15917-91-6Relevant academic research and scientific papers
Alternate Cyclization Cascade Initiated by Substrate Isomer in Multiproduct Terpene Synthase from Medicago truncatula
Vattekkatte, Abith,Garms, Stefan,Boland, Wilhelm
, p. 2855 - 2861 (2017)
Promiscuity of terpene synthases results in the enormous diversity of terpenes found in nature. Multiproduct sesquiterpene synthase MtTPS5 isolated from Medicago truncatula generates 27 optically pure products from its natural substrate (2E,6E)-farnesyl diphosphate (FDP). In order to study the promiscuity of MtTPS5, (2Z,6E)-FDP, an analogue of presumptive reaction intermediates from natural reaction cascade, was utilized as a substrate. This stereoisomer induced a novel cyclization pathway leading to sesquiterpenes based on humulane, amorphene, and himachalane skeletons. Interestingly, none of these products matched those observed on incubation of MtTPS5 with natural (2E,6E)-FDP. Further determination of the absolute configuration of each product helped rebuild the stereochemical route of the reaction cascade. Interestingly, the presence of only one enantiomer of each product was observed, indicating the highly stereospecific nature of the enzymatic reaction. Substrate promiscuity of terpene synthases provides organism access to novel chemical bouquets of high optical purity by utilizing existing enzymes. The presence of this mechanism was indicated by the presence of these alternate products in natural herbivore-induced volatiles of M. truncatula.
The role of germacrene D as a precursor in sesquiterpene biosynthesis: Investigations of acid catalyzed, photochemically and thermally induced rearrangements
Buelow, Nils,Koenig, Wilfried A
, p. 141 - 168 (2007/10/03)
Germacrene D is considered as a precursor of many sesquiterpene hydrocarbons. We have investigated the acid catalyzed as well as the photochemically and thermally induced rearrangement processes of germacrene D isolated from several Solidago species, which contain both enantiomers of germacrene D. Enantiomeric mixtures of sesquiterpenes of the cadinane, eudesmane (selinane), oppositane, axane, isodaucane, and bourbonane group as well as isogermacrene D were identified as main products and made available as reference compounds for structure investigations and stereochemical assignments of plant constituents. δ-Amorphene, one of the rearrangement products, was identified as a natural product for the first time. The absolute configuration of γ-amorphene was revised by correlation with the absolute configuration of germacrene D. The mechanisms of the rearrangement reactions are discussed. (C) 2000 Elsevier Science Ltd.
Total syntheses of (±)-α- And (±)-β-copaene and formal total syntheses of (±)-sativene, (±)-cis-sativenediol, and (±)-helminthosporal
Wenkert, Ernest,Bookser, Brett C.,Arrbenius, Thomas S.
, p. 644 - 654 (2007/10/02)
Conversion of the previously reported, carvacrol-based 4(S*)-isopropyl-7(R*)-chlorobicyclo[3.1.1]heptan-6-one and its bromo equivalent into (±)-α- and (±)-β-copaene it described. Model 5-nor-β-copaene was synthesized in the following manner, (a) γ-(trimet
SESQUITERPENE ALCOHOLS OF THE COPANE SERIES FROM ESSENTIAL OIL OF OCIMUM AMERICANUM
Upadhyay, Ram K.,Misra, Laxmi N.,Singh, Gurdip
, p. 691 - 693 (2007/10/02)
The volatile oil of Ocimum americanum afforded nine monoterpene hydrocarbons, four oxygenated monoterpenes, 12 sesquiterpene hydrocarbons, 7 sesquiterpene alcohols and a few unidentified trace compounds.Four new alcohols of the uncommon copane series have also been isolated and their structures elucidated by spectroscopic methods and chemical transformations.
