Docosapentaenoic acid (DPA) designates any straight chain 22:5

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, fr ...

, that is a straight chain

open chain In chemistry, an open-chain compound (also spelled as open chain compound) or acyclic compound (Greek prefix "α", ''without'' and "κύκλος", ''cycle'') is a compound with a linear structure, rather than a cyclic one. An open-chain compound h ...

type of

polyunsaturated fatty acid Polyunsaturated fatty acids (PUFAs) are fatty acids that contain more than one double bond in their backbone. This class includes many important compounds, such as essential fatty acids and those that give drying oils their characteristic proper ...

(PUFA) which contains 22 carbons and 5

double bond In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...

s. DPA is primarily used to designate two

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. I ...

s, ''all''-''cis''-4,7,10,13,16-docosapentaenoic acid (i.e. 4''Z'',7''Z'',10''Z'',13''Z'',16''Z''-docosapentaenoic acid) and ''all''-''cis''-7,10,13,16,19-docosapentaenoic acid (i.e. 7''Z'',10''Z'',13''Z'',16''Z'',19''Z''-docosapentaenoic acid). They are also commonly termed n-6 DPA and n-3 DPA, respectively; these designations describes the position of the double bond being 6 or 3 carbons closest to the (omega) carbon at the methyl end of the molecule and is based on the biologically important difference that n-6 and n-3 PUFA are separate PUFA classes, i.e. the

omega-6 fatty acid Omega-6 fatty acids (also referred to as ω-6 fatty acids or ''n''-6 fatty acids) are a family of polyunsaturated fatty acids that have in common a final carbon-carbon double bond in the ''n''-6 position, that is, the sixth bond, counting from ...

s and

omega-3 fatty acid Omega−3 fatty acids, also called Omega-3 oils, ω−3 fatty acids or ''n''−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond, three atoms away from the terminal methyl group in their chem ...

s, respectively. Mammals, including humans, can not interconvert these two classes and therefore must obtain dietary essential PUFA fatty acids from both classes in order to maintain normal health (see

essential fatty acid Essential fatty acids, or EFAs, are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them. Only two fatty acids are known to be essential for humans: alpha-linolenic ac ...

s).

Isomers

''all''-''cis''-4,7,10,13,16-docosapentaenoic acid (osbond acid)

n-6 DPA is an ω-6 fatty acid with the trivial name osbond acid. It is formed by the stepwise elongation and desaturation of

arachidonic acid Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega-6 fatty acid 20:4(ω-6), or 20:4(5,8,11,14). It is structurally related to the saturated arachidic acid found in cupuaçu butter. Its name derives from the New Latin word ''arachi ...

i.e. 5''Z'',8''Z'',11''Z'',14''Z''-eicosatetraenoic acid (5,8,11,14-20:4n-6) to the 24 carbon PUFA intermediate (i.e. 6,9,12,15,18:24-5n-6) and the retro-conversion of this intermediate to DPAn-6 as follows:

''all''-''cis''-7,10,13,16,19-docosapentaenoic acid (clupanodonic acid)

n-3 DPA is an n-3 fatty acid with the trivial name clupanodonic acid. It is an intermediary between

eicosapentaenoic acid Eicosapentaenoic acid (EPA; also icosapentaenoic acid) is an omega-3 fatty acid. In physiological literature, it is given the name 20:5(n-3). It also has the trivial name timnodonic acid. In chemical structure, EPA is a carboxylic acid with a 20- c ...

(EPA, 5,8,11,14,17-20:5n-3) and

docosahexaenoic acid Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is a primary structural component of the human brain, cerebral cortex, skin, and retina. In physiological literature, it is given the name 22:6(n-3). It can be synthesized from alpha-lino ...

(DHA, 22:6 ω-3) in the following stepwise pathway in which DPAn-3 is a precursor to DHA (6,9,12,15,18,21:24:6n-3) and the final product, 4,7,10,13,16,19-22:6n-3, can be retro-converted to DPAn-3: Mammalian cells, including human cells, metabolize DPAn-3 to an array of products that are members of the

specialized proresolving mediators Specialized pro-resolving mediators (SPM, also termed specialized proresolving mediators) are a large and growing class of cell signaling molecules formed in cells by the metabolism of polyunsaturated fatty acids (PUFA) by one or a combination of ...

class of PUFA metabolites. These metabolites include seven resolvins Ds (RvT1, RvT2, RvT3, RvT4, RvD1_n-3, RvD2_n-3, and RvD5_n-3; see specialized proresolving mediators#n-3 DPA-derived resolvins and

Resolvin Resolvins are specialized pro-resolving mediators (SPMs) derived from omega-3 fatty acids, primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), as well as docosapentaenoic acid (DPA) and clupanodonic acid. As autacoids simila ...

); two protectins (PD1_n-3 and PD2_n-3; see specialized proresolving mediators#n-3 DPA-derived protectins/neuroprotectins and

neuroprotectin Neuroprotectin D1 (NPD1) (10''R'',17''S''-dihydroxy-4''Z'',7''Z'',11''E'',13''E'',15''Z'',19''Z''-docosahexaenoic acid) also known as Protectin D1 (PD1) is a docosanoid derived from the polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) ...

); and three maresins (MaR1_n-3, MaR2_n-3,and MaR3_n-3l see specialized proresolving mediators#n-3 DPA-derived maresins and

maresin Maresin 1 (MaR1 or 7''R'',14''S''-dihydroxy-4''Z'',8''E'',10''E'',12''Z'',16''Z'',19''Z''-docosahexaenoic acid) is a macrophage-derived mediator of inflammation resolution coined from macrophage mediator in resolving inflammation. Maresin 1, and ...

Nutrition

Docosapentaenoic acid (DPA) is an n-3 fatty acid that is structurally similar to

(EPA) with the same number of double bonds, but two more carbon chain units. Dietary sources These are the top five sources for DPA according to the USDA

Agricultural Research Service The Agricultural Research Service (ARS) is the principal in-house research agency of the United States Department of Agriculture (USDA). ARS is one of four agencies in USDA's Research, Education and Economics mission area. ARS is charged with ext ...

: # Fish oil, menhaden 0.668g in 1 tbsp. (13.6g) # Fish oil, salmon 0.407g in 1 tbsp. (13.6g) # Salmon, red (sockeye), filets with skin, smoked (Alaska Native) 0.335g in 1 filet (108g) # Fish, salmon, Atlantic, farmed, raw 0.334g in 3 oz (85g) # Beef, variety meats and by-products, brain, cooked, simmered 0.326g in 3oz (85g) Seal meat and human breast milk are rich in DPA.

Functions

Clupanodonic acid, an

, along with its metabolite DHA and other long chain omega-3 fatty acids, is under study to determine properties of omega-3 fats in humans, such as in

inflammation Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molec ...

mechanisms.

References