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Macrolide
Macrolides are a class of mostly natural products with a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. Macrolides belong to the polyketide class of natural products. Some macrolides have antibiotic or antifungal activity and are used as pharmaceutical drugs. Rapamycin is also a macrolide and was originally developed as an antifungal, but has since been used as an immunosuppressant drug and is being investigated as a potential longevity therapeutic. Macrolides are a diverse group with many members of very different properties: * Macrolides with 14-, 15-, or 16-membered rings and two attached sugar molecules are antibiotics that bind to bacterial ribosomes, the key representative being erythromycin. The term "macrolide antibiotics" tend to refer to just this class. * Some macrolides with very large (20+ membered) rings are immunosuppresants, the prototypical one being rapamycin. * Some 23-membered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azithromycin
Azithromycin, sold under the brand names Zithromax (in oral form) and Azasite (as an eye drop), is an antibiotic medication used for the treatment of several bacterial infections. This includes otitis media, middle ear infections, strep throat, pneumonia, traveler's diarrhea, Sexually transmitted infection, STI and certain other gastroenteritis, intestinal infections. Along with other medications, it may also be used for malaria. It is Drug administration, administered by mouth, intravenously, into a vein, or into the eye drops, eye. Common side effects include nausea, vomiting, diarrhea and upset stomach. An allergic reaction, such as anaphylaxis, or a type of diarrhea caused by Clostridioides difficile infection, ''Clostridioides difficile'' is possible. Azithromycin causes drug-induced QT prolongation, QT prolongation that may cause life-threatening arrhythmias such as torsades de pointes. While some studies claim that no harm has been found with use during pregnancy, more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erythromycin A
Erythromycin is an antibiotic used for the treatment of a number of bacterial infections. This includes respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used during pregnancy to prevent Group B streptococcal infection in the newborn, and to improve delayed stomach emptying. It can be given intravenously and by mouth. An eye ointment is routinely recommended after delivery to prevent eye infections in the newborn. Common side effects include abdominal cramps, vomiting, and diarrhea. More serious side effects may include ''Clostridioides difficile'' colitis, liver problems, prolonged QT, and allergic reactions. It is generally safe in those who are allergic to penicillin. Erythromycin also appears to be safe to use during pregnancy. While generally regarded as safe during breastfeeding, its use by the mother during the first two weeks of life may increase the risk of pyloric stenosis in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erythromycin
Erythromycin is an antibiotic used for the treatment of a number of bacterial infections. This includes respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used during pregnancy to prevent Group B streptococcal infection in the newborn, and to improve delayed stomach emptying. It can be given intravenously and by mouth. An eye ointment is routinely recommended after delivery to prevent eye infections in the newborn. Common side effects include abdominal cramps, vomiting, and diarrhea. More serious side effects may include ''Clostridioides difficile'' colitis, liver problems, prolonged QT, and allergic reactions. It is generally safe in those who are allergic to penicillin. Erythromycin also appears to be safe to use during pregnancy. While generally regarded as safe during breastfeeding, its use by the mother during the first two weeks of life may increase the risk of pyloric stenosis in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarithromycin Structure
Clarithromycin, sold under the brand name Biaxin among others, is an antibiotic used to treat various bacterial infections. This includes strep throat, pneumonia, skin infections, '' H. pylori'' infection, and Lyme disease, among others. Clarithromycin can be taken by mouth as a tablet or liquid or can be infused intravenously. Common side effects include nausea, vomiting, headaches, and diarrhea. Severe allergic reactions are rare. Liver problems have been reported. It may cause harm if taken during pregnancy. It is in the macrolide class and works by slowing down bacterial protein synthesis. Clarithromycin resistance is already a major challenge to healthcare systems and such resistance is spreading, leading to recommendations to test the susceptibility of pathogenic organisms to the antibiotic before commencing clarithromycin therapy. Clarithromycin was developed in 1980 and approved for medical use in 1990. It is on the World Health Organization's List of Essential Medic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desosamine
Desosamine is a 3-(dimethylamino)-3,4,6-trideoxyhexose found in certain macrolide, macrolide antibiotics (contain a high level of microbial resistance) such as the commonly prescribed erythromycin, azithromycin, clarithromycin, methymycin, narbomycin, oleandomycin, Pikromycin, picromycin and roxithromycin. As the name suggests, these macrolide antibiotics contain a macrolide or lactone ring and they are attached to the ring desosamine which is crucial for bactericidal activity. The biological action of the desosamine-based macrolide antibiotics is to inhibit the bacterial ribosomal protein synthesis. These antibiotics which contain desosamine are widely used to cure bacterial infections in human respiratory system, skin, muscle tissues, and urethra. Discovery Although desosamine has been found in many macrolide antibiotics, the complete chemical structure of desosamine was not determined until 1962. Nuclear magnetic resonance spectroscopy data was used to establish the complete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tacrolimus
Tacrolimus, sold under the brand name Prograf among others, is an immunosuppressive drug. After Allotransplantation, allogenic organ transplant, the risk of organ Transplant rejection, rejection is moderate. To lower the risk of organ rejection, tacrolimus is given. The drug can also be sold as a topical medication in the treatment of T cell-mediated diseases such as atopic dermatitis, eczema and psoriasis. For example, it is prescribed for severe refractory uveitis after a bone marrow transplant, exacerbations of minimal change disease, Kimura's disease, and vitiligo. It can be used to treat Dry eye syndrome#Other, dry eye syndrome in cats and dogs. Tacrolimus inhibits calcineurin, which is involved in the production of interleukin-2, a molecule that promotes the development and cell proliferation, proliferation of T cells, as part of the body's learned (or adaptive immune response, adaptive) immune response. Chemically, it is a macrolide lactone that was first discovered in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyene Antimycotic
Polyene antimycotics, sometimes referred to as polyene antibiotics, are a class of antimicrobial polyene compounds that target fungi. These polyene antimycotics are typically obtained from certain species of ''Streptomyces'' bacteria. Previously, polyenes were thought to bind to ergosterol in the fungal cell membrane, weakening it and causing leakage of K+ and Na+ ions, which could contribute to fungal cell death. However, more detailed studies of polyene molecular properties have challenged this model suggesting that polyenes instead bind and extract ergosterol directly from the cellular membrane thus disrupting the many cellular functions ergosterols perform. Amphotericin B, nystatin, and natamycin are examples of polyene antimycotics. They are a subgroup of macrolides. Structures Their chemical structures feature a large ring of atoms (in essence, a cyclic ester ring) containing multiple conjugated carbon-carbon double bonds (hence ''polyene'') on one side of the ring and mul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roxithromycin
Roxithromycin is a semi-synthetic macrolide antibiotic used to treat respiratory tract, urinary and soft tissue infections. It is a derivative of erythromycin - comprising the same 14-membered lactone ring - with an oxime-based side chain attached to the macrolide ring. Roxithromycin was patented in 1980 and approved for medical use in 1987. It is available under several brand names in Australia, France, Germany, Israel, South Korea and New Zealand, but not in the United States. Roxithromycin has also been shown to possess antimalarial activity. Side effects The most common side effects are gastrointestinal: diarrhoea, nausea, abdominal pain and vomiting. Less common side effects include central or peripheral nervous system events such as headaches, dizziness, vertigo.Rarely seen side effects are rashes, abnormal liver function values and alteration in the senses of smell and taste. Drug interactions Roxithromycin has fewer interactions than erythromycin as it has a lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapamycin
Sirolimus, also known as rapamycin and sold under the brand name Rapamune among others, is a macrolide compound that is used to coat coronary stents, prevent organ rejection, organ transplant rejection, treat a rare lung disease called lymphangioleiomyomatosis, and treat perivascular epithelioid cell tumour (PEComa). It has immunosuppressant functions in humans and is especially useful in preventing the rejection of kidney transplants. It is a mammalian target of rapamycin (mTOR) kinase inhibitor that reduces the sensitivity of T cells and B cells to interleukin-2 (IL-2), inhibiting their activity. This compound also has a use in cardiovascular drug-eluting stent technologies to inhibit restenosis. It is produced by the bacteria, bacterium ''Streptomyces hygroscopicus'' and was isolated for the first time in 1972, from samples of ''Streptomyces hygroscopicus'' found on Easter Island. The compound was originally named rapamycin after the native name of the island, Rapa Nui. Siro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrocycle
Macrocycles are often described as molecules and ions containing a ring of twelve or more atoms. Classical examples include the crown ethers, calixarenes, porphyrins, and cyclodextrins. Macrocycles describe a large, mature area of chemistry. Synthesis The formation of macrocycles by ring-closure is called macrocyclization. The central challenge to macrocyclization is that ring-closing reactions do not favor the formation of large rings. Instead, medium sized rings or polymers tend to form. Early macrocyclizations were achieved ketonic decarboxylations for the preparation of terpenoid macrocycles. So, while Ružička was able to produce various macrocycles, the yields were low. This kinetic problem can be addressed by using high-dilution reactions, whereby intramolecular processes are favored relative to polymerizations. Reactions amenable to high dilution include Dieckmann condensation and related based-induced reactions of esters with remote halides. Some macrocyc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapamycin
Sirolimus, also known as rapamycin and sold under the brand name Rapamune among others, is a macrolide compound that is used to coat coronary stents, prevent organ rejection, organ transplant rejection, treat a rare lung disease called lymphangioleiomyomatosis, and treat perivascular epithelioid cell tumour (PEComa). It has immunosuppressant functions in humans and is especially useful in preventing the rejection of kidney transplants. It is a mammalian target of rapamycin (mTOR) kinase inhibitor that reduces the sensitivity of T cells and B cells to interleukin-2 (IL-2), inhibiting their activity. This compound also has a use in cardiovascular drug-eluting stent technologies to inhibit restenosis. It is produced by the bacteria, bacterium ''Streptomyces hygroscopicus'' and was isolated for the first time in 1972, from samples of ''Streptomyces hygroscopicus'' found on Easter Island. The compound was originally named rapamycin after the native name of the island, Rapa Nui. Siro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptogramin A
Streptogramin A is a group of antibiotics within the larger family of antibiotics known as streptogramins. They are synthesized by the bacteria '' Streptomyces virginiae''. The streptogramin family of antibiotics consists of two distinct groups: group A antibiotics contain a 23-membered unsaturated ring with lactone and peptide bonds while group B antibiotics are depsipeptides (lactone-cyclized peptides). While structurally different, these two groups of antibiotics act synergistically, providing greater antibiotic activity than the combined activity of the separate components. These antibiotics have until recently been commercially manufactured as feed additives in agriculture, although today there is increased interest in their ability to combat antibiotic-resistant bacteria, particularly vancomycin-resistant bacteria. Biosynthesis Streptogramin A is a polyketide in nature, but contains some amino acid components as well. Its gene cluster codes for a hybrid PKS-NRPS protein t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
