The only component of this group is a diacyl form: 1,2-diacyl-sn-glycero-3-phospho-L-serine or phosphatidylserine. It is the only amino acid-containing glycerophospholipid in animal cells.

Folch isolated a preparation of phosphatidylserine about 92% pure from brain "cephalin" by means of solvent fractionation and determined its exact composition (J Biol Chem 1948, 174, 439). This phospholipid occurs quite widely in nature but usually in concentrations less than 10% of the cell phospholipid pool. In brain tissue, myelin (white matter) has the highest amounts. Phosphatidylserine has generally highly unsaturated acyl chains.
From the formula it appears clearly that phosphatidylserine possesses three ionizable groups: a diester phosphoric acid, an amino group and a carboxyl function. Thus at pH 7, the phosphate and the carboxyl functions are in anionic form and the amino group is positively charged. When isolated, this lipid contains 1 mol of a cation (K or Na) which can be removed by washing the solvent with 0.05 N HCl.
Phosphatidylserine was not shown to be involved in cell signaling through the formation of metabolites (as phosphatidylcholine or phosphatidylinositol) but is a key component in the activation of protein kinase C as well as the blood coagulation process. For this last effect, it has been shown that both the PS head-group per se and unsaturation of the 1,2 fatty acids are important (Smirnov MD et al., Biochemistry 1999, 38, 3591). However, lyso derivatives of phosphatidylserine were detected after corneal injury and may be involved in maintaining the integrity of the normal cornea in promoting cellular regeneration (Liliom K et al., Am J Physiol 1998, 274, C1065).
Phosphatidylserine is located entirely on the inner layer of the plasma membrane. This normal distribution is altered during platelet activation and cellular apoptosis. Thus, it has been shown that phosphatidylserine is exposed on the surface of apoptotic cells (Fadok VA et al., J Immunol 1992, 148, 2207) and on the nuclei expelled from erythroid precursor cells (Yoshida H et al., Nature 2005, 437, 754). This signal works as an "eat me" signal for phagocytes. Further investigations have shown that a transmembrane protein (Tim4) is the phosphatidylserine receptor for the engulfment of apoptotic cells (Miyanishi M et al., Nature 2007, 450, 435). Phosphatidylserine was shown to modulate the activity of several key enzymes involved in cellular signaling. The detection of the movement of phosphatidylserine across membranes may be visualized using a complex of annexin V fused with a green fluorescence protein (Calderon F et al., J Neurochem 2008, 104, 1271).
A N-acylphosphatidylserine has been described in lipid extracts of mouse brain (Guan Z et al., Biochemistry 2007, 46, 14500). The complexity of this phospholipid is further increased by the presence of diverse amide-linked N-acyl chains, which include saturated, monounsaturated, and polyunsaturated species. N-Acylphosphatidylserine was also detected in the lipids of pig brain, mouse macrophage tumor cells, and yeast. It may be a biosynthetic precursor of N-acylserine which may have mediator functions.

A graphical chart of the metabolism of phosphatidylserine may be found on the BioCarta web site.

Glycine glycerophospholipids

It was shown that in that Phaeophyceae the fatty acid composition (R1 and R2) was about 80% arachidonic acid (20:4n-6) and 10% 20:5n-3. A large survey proved that this phospholipid was present in 30 different species representing the 16 orders of brown algae and in amounts of 8-25 mol% of total phospholipids. Furthermore, this lipid is very likely a specific constituent of Phaeophyceae, since it has not been observed in green algae or vascular plants so far.

Phosphatidylglycerol

This simplest polyol-phospholipid was first isolated in 1958 (Benson et al., Biochim Biophys Acta 1958, 27, 189) who described its structure. It can be defined as 1,2-diacyl-sn-glycero-3-phospho-1'-sn-glycerol.

Diphosphatidylglycerol

Also referred historically to cardiolipin, this curious lipid is found almost exclusively in mitochondria and in bacteria. It can account for as much as 20% of mitochondrial lipids. Cardiolopin was first discovered in beef heart tissue (Pangborn MC, J Biol Chem 1942, 143, 247) but, later, it was recognized to be not specific to the heart.
This phospholipid was discovered in 1906 by Wasserman through its antigenic properties in attempting to isolate the substance that confers on alcoholic extracts of beef heart the property of reacting with sera from cases of syphilis (Wassermann test) (Wassermann A et al., Dtsch Med Wochenschr 1906, 32, 745). A popular serological test, similar to the Wassermann reaction for detection of syphilis, used a mixture of cardiolipin, phosphatidylcholine and cholesterol (for details on antiphosphospholipid antibodies see the review of McIntyre JA et al. (Prog Lipid Res 2003, 42, 176 ). Since 1911, it is known that the antigenic activity is associated with the acetone-insoluble portion of the heart extract. Mrs Mary C. Pangborn was the first to "isolate and purify a serologically active phospholipid from beef heart". She proposed to designate this compound "cardiolipin" (heart lipid). In her first report (Pangborn M., Proc Soc Exp Biol Med 1941, 48, 484) she claimed that :

This phospholipid can be defined as 1,3-bis(sn-3-phosphatidyl)-sn-glycerol. Curiously, mammalian cardiolipin contains up to 90 mol% of one fatty acid, linoleic acid. 
Curiously, it was shown that the most abundant cardiolipin species from various organisms and tissues (human heart, human lymphoblasts, rat liver, Drosophila, sea urchin sperm, yeast, vegetal cells) contained only one or two types of fatty acids, which generated a high degree of structural uniformity (Schlame M et al., Chem Phys Lipids 2005, 138, 38).

In some marine bivalves (Pecten maximus, Crassostrea gigas and Mytilus edulis), cardiolipin molecules are found predominently with four docosahexaenoyl chains (22:6 n-3) and are presumed to reflect a specific adaptation to environmental conditions (Kraffe E et al. Lipids 2002, 37, 507). Cardiolipin from a Manila clam, Ruditapes philippinarum, was shown to contain EPA and DHA in approximately equal proportions and contributing together up to 73% of the total fatty acids of that phospholipid (Kraffe E et al., Lipids 2005, 40, 619). 

This phospholipid has been extensively studied since it was found to be associated to cytochrome oxidase in the electron transport system located in the mitochondrial cristae membranes, in chloroplast thylakoid membranes, and in bacterial membranes (review in Robinson NC, J Bioenerg Biomembr 1993, 25, 153). Although its exact function remains to be defined, cardiolipin seems to be a potential factor in several pathologies, such as thyroid disease (Paradies GFM et al., Arch Biochem Biophys 1993, 307, 91), oxidative stress (Iwase HT et al., Biochem Biophys Res Comm 1996, 222, 83), and aging (Paradies GFM et al., FEBS Lett 1997, 406, 136).
The fluorescent dye 10-N-nonyl acridine orange is extensively used for location and quantitative assays of cardiolipin in living cells on the assumption of its high specificity for cardiolipin (Garcia Fernandez MI et al., Anal Biochem 2004, 328, 174; Kaewsuya P et al., Anal Bioanal Chem 2007, 387, 2775). 
It was shown that a lyso precursor of cardiolipin (monolysocardiolipin) could be used as a specific marker for  the Barth Syndrome (an X-linked recessive disorder) when measured in patient fibroblasts (van Werkhoven MA et al., J Lipid Res 2006, 47, 2346). 
A large review on the biosynthesis and functional role of cardiolipin was proposed by Schlame M et al. (Prog Lipid Res 2000, 39, 257). 

As phosphatidylglycerol, it must be extracted from tissue homogenates using acidic solvents and some precautions are needed to prevent its loss in aqueous solutions.
Cardiolipin has been identified in quite all mammalian tissues (not found in erythrocytes, skin...) where it constitutes 2-10% of total phospholipids. It occurs also in invertebrates, plants, algae, yeast and bacteria.

From a streptococci Vagococcus fluviatilis, alanylcardiolipin was isolated and characterized (Fisher W et al., J Bacteriol 1998, 180, 2093). This phospholipid was shown to contribute up to 38% of the lipid phosphorus. Similarly, a lysyl derivative of cardiolipin has been described first in several species of Listeria, a gram-positive bacteria (Peter-Katalinic J et al., J Lipid Res 1998, 39, 2286) where it could be valuable as chemotaxonomic marker. In that phospholipid, the hydroxyl group of the middle glycerol moiety is esterified with a lysyl residue.
 A glucosylated cardiolipin was described in several strains of Streptococcus (Fisher W, Biochim Biophys Acta 1977, 487, 74).

Lysobisphosphatidic acid

This curious phospholipid known also as bis(monoacylglycero)phosphate has a stereochemical configuration, 3-acyl-sn-glycero-1-phosphoryl-1'-sn-[3'-acylglycerol], different from that of all the other known mammalian phospholipids, that have the sn-glycero-3-phosphoryl configuration (Brotherus J et al., Chem Phys Lipids 1974, 13, 178).

This phospholipid was first identified in the lung of mammals (Body DR et al., Chem Phys Lipids 1967, 1, 254) and was later shown to be enriched in lysosomes of rat liver (Wherrett JR et al., J Biol Chem 1972, 247, 4114). Its accumulation was demonstrated in some lipid storage disease. In addition, R1 or R2 are frequently arachidonic acid (alveolar macrophages) or  docosahexaenoic acid in some other cells (Holbrook PG et al., Biochim Biophys Acta 1992, 1125, 330), oleic acid being the other acyl group.
More recently, it was shown that lysobisphosphatidic acid is a major phospholipid, with phosphatidylcholine, in the late endosomes (Kobayashi T et al., J Biol Chem 2002, 277, 32157). It was also found that lysobisphosphatidic acid exhibited unique pH-dependent fusogenic properties, thus, this lipid is an ideal candidate to regulate the dynamic properties of these cellular membranes.

This unusual phospholipid has also been described in various obligatory and facultatively alkalophilic Bacillus strains (Clejan S et al., J Bacteriol 1986, 168, 334).

An alanyl derivative of bis(acylglycero)phosphate was isolated from various bavteria and characterized (Fisher W et al., J Bacteriol 1998, 180, 2093).