Chemical Properties
Dark Yellow Solid
Chemical Properties
Aminopterin is a white to yellow powder; commonly used as the dihydrate which forms clustersof yellow needles
Uses
A folic acid antagonist. Its actively transported into cells by thefolate transporter. In the cell, its converted to a high molecular weight polyglutamate metabolite by folylpolyglutamate synthase, that, in turn, binds to dihydrofolate reductase and inhibits its activity.
Uses
antineoplastic, antirheumatic, folic acid antagonist
Definition
Differs slightly in structure from folic acid and antagonizes the utilization of folic acid by the body, an antimetabolite.
General Description
Clusters of yellow needles. Used as a rodenticide, medicine and rodenticide. Not registered as a rodenticide in the U.S.
Health Hazard
An antimetabolite; antagonizes the utilization of folic acid by the body. Highly toxic by ingestion.
Safety Profile
Poison by ingestion and intraperitoneal routes. Human and experimental teratogenic data. Other experimental reproductive effects. Mutation data reported. Human systemic effects by ingestion: gastrointestinal. Questionable carcinogen with experimental tumorigenic data. When heated to decomposition it emits toxic fumes of NOx,.
Potential Exposure
Aminopterin is used as a medicine (as a folic acid antagonist), rodenticide, and agricultural chemical.
Shipping
UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required
Purification Methods
Purify aminopterin by recrystallisation from H2O. It has properties similar to those of methotrexate (above). It has UV at max 244, 290 and 355nm ( 18600, 21300 and 12000) in H2O at pH 1; 260, 284 and 370nm ( 28500, 26400 and 8600) in H2O at pH 13. [Seeger et al. J Am Chem Soc 71 1753 1949, Angier & Curran J Am Chem Soc 8 1 2814 1959, Blakley The Biochemistry of Folic Acid and Related Pteridines, North-Holland Publ Co., Amsterdam, NY, pp 157-163 1969.] For small quantities, chromatograph it on DEAE cellulose with a linear gradient of ammonium bicarbonate pH 8 and increase the molarity from 0.1 to 0.4. Monitoring is by following the UV absorption of the fractions. For larger quantities, a near boiling solution of aminopterin (5g) in H2O (400mL) is slowly treated with small portions of MgO powder (~0.7g, calcined magnesia) with vigorous stirring until a small amount of MgO remained undissolved and the pH rises from 3-4 to 7-8. Charcoal (1g) is added to the hot solution and filtered immediately through a large sintered glass funnel of medium porosity and lined with a hot wet pad of Celite (~2-3 mm thick). The filtrate is cooled in ice, and the crystals of the Mg salt are collected by filtration and recrystallised from boiling H2O (200mL). The crystals are washed with EtOH and dried in vacuo. The Mg salt is redissolved in boiling H2O (200mL) and carefully acidified with vigorous agitation with AcOH (2mL). Pure aminopterin (3g) separates in fine yellow needles (dihydrate) which are easily filtered. The solid is washed with cold H2O, then Me2CO and dried in vacuo. If a trace of impurity is still present as shown by DEAE cellulose chromatography or TLC, repetition of the process will remove it; see UV above. [Loo J Med Chem 8 139 1965, Beilstein 26 IV 3831.] CARCINOGENIC.
Waste Disposal
It is inappropriate and possibly dangerous to the environment to dispose of expired or wastepharmaceuticals by flushing them down the toilet or discarding them to the trash. Household quantities of expired or waste pharmaceuticals may be mixed with wet cat litter or coffee grounds, double-bagged in plastic, discard in trash. Larger quantities shall carefully take into consideration applicable DEA, EPA, and FDA regulations. If possible return the pharmaceutical to the manufacturer for proper disposal being careful to properly label and securely package the material. Alternatively, the waste pharmaceutical shall be labeled, securely packaged and transported by a state licensed medical waste contractor to dispose by burial in a licensed hazardous or toxic waste landfill or incinerator
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