Mevalonic AcidSqualeneLovastatin: A fungal metabolite isolated from cultures of Aspergillus terreus. The compound is a potent anticholesteremic agent. It inhibits 3-hydroxy-3-methylglutaryl coenzyme A reductase (HYDROXYMETHYLGLUTARYL COA REDUCTASES), which is the rate-limiting enzyme in cholesterol biosynthesis. It also stimulates the production of low-density lipoprotein receptors in the liver.Lanosterol: A triterpene that derives from the chair-boat-chair-boat folding of 2,3-oxidosqualene. It is metabolized to CHOLESTEROL and CUCURBITACINS.Hydroxymethylglutaryl CoA Reductases: Enzymes that catalyze the reversible reduction of alpha-carboxyl group of 3-hydroxy-3-methylglutaryl-coenzyme A to yield MEVALONIC ACID.Terpenes: A class of compounds composed of repeating 5-carbon units of HEMITERPENES.Optical Rotation: The rotation of linearly polarized light as it passes through various media.Sterols: Steroids with a hydroxyl group at C-3 and most of the skeleton of cholestane. Additional carbon atoms may be present in the side chain. (IUPAC Steroid Nomenclature, 1987)Polyisoprenyl Phosphates: Phosphoric or pyrophosphoric acid esters of polyisoprenoids.Cholestyramine Resin: A strongly basic anion exchange resin whose main constituent is polystyrene trimethylbenzylammonium Cl(-) anion.Dolichol: Eicosamethyl octacontanonadecasen-1-o1. Polyprenol found in animal tissues that contains about 20 isoprene residues, the one carrying the alcohol group being saturated.Cholesterol: The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.Xanthomatosis, Cerebrotendinous: An autosomal recessive lipid storage disorder due to mutation of the gene CYP27A1 encoding a CHOLESTANETRIOL 26-MONOOXYGENASE. It is characterized by large deposits of CHOLESTEROL and CHOLESTANOL in various tissues resulting in xanthomatous swelling of tendons, early CATARACT, and progressive neurological symptoms.Larix: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta.Farnesol: A colorless liquid extracted from oils of plants such as citronella, neroli, cyclamen, and tuberose. It is an intermediate step in the biological synthesis of cholesterol from mevalonic acid in vertebrates. It has a delicate odor and is used in perfumery. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Carbon Isotopes: Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.Acetates: Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.Hydroxymethylglutaryl-CoA Reductase Inhibitors: Compounds that inhibit HMG-CoA reductases. They have been shown to directly lower cholesterol synthesis.Protein Prenylation: A post-translational modification of proteins by the attachment of an isoprenoid to the C-terminal cysteine residue. The isoprenoids used, farnesyl diphosphate or geranylgeranyl diphosphate, are derived from the same biochemical pathway that produces cholesterol.Chromatography, Thin Layer: Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Hydroxycholesterols: Cholesterol which is substituted by a hydroxy group in any position.Lamin Type B: A subclass of ubiquitously-expressed lamins having an acidic isoelectric point. They are found to remain bound to nuclear membranes during mitosis.Simvastatin: A derivative of LOVASTATIN and potent competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HYDROXYMETHYLGLUTARYL COA REDUCTASES), which is the rate-limiting enzyme in cholesterol biosynthesis. It may also interfere with steroid hormone production. Due to the induction of hepatic LDL RECEPTORS, it increases breakdown of LDL CHOLESTEROL.FluorobenzenesNaphthalenes: Two-ring crystalline hydrocarbons isolated from coal tar. They are used as intermediates in chemical synthesis, as insect repellents, fungicides, lubricants, preservatives, and, formerly, as topical antiseptics.Ubiquinone: A lipid-soluble benzoquinone which is involved in ELECTRON TRANSPORT in mitochondrial preparations. The compound occurs in the majority of aerobic organisms, from bacteria to higher plants and animals.Pravastatin: An antilipemic fungal metabolite isolated from cultures of Nocardia autotrophica. It acts as a competitive inhibitor of HMG CoA reductase (HYDROXYMETHYLGLUTARYL COA REDUCTASES).TritiumAnticholesteremic Agents: Substances used to lower plasma CHOLESTEROL levels.Hemiterpenes: The five-carbon building blocks of TERPENES that derive from MEVALONIC ACID or deoxyxylulose phosphate.Carotenoids: The general name for a group of fat-soluble pigments found in green, yellow, and leafy vegetables, and yellow fruits. They are aliphatic hydrocarbons consisting of a polyisoprene backbone.Phosphotransferases: A rather large group of enzymes comprising not only those transferring phosphate but also diphosphate, nucleotidyl residues, and others. These have also been subdivided according to the acceptor group. (From Enzyme Nomenclature, 1992) EC 2.7.Metabolism: The chemical reactions that occur within the cells, tissues, or an organism. These processes include both the biosynthesis (ANABOLISM) and the breakdown (CATABOLISM) of organic materials utilized by the living organism.Carbon Radioisotopes: Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.Mevalonate Kinase Deficiency: Autosomal recessive disorder caused by mutations in the mevalonate kinase gene. Because of the mutations cholesterol biosynthesis is disrupted and MEVALONIC ACID accumulates. It is characterized by a range of symptoms, including dysmorphic FACIES, psychomotor retardation, CATARACT, hepatosplenomegaly, CEREBELLAR ATAXIA, elevated IMMUNOGLOBULIN D, and recurrent febrile crises with FEVER; LYMPHADENOPATHY; ARTHRALGIA; EDEMA; and rash.Pentanes: Five-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives.Diterpenes: Twenty-carbon compounds derived from MEVALONIC ACID or deoxyxylulose phosphate.Alkyl and Aryl Transferases: A somewhat heterogeneous class of enzymes that catalyze the transfer of alkyl or related groups (excluding methyl groups). EC 2.5.Haloferax: A genus of extremely halophilic HALOBACTERIACEAE which are chemoheterotropic and strictly aerobic. They are found in neutral saline environments such as salt lakes (especially the Dead Sea) and marine salterns.Chromatography, Gas: Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.Mycoplasma: A genus of gram-negative, mostly facultatively anaerobic bacteria in the family MYCOPLASMATACEAE. The cells are bounded by a PLASMA MEMBRANE and lack a true CELL WALL. Its organisms are pathogens found on the MUCOUS MEMBRANES of humans, ANIMALS, and BIRDS.Protein Processing, Post-Translational: Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.Heptanoic Acids: 7-carbon saturated monocarboxylic acids.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Phosphotransferases (Alcohol Group Acceptor): A group of enzymes that transfers a phosphate group onto an alcohol group acceptor. EC 2.7.1.Cell Cycle: The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.Cholesterol, Dietary: Cholesterol present in food, especially in animal products.Cholesterol 7-alpha-Hydroxylase: A membrane-bound cytochrome P450 enzyme that catalyzes the 7-alpha-hydroxylation of CHOLESTEROL in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP7, converts cholesterol to 7-alpha-hydroxycholesterol which is the first and rate-limiting step in the synthesis of BILE ACIDS.Deuterium: Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.Cholesterol, LDL: Cholesterol which is contained in or bound to low density lipoproteins (LDL), including CHOLESTEROL ESTERS and free cholesterol.Cholesterol, HDL: Cholesterol which is contained in or bound to high-density lipoproteins (HDL), including CHOLESTEROL ESTERS and free cholesterol.