Methionine is an essential amino acid in humans. As the precursor of other amino acids such as cysteine and taurine, versatile compounds such as SAM-e, and the important antioxidant glutathione, methionine plays a critical role in the metabolism and health of many species, including humans. It is encoded by the codon AUG.
Terpenes are a class of natural products consisting of compounds with the formula (C5H8)n for n > 1. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predominantly by plants, particularly conifers. Terpenes are further classified by the number of carbons: monoterpenes (C10), sesquiterpenes (C15), diterpenes (C20), as examples. The terpene alpha-pinene, is a major component of the common solvent, turpentine.
Nepetalactone is a name for multiple iridoid analog stereoisomers. Nepetalactones are produced by Nepeta cataria (catnip) and many other plants belonging to the genus Nepeta, in which they protect these plants from herbivorous insects by functioning as insect repellents. They are also produced by many aphids, in which they are sex pheromones. Nepetalactones are cat attractants, and cause the behavioral effects that catnip induces in domestic cats. However, they affect visibly only about two thirds of adult cats. They produce similar behavioral effects in many other felids, especially in lions and jaguars. In 1941, the research group of Samuel M. McElvain was the first to determine the structures of nepetalactones and several related compounds.
In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. These can be activated by enzyme hydrolysis, which causes the sugar part to be broken off, making the chemical available for use. Many such plant glycosides are used as medications. Several species of Heliconius butterfly are capable of incorporating these plant compounds as a form of chemical defense against predators. In animals and humans, poisons are often bound to sugar molecules as part of their elimination from the body.
Actinidine is an iridoid produced in nature by a wide variety of plants and animals. It was the first cyclopentanoid monoterpene alkaloid to be discovered. It is one of several compounds that may be extracted from the valerian root and silver vine, as well as several types of insects in the larval and imaginal stages. Actinidine is a cat attractant, with effects like those of nepetalactone, the active compound found in catnip.
Daidzein is a naturally occurring compound found exclusively in soybeans and other legumes and structurally belongs to a class of compounds known as isoflavones. Daidzein and other isoflavones are produced in plants through the phenylpropanoid pathway of secondary metabolism and are used as signal carriers, and defense responses to pathogenic attacks. In humans, recent research has shown the viability of using daidzein in medicine for menopausal relief, osteoporosis, blood cholesterol, and lowering the risk of some hormone-related cancers, and heart disease. Despite the known health benefits, the use of both puerarin and daidzein is limited by their poor bioavailability and low water solubility.
Rosmarinic acid, named after rosemary, is a polyphenol constituent of many culinary herbs, including rosemary, perilla, sage, mint, and basil.
Amino acid synthesis is the set of biochemical processes by which the amino acids are produced. The substrates for these processes are various compounds in the organism's diet or growth media. Not all organisms are able to synthesize all amino acids. For example, humans can synthesize 11 of the 20 standard amino acids. These 11 are called the non-essential amino acids).
Iridoids are a type of monoterpenoids in the general form of cyclopentanopyran, found in a wide variety of plants and some animals. They are biosynthetically derived from 8-oxogeranial. Iridoids are typically found in plants as glycosides, most often bound to glucose.
1-Pyrroline-5-carboxylic acid is a cyclic imino acid. Its conjugate base and anion is 1-pyrroline-5-carboxylate (P5C). In solution, P5C is in spontaneous equilibrium with glutamate-5-semialdhyde (GSA). The stereoisomer (S)-1-pyrroline-5-carboxylate is an intermediate metabolite in the biosynthesis and degradation of proline and arginine.
Important structures in plant development are buds, shoots, roots, leaves, and flowers; plants produce these tissues and structures throughout their life from meristems located at the tips of organs, or between mature tissues. Thus, a living plant always has embryonic tissues. By contrast, an animal embryo will very early produce all of the body parts that it will ever have in its life. When the animal is born, it has all its body parts and from that point will only grow larger and more mature. However, both plants and animals pass through a phylotypic stage that evolved independently and that causes a developmental constraint limiting morphological diversification.
Nepeta cataria, commonly known as catnip, catswort, catwort, and catmint, is a species of the genus Nepeta in the family Lamiaceae, native to southern and eastern Europe, the Middle East, Central Asia, and parts of China. It is widely naturalized in northern Europe, New Zealand, and North America. The common name catmint can also refer to the genus as a whole.
Catalpol is an iridoid glucoside. This natural product falls in the class of iridoid glycosides, which are simply monoterpenes with a glucose molecule attached.
Aucubin is an iridoid glycoside. Iridoids are commonly found in plants and function as defensive compounds. Iridoids decrease the growth rates of many generalist herbivores.
Secologanin is a secoiridoid monoterpene synthesized from geranyl pyrophosphate in the mevalonate pathway. Secologanin then proceeds with dopamine or tryptamine to form ipecac and terpene indole alkaloids, respectively.
8-Oxogeranial is a chemical substance, that is a monoterpene. The terpenoid is produced by 8-hydroxygeraniol dehydrogenase which uses 8-hydroxygeraniol as its substrate. 8-Oxogeranial is itself a substrate for iridoid synthase which synthesizes cis–trans-iridodial and cis–trans-nepetalactol.
Nepetalactol is an iridoid. It is produced from 8-oxogeranial by the enzyme iridoid synthase. Nepetalactol is a substrate for the enzyme iridoid oxidase (IO) which produces 7-deoxyloganetic acid. It has been identified in Actinidia polygama as a major cat attractant, and a mosquito repellent. The fact that mosquitos bite cats with nepetalactol on their fur less often may explain why cats are attracted to silver vine in the first place.
7-Deoxyloganic acid is an iridoid monoterpene. 7-Deoxyloganic acid is produced from 7-deoxyloganetic acid by the enzyme 7-deoxyloganetic acid glucosyltransferase (7-DLGT). The metabolite is a substrate for the enzyme 7-deoxyloganic acid hydroxylase (7-DLH) which synthesizes loganic acid.
Strigolactones are a group of chemical compounds produced by a plant's roots. Due to their mechanism of action, these molecules have been classified as plant hormones or phytohormones. So far, strigolactones have been identified to be responsible for three different physiological processes: First, they promote the germination of parasitic organisms that grow in the host plant's roots, such as Strigalutea and other plants of the genus Striga. Second, strigolactones are fundamental for the recognition of the plant by symbiotic fungi, especially arbuscular mycorrhizal fungi, because they establish a mutualistic association with these plants, and provide phosphate and other soil nutrients. Third, strigolactones have been identified as branching inhibition hormones in plants; when present, these compounds prevent excess bud growing in stem terminals, stopping the branching mechanism in plants.
Sarah E. O'Connor is an American molecular biologist working to understand the molecular machinery involved in assembling important plant natural products – vinblastine, morphine, iridoids, secologanin – and how changing the enzymes involved in this pathway lead to diverse analogs. She was a Project Leader at the John Innes Centre in the UK between 2011 and 2019. O'Connor was appointed by the Max Planck Society in 2018 to head the Department of Natural Product Biosynthesis at the Max Planck Institute for Chemical Ecology in Jena, Germany, taking up her role during 2019.
