Search results for "terpenoids"
showing 10 items of 34 documents
Lipase-catalysed preparation of acyl derivatives of the germacranolide cnicin
2009
Several acyl derivatives of cnicin were obtained through lipase-catalysed acylation and alcoholysis reactions. In most reactions lipases showed a regioselective behaviour affording only one product. Longer chain acyl derivatives were prepared at lower temperature than the used in lipase-catalysed reactions, to preclude side products formation. The enzymatic approach let to prepare a family of novel acetyl and fatty acid derivatives of cnicin which are not obtainable following traditional organic synthetic procedures. Fil: Monsalve, Leandro Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis…
Pyrolysis-gas chromatography : mass spectrometry analysis of di- and triterpenoids
2017
The objective of this work was to study a specific class of extractives existing in lignocellulosic biomass and more precisely in wood materials, and their thermochemical behavior during pyrolysis. The focus was centered on the class of terpenes and terpenoids; specifically two model compounds, abietic acid and betulinol, were chosen to represent the subclasses of di- and triterpenoids, respectively. The model compounds were investigated via pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and the main objective was to study their product profiles and characteristic fragmentations, as well as the influence of specific variables (pyrolysis temperature and time) on pyrolysis products…
The Diterpenoids of the Genus Elaeoselinum (Apiaceae) and their Biological Properties
2008
The natural kaurane, beyerane and atisane diterpenoids isolated from the genus Elaeoselinum (Apiaceae)and their semi-synthetic derivatives are reviewed. Published 13C NMR spectroscopic data and biological properties of these diterpenes are also reported.
Clerodane diterpenoids from Salvia splendens.
2006
Four new clerodane diterpenoids, salvisplendins A-D (1-4), have been isolated from an acetone extract of the flowers of SalVia splendens, together with an artifact (5), arising from salvisplendin D (4) by addition of diazomethane, and the already known clerodane olearin (6). The structures of the new compounds (1-5) were established mainly by 1D and 2D NMR spectroscopic studies and, in the case of salvisplendin A (1), by chemical correlation with splenolide B (7). Complete 1H and 13C NMR assignments for olearin (6), not published hitherto, are also reported.
Acid-induced rearrangement of epoxygermacra-8,12-olides: synthesis and absolute configuration of guaiane and eudesmane derivatives from artemisiifolin
2010
A study on the acid-induced rearrangement of 4,5-epoxy- and 1,10-epoxygermacra-8,12-olides was carried out. From a 4,5-epoxy derivative, guaianes were obtained, whereas 1,10-epoxy derivatives furnished, depending on the stereochemistry of the C-1/C-10 epoxy ring, trans-5β,10α- or trans-5α,10β-eudesmanolides.
Lipase-catalysed preparation of acyl derivatives of the germacranolide sesquiterpenoid cnicin
2009
Several acyl derivatives of cnicin were obtained through lipase-catalysed acylation and alcoholysis reactions. In most reactions lipases showed a regioselective behaviour affording only one product. Longer chain acyl derivatives were prepared at lower temperature than the used in lipase-catalysed reactions, to preclude side products formation. The enzymatic approach let to prepare a family of novel acetyl and fatty acid derivatives of cnicin which are not obtainable following traditional organic synthetic procedures.
Essential oils of Chiliadenus lopadusanus (Asteraceae).
2013
The essential oils from the leaves and flowers of Chiliadenus lopadusanus growing on Lampedusa Island were obtained by hydrodistillation and analyzed by GC-MS. The major component was camphor (39.4% in the leaves and 24.0% in the flowers), followed in the leaves by torreyol (6.7%), t-cadinol (5.2%) and 1,8-cineole (3.8%), while in the flowers by t-cadinol (15.2%), t-muurolol (5.1%) and torreyol (4.5%). Among the compounds identified, several seem to play a role in antibacterial, antifungal, allelopathic and spasmolytic activity. In addition, several compounds identified in this study seem to influence the attraction of Megachile (Eutricharaea) apicalis (Megachilidae) and Halictus (Seladonia…
Phytochemical analysis ofAchillea ligusticaAll. from Lipari Island (Aeolian Islands)
2016
A complete chemical investigation of Achillea ligustica All. growing at Lipari (Aeolian Island, Sicily) has been carried out. Seventeen metabolites have been isolated and characterised from dichloromethane and methanol extracts of flowers and aerial parts, and GC/MS analyses of petroleum ether extracts was carried out, revealing a composition in sesquiterpenoids similar to those reported for populations from Greece, Sicily and Algeria, showing the presence of (3RS,6RS)-2,6-dimethyl-1,7-octadiene-3,6-diol (1), 2,6-dimethyl-octa-3(E),7-diene-2,6-diol (2), iso-seco-tanapartholide (3) from DCM fraction. In addition from the methanolic extract of the aerial parts, peculiar flavonoid glucuronides…
A Short and Improved Synthesis of the Antiprotozoal Abietane Diterpenoid (–)-Sugikurojin A
2016
An efficient and straightforward semisynthesis of the antiprotozoal abietane diterpenoid (–)-sugikurojin A, starting from the readily available methyl ester of callitrisic acid (4-epi-dehydroabietic acid) isolated from sandarac resin, is reported. This optimized semisynthetic route provides a convenient source of the antiprotozoal compound, in four steps from methyl callitrisate in 50% overall yield, for further biological studies.
Recent Advances in Kaempferia Phytochemistry and Biological Activity : A Comprehensive Review
2019
Background: Plants belonging to the genus Kaempferia (family: Zingiberaceae) are distributed in Asia, especially in the southeast region, and Thailand. They have been widely used in traditional medicines to cure metabolic disorders, inflammation, urinary tract infections, fevers, coughs, hypertension, erectile dysfunction, abdominal and gastrointestinal ailments, asthma, wounds, rheumatism, epilepsy, and skin diseases. Objective: Herein, we reported a comprehensive review, including the traditional applications, biological and pharmacological advances, and phytochemical constituents of Kaempheria species from 1972 up to early 2019. Materials and methods: All the information and reported stu…