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Chiral Switch
The word "chiral switch" was introduced by Agranat and Caner in 1999. Chiral switches are chiral drugs that are already approved as racemates but that have been re-developed as single enantiomers. The term chiral switching has been coined to describe the development of single enantiomers from racemate drugs. For example, levofloxacin is a chiral switch of racemic ofloxacin. The essential principle of a chiral switch is that there is a change in the status of chirality. In general, the term chiral switch is preferred over racemic switch because the switch is usually happening from a racemic drug to the corresponding single enantiomer(s). It is important to understand that chiral switches are treated as a selection invention. A selection invention is an invention that selects a group of new members from a previously known class on the basis of superior properties. To express the pharmacological activities of each of the chiral twins of a racemic drug two technical terms have been c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chiral Drugs
Chemical compounds that come as mirror-image pairs are referred to by chemists as chiral or handed molecules. Each twin is called an enantiomer. Drugs that exhibit handedness are referred to as chiral drugs. Chiral drugs that are equimolar (1:1) mixture of enantiomers are called racemic drugs and these are obviously devoid of optical rotation. The most commonly encountered stereogenic unit, that confers chirality to drug molecules are stereogenic center. Stereogenic center can be due to the presence of tetrahedral tetra coordinate atoms (C,N,P) and pyramidal tricoordinate atoms (N,S). The word chiral describes the three-dimensional architecture of the molecule and does not reveal the stereochemical composition. Hence "chiral drug" does not say whether the drug is racemic (racemic drug), single enantiomer (chiral specific drug) or some other combination of stereoisomers. To resolve this issue ''Joseph Gal'' introduced a new term called ''unichiral.'' Unichiral indicates that the stere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Novo Synthesis
In chemistry, ''de novo'' synthesis () refers to the synthesis of complex molecules from simple molecules such as sugars or amino acids, as opposed to recycling after partial degradation. For example, nucleotides are not needed in the diet as they can be constructed from small precursor molecules such as formate and aspartate. Methionine, on the other hand, is needed in the diet because while it can be degraded to and then regenerated from homocysteine, it cannot be synthesized ''de novo''. Nucleotide ''De novo'' pathways of nucleotides do not use free bases: adenine (abbreviated as A), guanine (G), cytosine (C), thymine (T), or uracil (U). The purine ring is built up one atom or a few atoms at a time and attached to ribose throughout the process. Pyrimidine ring is synthesized as orotate and attached to ribose phosphate and later converted to common pyrimidine nucleotides. Cholesterol Cholesterol is an essential structural component of animal cell membranes. Chole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chirality
Chirality is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is distinguishable from its mirror image; that is, it cannot be superimposed onto it. Conversely, a mirror image of an ''achiral'' object, such as a sphere, cannot be distinguished from the object. A chiral object and its mirror image are called ''enantiomorphs'' (Greek, "opposite forms") or, when referring to molecules, '' enantiomers''. A non-chiral object is called ''achiral'' (sometimes also ''amphichiral'') and can be superposed on its mirror image. The term was first used by Lord Kelvin in 1893 in the second Robert Boyle Lecture at the Oxford University Junior Scientific Club which was published in 1894: Human hands are perhaps the most recognized example of chirality. The left hand is a non-superimposable mirror image of the right hand; no matter ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chiral Drugs
Chemical compounds that come as mirror-image pairs are referred to by chemists as chiral or handed molecules. Each twin is called an enantiomer. Drugs that exhibit handedness are referred to as chiral drugs. Chiral drugs that are equimolar (1:1) mixture of enantiomers are called racemic drugs and these are obviously devoid of optical rotation. The most commonly encountered stereogenic unit, that confers chirality to drug molecules are stereogenic center. Stereogenic center can be due to the presence of tetrahedral tetra coordinate atoms (C,N,P) and pyramidal tricoordinate atoms (N,S). The word chiral describes the three-dimensional architecture of the molecule and does not reveal the stereochemical composition. Hence "chiral drug" does not say whether the drug is racemic (racemic drug), single enantiomer (chiral specific drug) or some other combination of stereoisomers. To resolve this issue ''Joseph Gal'' introduced a new term called ''unichiral.'' Unichiral indicates that the stere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CC BY-SA Icon
CC, cc, or C-C may refer to: Arts, entertainment, and media Fictional characters * C.C. (''Code Geass''), a character in the ''Code Geass'' anime series, pronounced "C-two" * C.C. Babcock, a character in the American sitcom ''The Nanny'' * Comedy Chimp, a character in '' Sonic Boom'', called "CC" by Doctor Eggman Gaming * ''Command & Conquer'' (''C&C''), a series of real-time strategy games and the first game in the series * Crowd control (video gaming), the ability to limit the number of mobs actively fighting during an encounter Other arts, music, entertainment, and media * Cannibal Corpse, an American death metal band. * CC Media Holdings, the former name of iHeartMedia * Closed captioning, a process of displaying text on a visual display, such as a TV screen * Comedy Central, an American television network (URL is cc.com) Brands and enterprises Food and drink * Canadian Club, a brand of whisky * CC's, a tortilla chip brand in Australia Other companies * Stylized inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evergreening
Evergreening is any of various legal, business, and technological strategies by which producers (often pharmaceutical companies) extend the lifetime of their patents that are about to expire in order to retain revenues from them. Often the practice includes taking out new patents (for example over associated delivery systems or new pharmaceutical mixtures), or by buying out or frustrating competitors, for longer periods of time than would normally be permissible under the law. Robin Feldman, a law professor at UC Hastings and a leading researcher in intellectual property and patents, defines evergreening as "artificially extending the life of a patent or other exclusivity by obtaining additional protections to extend the monopoly period." Overview Evergreening is not a formal concept of patent law; it is best understood as a social idea used to refer to the myriad ways in which pharmaceutical patent owners use the law and related regulatory processes to extend their high-earning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esketamine
Esketamine, also known as (S)-ketamine or S(+)-ketamine, is the ''S''(+) enantiomer of ketamine, is a dissociative hallucinogen drug used as a general anesthetic and as an antidepressant for treatment of depression. It is sold under the brand names Spravato (for depression), Ketanest (for anesthesia), among others. Esketamine is the active enantiomer of ketamine in terms of NMDA receptor antagonism and is more potent than racemic ketamine. It is specifically used as a therapy for treatment-resistant depression (TRD) and for major depressive disorder (MDD) with co-occurring suicidal ideation or behavior. Its effectiveness for depression is modest and similar to that of other antidepressants. Esketamine is used by infusion into a vein for anesthesia and under direct medical supervision as a nasal spray once or twice weekly for depression. Adverse effects of esketamine include dissociation, dizziness, sedation, nausea, vomiting, vertigo, numbness, anxiety, lethargy, incre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escitalopram
Escitalopram, sold under the brand names Lexapro and Cipralex, among others, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. Escitalopram is mainly used to treat major depressive disorder and generalized anxiety disorder. It is taken by mouth, available commercially as an oxalate salt exclusively. Common side effects include trouble sleeping, nausea, sexual problems, and feeling tired. More serious side effects may include suicidal thoughts in people up to the age of 24 years. It is unclear if use during pregnancy or breastfeeding is safe. Escitalopram is the (''S'')-enantiomer of citalopram (which exists as a racemate), hence the name ''es''-citalopram. Escitalopram was approved for medical use in the United States in 2002. Escitalopram is rarely replaced by twice the dose of citalopram, though escitalopram is safer and more effective. It is on the World Health Organization's List of Essential Medicines. In 2020, it was the fifteenth most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Levocetirizine
Levocetirizine, sold under the brand name Xyzal among others, is a second-generation antihistamine used for the treatment of allergic rhinitis (hay fever) and long term hives of unclear cause. It is less sedating than older antihistamines. It is taken by mouth. Common side effects include sleepiness, dry mouth, cough, vomiting, and diarrhea. Use in pregnancy appears safe but has not been well studied and use when breastfeeding is of unclear safety. It is classified as a second-generation antihistamine and works by blocking histamine H1-receptors. Levocetirizine was approved for medical use in the United States in 2007. It is available as a generic medication. In 2020, it was the 179th most commonly prescribed medication in the United States, with more than 3million prescriptions. Medical uses Levocetirizine is used for allergic rhinitis. This includes allergy symptoms such as watery eyes, runny nose, sneezing, hives, and itching. Side effects Levocetirizine is referred ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Levobupivacaine
Levobupivacaine (International Nonproprietary Name, rINN) is a local anaesthetic drug belonging to the amino amide group. It is the ''S''-enantiomer of bupivacaine. Levobupivacaine hydrochloride is commonly marketed by AbbVie under the trade name Chirocaine.Rossi S, editor. Australian Medicines Handbook 2006. Adelaide: Australian Medicines Handbook; 2006. Clinical use Compared to bupivacaine, levobupivacaine is associated with less vasodilation and has a longer duration of action. It is approximately 13 percent less potent (by molarity) than racemic bupivacaine and has a longer motor block onset time. Indications Levobupivacaine is indicated for local anaesthesia including infiltration, nerve block, Ophthalmology, ophthalmic, epidural and intrathecal anaesthesia in adults; and infiltration analgesia in children. Contraindications Levobupivacaine is contraindicated for IV regional anaesthesia (IVRA). Adverse effects Adverse drug reactions (ADRs) are rare when it is administer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esomeprazole
Esomeprazole, sold under the brand name Nexium among others, is a medication which reduces stomach acid. It is used to treat gastroesophageal reflux disease, peptic ulcer disease, and Zollinger–Ellison syndrome. Effectiveness is similar to other proton pump inhibitors (PPIs). It is taken by mouth or injection into a vein. Common side effects include headache, constipation, dry mouth, and abdominal pain. Serious side effects may include angioedema, ''Clostridium difficile'' infection, and pneumonia. Use in pregnancy appears to be safe, while safety during breastfeeding is unclear. Esomeprazole is the (''S'')-(−)-isomer of omeprazole. It works by blocking H+/K+-ATPase in the parietal cells of the stomach. It was patented in 1993 and approved for medical use in 2000. It is available as a generic medication and sold over the counter in a number of countries. In 2020, it was the 122nd most commonly prescribed medication in the United States, with more than 5million pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Levalbuterol
Levosalbutamol, also known as levalbuterol, is a short-acting β2 adrenergic receptor agonist used in the treatment of asthma and chronic obstructive pulmonary disease (COPD). Evidence is inconclusive regarding the efficacy of levosalbutamol versus salbutamol or salbutamol-levosalbutamol combinations, however levosalbutamol is believed to have a better safety profile due to its more selective binding to β2 receptors (primarily in the lungs) versus β1 (primarily in heart muscle). The drug is the (''R'')-(−)-enantiomer of its prototype drug salbutamol. It is available in some countries in generic formulations from pharmaceutical companies including Cipla, Teva, and Dey, among others. Medical use Levosalbutamol's bronchodilator properties give it indications in treatment of COPD (chronic obstructive pulmonary disease, also known as chronic obstructive lung disease) and asthma. Like other bronchodilators, it acts by relaxing smooth muscle in the bronchial tubes, and thus sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
