Molecules/Elements/Particles

 

Sunday
Jun302013

Ethanolamine

"Ethanolamine, also called 2-aminoethanol or monoethanolamine (often abbreviated as ETA or MEA), is an organic chemical compound that is both a primary amine and a primary alcohol (due to a hydroxyl group). Like other amines, monoethanolamine acts as a weak base. Ethanolamine is a toxicflammablecorrosivecolorlessviscous liquid with an odor similar to that of ammonia."

"Ethanolamine is commonly called monoethanolamine or MEA in order to be distinguished from diethanolamine (DEA) and triethanolamine (TEA). Ethanolamine is the second-most-abundant head group forphospholipids, substances found in biological membranes, and is also used in messenger molecules such as palmitoylethanolamide which has an effect on CB1 receptors."

"The term ethanolamines (plural) is a group of amino alcohols. A class of antihistamines is identified as ethanolamines which includes carbinoxamineclemastinedimenhydrinatediphenhydramine, and doxylamine."

Saturday
Jun152013

Dysprosium

"Dysprosium is a chemical element with the symbol Dy and atomic number 66. It is a rare earth element with a metallic silver luster. Dysprosium is never found in nature as a free element, though it is found in various minerals, such as xenotime. Naturally occurring dysprosium is composed of 7 isotopes, the most abundant of which is 164Dy."

"Dysprosium was first identified in 1886 by Paul Émile Lecoq de Boisbaudran, but was not isolated in pure form until the development of ion exchange techniques in the 1950s. Dysprosium is used for its high thermal neutron absorption cross-section in making control rods in nuclear reactors, for its high magnetic susceptibility in data storage applications, and as a component of Terfenol-D. Soluble dysprosium salts are mildly toxic, while the insoluble salts are considered non-toxic."

"Dysprosium and holmium have the highest magnetic strengths of the elements,[2] especially at low temperatures.[3] Dysprosium has a simple ferromagnetic ordering at temperatures below 85 K(−188.2 °C). Above 85 K (−188.2 °C), it turns into an helical antiferromagnetic state in which all of the atomic moments in a particular basal plane layer are parallel, and oriented at a fixed angle to the moments of adjacent layers. This unusual antiferromagnetism transforms into a disordered (paramagnetic) state at 179 K (−94 °C)."

Friday
Jun072013

Carnosine

"Carnosine (beta-alanyl-L-histidine) is a dipeptide of the amino acids beta-alanine and histidine. It is highly concentrated in muscle and brain tissues."

"Carnosine and carnitine were discovered by Russian chemist V.Gulevich.[2] Researchers in Britain,[3] South Korea,[4] Russia[5][6] and other countries[7][8][9] have shown that carnosine has a number of antioxidant properties that may be beneficial. Carnosine has been proven to scavenge reactive oxygen species (ROS) as well as alpha-beta unsaturated aldehydesformed from peroxidation of cell membrane fatty acids during oxidative stress."

"Carnosine can oppose glycation[10][11] and it can chelate divalent metal ions. Chronic glycolysis is suspected to accelerate aging.[12] Carnosine was found to inhibit diabetic nephropathy by protecting the podocytes and mesangial cells."

"Carnosine containing products are also used in topical preparations to reduce wrinkles on the skin."

"Some studies have detected beneficial effects of N-acetylcarnosine in preventing and treating cataracts of the eyes; in one of these, carnosine was found to reduce cloudiness in rat lenses that were exposed to guanidine to cause cataracts.[15] However, claims that carnosine confers these and other posited ophthalmological benefits are, as yet, insufficiently supported for endorsement by the mainstream medical community; Britain's Royal College of Ophthalmologists, for instance, has asserted that neither safety nor efficacy has been sufficiently demonstrated to recommend carnosine's use as a topical treatment for cataracts."

Saturday
Jun012013

Lysine

"Lysine (abbreviated as Lys or K)[1] is an α-amino acid with the chemical  formula HO2CCH(NH2)(CH2)4NH2. It is an essential amino acidfor humans. Lysine's codons are AAA and AAG."

"Lysine is a base, as are arginine and histidine. The ε-amino group often participates in hydrogen bonding and as a general base incatalysis. (The ε-amino group (NH3+) is attached to the fifth carbon beginning from the α-carbon, which is attached to the carboxyl (C=OOH) group.[2])"

"Common posttranslational modifications include methylation of the ε-amino group, giving methyl-dimethyl-, and trimethyllysine. The latter occurs in calmodulin. Other posttranslational modifications at lysine residues include acetylation and ubiquitinationCollagencontains hydroxylysine, which is derived from lysine by lysyl hydroxylaseO-Glycosylation of hydroxylysine residues in the endoplasmic reticulum or Golgi apparatus is used to mark certain proteins for secretion from the cell."


Saturday
May252013

Thymine

"Thymine /ˈθmɨn/ (TThy) is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenineguanine, and cytosine. Thymine is also known as 5-methyluracil, a pyrimidine nucleobase. As the name suggests, thymine may be derived by methylation of uracil at the 5th carbon. In RNA, thymine is replaced with uracil in most cases. In DNA, thymine (T) binds to adenine (A) via two hydrogen bonds, thus stabilizing the nucleic acid structures."

"Thymine combined with deoxyribose creates the nucleoside deoxythymidine, which is synonymous with the term thymidine. Thymidine can be phosphorylated with one, two, or three phosphoric acid groups, creating, respectively, TMP, TDP, or TTP (thymidine mono-, di-, or triphosphate)."

Sunday
May122013

Zeise Salt

"Zeise's salt, potassium trichloro(ethene)platinate(II), is the chemical  compound with the formula K[PtCl3(C2H4)]·H2O. The anion of this air-stable, yellow, coordination complex contains an η2-ethylene ligand. The anion features a platinum atom with a square planargeometry. The salt is of historical importance in the area of organometallic chemistry as one of the first examples of an alkene complex."

"In Zeise's salt and related compounds, the alkene rotates about the metal-alkene bond with a modest activation energy. Analysis of the barrier heights indicates that the π-bonding between most metals and the alkene is weaker than the σ-bonding. In Zeise's anion, this rotational barrier cannot be assessed by NMR spectroscopy because all four protons are equivalent. Lower symmetry complexes of ethylene, e.g. CpRh(C2H4)2, are, however, suitable for analysis of the rotational barriers associated with the metal-ethylene bond."


Friday
May102013

Tricyclic Compound

"Tricyclics are chemical compounds that contain three interconnected rings  of atoms."

"Many compounds have a tricyclic structure, but in pharmacology, the term has traditionally been reserved to describe heterocyclic drugs. Among these are antidepressantsantipsychotics, and antihistamines (as antiallergens, anti-motion sickness drugs, antipruritics, and hypnotics/sedatives) of the dibenzazepinedibenzocycloheptenedibenzothiazepinedibenzothiepinphenothiazine, and thioxanthene chemical classes, and others."


Thursday
May022013

Polyene

"Polyenes are poly-unsaturated organic compounds that contain one or more sequences of alternating double and single carbon–carbon bonds. These double carbon–carbon bonds interact in a process known as conjugation, which results in an overall lower energy state of the molecule."

"Organic compounds with two carbon–carbon double bonds are dienes; those with three such double bonds are trienes; those with four are tetraenes, etc."

"Normally carbon–carbon double bonds which are not conjugated or only conjugated with only one or two other carbon–carbon double bonds have high enough energy that they absorb in the ultraviolet region of a spectrum, but the absorption energy state of polyenes with numerous conjugated double bonds can be lowered such that they enter the visible region of the spectrum, resulting in compounds which are coloured."

Tuesday
Mar122013

Polyanhydrides

"Polyanhydrides are a class of biodegradable polymers characterized by anhydride bonds that connect repeat units of the polymer backbone chain. Their main application is in the medical device and pharmaceutical industry. In vivo, polyanhydrides degrade into non-toxic diacid monomers that can be metabolized and eliminated from the body. Owing to their safe degradation products, polyanhydrides are considered to be biocompatible."

"The characteristic anhydride bonds in polyanhydrides are water-labile (the polymer chain breaks apart at the anhydride bond). This results in two carboxylic acid groups which are easily metabolized and biocompatibleBiodegradable polymers, such as polyanhydrides, are capable of releasing physically entrapped or encapsulated drugs by well-defined kinetics and are a growing area of medical research. Polyanhydrides have been investigated as an important material for the short-term release of drugs or bioactive agents. The rapid degradation and limited mechanical properties of polyanhydrides render them ideal as controlled drug delivery devices."


Friday
Mar082013

Indazole

"Indazole, also called benzpyrazole or isoindazone, is a heterocyclic aromatic organic compound."

"Indazole derivatives display a broad variety of biological activities."

"Indazoles are rare in Nature. The alkaloids NigellicineNigeglanine, and Nigellidine are indazoles. Nigellicine was isolated from the widely distributed plant Nigella sativa L. (black cumin). Nigeglanine was isolated from extracts of Nigella glandulifera."