Description
3-Methylcholanthrene (3-MC) is a member of the polycyclic
aromatic hydrocarbon (PAH) family and is used as an experimental
cancer research chemical. As other PAHs, 3-MC might be
found in trace quantities in coal tar and heavy-end petroleum
hydrocarbons.
Chemical Properties
The term “coal tar products,” as used by NIOSH, includes coal tar and two of the fractionation products of coal tar, creosote and coal tar pitch, derived from the carbonization of bituminous coal. Coal tar, coal tar pitch, and creosote (coal tar creosote 8001-58-9) derived from bituminous coal often contain identifiable components which by themselves are carcinogenic, such as benzo(a) pyrene, benzanthracene, chrysene, and phenanthrene. Other chemicals from coal tar products, such as anthracene, carbazole, fluoranthene, and pyrene may also cause cancer,but these causal relationships have not been adequately documented. Also, the research chemical methylcholanthrene (CAS: 56-49-5), a powerful carcinogen, fits this category. Coal tar pitch is a black viscous liquid. Aromatic solvent odor. Boiling point =>260°C; specific gravity (H2O:1) = 1.07-108; freezing/melting point = 250-°180C;flash point = 207°C (coal tar pitch); 74C (creosote oil);autoignition temperature =>510°C. Insoluble in water.Coal tar creosote (8001-58-9, crosote) is an black oily,tar-like substance. Pungent odor
Chemical Properties
Yellow Crystalline Solid
Chemical Properties
3-Methylcholanthrene is a solid that crystallizes from benzene
and ether as pale yellow prisms. 3-methylcholanthrene
is insoluble in water and
soluble in alcohol. It is combustible, and can react with
oxidizing materials.
Uses
3-MC is used experimentally as a positive control in cancer
research and in biochemical research to induce specific forms
of cytochrome P450. Other than this, there is no particular
use for this chemical except as a possible chemical
intermediate.
Uses
3-Methylcholanthrene has been used to assess its tumor initiation activity by Bhas 42 cell transformation assay. It has also been used to induce the activity of cytochrome P450.
Definition
ChEBI: A pentacyclic ortho- and peri-fused polycyclic arene consisting of a dihydrocyclopenta[ij]tetraphene ring system with a methyl substituent at the 3-position.
Synthesis Reference(s)
The Journal of Organic Chemistry, 47, p. 2120, 1982
DOI: 10.1021/jo00132a026
General Description
Yellow crystals or solid.
Air & Water Reactions
Insoluble in water.
Reactivity Profile
3-METHYLCHOLANTHRENE can react with oxidizing materials. Ozone and chlorinating agents oxidize 3-METHYLCHOLANTHRENE.
Hazard
Powerful carcinogen.
Fire Hazard
Flash point data for 3-METHYLCHOLANTHRENE are not available; however, 3-METHYLCHOLANTHRENE is probably combustible.
Biochem/physiol Actions
3-Methylcholanthrene is a carcinogen used to induce transformation of cultured cells. It is also used to induce fibrosarcomas and skin carcinomas in laboratory animals. 3-methylcholanthrene is a potent aryl hydrocarbon receptor agonist.
Safety Profile
Suspected carcinogen
with experimental carcinogenic,
neoplastigenic, and tumorigenic data. Poison
by intravenous and intraperitoneal routes.
Experimental teratogenic and reproductive
effects. Human mutation data reported.
When heated to decomposition it emits
acrid smoke and irritating fumes.
Potential Exposure
The coke-oven plant is the principal source of coal tar. The hot gases and vapors produced during the conversion of coal to coke are collected by means of a scrubber, which condenses the effluent into ammonia, water, crude tar, and other by-products. Crude tar is separated from the remainder of the condensate for refining and may undergo further processing. Employees may be exposed to pitch and creosote in metal and foundry operations; when installing electrical equipment; in construction, railway, utility; and briquette manufacturing.
Carcinogenicity
3-Methylcholanthrene is a rapid,
all-around neoplastic agent and a potent liver
tumorigen.
Environmental Fate
3-MC, when released to soil, adsorbs strongly to the soil and
does not leach. It does not biodegrade or hydrolyze significantly
but may evaporate from dry soil. If released to water, it is
expected to adsorb strongly to sediment and to bioconcentrate
in aquatic organisms. If released into the atmosphere, it may be
subject to direct photolysis because it absorbs strongly in the
ultraviolet (UV) spectrum of light. It may also react with peroxyl
radicals already present in the atmosphere. Its estimated
half-life in the atmosphere is 2.8 h. Considering an octanol/
water log concentration ratio of 6.42, a bioconcentration factor
of 45 000 has been estimated.
Shipping
UN1136 Coal tar distillates, flammable, Hazard Class: 3; Labels: 3-Flammable liquid
Toxicity evaluation
Metabolic activation of PAHs consists of oxidation of the rings
of unsubstituted PAHs. These oxidations are carried out by
mixed function oxidases of the liver, which contain cytochromes
P450 and P448 and require reduced nicotine adenine dinucleotide
and oxygen. In this oxidation, an epoxide intermediate is
formed that has been shown to have the requisite chemical
reactivity to bind covalently with DNA and histones and to serve
as the ultimate carcinogenic form of PAH. Administration of 3-
MC to rats increased hepatic nuclear proteins and caused
a turnover of protein of the endoplasmic reticulum. Studies of
14C amino acid incorporation showed that 3-MC causes
increased protein synthesis and reduced degradation of protein.
Incompatibilities
Incompatible with strong oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Phenols, such as creosote react as weak organic acids. Phenols and cresols are much weaker as acids than common carboxylic acids (phenol has pKa = 9.88). These materials are incompatible with strong reducing agents such as hydrides, nitrides, alkali metals, and sulfides. Flammable hydrogen gas is often generated, and the heat of the reaction may ignite the gas. Heat is also generated by the acid-base reaction between phenols and bases. Such heating may initiate polymerization of the organic compound. Phenols are sulfonated very readily (e.g., by concentrated sulfuric acid at room temperature). The reactions generate heat. Phenols are also nitrated very rapidly, even by dilute nitric acid
Waste Disposal
Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.
