Pyridinium refers to the cation [C5H5NH]+. It is the conjugate acid of pyridine. Many related cations are known involving substituted pyridines, e.g. picolines, lutidines, collidines. They are prepared by treating pyridine with acids.
Antimycins are produced as secondary metabolites by Streptomyces bacteria, a soil bacteria. These specialized metabolites likely function to kill neighboring organisms in order to provide the streptomyces bacteria with a competitive edge.
Lysergol is an alkaloid of the ergoline family that occurs as a minor constituent in some species of fungi, and in the morning glory family of plants (Convolvulaceae), including the hallucinogenic seeds of Rivea corymbosa (ololiuhqui), Argyreia nervosa and Ipomoea violacea. Lysergol is not a controlled substance in the USA. Its possession and sale is also legal under the U.S. Federal Analog Act because it does not have a known pharmacological action or a precursor relationship to LSD, which is a controlled substance. However, lysergol is an intermediate in the manufacture of some ergoloid medicines.
Diphenyl disulfide is the chemical compound with the formula (C6H5S)2. This colorless crystalline material is often abbreviated Ph2S2. It is one of the more commonly encountered organic disulfides in organic synthesis. Minor contamination by thiophenol is responsible for the disagreeable odour associated with this compound.
2-Methyl-2-nitrosopropane (MNP or t-nitrosobutane) is the organic compound with the formula (CH3)3CNO. It is a blue liquid that is used in chemical research as a spin trap, i.e. it binds to radicals.
Paxilline is a toxic, tremorgenic diterpene indole polycyclic alkaloid molecule produced by Penicillium paxilli which was first characterized in 1975. Paxilline is one of a class of tremorigenic mycotoxins, is a potassium channel blocker, and is potentially genotoxic.
Zirconocene dichloride is an organozirconium compound composed of a zirconium central atom, with two cyclopentadienyl and two chloro ligands. It is a colourless diamagnetic solid that is somewhat stable in air.
The Liebeskind–Srogl coupling reaction is an organic reaction forming a new carbon–carbon bond from a thioester and a boronic acid using a metal catalyst. It is a cross-coupling reaction. This reaction was invented by and named after Jiri Srogl from the Academy of Sciences, Czech Republic, and Lanny S. Liebeskind from Emory University, Atlanta, Georgia, USA. There are three generations of this reaction, with the first generation shown below. The original transformation used catalytic Pd(0), TFP = tris(2-furyl)phosphine as an additional ligand and stoichiometric CuTC = copper(I) thiophene-2-carboxylate as a co-metal catalyst. The overall reaction scheme is shown below.
Tris(2,2,2-trifluoroethyl) borate, also commonly referred to as the Sheppard amidation reagent, is a chemical compound with the formula B(OCH2CF3)3. This borate ester reagent is used in organic synthesis.
Tsukamurella pulmonis is a Gram-positive and aerobic bacterium from the genus Tsukamurella which has been isolated from the sputum from a patient with lung tuberculosis in Germany.
The Roskamp reaction was first discovered by Eric J. Roskamp and co-workers in 1989. This reaction is very useful in synthesizing β-keto esters from aldehydes and diazoacetate, using various Lewis acids as catalysts (such as BF3, SnCl2, GeCl2).
The Mukaiyama hydration is an organic reaction involving formal addition of an equivalent of water across an olefin by the action of catalytic bis(acetylacetonato)cobalt(II) complex, phenylsilane and atmospheric oxygen to produce an alcohol with Markovnikov selectivity.
The phomoxanthones are a loosely defined class of natural products. The two founding members of this class are phomoxanthone A and phomoxanthone B. Other compounds were later also classified as phomoxanthones, although a unifying nomenclature has not yet been established. The structure of all phomoxanthones is derived from a dimer of two covalently linked tetrahydroxanthones, and they differ mainly in the position of this link as well as in the acetylation status of their hydroxy groups. The phomoxanthones are structurally closely related to other tetrahydroxanthone dimers such as the secalonic acids and the eumitrins. While most phomoxanthones were discovered in fungi of the genus Phomopsis, most notably in the species Phomopsis longicolla, some have also been found in Penicillium sp.
Anisyl sulfanyl methyl isocyanide (Asmic) is an organic molecule that contains an isocyanide group and an ortho-methoxy-phenyl sulfide group. Asmic can be used to synthesize tri-substituted isocyanides. Asmic is a colorless to off-white solid with a melting point of 27 °C that can be prepared by dehydration of the corresponding formamide by POCl3.
Peter J. H. Scott FRSC CChem is a British and American chemist and radiochemist who is an Associate Professor of Radiology and Pharmacology, as well as a Faculty Scientist in the Interdepartmental Program in Medicinal Chemistry and a Core Member of the Rogel Cancer Center at the University of Michigan in the United States. He is Chief of Nuclear Medicine and Director of the University of Michigan Positron Emission Tomography (PET) Center, and runs a research group developing new radiochemistry methodology and novel PET radiotracers.
Methyl 2-acetamidoacrylate is the organic compound with the formula CH2=C(NHC(O)CH3)CO2CH3. It is the methyl ester of an N-acetylacrylic acid, which in turn is a derivative of the unstable compound dehydroalanine. Acetylation of the amine in the latter compound prevents tautomerization. It is a white solid.
Pyonitrins are a family of highly hydrogen-deficient alkaloids discovered from an insect-associated Pseudomonas protegens strain. In vivo, pyonitrins A-D show activity against pathogen Candida albicans, which commonly cause bloodstream infections.
Quinolidomicin A1 is a 60-membered macrocyclic compound isolated from Micromonospora sp. JY16. Quinolidomicins are a class of macrolides that contain a benzoquinone chromophore as well as an immense lactone ring, which far surpasses that in monozanomycin. It is currently the largest identified macrolide of terrestrial origin. It was initially discovered when in a screening for anti-tumor antibiotics, where it was found to be cytotoxic against P388 murine leukemia cells (IC50 8 nM), and has later been found to have strong cytotoxic activity against HT-29, MKN28, K562, and KB.
The ketimine Mannich reaction is an asymmetric synthetic technique using differences in starting material to push a Mannich reaction to create an enantiomeric product with steric and electronic effects, through the creation of a ketimine group. Typically, this is done with a reaction with proline or another nitrogen-containing heterocycle, which control chirality with that of the catalyst. This has been theorized to be caused by the restriction of undesired (E)-isomer by preventing the ketone from accessing non-reactive tautomers. Generally, a Mannich reaction is the combination of an amine, a ketone with a β-acidic proton and aldehyde to create a condensed product in a β-addition to the ketone. This occurs through an attack on the ketone with a suitable catalytic-amine unto its electron-starved carbon, from which an imine is created. This then undergoes electrophilic addition with a compound containing an acidic proton. It is theoretically possible for either of the carbonyl-containing molecules to create diastereomers, but with the addition of catalysts which restrict addition as of the enamine creation, it is possible to extract a single product with limited purification steps and in some cases as reported by List et al.; practical one-pot syntheses are possible. The process of selecting a carbonyl-group gives the reaction a direct versus indirect distinction, wherein the latter case represents pre-formed products restricting the reaction's pathway and the other does not. Ketimines selects a reaction group, and circumvent a requirement for indirect pathways.
Rubellin B is a phytotoxic chemical responsible for the Ramularia leaf spot disease due to its ability to create reactive radical superoxides. The drug has not been involved in many clinical studies, but has been found to prevent tau aggregation pointing to its potential in the treatment of Alzheimer's disease.
