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.
Catharanthus is a genus of flowering plants in the family Apocynaceae. Like the genus Vinca, they are known commonly as periwinkles. There are eight known species. Seven are endemic to Madagascar, though one, C. roseus, is widely naturalized around the world. The eighth species, C. pusillus, is native to India and Sri Lanka. The name Catharanthus comes from the Greek for "pure flower".
Catharanthus roseus, commonly known as bright eyes, Cape periwinkle, graveyard plant, Madagascar periwinkle, old maid, pink periwinkle, rose periwinkle, is a perennial species of flowering plant in the family Apocynaceae. It is native and endemic to Madagascar, but grown elsewhere as an ornamental and medicinal plant. It is a source of the drugs vincristine and vinblastine, used to treat cancer. It was formerly included in the genus Vinca as Vinca rosea.
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.
In enzymology, a desacetoxyvindoline 4-hydroxylase (EC 1.14.11.20) is an enzyme that catalyzes the chemical reaction
In enzymology, a tabersonine 16-hydroxylase (EC 1.14.13.73) is an enzyme that catalyzes the chemical reaction
Strictosidine synthase (EC 4.3.3.2) is an enzyme in alkaloid biosynthesis that catalyses the condensation of tryptamine with secologanin to form strictosidine in a formal Pictet–Spengler reaction:
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.
The O-methylated flavonoids or methoxyflavonoids are flavonoids with methylations on hydroxyl groups. O-methylation has an effect on the solubility of flavonoids.
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.
Strictosidine is a natural chemical compound and is classified as a glucoalkaloid and a vinca alkaloid. It is formed by the Pictet–Spengler condensation reaction of tryptamine with secologanin, catalyzed by the enzyme strictosidine synthase. Thousands of strictosidine derivatives are sometimes referred to by the broad phrase of monoterpene indole alkaloids. Strictosidine is an intermediate in the biosynthesis of numerous pharmaceutically valuable metabolites including quinine, camptothecin, ajmalicine, serpentine, vinblastine, vincristine and mitragynine.
Tabersonine is a terpene indole alkaloid found in the medicinal plant Catharanthus roseus and also in the genus Voacanga. Tabersonine is hydroxylated at the 16 position by the enzyme tabersonine 16-hydroxylase (T16H) to form 16-hydroxytabersonine. The enzyme leading to its formation is currently unknown. Tabersonine is the first intermediate leading to the formation of vindoline one of the two precursors required for vinblastine biosynthesis.
16-Hydroxytabersonine is a terpene indole alkaloid produced by the plant Catharanthus roseus. The metabolite is an intermediate in the formation of vindoline, a precursor needed for formation of the pharmaceutically valuable vinblastine and vincristine. 16-hydroxytabersonine is formed from the hydroxylation of tabersonine by tabersonine 16-hydroxylase (T16H). Tabersonine 16-O-methyltransferase (16OMT) methylates the hydroxylated 16 position to form 16-methoxytabersonine.
Desacetoxyvindoline is a terpene indole alkaloid produced by the plant Catharanthus roseus. Desacetoxyvindoline is a product formed by the methylation of the nitrogen on the indole ring by the enzyme 3-hydroxy-16-methoxy-2,3-dihydrotabersonine N-methyltransferase (NMT). The metabolite is a substrate for desacetoxyvindoline 4-hydroxylase (D4H) which catalyzes a hydroxylation to yield deacetylvindoline.
Deacetylvindoline is a terpene indole alkaloid produced by Catharanthus roseus. Deacetylvindoline is the product of a hydroxylation of desacetoxyvindoline by deacetoxyvindoline 4-hydroxylase (D4H). It is a substrate for deacetylvindoline O-acetyltransferase (DAT) which acetylates a hydroxy group to form vindoline, one of the two immediate precursors for the formation of the pharmacetucially valuable bisindole alkaloid vinblastine.
8-Hydroxygeraniol is a monoterpene synthesized from geraniol by the enzyme geraniol 8-hydroxylase. 8-Hydroxygeraniol is a substrate for 8-hydroxygeraniol dehydrogenase (G80) which synthesizes 8-oxogeranial. 8-Hydroxygeraniol is step in the synthesis of the secologanin, a key monoterpene needed for formation of terpene indole alkaloids.
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.
7-Deoxyloganetic acid is an iridoid monoterpene. It is produced from nepetalactol or iridodial by the enzyme iridoid oxidase (IO). 7-Deoxyloganetic acid is a substrate for 7-deoxyloganetic acid glucosyltransferase (7-DLGT) which synthesizes 7-deoxyloganic acid.
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.
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.
