Record Information
Version1.0
Creation date2011-09-21 00:27:42 UTC
Update date2015-07-21 06:57:38 UTC
Primary IDFDB023298
Secondary Accession NumbersNot Available
Chemical Information
FooDB NameMelanin
DescriptionDermal melanin is produced by melanocytes, which are found in the stratum basale of the epidermis. Although human beings generally possess a similar concentration of melanocytes in their skin, the melanocytes in some individuals and races more frequently or less frequently express the melanin-producing genes, thereby conferring a greater or lesser concentration of skin melanin. Some individual animals and humans have no or very little melanin in their bodies, which is a condition known as albinism. Higher eumelanin levels also can be a disadvantage, however, beyond a higher disposition toward vitamin D deficiency. Dark skin is a complicating factor in the laser removal of port-wine stains. Effective in treating fair skin, lasers generally are less successful in removing port-wine stains in Asians and people of African descent. Higher concentrations of melanin in darker-skinned individuals simply diffuse and absorb the laser radiation, inhibiting light absorption by the targeted tissue. Melanin similarly can complicate laser treatment of other dermatological conditions in people with darker skin. Under the microscope melanin is brown, non-refractile and finely granular with individual granules having a diameter of less than 800 nanometers. This differentiates melanin from common blood breakdown pigments which are larger, chunky and refractile and range in color from green to yellow or red-brown. In heavily pigmented lesions, dense aggregates of melanin can obscure histologic detail. A dilute solution of potassium permanganate is an effective melanin bleach. Pigments causing darkness in skin, hair, feathers, etc. They are irregular polymeric structures and are divided into three groups: allomelanins in the plant kingdom and eumelanins and phaeomelanins in the animal kingdom. When skin pigmentation as a characteristic of race is linked to social status or other human attributes, this phenomenon is known as racialism. Many people and societies overlay racialism with racist perceptions and systems which arbitrarily assign to groups of people a status of inherent superiority or inferiority, privilege or disadvantage based on skin color or racial classification. Apartheid-era South Africa is an example of a white supremacist society based on a system of stratification of power and privilege by skin color, as well as racial admixture. Similar examples can be found in Brazil's highly socially color-stratified society; and, in the U.S., segregation and institutional racism on the part of white-controlled and black-controlled institutions, and internal 'color consciousness' on the part of some ethnic minorities. Prejudice against people with more highly pigmented skin is the most pervasive form of color bias. Many other societies remain informally divided on the basis of skin color and, often, related ethnicity. (See also colonialism, Nazism, pigmentocracy and institutional racism.) Because melanin is an aggregate of smaller component molecules, there are a number of different types of melanin with differing proportions and bonding patterns of these component molecules. Both pheomelanin and eumelanin are found in human skin and hair, but eumelanin is the most abundant melanin in humans, as well as the form most likely to be deficient in albinism. Freckles and moles are formed where there is a localized concentration of melanin in the skin. They are highly associated with pale skin. Melanin is a biopolymer and a neuropeptide. In the early 1970s, John McGinness, Peter Corry, and Peter Proctor reported that melanin is a high-conductivity organic semiconductor (Science, vol 183, 853-855 (1974)). Studies revealed that melanin acted as a voltage-controlled solid-state threshold switch. Further, it emitting a flash of light electroluminescence when it switched. There are approximately ten different types of oculocutaneous albinism, which is mostly an autosomal recessive disorder. Certain ethnicities have higher incidences of different forms. For example, the most common type, called oculocutaneous albinism type 2 (OCA2), is especially frequent among people of indigenous African descent. It is an autosomal recessive disorder characterized by a congenital reduction or absence of melanin pigment in the skin, hair and eyes. The estimated frequency of OCA2 among African-Americans is 1 in 10,000, which contrasts with a frequency of 1 in 36,000 in white Americans . In some African nations, the frequency of the disorder is even higher, ranging from 1 in 2,000 to 1 in 5,000. Another form of Albinism, the 'yellow oculocutaneous albinism', appears to be more prevalent among the Amish, who are of primarily Swiss and German ancestry. People with this IB variant of the disorder commonly have white hair and skin at birth, but rapidly develop normal skin pigmentation in infancy. Broadly, melanin is any of the polyacetylene, polyaniline, and polypyrrole 'blacks' and "browns" or their mixed copolymers. The most common form of biological melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. In contrast, some fungal melanin is polyacetylene black. Melanin exists in the plant, animal and protista kingdoms, where it serves as a pigment. The presence of melanin in the archaea and bacteria kingdoms is an issue of ongoing debate amongst researchers in the field. [HMDB]
CAS Number8049-97-6
Structure
Thumb
Synonyms
SynonymSource
AllomelaninsHMDB
MelaninsHMDB
PhaeomelaninsHMDB
Predicted Properties
PropertyValueSource
Water Solubility0.31 g/LALOGPS
logP1.76ALOGPS
logP-0.27ChemAxon
logS-3ALOGPS
pKa (Strongest Acidic)12.65ChemAxon
pKa (Strongest Basic)1.34ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count6ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area92.34 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity88.28 m³·mol⁻¹ChemAxon
Polarizability31.77 ųChemAxon
Number of Rings5ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Chemical FormulaC18H10N2O4
IUPAC name6,14-dimethyl-4,12-diazapentacyclo[8.6.1.1²,⁵.0¹³,¹⁷.0⁹,¹⁸]octadeca-1(17),2,5,9(18),10,13-hexaene-7,8,15,16-tetrone
InChI IdentifierInChI=1S/C18H10N2O4/c1-5-13-9-7(3-19-13)12-10-8(11(9)17(23)15(5)21)4-20-14(10)6(2)16(22)18(12)24/h3-4,19-20H,1-2H3
InChI KeyXUMBMVFBXHLACL-UHFFFAOYSA-N
Isomeric SMILESCC1=C2NC=C3C2=C(C2=CNC4=C(C)C(=O)C(=O)C3=C24)C(=O)C1=O
Average Molecular Weight318.283
Monoisotopic Molecular Weight318.064056818
Classification
Description belongs to the class of organic compounds known as anthracenes. These are organic compounds containing a system of three linearly fused benzene rings.
KingdomOrganic compounds
Super ClassBenzenoids
ClassAnthracenes
Sub ClassNot Available
Direct ParentAnthracenes
Alternative Parents
Substituents
  • Anthracene
  • Indolequinone
  • Indole
  • Indole or derivatives
  • Isoindole
  • Isoindole or derivatives
  • Quinone
  • Vinylogous amide
  • Pyrrole
  • Heteroaromatic compound
  • Cyclic ketone
  • Organoheterocyclic compound
  • Azacycle
  • Organic nitrogen compound
  • Organooxygen compound
  • Organonitrogen compound
  • Hydrocarbon derivative
  • Organic oxide
  • Organopnictogen compound
  • Organic oxygen compound
  • Aromatic heteropolycyclic compound
Molecular FrameworkAromatic heteropolycyclic compounds
External DescriptorsNot Available
Ontology
Physiological effect

Health effect:

Disposition

Source:

Biological location:

Physico-Chemical Properties - Experimental
Physico-Chemical Properties - Experimental
PropertyValueReference
Physical stateSolid
Physical DescriptionNot Available
Mass CompositionNot Available
Melting PointNot Available
Boiling PointNot Available
Experimental Water SolubilityNot Available
Experimental logPNot Available
Experimental pKaNot Available
Isoelectric pointNot Available
ChargeNot Available
Optical RotationNot Available
Spectroscopic UV DataNot Available
DensityNot Available
Refractive IndexNot Available
Spectra
Spectra
Spectrum TypeDescriptionSplash KeyView
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-00ku-0094000000-94704d5e412ed2489f17JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-014i-0009000000-ca3bb49729033ec75f80JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-014l-0089000000-bc7ad58775b231f90e84JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0229-0090000000-dc286795a5fc4078c357JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-014i-0009000000-80dff8e14771680560aaJSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-014i-0019000000-395c4a7d06b442e4dcf1JSpectraViewer
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-06ri-0091000000-760c7a558bb6db841316JSpectraViewer
ChemSpider ID4884931
ChEMBL IDNot Available
KEGG Compound IDC05606
Pubchem Compound ID6325610
Pubchem Substance IDNot Available
ChEBI IDNot Available
Phenol-Explorer IDNot Available
DrugBank IDNot Available
HMDB IDHMDB04068
CRC / DFC (Dictionary of Food Compounds) IDNot Available
EAFUS IDNot Available
Dr. Duke IDNot Available
BIGG ID46115
KNApSAcK IDNot Available
HET IDNot Available
Food Biomarker OntologyNot Available
VMH IDNot Available
Flavornet IDNot Available
GoodScent IDNot Available
SuperScent IDNot Available
Wikipedia IDMelanin
Phenol-Explorer Metabolite IDNot Available
Duplicate IDSNot Available
Old DFC IDSNot Available
Associated Foods
FoodContent Range AverageReference
FoodReference
Biological Effects and Interactions
Health Effects / BioactivitiesNot Available
EnzymesNot Available
Pathways
NameSMPDB LinkKEGG Link
Tyrosine MetabolismSMP00006 map00350
MetabolismNot Available
BiosynthesisNot Available
Organoleptic Properties
FlavoursNot Available
Files
MSDSNot Available
References
Synthesis ReferenceNot Available
General ReferenceNot Available
Content Reference