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Filipin
Filipin is a mixture of chemical compounds first isolated by chemists at the Upjohn company in 1955 from the mycelium and culture filtrates of a previously unknown actinomycete, '' Streptomyces filipinensis''. It was discovered in a soil sample collected in the Philippine Islands, hence the name filipin. The isolate possessed potent antifungal activity. It was identified as a polyene macrolide based on its characteristic UV-Vis and IR spectra. Functions Although the polyene macrolide antibiotics exhibit potent antifungal activity, most are too toxic for therapeutic applications, with the exceptions of amphotericin B and nystatin A1. Unlike amphotericin B and nystatin A1 which form sterol-dependent ion channels, filipin is thought to be a simple membrane disrupter. Since filipin is highly fluorescent and binds specifically to cholesterol, it has found widespread use as a histochemical stain for cholesterol. This method of detecting cholesterol in cell membranes is used clin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philippine Islands
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republika sang Filipinas * ibg, Republika nat Filipinas * ilo, Republika ti Filipinas * ivv, Republika nu Filipinas * pam, Republika ning Filipinas * krj, Republika kang Pilipinas * mdh, Republika nu Pilipinas * mrw, Republika a Pilipinas * pag, Republika na Filipinas * xsb, Republika nin Pilipinas * sgd, Republika nan Pilipinas * tgl, Republika ng Pilipinas * tsg, Republika sin Pilipinas * war, Republika han Pilipinas * yka, Republika si Pilipinas In the recognized optional languages of the Philippines: * es, República de las Filipinas * ar, جمهورية الفلبين, Jumhūriyyat al-Filibbīn is an archipelagic country in Southeast Asia. It is situated in the western Pacific Ocean and consists of around 7,641 islands t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antifungals
An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as cryptococcal meningitis, and others. Such drugs are usually yes obtained by a doctor's prescription, but a few are available over the counter (OTC). Types of antifungal There are two types of antifungals: local and systemic. Local antifungals are usually administered topically or vaginally, depending on the condition being treated. Systemic antifungals are administered orally or intravenously. Of the clinically employed azole antifungals, only a handful are used systemically. These include ketoconazole, itraconazole, fluconazole, fosfluconazole, voriconazole, posaconazole, and isavuconazole. Examples of non-azole systemic antifungals include griseofulvin and terbinafine. Classes Polyenes A polyene is a molecule with multiple conjugated do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyene Antibiotic
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 some species of '' Streptomyces'' bacteria. Previously, polyenes were thought to bind to ergosterol in the fungal cell membrane and thus 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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholesterol
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membranes. When chemically isolated, it is a yellowish crystalline solid. Cholesterol also serves as a precursor for the biosynthesis of steroid hormones, bile acid and vitamin D. Cholesterol is the principal sterol synthesized by all animals. In vertebrates, hepatic cells typically produce the greatest amounts. It is absent among prokaryotes (bacteria and archaea), although there are some exceptions, such as '' Mycoplasma'', which require cholesterol for growth. François Poulletier de la Salle first identified cholesterol in solid form in gallstones in 1769. However, it was not until 1815 that chemist Michel Eugène Chevreul named the compound "cholesterine". Etymology The word "cholesterol" comes from the Ancient Greek ''chole-'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrolides
The Macrolides are a class of natural products that consist of a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered. 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 is now used as an immunosuppressant drug and is being investigated as a potential longevity therapeutic. Macrolides are bacteriostatic in that they suppress or inhibit bacterial growth rather than killing bacteria completely. Definition In general, any macrocyclic lactone having greater than 8-membered rings are candidates for this class. The macrocycle may contain amino nitrogen, amide nitrogen (but should be differentiated from cyclopeptides), an oxazole ring, or a thiazole ring. Benzene rings are exclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
13C NMR Acetonide Analysis
Carbon-13 (13C) is a natural, stable isotope of carbon with a nucleus containing six protons and seven neutrons. As one of the environmental isotopes, it makes up about 1.1% of all natural carbon on Earth. Detection by mass spectrometry A mass spectrum of an organic compound will usually contain a small peak of one mass unit greater than the apparent molecular ion peak (M) of the whole molecule. This is known as the M+1 peak and comes from the few molecules that contain a 13C atom in place of a 12C. A molecule containing one carbon atom will be expected to have an M+1 peak of approximately 1.1% of the size of the M peak, as 1.1% of the molecules will have a 13C rather than a 12C. Similarly, a molecule containing two carbon atoms will be expected to have an M+1 peak of approximately 2.2% of the size of the M peak, as there is double the previous likelihood that any molecule will contain a 13C atom. In the above, the mathematics and chemistry have been simplified, however it can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereochemistry
Stereochemistry, a subdiscipline of chemistry, involves the study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation. The study of stereochemistry focuses on the relationships between stereoisomers, which by definition have the same molecular formula and sequence of bonded atoms (constitution), but differ in structural formula (the three-dimensional orientations of their atoms in space). For this reason, it is also known as 3D chemistry—the prefix "stereo-" means "three-dimensionality". Stereochemistry spans the entire spectrum of organic, inorganic, biological, physical and especially supramolecular chemistry. Stereochemistry includes methods for determining and describing these relationships; the effect on the physical or biological properties these relationships impart upon the molecules in question, and the manner in which these relationships influence the reactivity of the molecules in question ( dynamic stereochemis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Spectrometry
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures. A mass spectrum is a type of plot of the ion signal as a function of the mass-to-charge ratio. These spectra are used to determine the elemental or isotopic signature of a sample, the masses of particles and of molecules, and to elucidate the chemical identity or structure of molecules and other chemical compounds. In a typical MS procedure, a sample, which may be solid, liquid, or gaseous, is ionized, for example by bombarding it with a beam of electrons. This may cause some of the sample's molecules to break up into positively charged fragments or simply become positively charged without fragmenting. These ions (fragments) are then separated accordin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upjohn
The Upjohn Company was a pharmaceutical manufacturing firm founded in 1886 in Hastings, Michigan, by Dr. William E. Upjohn who was an 1875 graduate of the University of Michigan medical school. The company was originally formed to make ''friable pills'', which were specifically designed to be easily digested. These could be "reduced to a powder under the thumb", a strong marketing argument at the time. History Upjohn developed a process for the large scale production of cortisone. The oxygen atom at the 11 position in this steroid is an absolute requirement for biological activity. There are however no known natural sources for starting materials that contain that feature. The only method for preparing this drug prior to 1952 was a lengthy synthesis starting from cholic acid isolated from bile. In 1952, two Upjohn biochemists, Dury Peterson and Herb Murray announced that they were able to introduce this crucial oxygen atom by fermentation of the steroid progesterone with a comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescence
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, than the absorbed radiation. A perceptible example of fluorescence occurs when the absorbed radiation is in the ultraviolet region of the electromagnetic spectrum (invisible to the human eye), while the emitted light is in the visible region; this gives the fluorescent substance a distinct color that can only be seen when the substance has been exposed to UV light. Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike phosphorescent materials, which continue to emit light for some time after. Fluorescence has many practical applications, including mineralogy, gemology, medicine, chemical sensors (fluorescence spectroscopy), fluorescent labelling, dyes, biological detectors, cosmic-ray detection, vacu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinomycete
The Actinomycetales is an order of Actinomycetota. A member of the order is often called an actinomycete. Actinomycetales are generally gram-positive and anaerobic and have mycelia in a filamentous and branching growth pattern. Some actinomycetes can form rod- or coccoid-shaped forms, while others can form spores on aerial hyphae. Actinomycetales bacteria can be infected by bacteriophages, which are called actinophages. Actinomycetales can range from harmless bacteria to pathogens with resistance to antibiotics. Reproduction Actinomycetales have 2 main forms of reproduction: spore formation and hyphae fragmentation. During reproduction, Actinomycetales can form conidiophores, sporangiospores, and oidiospores. In reproducing through hyphae fragmentation, the hyphae formed by Actinomycetales can be a fifth to half the size of fungal hyphae, and bear long spore chains. Presence and associations Actinomycetales can be found mostly in soil and decaying organic matter, as well as in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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