A benzopyrene is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with the formula C₂₀H₁₂. Structurally speaking, the colorless isomers of benzopyrene are pentacyclic hydrocarbons and are fusion products of pyrene and a phenylene group. Two

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the exi ...

ic species of benzopyrene are benzo 'a''yrene and the less common benzo 'e''yrene. They belong to the chemical class of

polycyclic aromatic hydrocarbon A Polycyclic aromatic hydrocarbon (PAH) is any member of a class of organic compounds that is composed of multiple fused aromatic rings. Most are produced by the incomplete combustion of organic matter— by engine exhaust fumes, tobacco, incine ...

Overview

Related compounds include cyclopentapyrenes, dibenzopyrenes, indenopyrenes and naphthopyrenes. Benzopyrene is a component of pitch and occurs together with other related pentacyclic

aromatic In organic chemistry, aromaticity is a chemical property describing the way in which a conjugated system, conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibits a stabilization stronger than would be expected from conjugati ...

species such as picene, benzo fluoranthenes, and perylene. It is naturally emitted by

forest fire A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a bushfire ( in Australia), dese ...

s and volcanic eruptions and can also be found in

coal tar Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It is a type of creosote. It has both medical and industrial uses. Medicinally it is a topical medication applied to skin to treat psoria ...

, cigarette smoke, wood smoke, and burnt foods such as

coffee Coffee is a beverage brewed from roasted, ground coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content, but decaffeinated coffee is also commercially a ...

. Fumes that develop from fat dripping on blistering charcoal are rich in benzopyrene, which can condense on grilled goods. Benzopyrenes are harmful because they form carcinogenic and mutagenic

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

s (such as (+)-benzo 'a''yrene-7,8-dihydrodiol-9,10-epoxide from benzo 'a''yrene) which intercalate into DNA, interfering with transcription. They are considered pollutants and carcinogens. The mechanism of action of benzo yrene-related DNA modification has been investigated extensively and relates to the activity of cytochrome P450 subclass 1A1 ( CYP1A1). Seemingly, the high activity of CYP1A1 in the intestinal mucosa prevents major amounts of ingested benzo yrene from entering portal blood and systemic circulation. The intestinal (but not hepatic) detoxification mechanism seems to depend on receptors that recognize bacterial surface components ( TLR2). Evidence exists to link benzo 'a''yrene to the formation of

lung cancer Lung cancer, also known as lung carcinoma, is a malignant tumor that begins in the lung. Lung cancer is caused by genetic damage to the DNA of cells in the airways, often caused by cigarette smoking or inhaling damaging chemicals. Damaged ...

. In February 2014,

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

announced
greatly upgraded database
for tracking polycyclic aromatic hydrocarbons (PAHs), including benzopyrene, in the

universe The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of matter and energy, and the structures they form, from s ...

. According to scientists, more than 20% of the

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

in the universe may be associated with PAHs, possible starting materials for the formation of

life Life, also known as biota, refers to matter that has biological processes, such as Cell signaling, signaling and self-sustaining processes. It is defined descriptively by the capacity for homeostasis, Structure#Biological, organisation, met ...

. PAHs seem to have been formed several billion years after the

Big Bang The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models based on the Big Bang concept explain a broad range of phenomena, including th ...

, are widespread throughout the universe, and are associated with new stars and

exoplanets An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first detec ...

References

External links

{{PAHs Endocrine disruptors Carcinogens Polycyclic aromatic hydrocarbons

Overview

See also

References

External links