Heterocyclic compound


Heterocyclic compound

Heterocyclic compounds are organic compounds containing at least one atom of carbon, and at least one element other than carbon, such as sulfur, oxygen or nitrogen within a "ring structure".cite book
author = Eicher, T.; Hauptmann, S.
title = The Chemistry of Heterocycles: Structure, Reactions, Syntheses, and Applications
publisher = Wiley-VCH
date = 2nd ed. 2003
location =
pages =
id = ISBN 3527307206
] These structures may comprise either simple aromatic rings or non-aromatic rings. Some examples are pyridine (C5H5N), pyrimidine (C4H4N2) and dioxane (C4H8O2).

Note that compounds such as "cyclopropane", an anaesthetic with explosive properties, and "cyclohexane", a solvent, are not heterocyclic; they are merely cycloalkanes. The prefix 'cyclic' implies a ring structure, whereas 'hetero' refers to an atom other than carbon, as above. Many heterocyclic compounds, including some amines, are carcinogenic.

Heterocyclic chemistry is the chemistry branch dealing exclusively with synthesis, properties, and applications of heterocycles.

3-Membered rings

Heterocycles with three atoms in the ring are more reactive because of ring strain. Those containing one heteroatom are, in general, stable. Those with two heteroatoms are more likely to occur as reactive intermediates. Common 3-membered heterocycles are:

A large group of 5-membered ring compounds with two heteroatoms are collectively called the azoles. Dithiolanes have two sulfur atoms.

6-Membered rings

Six membered rings with a single heteroatom:

With two heteroatoms:

Heterocyclic amines and cancer

Some heterocyclic amines (HCAs) found in cooked meat are known carcinogens. Research has shown that cooking certain meats at high temperatures creates chemicals that are not present in uncooked meats. For example, heterocyclic amines are the carcinogenic chemicals formed from the cooking of muscle meats such as beef, pork, fowl, and fish. HCAs form when amino acids and creatine (a chemical found in muscles) react at high cooking temperatures. Researchers have identified 17 different HCAs resulting from the cooking of muscle meats that may pose human cancer risk. [cite web | title = Heterocyclic Amines in Cooked Meats | date = 15 Sep 2004 | publisher = National Cancer Institute | accessdate = 2007-08-09 | url = http://www.cancer.gov/cancertopics/factsheet/Risk/heterocyclic-amines] NCI's Division of Cancer Epidemiology and Genetics found a link between individuals with stomach cancer and the consumption of cooked meat, and other studies for colorectal, pancreatic, and breast cancer is associated with high intakes of well-done, fried, or barbecued meats. Other sources of protein (milk, eggs, tofu, and organ meats such as liver) have very little or no HCA content naturally or when cooked.

References

External links

* [http://www.chem.qmul.ac.uk/iupac/hetero/HW.html Nomenclature, IUPAC]
* [http://www.cancer.gov/cancertopics/factsheet/Risk/heterocyclic-amines Heterocyclic amines in cooked meat, US CDC]
* [http://www.cancer.org/docroot/PED/content/PED_1_3x_Known_and_Probable_Carcinogens.asp List of known and probable carcinogens, American Cancer Society]
* [http://www.scorecard.org/chemical-groups/one-list.tcl?short_list_name=p65 List of known carcinogens by the State of California, Proposition 65] (more comprehensive)


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • heterocyclic compound — heterocyclic compound. См. гетероциклическое соединение. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • heterocyclic compound — Any of a class of organic compounds whose molecules contain one or more rings of atoms with at least one atom (the heteroatom) being an element other than carbon, most frequently oxygen, nitrogen, or sulfur. As in regular cyclic hydrocarbons,… …   Universalium

  • heterocyclic compound — heterociklinis junginys statusas T sritis chemija apibrėžtis Junginys, turintis heterociklų. atitikmenys: angl. heterocyclic compound rus. гетероциклическое соединение …   Chemijos terminų aiškinamasis žodynas

  • heterocyclic compound — noun a compound containing a heterocyclic ring • Syn: ↑heterocyclic, ↑heterocycle • Derivationally related forms: ↑heterocyclic (for: ↑heterocycle) • Hypernyms: ↑ …   Useful english dictionary

  • heterocyclic compound — a chemical substance that contains a ring shaped nucleus composed of dissimilar elements …   Medical dictionary

  • compound — compound1 compoundable, adj. compoundedness, n. compounder, n. adj. /kom pownd, kom pownd /; n. /kom pownd/; v. /keuhm pownd , kom pownd/, adj. 1. composed of two or more parts, elements, or ingredients: Soap is a compound substance. 2 …   Universalium

  • compound — 1. In chemistry, a substance formed by the covalent or electrostatic union of two or more elements, generally differing entirely in physical characteristics from any of its components. 2. In pharmacy, denoting a preparation containing several… …   Medical dictionary

  • heterocyclic — [ˌhɛt(ə)rə(ʊ) sʌɪklɪk, sɪklɪk] adjective Chemistry denoting a compound whose molecule contains a ring of atoms of at least two elements (one of which is generally carbon) …   English new terms dictionary

  • heterocyclic — /hɛtəroʊˈsaɪklɪk/ (say hetuhroh suyklik), / ˈsɪklɪk/ (say siklik) –noun 1. Chemistry an organic compound with one or more rings which contain at least one atom which is not carbon (most commonly nitrogen, oxygen or sulphur). –adjective 2.… …   Australian English dictionary

  • heterocyclic — adj. Chem. (of a compound) with a bonded ring of atoms of more than one kind …   Useful english dictionary


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.