An enamine is an unsaturated compound derived by the condensation of an aldehyde or ketone with a secondary amine. Enamines are versatile intermediates.
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.
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.
The Weinreb–Nahm ketone synthesis is a chemical reaction used in organic chemistry to make carbon–carbon bonds. It was discovered in 1981 by Steven M. Weinreb and Steven Nahm as a method to synthesize ketones. The original reaction involved two subsequent nucleophilic acyl substitutions: the conversion of an acid chloride with N,O-Dimethylhydroxylamine, to form a Weinreb–Nahm amide, and subsequent treatment of this species with an organometallic reagent such as a Grignard reagent or organolithium reagent. Nahm and Weinreb also reported the synthesis of aldehydes by reduction of the amide with an excess of lithium aluminum hydride.
Prodigiosin is the red dyestuff produced by many strains of the bacterium Serratia marcescens, as well as other Gram-negative, gamma proteobacteria such as Vibrio psychroerythrus and Hahella chejuensis. It is responsible for the pink tint occasionally found in grime that accumulates on porcelain surfaces such as bathtubs, sinks, and toilet bowls. It is in the prodiginines family of compounds which are produced in some Gram-negative gamma proteobacteria, as well as select Gram-positive Actinobacteria. The name prodigiosin is derived from prodigious.
Sparteine is a class 1a antiarrhythmic agent; a sodium channel blocker. It is an alkaloid and can be extracted from scotch broom. It is the predominant alkaloid in Lupinus mutabilis, and is thought to chelate the bivalent metals calcium and magnesium. It is not FDA approved for human use as an antiarrhythmic agent, and it is not included in the Vaughan Williams classification of antiarrhythmic drugs.
Convolutindole A (2,4,6-tribromo-1,7-dimethoxy-N,N-dimethyltryptamine) is a brominated tryptamine alkaloid that was first identified in 2001 in Amathia convoluta, a marine bryozoan. Bryozoans are aquatic invertebrates that grow in colonies and may resemble coral.
Roseophilin is an antibiotic isolated from Streptomyces griscovirides shown to have antitumor activity. The chemical structure can be considered in terms of two components, a macrotricyclic segment and a heterocyclic side-chain. Several laboratory syntheses of roseophilin are based upon the Paal-Knorr synthesis, and two others are based on the Nazarov cyclization reaction. The compound is related to the prodiginines.
Tropane alkaloids are a class of bicyclic [3.2.1] alkaloids and secondary metabolites that contain a tropane ring in their chemical structure. Tropane alkaloids occur naturally in many members of the plant family Solanaceae. Certain tropane alkaloids such as cocaine and scopolamine are notorious for their psychoactive effects, related usage and cultural associations. Particular tropane alkaloids such as these have pharmacological properties and can act as anticholinergics or stimulants.
Ergocryptine is an ergopeptine and one of the ergot alkaloids. It is isolated from ergot or fermentation broth and it serves as starting material for the production of bromocriptine.
Tyrannodoris tigris is a species of sea slug, a polycerid nudibranch, a marine gastropod mollusk in the family Polyceridae. It is a known predator of Tambje eliora and Tambje abdere, two species of smaller nudibranchs. The chemical extracts of all three species contain tambjamines, which were traced to Sessibugula translucens, a food source of these species. It is hypothesized that tambjamines are a chemical defence mechanism against feeding by the spotted kelpfish Gibbonsia elegans.
Lyngbyatoxin-a is a cyanotoxin produced by certain cyanobacteria species, most notably Moorea producens. It is produced as defense mechanism to ward off any would-be predators of the bacterium, being a potent blister agent as well as carcinogen. Low concentrations cause a common skin condition known as seaweed dermatitis.
The Enders SAMP/RAMP hydrazone alkylation reaction is an asymmetric carbon-carbon bond formation reaction facilitated by pyrrolidine chiral auxiliaries. It was pioneered by E. J. Corey and D. Enders in 1976, and was further developed by D. Enders and his group. This method is usually a three-step sequence. The first step is to form the hydrazone between (S)-1-amino-2-methoxymethylpyrrolidine (SAMP) or (R)-1-amino-2-methoxymethylpyrrolidine (RAMP) and a ketone or aldehyde. Afterwards, the hydrazone is deprotonated by lithium diisopropylamide (LDA) to form an azaenolate, which reacts with alkyl halides or other suitable electrophiles to give alkylated hydrazone species with the simultaneous generation of a new chiral center. Finally, the alkylated ketone or aldehyde can be regenerated by ozonolysis or hydrolysis.
Stevensine is a bromopyrrole alkaloid originally isolated from an unidentified Micronesian marine sponge, as well as a New Caledonian sponge, Pseudaxinyssa cantharella and Axinella corrugata. Total synthesis of stevensine has been achieved by Ying-zi Xu et al., and investigations into the biosynthetic origin has been explored by Paul Andrade et al. Understanding methods to synthesize stevensine and other similar compounds is an important step to accomplish, as marine sponges contain numerous biologically active metabolites that have been shown to function as anything from antitumor to antibacterial agents when tested for medicinal applications. Reasons for why marine sponges contain so many bio-active chemicals has been attributed to their sessile nature, and the need to produce chemical defenses to ensure survival. However, since many of these compounds naturally occur in small amounts, harvesting the sponges has in the past led to near-extinction of some species.
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.
Fumiquinazolines are bio-active isolates of Aspergillus.
Mitragynine pseudoindoxyl is a rearrangement product of 7-hydroxymitragynine. It is an analgesic being more potent than morphine.
Swinholides are dimeric 42 carbon-ring polyketides that exhibit a 2-fold axis of symmetry. Found mostly in the marine sponge Theonella, swinholides encompass cytotoxic and antifungal activities via disruption of the actin skeleton. Swinholides were first described in 1985 and the structure and stereochemistry were updated in 1989 and 1990, respectively. Thirteen swinholides have been described in the literature, including close structural compounds such as misakinolides/bistheonellides, ankaraholides, and hurgholide A It is suspected that symbiotic microbes that inhabit the sponges rather than the sponges themselves produce swinholides since the highest concentration of swinholides are found in the unicellular bacterial fraction of sponges and not in the sponge fraction or cyanobacteria fraction that also inhabit the sponges.
Undecylprodigiosin is an alkaloid produced by some Actinomycetes bacteria. It is a member of the prodiginines group of natural products and has been investigated for potential antimalarial activity.
The prodiginines are a family of red tripyrrole dyestuffs produced by Gammaproteobacteria as well as some Actinomycetota. The group is named after prodigiosin (prodiginine) and is biosynthesized through a common set of enzymes. They are interesting due to their history and their varied biological activity.
