In organic chemistry, a peptide bond is an amide type of covalent chemical bond linking two consecutive alpha-amino acids from C1 of one alpha-amino acid and N2 of another, along a peptide or protein chain.
A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical synthesis and have played a central role in the development of the field of organic chemistry by providing challenging synthetic targets. The term natural product has also been extended for commercial purposes to refer to cosmetics, dietary supplements, and foods produced from natural sources without added artificial ingredients.
Thapsigargin is a non-competitive inhibitor of the sarco/endoplasmic reticulum Ca2+ ATPase (SERCA). Structurally, thapsigargin is classified as a guaianolide, and is extracted from a plant, Thapsia garganica. It is a tumor promoter in mammalian cells.
Noscapine is a benzylisoquinoline alkaloid, of the phthalideisoquinoline structural subgroup, which has been isolated from numerous species of the family Papaveraceae. It lacks significant hypnotic, euphoric, or analgesic effects affording it with very low addictive potential. This agent is primarily used for its antitussive (cough-suppressing) effects.
Tropinone is an alkaloid, famously synthesised in 1917 by Robert Robinson as a synthetic precursor to atropine, a scarce commodity during World War I. Tropinone and the alkaloids cocaine and atropine all share the same tropane core structure. Its corresponding conjugate acid at pH 7.3 major species is known as tropiniumone.
Okadaic acid, C44H68O13, is a toxin produced by several species of dinoflagellates, and is known to accumulate in both marine sponges and shellfish. One of the primary causes of diarrhetic shellfish poisoning, okadaic acid is a potent inhibitor of specific protein phosphatases and is known to have a variety of negative effects on cells. A polyketide, polyether derivative of a C38 fatty acid, okadaic acid and other members of its family have shined light upon many biological processes both with respect to dinoflagellete polyketide synthesis as well as the role of protein phosphatases in cell growth.
2-Imidazoline (Preferred IUPAC name: 4,5-dihydro-1H-imidazole) is one of three isomers of the nitrogen-containing heterocycle imidazoline, with the formula C3H6N2. The 2-imidazolines are the most common imidazolines commercially, as the ring exists in some natural products and some pharmaceuticals. They also have been examined in the context of organic synthesis, coordination chemistry, and homogeneous catalysis.
Swainsonine is an indolizidine alkaloid. It is a potent inhibitor of Golgi alpha-mannosidase II, an immunomodulator, and a potential chemotherapy drug. As a toxin in locoweed it also is a significant cause of economic losses in livestock industries, particularly in North America. It was first isolated from Swainsona canescens.
Iodolactonization is an organic reaction that forms a ring by the addition of an oxygen and iodine across a carbon-carbon double bond. It is an intramolecular variant of the halohydrin synthesis reaction. The reaction was first reported by M. J. Bougalt in 1904 and has since become one of the most effective ways to synthesize lactones. Strengths of the reaction include the mild conditions and incorporation of the versatile iodine atom into the product.
Thiostrepton is a natural cyclic oligopeptide antibiotic of the thiopeptide class, derived from several strains of streptomycetes, such as Streptomyces azureus and Streptomyces laurentii. Thiostrepton is a natural product of the ribosomally synthesized and post-translationally modified peptide (RiPP) class.
Indolocarbazoles (ICZs) are a class of compounds that are under current study due to their potential as anti-cancer drugs and the prospective number of derivatives and uses found from the basic backbone alone. First isolated in 1977, a wide range of structures and derivatives have been found or developed throughout the world. Due to the extensive number of structures available, this review will focus on the more important groups here while covering their occurrence, biological activity, biosynthesis, and laboratory synthesis.
Indole is an aromatic, heterocyclic, organic compound with the formula C8H7N. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered pyrrole ring. Indole is widely distributed in the natural environment and can be produced by a variety of bacteria. As an intercellular signal molecule, indole regulates various aspects of bacterial physiology, including spore formation, plasmid stability, resistance to drugs, biofilm formation, and virulence. The amino acid tryptophan is an indole derivative and the precursor of the neurotransmitter serotonin.
The cortistatins are a group of steroidal alkaloids first isolated in 2006 from the marine sponge Corticium simplex. The cortistatins were first discovered in a search for naturally occurring compounds that inhibit proliferation of human umbilical vein endothelial cells (HUVECs), with cortistatin A being the most potent compound in the class.
Sodium trifluoromethanesulfinate (CF3SO2Na) is the sodium salt of trifluoromethanesulfinic acid. Together with t-butyl hydroperoxide, an oxidant, this compound was found to be a suitable reagent for introducing trifluoromethyl groups onto electron-rich aromatic compounds by Langlois; this reagent is also known as the Langlois reagent. This reaction operates via a free radical mechanism.
Communesin B is a cytotoxic fungi isolate from marine Penicillium strains. Its cytotoxicity makes it a potential anticancer compound.
Gigactonine is a naturally occurring diterpene alkaloid first isolated from Aconitum gigas. It occurs widely in the Ranunculaceae plant family. The polycyclic ring system of this chemical compound contains nineteen carbon atoms and one nitrogen atom, which is the same as in aconitine and this is reflected in its preferred IUPAC name.
Oroidin is a bromopyrrole alkaloid, originally isolated from marine sponges in the genus Agelas. Its complex structure leads to wide biological activities, which makes Oroidin a potential drug candidate for various diseases. It also serves as chemical defense in marine sponges.
2-Carbomethoxytropinone (2-CMT) is a commonly used organic intermediate in the synthesis of cocaine and its analogues. As of at least 1999 no reaction pathway has been discovered that synthesizes cocaine-like compounds without utilizing the reduction of 2-CMT. The structure of cocaine was discovered by Richard Willstätter in 1898 after he synthesized it from 2-carbomethoxytropinone. Although it was originally believed that 2-CMT in nature was ultimately derived from ornithine and acetic acid, subsequent research has indicated other pathways exist for the biosynthesis of 2-CMT. A β-keto ester, 2-CMT exists in equilibrium with its keto–enol tautomer.
Virstatin is a small molecule that inhibits the activity of the cholera protein, ToxT.
Fascaplysin is a marine alkaloid based on 12H-pyrido[1–2-a:3,4-b′]diindole ring system. It was first isolated as a red pigment from the marine sponge Fascaplysinopsis bergquist collected in the South Pacific near Fiji in 1988. Fascaplysin possesses a broad range of in vitro biological activities including analgesic, antimicrobial, antifungal, antiviral, antimalarial, anti-angiogenic, and antiproliferative activity against numerous cancer cell lines.
