Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest halogen, and is a fuming red-brown liquid at room temperature that evaporates readily to form a similarly coloured gas. Its properties are thus intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig and Antoine Jérôme Balard, its name was derived from the Ancient Greek βρῶμος ("stench"), referencing its sharp and disagreeable smell.
Mentha pulegium, commonly (European) pennyroyal, or pennyrile, also called squaw mint, mosquito plant and pudding grass, is a species of flowering plant in the mint family, Lamiaceae, native to Europe, North Africa, and the Middle East. Crushed pennyroyal leaves emit a very strong fragrance similar to spearmint. Pennyroyal is a traditional folk remedy, emmenagogue, abortifacient, and culinary herb, but is toxic to the liver and has caused some deaths. European pennyroyal is related to an American species, Hedeoma pulegioides. Though they differ in genera, they share similar chemical properties.
Strychnine is a highly toxic, colorless, bitter, crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine, when inhaled, swallowed, or absorbed through the eyes or mouth, causes poisoning which results in muscular convulsions and eventually death through asphyxia. While it has no known medicinal effects, in the past the convulsant effect was believed to be beneficial in small doses. The most common source is from the seeds of the Strychnos nux-vomica tree.
Reactive oxygen species (ROS) are chemically reactive chemical species containing oxygen. Examples include peroxides, superoxide, hydroxyl radical, singlet oxygen, and alpha-oxygen.
Toxication or toxification is the conversion of a chemical compound into a more toxic form in living organisms or in substrates such as soil or water. The conversion can be caused by enzymatic metabolism in the organisms, as well as by abiotic chemical reactions. While the parent drug are usually less active, both the parent drug and its metabolite can be chemically active and cause toxicity, leading to mutagenesis, teratogenesis, and carcinogenesis. Different classes of enzymes, such as P450-monooxygenases, epoxide hydrolase, or acetyltransferases can catalyze the process in the cell, mostly in the liver.
Saxitoxin (STX) is a potent neurotoxin and the best-known paralytic shellfish toxin (PST). Ingestion of saxitoxin by humans, usually by consumption of shellfish contaminated by toxic algal blooms, is responsible for the illness known as paralytic shellfish poisoning (PSP).
Tienilic acid or ticrynafen (USAN) is a loop diuretic drug with uric acid-lowering (uricosuric) action, formerly marketed for the treatment of hypertension. It was approved by FDA on May 2, 1979, and withdrawn in 1982, after case reports in the United States indicated a link between the use of ticrynafen and hepatitis.
The Baeyer–Villiger oxidation is an organic reaction that forms an ester from a ketone or a lactone from a cyclic ketone, using peroxyacids or peroxides as the oxidant. The reaction is named after Adolf von Baeyer and Victor Villiger who first reported the reaction in 1899.
Pulegone is a naturally occurring organic compound obtained from the essential oils of a variety of plants such as Nepeta cataria (catnip), Mentha piperita, and pennyroyal. It is classified as a monoterpene.
Trichothecenes are a very large family of chemically related mycotoxins produced by various species of Fusarium, Myrothecium, Trichoderma, Trichothecium, Cephalosporium, Verticimonosporium, and Stachybotrys. Trichothecenes are a class of sesquiterpenes. The most important structural features causing the biological activities of trichothecenes are the 12,13-epoxy ring, the presence of hydroxyl or acetyl groups at appropriate positions on the trichothecene nucleus, and the structure and position of the side-chain. They are produced on many different grains like wheat, oats or maize by various Fusarium species such as F. graminearum, F. sporotrichioides, F. poae and F. equiseti.
Umpolung or polarity inversion in organic chemistry is the chemical modification of a functional group with the aim of the reversal of polarity of that group. This modification allows secondary reactions of this functional group that would otherwise not be possible. The concept was introduced by D. Seebach and E.J. Corey. Polarity analysis during retrosynthetic analysis tells a chemist when umpolung tactics are required to synthesize a target molecule.
In genetics, crosslinking of DNA occurs when various exogenous or endogenous agents react with two nucleotides of DNA, forming a covalent linkage between them. This crosslink can occur within the same strand (intrastrand) or between opposite strands of double-stranded DNA (interstrand). These adducts interfere with cellular metabolism, such as DNA replication and transcription, triggering cell death. These crosslinks can, however, be repaired through excision or recombination pathways.
Glutathione synthetase (GSS) is the second enzyme in the glutathione (GSH) biosynthesis pathway. It catalyses the condensation of gamma-glutamylcysteine and glycine, to form glutathione. Glutathione synthetase is also a potent antioxidant. It is found in many species including bacteria, yeast, mammals, and plants.
Bioconjugation is a chemical strategy to form a stable covalent link between two molecules, at least one of which is a biomolecule.
Cephaloridine is a first-generation semisynthetic derivative of antibiotic cephalosporin C. It is a Beta lactam antibiotic, like penicillin. Its chemical structure contains 3 cephems, 4 carboxyl groups and three pyridinium methyl groups.
3-Nitrobenzanthrone (3-nitro-7H-benz[de]anthracen-7-one) is a chemical compound emitted in diesel exhaust; it is a potent carcinogen. It produced the highest score ever reported in the Ames test, a standard measure of the cancer-causing potential of toxic chemicals, far greater than the previous known strongest.
Pharmacotoxicology entails the study of the consequences of toxic exposure to pharmaceutical drugs and agents in the health care field. The field of pharmacotoxicology also involves the treatment and prevention of pharmaceutically induced side effects. Pharmacotoxicology can be separated into two different categories: pharmacodynamics, and pharmacokinetics.
The term bioorthogonal chemistry refers to any chemical reaction that can occur inside of living systems without interfering with native biochemical processes. The term was coined by Carolyn R. Bertozzi in 2003. Since its introduction, the concept of the bioorthogonal reaction has enabled the study of biomolecules such as glycans, proteins, and lipids in real time in living systems without cellular toxicity. A number of chemical ligation strategies have been developed that fulfill the requirements of bioorthogonality, including the 1,3-dipolar cycloaddition between azides and cyclooctynes, between nitrones and cyclooctynes, oxime/hydrazone formation from aldehydes and ketones, the tetrazine ligation, the isocyanide-based click reaction, and most recently, the quadricyclane ligation.
HaloTag is a self-labeling protein tag. It is a 297 residue peptide derived from a bacterial enzyme, designed to covalently bind to a synthetic ligand, which can be fused to a protein of interest. The synthetic ligand is chosen from a number of available ligands in accordance with the type of experiments to be performed. This bacterial enzyme is a haloalkane dehalogenase, which acts as a hydrolase and is designed to facilitate visualization of the subcellular localization of a protein of interest, immobilization of a protein of interest, or capture of the binding partners of a protein of interest within its biochemical environment. The HaloTag is composed of two covalently bound segments including a haloalkane dehalogenase and a synthetic ligand of choice. These synthetic ligands consist of a reactive chloroalkane linker bound to a functional group. Functional groups can either be biotin or can be chosen from five available fluorescent dyes including Coumarin, Oregon Green, Alexa Fluor 488, diAcFAM, and TMR. These fluorescent dyes can be used in the visualization of either living or chemically fixed cells.
Metabolite damage can occur through enzyme promiscuity or spontaneous chemical reactions. Many metabolites are chemically reactive and unstable and can react with other cell components or undergo unwanted modifications. Enzymatically or chemically damaged metabolites are always useless and often toxic. To prevent toxicity that can occur from the accumulation of damaged metabolites, organisms have damage-control systems that:
- Reconvert damaged metabolites to their original, undamaged form
- Convert a potentially harmful metabolite to a benign one
- Prevent damage from happening by limiting the build-up of reactive, but non-damaged metabolites that can lead to harmful products
