In organic chemistry a diene is a covalent compound that contains two double bonds, usually among carbon atoms. They thus contain two alkene units, with the standard prefix di of systematic nomenclature. As a subunit of more complex molecules, dienes occur in naturally occurring and synthetic chemicals and are used in organic synthesis. Conjugated dienes are widely used as monomers in the polymer industry. Polyunsaturated fats are of interest to nutrition.
Polyenes are poly-unsaturated organic compounds that contain at least three alternating double and single carbon–carbon bonds. These carbon–carbon double bonds interact in a process known as conjugation resulting in some unusual optical properties. Related to polyenes are dienes, where there are only two alternating double and single bonds.
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 obtained by a doctor's prescription, but a few are available over the counter (OTC).
Nystatin, sold under the brandname Mycostatin among others, is an antifungal medication. It is used to treat Candida infections of the skin including diaper rash, thrush, esophageal candidiasis, and vaginal yeast infections. It may also be used to prevent candidiasis in those who are at high risk. Nystatin may be used by mouth, in the vagina, or applied to the skin.
The retinoids are a class of chemical compounds that are vitamers of vitamin A or are chemically related to it. Retinoids have found use in medicine where they regulate epithelial cell growth.
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.
Cyclooctadecanonaene or [18]annulene is an organic compound with chemical formula C
18H
18. It belongs to the class of highly conjugated compounds known as annulenes and is aromatic. The usual isomer that [18]annulene refers to is the most stable one, containing six interior hydrogens and twelve exterior ones, with the nine formal double bonds in the cis,trans,trans,cis,trans,trans,cis,trans,trans configuration. It is reported to be a red-brown crystalline solid.
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.
Hamycin is a pair polyene antimycotic organic compounds described in India. It is a heptaene antifungal compound rather similar in chemical structure to amphotericin B except that it has an additional aromatic group bonded to the molecule. When pure, hamycin is a yellow, powdered solid. There are two versions of hamycin with very similar chemical structures: hamycin A and hamycin B.
In chemistry, a ladderane is an organic molecule containing two or more fused cyclobutane rings. The name arises from the resemblance of a series of fused cyclobutane rings to a ladder. Numerous synthetic approaches have been developed for the synthesis of ladderane compounds of various lengths. The mechanisms often involve [2 + 2] photocycloadditions, a useful reaction for creating strained 4-membered rings. Naturally occurring ladderanes have been identified as major components of the anammoxosome membrane of the anammox bacteria, phylum Planctomycetota.
Woodward's rules, named after Robert Burns Woodward and also known as Woodward–Fieser rules are several sets of empirically derived rules which attempt to predict the wavelength of the absorption maximum (λmax) in an ultraviolet–visible spectrum of a given compound. Inputs used in the calculation are the type of chromophores present, the auxochromes (substituents on the chromophores, and solvent. Examples are conjugated carbonyl compounds, conjugated dienes, and polyenes.
Diphosphorus tetraiodide is an orange crystalline solid with the formula P2I4. It has been used as a reducing agent in organic chemistry. It is a rare example of a compound with phosphorus in the +2 oxidation state, and can be classified as a subhalide of phosphorus. It is the most stable of the diphosphorus tetrahalides.
In organometallic chemistry, the Green–Davies–Mingos rules predict the regiochemistry for nucleophilic addition to 18-electron metal complexes containing multiple unsaturated ligands. The rules were published in 1978 by organometallic chemists Stephen G. Davies, Malcolm Green, and Michael Mingos. They describe how and where unsaturated hydrocarbon generally become more susceptibile to nucleophilic attack upon complexation.
Calostoma is a genus of 29 species of gasteroid fungi in the suborder Sclerodermatineae. Like other gasteroid fungi, Calostoma do not have the spore discharge mechanism associated with typical gilled fungi (ballistospory), and instead have enclosed spore-bearing structures. Resembling round puffballs with raised, brightly-colored spore openings (osteoles), elevated on a thick, gelatinous stalks, species have been collected in regions of deciduous, temperate, tropical or subtropical forests. Their distribution includes eastern North America, Central America, Asia, and Australasia. The common name given to some species, "prettymouth", alludes to the brightly-colored raised openings (osteoles) that may somewhat resemble lips. Other common names include "hotlips" and "puffball in aspic".
Ampelopsin, also known as dihydromyricetin and DHM, when purported as an effective ingredient in supplements and other tonics, is a flavanonol, a type of flavonoid. It is extracted from the Japanese raisin tree and found in Ampelopsis species japonica, megalophylla, and grossedentata; Cercidiphyllum japonicum; Hovenia dulcis; Rhododendron cinnabarinum; some Pinus species; and some Cedrus species, as well as in Salix sachalinensis.
Perimycin, also known as aminomycin and fungimycin, is polyene antibiotic produced by Streptomyces coelicolor var. aminophilus. The compound exhibits antifungal properties.
Xylylene (sometimes quinone-dimethides) comprises two isomeric organic compounds with the formula C6H4(CH2)2. These compounds are related to the corresponding quinones and quinone methides by replacement of the oxygen atoms by CH2 groups. ortho- and para-xylylene are best known, although neither is stable in solid or liquid form. The meta form is a diradical. Certain substituted derivatives of xylylenes are however highly stable, an example being tetracyanoquinodimethane.
Calostoma cinnabarinum is a species of gasteroid fungus in the family Sclerodermataceae, and is the type species of the genus Calostoma. It is known by several common names, including stalked puffball-in-aspic and gelatinous stalked-puffball. The fruit body has a distinctive color and overall appearance, featuring a layer of yellowish jelly surrounding a bright red, spherical head approximately 2 centimeters (0.8 in) in diameter atop a red or yellowish brown spongy stipe 1.5 to 4 cm tall. The innermost layer of the head is the gleba, containing clear or slightly yellowish elliptical spores, measuring 14–20 micrometers (µm) long by 6–9 µm across. The spore surface features a pattern of small pits, producing a net-like appearance. A widely distributed species, it grows naturally in eastern North America, Central America, northeastern South America, and East Asia. C. cinnabarinum grows on the ground in deciduous forests, where it forms mycorrhizal associations with oaks.
Boletocrocin is any one of a group of seven closely related organic compounds, individually named boletocrocin A through boletrocrocin G. These compounds are polyene dicarboxylic acids that include both lipophilic and polar amino acids. They were extracted from the brightly colored mushrooms Boletus laetissimus and B. rufoaureus. The boletocrocins' conjugated systems account for the intense color.
Sclerodermatineae is a suborder of the fungal order Boletales. Circumscribed in 2002 by mycologists Manfred Binder and Andreas Bresinsky, it contains nine genera and about 80 species. The suborder contains a diverse assemblage fruit body morphologies, including boletes, gasteroid forms, earthstars, and puffballs. Most species are ectomycorrhizal, although the ecological role of some species is not known with certainty. The suborder is thought to have originated in the late Cretaceous (145–66 Ma) in Asia and North America, and the major genera diversified around the mid Cenozoic (66–0 Ma).
