Naphthoquinones constitute a class of organic compounds structurally related to naphthalene. Two isomers are common for the parent naphthoquinones:
The quinones are a class of organic compounds that are formally "derived from aromatic compounds [such as benzene or naphthalene] by conversion of an even number of –CH= groups into –C(=O)– groups with any necessary rearrangement of double bonds", resulting in "a fully conjugated cyclic dione structure". The archetypical member of the class is 1,4-benzoquinone or cyclohexadienedione, often called simply "quinone". Other important examples are 1,2-benzoquinone (ortho-quinone), 1,4-naphthoquinone and 9,10-anthraquinone.
1,2-Naphthoquinone or ortho-naphthoquinone is a polycyclic aromatic organic compound with formula C
10H
6O
2. This yellow solid is prepared by oxidation of 1-amino-2-hydroxynaphthalene with ferric chloride.
Menadione is a natural organic compound with the formula C6H4(CO)2C2H(CH3). It is an analog of 1,4-naphthoquinone with a methyl group in the 2-position. It is sometimes called vitamin K3. Use is allowed as a nutritional supplement in animal feed because of its vitamin K activity.
Phytomenadione, also known as vitamin K1 or phylloquinone, is a vitamin found in food and used as a dietary supplement. It is on the World Health Organization's List of Essential Medicines.
A diamine is an amine with exactly two amino groups. Diamines are used as monomers to prepare polyamides, polyimides, and polyureas. The term diamine refers mostly to primary diamines, as those are the most reactive.
Divinylbenzene (DVB) is an organic compound with the chemical formula C6H4(CH=CH2)2 and structure H2C=CH−C6H4−HC=CH2. It is related to styrene by the addition of a second vinyl group. It is a colorless liquid manufactured by the thermal dehydrogenation of isomeric diethylbenzenes. Under synthesis conditions, o-divinylbenzene converts to naphthalene and thus is not a component of the usual mixtures of DVB.
In enzymology, a vitamin-K-epoxide reductase (warfarin-sensitive) is an enzyme that catalyzes the chemical reaction
1-Naphthol, or α-naphthol, is a organic compound with the formula C10H7OH. It is a fluorescent white solid. 1-Naphthol differs from its isomer 2-naphthol by the location of the hydroxyl group on the naphthalene ring. The naphthols are naphthalene homologues of phenol. Both isomers are soluble in simple organic solvents. They are precursors to a variety of useful compounds.
Spinochrome E is a polyhydroxylated 1,4-naphthoquinone pigment found in sea urchin shell ("test"), spine, gonads, coelomic fluid, and eggs, of sea urchin commonly known as spinochromes. These natural phenolic compounds are quinones with potential pharmacological properties. The several hydroxyl groups are appropriate for free-radical scavenging, which diminishes ROS and prevents redox imbalance. Mechanisms are described such as scavenging of reactive oxygen species (ROS), interaction with lipid peroxide radicals, chelation of metal ions, inhibition of lipid peroxidation and regulation of the cell redox potential.
A hydroxynaphthoquinone is any of several organic compounds that can be viewed as derivatives of a naphthoquinone through replacement of one hydrogen atom (H) by a hydroxyl group (-OH).
Spinochrome D (2,3,5,6,8-pentahydroxy-1,4-naphthoquinone) is an organic compound with formula C
10H
6O
5, formally derived from 1,4-naphthoquinone through the replacement of five hydrogen atoms by hydroxyl (OH) groups.
Spinochrome B (2,3,5,7-tetrahydroxynaphthoquinone) is an organic compound with formula C
10H
6O
4, formally derived from 1,4-naphthoquinone through the replacement of four hydrogen atoms by hydroxyl (OH) groups.
A dihydroxynaphthoquinone is any of several organic compounds that can be viewed as derivatives of naphthoquinone through replacement of two hydrogen atoms (H) by hydroxyl groups (OH).
Hydroxyquinone often refers to a hydroxybenzoquinone, any organic compound with formula C
6H
4O
3 which can be viewed as a derivative of a benzoquinone through replacement of one hydrogen atom (H) by a hydroxyl group (-OH). When unqualified, the terms usually mean specifically the compound 2-hydroxy-1,4-benzoquinone, derived from 1,4-benzoquinone. That parent is sometimes simply called quinone, and this is the only hydroxy derivative of it.
1,4-Naphthoquinone or para-naphthoquinone is a quinone derived from naphthalene. It forms volatile yellow triclinic crystals and has a sharp odor similar to benzoquinone. It is almost insoluble in cold water, slightly soluble in petroleum ether, and more soluble in polar organic solvents. In alkaline solutions it produces a reddish-brown color. Vitamin K is a derivative of 1,4-naphthoquinone. It is a planar molecule with one aromatic ring fused to a quinone subunit. It is an isomer of 1,2-naphthoquinone.
The enzyme 1,4-dihydroxy-2-naphthoyl-CoA hydrolase (EC 3.1.2.28; systematic name 1,4-dihydroxy-2-naphthoyl-CoA hydrolase) catalyses the following reaction:
Peptidyl-glutamate 4-carboxylase (EC 4.1.1.90, vitamin K-dependent carboxylase, gamma-glutamyl carboxylase) is an enzyme with systematic name peptidyl-glutamate 4-carboxylase (2-methyl-3-phytyl-1,4-naphthoquinone-epoxidizing). This enzyme catalyses the following chemical reaction
4-Amino-2-methyl-1-naphthol is a menadione analog. Its water-soluble hydrochloride (HCl) salt is often called vitamin K5. The HCl salt has been used as a medicine for vitamin K deficiency under tradenames such as Synkamin, which was sold by Parke-Davis, but has since been discontinued.
2-Methylnaphthalene-1,4-diamine is a synthetic menadione analog with vitamin K activity.
Echinochrome A (7-ethyl-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone) is a polyhydroxylated 1,4-naphthoquinone, a type of pigments commonly found in sea urchin shell ("test"), spine, gonads, coelomic fluid, and eggs, of sea urchin. These type of pigments are commonly known as spinochromes and are natural marine phenolic compounds with potential pharmacological effects and modes of action.