Fatty acid - Revision history

Fire: Marked this version for translation

2024-02-26T03:26:42Z

Marked this version for translation

Fire at 03:26, 26 February 2024

2024-02-26T03:26:31Z

← Older revision		Revision as of 12:26, 26 February 2024
Line 1:		Line 1:
	{{short description\|~~Carboxylic~~ acid}}		<languages />
			<translate>
			{{short description\|carboxylic acid with a long aliphatic chain, either saturated or unsaturated}}
	{{Fats}}		{{Fats}}
	[[Image:rasyslami.jpg\|thumb\|right\|300px\|Three-dimensional representations of several fatty acids. [[Saturated and unsaturated compounds\|Saturated]] fatty acids have perfectly straight chain structure. [[Unsaturated compound\|Unsaturated]] ones are typically bent, unless they have a [[#Unsaturated fatty acids\|trans]] configuration.]]		[[Image:rasyslami.jpg\|thumb\|right\|300px\|Three-dimensional representations of several fatty acids. [[Saturated and unsaturated compounds\|Saturated]] fatty acids have perfectly straight chain structure. [[Unsaturated compound\|Unsaturated]] ones are typically bent, unless they have a [[#Unsaturated fatty acids\|trans]] configuration.]]
Line 320:		Line 322:
	[[Category:E-number additives]]		[[Category:E-number additives]]
	[[Category:Edible oil chemistry]]		[[Category:Edible oil chemistry]]
			</translate>

Fire at 01:04, 26 February 2024

2024-02-26T01:04:18Z

Fire: /* Naming of fatty acids */

2024-02-26T01:03:27Z

Naming of fatty acids

← Older revision		Revision as of 10:03, 26 February 2024
Line 150:		Line 150:
	!Lipid numbers		!Lipid numbers
	\|18:3<br />[[α-Linolenic acid\|18:3n3]]<br />[[α-Linolenic acid\|18:3, ''cis'',''cis'',''cis''-Δ<sup>9</sup>,Δ<sup>12</sup>,Δ<sup>15</sup>]]<br />[[α-Linolenic acid\|18:3(9,12,15)]]		\|18:3<br />[[α-Linolenic acid\|18:3n3]]<br />[[α-Linolenic acid\|18:3, ''cis'',''cis'',''cis''-Δ<sup>9</sup>,Δ<sup>12</sup>,Δ<sup>15</sup>]]<br />[[α-Linolenic acid\|18:3(9,12,15)]]
	\|'''Lipid numbers''' take the form ''C'':''D'',~~{{efn\|name=c:d}}~~ where ''C'' is the number of carbon atoms in the fatty acid and ''D'' is the number of double bonds in the fatty acid. If D is more than one, the double bonds are assumed to be interrupted by [[methylene bridge\|{{chem\|CH\|2}} units]], ''i.e.'', at intervals of 3 carbon atoms along the chain. For instance, [[α-Linolenic acid\|α-linolenic acid]] is an 18:3 fatty acid and its three double bonds are located at positions Δ<sup>9</sup>, Δ<sup>12</sup>, and Δ<sup>15</sup>. This notation can be ambiguous, as some different fatty acids can have the same ''C'':''D'' numbers. Consequently, when ambiguity exists this notation is usually paired with either a Δ<sup>''x''</sup> or ''n''−''x'' term. For instance, although [[α-Linolenic acid\|α-linolenic acid]] and [[gamma-Linolenic acid\|γ-linolenic acid]] are both 18:3, they may be unambiguously described as 18:3n3 and 18:3n6 fatty acids, respectively. For the same purpose, IUPAC recommends using a list of double bond positions in parentheses, appended to the C:D notation. For instance, IUPAC recommended notations for α- and γ-linolenic acid are 18:3(9,12,15) and 18:3(6,9,12), respectively.		\|'''Lipid numbers''' take the form ''C'':''D'', where ''C'' is the number of carbon atoms in the fatty acid and ''D'' is the number of double bonds in the fatty acid. If D is more than one, the double bonds are assumed to be interrupted by [[methylene bridge\|{{chem\|CH\|2}} units]], ''i.e.'', at intervals of 3 carbon atoms along the chain. For instance, [[α-Linolenic acid\|α-linolenic acid]] is an 18:3 fatty acid and its three double bonds are located at positions Δ<sup>9</sup>, Δ<sup>12</sup>, and Δ<sup>15</sup>. This notation can be ambiguous, as some different fatty acids can have the same ''C'':''D'' numbers. Consequently, when ambiguity exists this notation is usually paired with either a Δ<sup>''x''</sup> or ''n''−''x'' term. For instance, although [[α-Linolenic acid\|α-linolenic acid]] and [[gamma-Linolenic acid\|γ-linolenic acid]] are both 18:3, they may be unambiguously described as 18:3n3 and 18:3n6 fatty acids, respectively. For the same purpose, IUPAC recommends using a list of double bond positions in parentheses, appended to the C:D notation. For instance, IUPAC recommended notations for α- and γ-linolenic acid are 18:3(9,12,15) and 18:3(6,9,12), respectively.
	\|}		\|}

Fire: /* Unsaturated fatty acids */

2024-02-26T01:02:27Z

Unsaturated fatty acids

← Older revision		Revision as of 10:02, 26 February 2024
Line 65:		Line 65:
	\|+ Examples of Unsaturated Fatty Acids		\|+ Examples of Unsaturated Fatty Acids
	\|-		\|-
	! Common name \|\| Chemical structure \|\| Δ{{sup\|''x''~~}}{{efn\|Each double bond in the fatty acid is indicated by Δx, where the double bond is located on the xth carbon–carbon bond, counting from the carboxylic acid end.~~}} \|\| ''C'':''D''{{efn\|name=c:d\|1="C:D" is the numerical symbol: total amount of (C)arbon atoms of the fatty acid, and the number of (D)ouble (''unsaturated'') bonds in it; if D > 1 it is assumed that the double bonds are separated by one or more [[methylene bridge]](s).}} \|\| IUPAC \|\| ''n''−''x''{{efn\|name=omega-x\|1=In ''n minus x'' (also ω−x or omega-x) nomenclature a double bond of the fatty acid is located on the xth carbon–carbon bond, counting from the terminal methyl carbon (designated as n or ω) toward the carbonyl carbon.}}		! Common name \|\| Chemical structure \|\| Δ{{sup\|''x''}} \|\| ''C'':''D'' \|\| IUPAC \|\| ''n''−''x''
	\|-		\|-
	\|[[Myristoleic acid]] \|\| CH{{sub\|3}}(CH{{sub\|2}}){{sub\|3}}'''CH=CH'''(CH{{sub\|2}}){{sub\|7}}COOH \|\| ''cis''-Δ{{sup\|9}} \|\| 14:1 \|\| 14:1(9) \|\| ''n''−5		\|[[Myristoleic acid]] \|\| CH{{sub\|3}}(CH{{sub\|2}}){{sub\|3}}'''CH=CH'''(CH{{sub\|2}}){{sub\|7}}COOH \|\| ''cis''-Δ{{sup\|9}} \|\| 14:1 \|\| 14:1(9) \|\| ''n''−5

Fire: Created page with "{{short description|Carboxylic acid}} {{Fats}} Saturated fatty acids have perfectly straight chain structure. Unsaturated ones are typically bent, unless they have a trans configuration.]] In chemistry, particularly in biochemistry, a '''fatty acid''' is a [[carboxylic acid]..."

2024-02-26T00:56:29Z

Created page with "{{short description|Carboxylic acid}} {{Fats}} thumb|right|300px|Three-dimensional representations of several fatty acids. [[Saturated and unsaturated compounds|Saturated fatty acids have perfectly straight chain structure. Unsaturated ones are typically bent, unless they have a trans configuration.]] In chemistry, particularly in biochemistry, a '''fatty acid''' is a [[carboxylic acid]..."

Show changes

← Older revision		Revision as of 10:04, 26 February 2024
Line 27:		Line 27:
	\|+ Examples of saturated fatty acids		\|+ Examples of saturated fatty acids
	\|-		\|-
	! Common name \|\| Chemical structure \|\| ''C'':''D''~~{{efn\|name=c:d}}~~		! Common name \|\| Chemical structure \|\| ''C'':''D''
	\|-		\|-
	\| [[Caprylic acid]] \|\| CH{{sub\|3}}(CH{{sub\|2}}){{sub\|6}}COOH \|\| 8:0		\| [[Caprylic acid]] \|\| CH{{sub\|3}}(CH{{sub\|2}}){{sub\|6}}COOH \|\| 8:0
Line 104:		Line 104:
	===Carbon atom numbering===		===Carbon atom numbering===
	{{See also\|Essential fatty acid#Nomenclature and terminology}}		{{See also\|Essential fatty acid#Nomenclature and terminology}}
	[[File:Fatty acid carbon numbering.svg\|thumb\|upright=2\|Numbering of carbon atoms. The systematic (IUPAC) C-''x'' numbers are in blue. The omega-minus "ω−''x''" labels are in red. The Greek letter labels are in green.~~{{efn\|name=note.omega}}~~ Note that [[#Unsaturated fatty acids\|unsaturated fatty acids]] with a ''cis'' configuration are actually "kinked" rather than straight as shown here.]]		[[File:Fatty acid carbon numbering.svg\|thumb\|upright=2\|Numbering of carbon atoms. The systematic (IUPAC) C-''x'' numbers are in blue. The omega-minus "ω−''x''" labels are in red. The Greek letter labels are in green. Note that [[#Unsaturated fatty acids\|unsaturated fatty acids]] with a ''cis'' configuration are actually "kinked" rather than straight as shown here.]]

	Most naturally occurring fatty acids have an [[branched chain fatty acids\|unbranched chain]] of carbon atoms, with a [[carboxyl group]] (–COOH) at one end, and a [[methyl group]] (–CH3) at the other end.		Most naturally occurring fatty acids have an [[branched chain fatty acids\|unbranched chain]] of carbon atoms, with a [[carboxyl group]] (–COOH) at one end, and a [[methyl group]] (–CH3) at the other end.
Line 112:		Line 112:
	Another convention uses letters of the [[Greek alphabet]] in sequence, starting with the first carbon ''after'' the carboxyl group. Thus carbon α ([[alpha]]) is C-2, carbon β ([[beta]]) is C-3, and so forth.		Another convention uses letters of the [[Greek alphabet]] in sequence, starting with the first carbon ''after'' the carboxyl group. Thus carbon α ([[alpha]]) is C-2, carbon β ([[beta]]) is C-3, and so forth.

	Although fatty acids can be of diverse lengths, in this second convention the last carbon in the chain is always labelled as ω ([[omega]]), which is the last letter in the Greek alphabet. A third numbering convention counts the carbons from that end, using the labels "ω", "ω−1", "ω−2". Alternatively, the label "ω−''x''" is written "n−''x''", where the "n" is meant to represent the number of carbons in the chain.{{efn\|name=note.omega\|A common mistake is to say that the last carbon is "ω−1".<br />Another common mistake is to say that the position of a bond in omega-notation is the number of the carbon closest to the END.<br />For double bonds, these two mistakes happen to compensate each other; so that a "ω−3" fatty acid indeed has the double bond between the 3rd and 4th carbons from the end, counting the methyl as 1.<br />However, for substitutions and other purposes, they don't: a hydroxyl "at ω−3" is on carbon 15 (4th from the end), not 16. See for example this article. {{doi\|10.1016/0005-2760(75)90089-2}}<br />Note also that the "−" in the omega-notation is a minus sign, and "ω−3" should in principle be read "omega minus three". However, it is very common (especially in non-scientific literature) to write it "ω-3" (with a hyphen/dash) and read it as "omega-three". See for example Karen Dooley (2008), [https://podcasts.ufhealth.org/omega-three-fatty-acids-and-diabetes/ Omega-three fatty acids and diabetes].}}		Although fatty acids can be of diverse lengths, in this second convention the last carbon in the chain is always labelled as ω ([[omega]]), which is the last letter in the Greek alphabet. A third numbering convention counts the carbons from that end, using the labels "ω", "ω−1", "ω−2". Alternatively, the label "ω−''x''" is written "n−''x''", where the "n" is meant to represent the number of carbons in the chain.

	In either numbering scheme, the position of a [[double bond]] in a fatty acid chain is always specified by giving the label of the carbon closest to the '''carboxyl''' end.~~{{efn\|name=note.omega}}~~ Thus, in an 18 carbon fatty acid, a double bond between C-12 (or ω−6) and C-13 (or ω−5) is said to be "at" position C-12 or ω−6. The IUPAC naming of the acid, such as "octadec-12-enoic acid" (or the more pronounceable variant "12-octadecanoic acid") is always based on the "C" numbering.		In either numbering scheme, the position of a [[double bond]] in a fatty acid chain is always specified by giving the label of the carbon closest to the '''carboxyl''' end. Thus, in an 18 carbon fatty acid, a double bond between C-12 (or ω−6) and C-13 (or ω−5) is said to be "at" position C-12 or ω−6. The IUPAC naming of the acid, such as "octadec-12-enoic acid" (or the more pronounceable variant "12-octadecanoic acid") is always based on the "C" numbering.

	The notation Δ<sup>''x'',''y'',...</sup> is traditionally used to specify a fatty acid with double bonds at positions ''x'',''y'',.... (The capital Greek letter "Δ" ([[Delta (letter)\|delta]]) corresponds to [[Latin alphabet\|Roman]] "D", for '''D'''ouble bond). Thus, for example, the 20-carbon [[arachidonic acid]] is Δ<sup>5,8,11,14</sup>, meaning that it has double bonds between carbons 5 and 6, 8 and 9, 11 and 12, and 14 and 15.		The notation Δ<sup>''x'',''y'',...</sup> is traditionally used to specify a fatty acid with double bonds at positions ''x'',''y'',.... (The capital Greek letter "Δ" ([[Delta (letter)\|delta]]) corresponds to [[Latin alphabet\|Roman]] "D", for '''D'''ouble bond). Thus, for example, the 20-carbon [[arachidonic acid]] is Δ<sup>5,8,11,14</sup>, meaning that it has double bonds between carbons 5 and 6, 8 and 9, 11 and 12, and 14 and 15.