Record Information
Version3.6
Creation Date2008-09-12 01:59:39 UTC
Update Date2013-02-09 00:23:14 UTC
HMDB IDHMDB09781
Secondary Accession NumbersNone
Metabolite Identification
Common NamePI(16:0/18:0)
DescriptionPI(16:0/18:0) is a phosphatidylinositol. Phosphatidylinositols are important lipids, both as a key membrane constituent and as a participant in essential metabolic processes, both directly and via a number of metabolites. Phosphatidylinositols are acidic (anionic) phospholipids that consist of a phosphatidic acid backbone, linked via the phosphate group to inositol (hexahydroxycyclohexane). Phosphatidylinositols can have many different combinations of fatty acids of varying lengths and saturation attached at the C-1 and C-2 positions. Fatty acids containing 18 and 20 carbons are the most common. PI(16:0/18:0), in particular, consists of one chain of palmitic acid at the C-1 position and one chain of stearic acid at the C-2 position. The palmitic acid moiety is derived from fish oils, milk fats, vegetable oils and animal fats, while the stearic acid moiety is derived from animal fats, coco butter and sesame oil. In most organisms, the stereochemical form of the last is myo-D-inositol (with one axial hydroxyl in position 2 with the remainder equatorial. Phosphatidylinositol is especially abundant in brain tissue, where it can amount to 10% of the phospholipids, but it is present in all tissues and cell types. There is usually less of it than of phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine. In animal tissues, phosphatidylinositol is the primary source of the arachidonic acid required for biosynthesis of eicosanoids, including prostaglandins, via the action of the enzyme phospholipase A2. Phosphatidylinositol can be phosphorylated by a number of different kinases that place the phosphate moiety on positions 4 and 5 of the inositol ring, although position 3 can also be phosphorylated by a specific kinase. Seven different isomers are known, but the most important in both quantitative and biological terms are phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate. Phosphatidylinositol and the phosphatidylinositol phosphates are the main source of diacylglycerols that serve as signaling molecules, via the action of phospholipase C enzymes.While most phospholipids have a saturated fatty acid on C-1 and an unsaturated fatty acid on C-2 of the glycerol backbone, the fatty acid distribution at the C-1 and C-2 positions of glycerol within phospholipids is continually in flux, owing to phospholipid degradation and the continuous phospholipid remodeling that occurs while these molecules are in membranes. PIs contain almost exclusively stearic acid at carbon 1 and arachidonic acid at carbon 2. PIs composed exclusively of non-phosphorylated inositol exhibit a net charge of -1 at physiological pH. Molecules with phosphorylated inositol (such as PIP, PIP2, PIP3, etc.) are termed polyphosphoinositides. The polyphosphoinositides are important intracellular transducers of signals emanating from the plasma membrane. The synthesis of PI involves CDP-activated 1,2-diacylglycerol condensation with myo-inositol.
Structure
Thumb
Synonyms
  1. 1-Hexadecanoyl-2-octadecanoyl-sn-glycero-3-phospho-(1'-myo-inositol)
  2. 1-Palmitoyl-2-stearoyl-sn-glycero-3-phosphoinositol
  3. Phosphatidylinositol(16:0/18:0)
  4. Phosphatidylinositol(34:0)
  5. PI(16:0/18:0)
  6. PI(34:0)
  7. PIno(16:0/18:0)
  8. PIno(34:0)
Chemical FormulaC43H83O13P
Average Molecular Weight839.0851
Monoisotopic Molecular Weight838.557129254
IUPAC Name[(2R)-3-(hexadecanoyloxy)-2-(octadecanoyloxy)propoxy]({[(1s,3R)-2,3,4,5,6-pentahydroxycyclohexyl]oxy})phosphinic acid
Traditional IUPAC Name(2R)-3-(hexadecanoyloxy)-2-(octadecanoyloxy)propoxy[(1s,3R)-2,3,4,5,6-pentahydroxycyclohexyl]oxyphosphinic acid
CAS Registry NumberNot Available
SMILES
[H][C@@](COC(=O)CCCCCCCCCCCCCCC)(COP(O)(=O)O[C@H]1C(O)C(O)C(O)[C@@H](O)C1O)OC(=O)CCCCCCCCCCCCCCCCC
InChI Identifier
InChI=1S/C43H83O13P/c1-3-5-7-9-11-13-15-17-18-20-22-24-26-28-30-32-37(45)55-35(34-54-57(51,52)56-43-41(49)39(47)38(46)40(48)42(43)50)33-53-36(44)31-29-27-25-23-21-19-16-14-12-10-8-6-4-2/h35,38-43,46-50H,3-34H2,1-2H3,(H,51,52)/t35-,38?,39-,40?,41?,42?,43-/m1/s1
InChI KeyNEXFZIYXCPIHEF-HGTJTCKHSA-N
Chemical Taxonomy
KingdomOrganic Compounds
Super ClassLipids
ClassGlycerophospholipids
Sub ClassGlycerophosphoinositols
Other Descriptors
  • Aliphatic Homomonocyclic Compounds
Substituents
  • 1,2 Diol
  • Carboxylic Acid Ester
  • Cyclic Alcohol
  • Cyclitol Derivative
  • Cyclohexane
  • Dicarboxylic Acid Derivative
  • Fatty Acid Ester
  • Inositol Phosphate
  • Organic Hypophosphite
  • Organic Phosphite
  • Phosphoric Acid Ester
  • Secondary Alcohol
Direct ParentPhosphatidylinositols
Ontology
StatusDetected and Quantified
Origin
  • Endogenous
  • Food
Biofunction
  • Cell signaling
  • Energy source
  • Fuel and energy storage
  • Fuel or energy source
  • Membrane component
  • Membrane integrity/stability
Application
  • Nutrients
  • Stabilizers
  • Surfactants and Emulsifiers
Cellular locations
  • Extracellular
  • Membrane
Physical Properties
StateSolid
Experimental Properties
PropertyValueReference
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
PropertyValueSource
water solubility7.580E-04 g/LALOGPS
logP7.22ALOGPS
logP9.88ChemAxon
logS-6ALOGPS
pKa (strongest acidic)1.83ChemAxon
pKa (strongest basic)-3.6ChemAxon
physiological charge-1ChemAxon
hydrogen acceptor count9ChemAxon
hydrogen donor count6ChemAxon
polar surface area209.51ChemAxon
rotatable bond count40ChemAxon
refractivity219.77ChemAxon
polarizability99.16ChemAxon
Spectra
SpectraNot Available
Biological Properties
Cellular Locations
  • Extracellular
  • Membrane
Biofluid Locations
  • Blood
Tissue Location
  • All Tissues
  • Brain
PathwaysNot Available
Normal Concentrations
BiofluidStatusValueAgeSexConditionReference
BloodDetected and Quantified0.473 +/- 0.101 uMAdult (>18 years old)BothNormal
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
DrugBank Metabolite IDNot Available
Phenol Explorer Compound IDNot Available
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB026971
KNApSAcK IDNot Available
Chemspider ID24767666
KEGG Compound IDC00626
BioCyc IDPhosphatidylinositols
BiGG IDNot Available
Wikipedia LinkLecithin
NuGOwiki LinkHMDB09781
Metagene LinkHMDB09781
METLIN IDNot Available
PubChem CompoundNot Available
PDB IDNot Available
ChEBI IDNot Available
References
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Not Available
General ReferencesNot Available

Only showing the first 50 proteins. There are 80 proteins in total.

Enzymes

Gene Name:
PLSCR1
Uniprot ID:
O15162
Gene Name:
PTDSS1
Uniprot ID:
P48651
Gene Name:
PLTP
Uniprot ID:
P55058
Gene Name:
PIGM
Uniprot ID:
Q9H3S5
Gene Name:
PTDSS2
Uniprot ID:
Q9BVG9
Gene Name:
PIGZ
Uniprot ID:
Q86VD9
Gene Name:
PLCXD2
Uniprot ID:
Q0VAA5
Gene Name:
PLSCR2
Uniprot ID:
Q9NRY7
Gene Name:
PLSCR3
Uniprot ID:
Q9NRY6

Only showing the first 50 proteins. There are 80 proteins in total.