Deuterium (or hydrogen-2, symbol 2
H
or D, also known as heavy hydrogen) is one of two stable isotopes of hydrogen (the other being protium, or hydrogen-1). The nucleus of a deuterium atom, called a deuteron, contains one proton and one neutron, whereas the far more common protium has no neutrons in the nucleus. Deuterium has a natural abundance in Earth's oceans of about one atom of deuterium among every 6,420 atoms of hydrogen (see heavy water). Thus deuterium accounts for approximately 0.0156% by number (0.0312% by mass) of all the naturally occurring hydrogen in the oceans (i.e., 4.85×1013 tonnes of deuterium – mainly in form of HOD and only rarely in form of D2O – in 1.4×1018 tonnes of water), while protium accounts for 99.98%. The abundance of deuterium changes slightly from one kind of natural water to another (see Vienna Standard Mean Ocean Water)
Omega−3 fatty acids, also called Omega−3 oils, ω−3 fatty acids or n−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond, three atoms away from the terminal methyl group in their chemical structure. They are widely distributed in nature, being important constituents of animal lipid metabolism, and they play an important role in the human diet and in human physiology. The three types of omega−3 fatty acids involved in human physiology are α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA can be found in plants, while DHA and EPA are found in algae and fish. Marine algae and phytoplankton are primary sources of omega−3 fatty acids. DHA and EPA accumulate in fish that eat these algae. Common sources of plant oils containing ALA include walnuts, edible seeds, and flaxseeds as well as hempseed oil, while sources of EPA and DHA include fish and fish oils, and algae oil.
α-Linolenic acid, also known as alpha-Linolenic acid (ALA), is an n−3, or omega-3, essential fatty acid. ALA is found in many seeds and oils, including flaxseed, walnuts, chia, hemp, and many common vegetable oils.
Isotope analysis is the identification of isotopic signature, abundance of certain stable isotopes of chemical elements within organic and inorganic compounds. Isotopic analysis can be used to understand the flow of energy through a food web, to reconstruct past environmental and climatic conditions, to investigate human and animal diets, for food authentification, and a variety of other physical, geological, palaeontological and chemical processes. Stable isotope ratios are measured using mass spectrometry, which separates the different isotopes of an element on the basis of their mass-to-charge ratio.
A saturated fat is a type of fat in which the fatty acid chains have all single bonds. A fat known as a glyceride is made of two kinds of smaller molecules: a short glycerol backbone and fatty acids that each contain a long linear or branched chain of carbon (C) atoms. Along the chain, some carbon atoms are linked by single bonds (-C-C-) and others are linked by double bonds (-C=C-). A double bond along the carbon chain can react with a pair of hydrogen atoms to change into a single -C-C- bond, with each H atom now bonded to one of the two C atoms. Glyceride fats without any carbon chain double bonds are called saturated because they are "saturated with" hydrogen atoms, having no double bonds available to react with more hydrogen.
An unsaturated fat is a fat or fatty acid in which there is at least one double bond within the fatty acid chain. A fatty acid chain is monounsaturated if it contains one double bond, and polyunsaturated if it contains more than one double bond.
Rudolf Schoenheimer was a German-American biochemist who developed the technique of isotope labelling/tagging of biomolecules, enabling detailed study of metabolism. This work revealed that all the constituents of an organism are in a constant state of chemical renewal.
Linoleic acid (LA) is an organic compound with the formula HOOC(CH
2)
7CH=CHCH
2CH=CH(CH
2)
4CH
3. Both alkene groups are cis. It is a fatty acid sometimes denoted 18:2 (n-6) or 18:2 cis-9,12. A linoleate is a salt or ester of this acid.
Lipid peroxidation is the conversion of lipids to peroxide and hydroperoxide derivatives. These derivatives, known as lipid peroxides or lipid oxidation products (LOPs), are susceptible to further reactions that are relevant to "DNA and protein modification, radiation damage, aging..." Lipid peroxidation mainly applies to unsaturated fats, especially polyunsaturated fats such as those derived from linoleic acid.
Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is a primary structural component of the human brain, cerebral cortex, skin, and retina. In physiological literature, it is given the name 22:6(n-3). It can be synthesized from alpha-linolenic acid or obtained directly from maternal milk, fatty fish, fish oil, or algae oil.
Lipid emulsion or fat emulsion refers to an emulsion of fat for human intravenous use, to administer nutrients to critically-ill patients that cannot consume food. It is often referred to by the brand name of the most commonly used version, Intralipid, which is an emulsion containing soybean oil, egg phospholipids and glycerin, and is available in 10%, 20% and 30% concentrations. The 30% concentration is not approved for direct intravenous infusion, but should be mixed with amino acids and dextrose as part of a total nutrient admixture.
In biochemistry and nutrition, a polyunsaturated fat is a fat that contains a polyunsaturated fatty acid, which is a subclass of fatty acid characterized by a backbone with two or more carbon–carbon double bonds. Some polyunsaturated fatty acids are essentials. Polyunsaturated fatty acids are precursors to and are derived from polyunsaturated fats, which include drying oils.
A deuterated drug is a small molecule medicinal product in which one or more of the hydrogen atoms contained in the drug molecule have been replaced by its heavier stable isotope deuterium. Because of the kinetic isotope effect, deuterium-containing drugs may have significantly lower rates of metabolism, and hence a longer half-life.
Hydrogen isotope biogeochemistry is the scientific study of biological, geological, and chemical processes in the environment using the distribution and relative abundance of hydrogen isotopes. There are two stable isotopes of hydrogen, protium 1H and deuterium 2H, which vary in relative abundance on the order of hundreds of permil. The ratio between these two species can be considered the hydrogen isotopic fingerprint of a substance. Understanding isotopic fingerprints and the sources of fractionation that lead to variation between them can be applied to address a diverse array of questions ranging from ecology and hydrology to geochemistry and paleoclimate reconstructions. Since specialized techniques are required to measure natural hydrogen isotope abundance ratios, the field of hydrogen isotope biogeochemistry provides uniquely specialized tools to more traditional fields like ecology and geochemistry.
Position-specific isotope analysis, also called site-specific isotope analysis, is a branch of isotope analysis aimed at determining the isotopic composition of a particular atom position in a molecule. Isotopes are elemental variants with different numbers of neutrons in their nuclei, thereby having different atomic masses. Isotopes are found in varying natural abundances depending on the element; their abundances in specific compounds can vary from random distributions due to environmental conditions that act on the mass variations differently. These differences in abundances are called "fractionations," which are characterized via stable isotope analysis.
Di-deuterated ethyl linoleate is an experimental, orally-bioavailable synthetic deuterated polyunsaturated fatty acid (PUFA), a part of reinforced lipids. It is an isotopologue of linoleic acid, an essential omega-6 PUFA. The deuterated compound, while identical to natural linoleic acid except for the presence of deuterium, is resistant to lipid peroxidation which makes studies of its cell-protective properties worthwhile.
Retrotope, Inc. is a drug development company advancing the idea that polyunsaturated fatty acids (PUFA) drugs fortified with heavy isotopes protect living cells by making bonds within the delicate molecules inside and around cells harder to break. This makes the cells less prone to damage caused by reactive oxygen species (ROS), one of the principal causes of ageing and age-associated diseases. Founded in 2006 by entrepreneurs and scientists with seed funding from private investors, Retrotope is developing a non-antioxidant approach to preventing lipid peroxidation, a detrimental factor in mitochondrial, neuronal, and retinal diseases. The company employs the virtual business model and works in scientific collaboration with more than 80 research groups in universities worldwide.
Isotope effect is observed when molecules containing heavier isotopes of the same atoms are engaged in a chemical reaction at a slower rate. Deuterium-reinforced lipids can be used for the protection of living cells by slowing the chain reaction of lipid peroxidation. The lipid bilayer of the cell and organelle membranes contain polyunsaturated fatty acids (PUFA) are key components of cell and organelle membranes. Any process that either increases oxidation of PUFAs or hinders their ability to be replaced can lead to serious disease. Correspondingly, drugs that stop the chain reaction of lipid peroxidation have preventive and therapeutic potential.
Reinforced lipids are lipid molecules in which some of the fatty acids contain deuterium instead of hydrogen. They can be used for the protection of living cells by slowing the chain reaction due to isotope effect on lipid peroxidation. The lipid bilayer of the cell and organelle membranes contain polyunsaturated fatty acids (PUFA) are key components of cell and organelle membranes. Any process that either increases oxidation of PUFAs or hinders their ability to be replaced can lead to serious disease. Correspondingly, use of reinforced lipids that stop the chain reaction of lipid peroxidation has preventive and therapeutic potential.
Chain reaction in chemistry and physics is a process that produces products capable of initiating subsequent processes of a similar nature. It is a self-sustaining sequence in which the resulting products continue to propagate further reactions. Examples of chain reactions in living organisms are lipid peroxidation in cell membranes and propagation of excitation of neurons in epilepsy.
