Search results for "Diterpenes"
showing 10 items of 84 documents
Innovative technologies for the recovery of phytochemicals from Stevia rebaudiana Bertoni leaves: A review.
2018
Stevia rebaudiana Bertoni has gained increased industrial and scientific interests in the last 20 years, representing a suitable nutritional alternative to sucrose and artificial sweeteners. Moreover, this plant contains polyphenols, chlorophylls, and carotenoids that may be extracted for production of nutraceuticals and functional foods. Because of nutritional and technological advantages over sucrose, innovative approaches for the extraction of highly valued compounds from Stevia leaves have been developed and optimized. In contrast to conventional alternatives, innovative extraction methods allow higher yields in a shorter time, less usage of organic solvents, and reduced energy consumpt…
An ex vivo model of the rat trachea to study the effect of inhalable toxic compounds
1996
Different cell culture and organ systems are used to evaluate the physiological responses of the airways to the effects of carcinogenic [e.g., benzo(a)pyrene] and anticarcinogenic (e.g., retinoids) compounds on cellular growth and differentiation. However, in contrast to in vivo conditions dissociated epithelial cells or tracheal ring cultures are covered with medium. Therefore, we developed an ex vivo perfusion model enabling evaluation of morphology and metabolism of different compounds under near-physiological conditions. The trachea was surrounded with culture medium and perfused with air by means of a small animal respirator. To test the viability of the system under various experiment…
Sarcophytolide: a new neuroprotective compound from the soft coral Sarcophyton glaucum
1998
Abstract Bioactivity-guided fractionation of an alcohol extract of the soft coral Sarcophyton glaucum collected from the intertidal areas and the fringing coral reefs near Hurghada, Red Sea, Egypt resulted in the isolation of a new lactone cembrane diterpene, sarcophytolide. The structure of this compound was deduced from its spectroscopic data and by comparison of the spectral data with those of known closely related cembrane-type compounds. In antimicrobial assays, the isolated compound exhibited a good activity towards Staphylococcus aureus, Pseudomonas aeruginosa , and Saccharomyces cerevisiae. Sarcophytolide was found to display a strong cytoprotective effect against glutamate-induced …
Synthesis and cytotoxic activity of novel C7-functionalized spongiane diterpenes.
2003
Based on two lead cytotoxic spongiane diterpenes, a new series of C7-oxygenated derivatives were synthesized and evaluated for their antitumor activity in vitro against the cancer cell lines HeLa and HEp-2. In general, introduction of either hydroxyl or acetoxy groups at C-7 did not improve the resultant cytotoxicity, while the presence of a butyrate ester led to more active compounds (CC(50)=4.0-9.5 microM).
Cytotoxic activity of diterpenoids isolated from the aerial parts of Elaeoselinum asclepium subsp. meoides.
2008
The phytochemical investigation of the acetone extract of the aerial parts of Elaeoselinum asclepium (L.) Bertol. subsp. meoides (Desf.) Fiori afforded several known diterpenoids as well as meoidic acid ( 5), new in the literature. The cytotoxic activities of elasclepic acid ( 1), ENT-atis-16-en-19-oic acid ( 2), ent-beyer-15-en-19-oic acid ( 3), ent-kaur-16-en-19-oic acid ( 4) and meoidic acid ( 5) were investigated on rat glioma C6 cells by evaluation of cell growth inhibition.
Labdane Diterpenoids from Marrubium globosum ssp. libanoticum
2006
From the aerial parts of Marrubium globosum ssp. libanoticum, seven labdane diterpenoids were isolated. Three of them are new natural products [(13R)-9alpha,13alpha-epoxylabda-6beta(19),16(15)-diol dilactone (2), deacetylvitexilactone (7), marrulanic acid (8)], whereas the other four, namely, (13S)-9alpha,13alpha-epoxylabda-6beta(19),16(15)-diol dilactone (1), cyllenin A (3), 15-epi-cyllenin A (4), and marrulibanoside, are previously known compounds. The structures of 2, 7, and 8 were determined by spectroscopic and chemical methods.
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.
Synthesis and antiviral activity of scopadulane-rearranged diterpenes.
2009
A new bioactive diterpene skeleton resulting from a backbone rearrangement is described. Activity of the rearranged product and several derivatives against Herpes Virus Simplex type 2 is reported.
Analytical characterization of diterpenoid resins present in pictorial varnishes using pyrolysis–gas chromatography–mass spectrometry with on line tr…
2005
Abstract A procedure based on the technique of the pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS) has been applied, in this work, in order to determine the composition of diterpenoid resin employed in art works. The method is based on the on line derivatization of these resins using hexamethyldisilazane (HMDS). Results obtained were compared with those previously reported in literature from Venice turpentine, Strasbourg turpentine, colophony, sandarac and Manila copal using this same method and with those others from in situ thermally assisted hydrolysis and methylation with tetramethylammonium hydroxide (TMAH). Canada balsam, copper resinate and Copaiba balsam have been also ana…
Cytotoxic neo-clerodane diterpenes from Stachys aegyptiaca
2018
Abstract Two new E/Z neo-clerodane diterpene isomers, trivially named stachaegyptin D (1) and E (2), together with known compounds, stachysolon monoacetate (3) and stachysolon diacetate (4), were isolated from an organic-solvent extract of the medicinal herb Stachys aegyptiaca. Structures were elucidated by a combination of spectroscopic methods, including HREIMS, 1H, 13C, DEPT, and 2D NMR analysis, as well as, first time X-ray analysis for stachysolone (3). All isolated metabolites showed some activity against the human hepatocellular cell line, HepG2. Compound 4 was the most active with an IC50 of 59.5 μM.