furcatus. Environ Toxicol. 2008 Aug;23(4):548-54. doi: 10.1002/tox.20371. PubMed PMID: 18247417.

10: Johnson JA, Wallace KB. Species-related differences in the inhibition of brain acetylcholinesterase by paraoxon and malaoxon. Toxicol Appl Pharmacol. 1987 Apr;88(2):234-41. PubMed PMID: 3564042.

11: Hirvonen MR, Komulainen H, Paljärvi L, Savolainen K. Time-course of malaoxon-induced alterations in brain regional inositol-1-phosphate levels in convulsing and nonconvulsing rats. Neurochem Res. 1989 Feb;14(2):143-7. PubMed PMID: 2725814.

12: Ehrich M, Cohen SD. DDVP (dichlorvos) detoxification by binding and interactions with DDT, dieldrin, and malaoxon. J Toxicol Environ Health. 1977 Oct;3(3):491-500. PubMed PMID: 597376.

13: Reuber MD. Carcinogenicity and toxicity of malathion and malaoxon. Environ Res. 1985 Jun;37(1):119-53. PubMed PMID: 3996333.

14: National Toxicology Program. Bioassay of malaoxon for possible carcinogenicity. Natl Cancer Inst Carcinog Tech Rep Ser. 1979;135:1-115. PubMed PMID: 12799657.

15: Huff JE, Bates R, Eustis SL, Haseman JK, McConnell EE. Malathion and malaoxon: histopathology reexamination of the National Cancer Institute's carcinogenesis studies. Environ Res. 1985 Jun;37(1):154-73. PubMed PMID: 3996335.

16: Rodriguez OP, Muth GW, Berkman CE, Kim K, Thompson CM. Inhibition of various cholinesterases with the enantiomers of malaoxon. Bull Environ Contam Toxicol. 1997 Feb;58(2):171-6. PubMed PMID: 8975790.

17: Samimi A, Last JA. Mechanism of inhibition of lysyl hydroxylase activity by the organophosphates malathion and malaoxon. Toxicol Appl Pharmacol. 2001 Nov 1;176(3):181-6. PubMed PMID: 11714250.

18: Hirvonen MR, Paljärvi L, Naukkarinen A, Komulainen H, Savolainen KM. Potentiation of malaoxon-induced convulsions by lithium: early neuronal injury, phosphoinositide signaling, and calcium. Toxicol Appl Pharmacol. 1990 Jun 15;104(2):276-89. PubMed PMID: 2363179.

19: Bavcon Kralj M, Cernigoj U, Franko M, Trebse P. Comparison of photocatalysis and photolysis of malathion, isomalathion, malaoxon, and commercial malathion--products and toxicity studies. Water Res. 2007 Nov;41(19):4504-14. Epub 2007 Jun 15. PubMed PMID: 17624398.

20: Bradman MA, Harnly ME, Goldman LR, Marty MA, Dawson SV, Dibartolomeis MJ. Malathion and malaoxon environmental levels used for exposure assessment and risk characterization of aerial applications to residential areas of southern California, 1989-1990. J Expo Anal Environ Epidemiol. 1994 Jan-Mar;4(1):49-63. PubMed PMID: 7894268.