Search results for "Diterpene"
showing 10 items of 139 documents
Anti-HIV Agents Derived from the ent-Kaurane Diterpenoid Linearol
2002
Twenty-six semisynthetic ent-kaurane derivatives of linearol (1) have been investigated for their anti-HIV effects. Five compounds (4, 7, 11, 25, and 26) showed significant activity against HIV replication in H9 lymphocyte cells with EC(50) values in the range <0.1-3.11 microg/mL. With TI values of 163 and 184, compounds 4 and 25 are especially promising for further development as potential anti-HIV agents.
Effects of ajugarins and related neoclerodane diterpenoids on feeding behaviour of Leptinotarsa decemlineata and Spodoptera exigua larvae
2001
Three naturally occurring ajugarins and seven semisynthetic derivatives of them, possessing different functionalities in the decalin part, together with two natural furoneoclerodane diterpenes, have been assessed as feeding behavior modifying agents of larvae of the generalist Spodoptera exigua and a specialist like Leptinotarsa decemlineata. Ajugarin I and some of its derivatives exhibited a significant antifeedant activity against larvae of S. exigua in both choice and no-choice assays. Conversely, the furoneoclerodane diterpenes only presented antifeedant activity against larvae of L. decemlineata. These results indicate that the biological action of the tested substances is strongly mod…
Physician–patient communication and patient-reported outcomes in the actinic keratosis treatment adherence initiative (AK-TRAIN): a multicenter, pros…
2017
Background: Patients with multiple actinic keratoses (AKs) should be treated with field-directed therapy. Such treatments challenge patients’ adherence due to out-of-pocket costs, length of treatment and severity of local skin reactions (LSRs). Effective physician–patient communication (PPC) may buffer therapy-related distress, thus improving quality of life, treatment satisfaction and adherence. Objectives: We evaluated the interplay between PPC, LSR intensity (safety) and lesion clearance rates (effectiveness) on treatment satisfaction, quality of life and treatment adherence among patients with multiple AKs receiving topical field-directed therapies. Methods: In this observational, multi…
Antispasmodic Effects and Structure−Activity Relationships of Labdane Diterpenoids from Marrubium globosum ssp. libanoticum
2009
Marrubium globosum ssp. libanoticum is a medicinal plant used in Lebanon to reduce pain and smooth muscle spasms. A chloroform extract obtained from M. globosum aerial parts reduced acetylcholine-induced contractions in the isolated mouse ileum. The purification of this extract identified, among 12 isolated labdane diterpenoids, four new compounds, named 13-epicyllenin A (4), 13,15-diepicyllenin A (5), marrulibacetal (9), and marrulactone (11). Their structures were determined by spectroscopic methods. Compound 9, which exerted antispasmodic activity, is likely the active ingredient of the extract. Preliminary structure-activity relationships for this class of compounds are suggested.
Phytochemical and pharmacological studies on the acetonic extract of Marrubium globosum ssp. libanoticum
2006
A new natural labdane diterpene, marrulibanoside, was isolated from the acetonic extract of aerial parts of M. globosum Montbr. et Auch. ex Benth. ssp. libanoticum Boiss. (Lamiaceae). Its structure was determined by spectroscopic methods such as 1D and 2D NMR and mass spectrometry. Pharmacological studies have shown that the extract of M. globosum exerts anti-inflammatory effects in the rat paw oedema induced by carrageenin resulting in reduced paw swelling. This activity, which seems due to marrulibanoside, is a consequence of iNOS and COX-2 activities inhibition.
Coffee and its chemopreventive components Kahweol and Cafestol increase the activity of O6-methylguanine-DNA methyltransferase in rat liver—compariso…
2003
Abstract A lower rate of colon cancer was observed in consumers of coffee with a high content of the diterpenes Kahweol and Cafestol (K/C). In animal models, K/C have been found to protect against the mutagenic/carcinogenic effects of compounds such as 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), aflatoxin B1, and 7,12-dimethylbenz[a]anthracene. Thus far, such chemoprotection by K/C has been attributed to modifications of xenobiotic metabolism, e.g. enhanced detoxification by UDP-glucuronosyltransferase (UDPGT) and/or glutathione transferase (GST). In the present study, we investigated the potential of several coffee-related treatments (K/C [1:1], Cafestol-alone, Turkish coffee) …
Phospholipid breakdown and choline release under hypoxic conditions: inhibition by bilobalide, a constituent of Ginkgo biloba
1997
A marked increase of choline release from rat hippocampal slices was observed when the slices were superfused with oxygen-free buffer, indicating hypoxia-induced hydrolysis of choline-containing phospholipids. This increase of choline release was suppressed by bilobalide, an ingredient of Ginkgo biloba, but not by a mixture of ginkgolides. The EC50 value for bilobalide was 0.38 microM. In ex vivo experiments, bilobalide also inhibited hypoxia-induced choline release when given p.o. in doses of 2-20 mg/kg 1 h prior to slice preparation. The half-maximum effect was observed with 6 mg/kg bilobalide. A similar effect was noted after p.o. administration of 200 mg/kg EGb 761, a ginkgo extract con…
Anti-inflammatory compounds from Sideritis javalambrensis n-hexane extract.
1989
The anti-inflammatory activities of the n-hexane extract of Sideritis javalambrensis and several purified fractions were investigated using the carrageenan mouse paw edema test. Progressive fractionation led to the isolation of the active principles ent-16-hydroxy-13-epimanoyl oxide [1] and esters of tyrosol with palmitic, stearic, behenic, and lignoceric acids.
Bilobalide, a constituent of Ginkgo biloba , inhibits NMDA-induced phospholipase A 2 activation and phospholipid breakdown in rat hippocampus
2000
In rat hippocampal slices superfused with magnesium-free buffer, glutamate (1 mM) caused the release of large amounts of choline due to phospholipid breakdown. This phenomenon was mimicked by N-methyl-D-aspartate (NMDA) in a calcium-sensitive manner and was blocked by NMDA receptor antagonists such as MK-801 and 7-chlorokynurenate. The NMDA-induced release of choline was not caused by activation of phospholipase D but was mediated by phospholipase A2 (PLA2) activation as the release of choline was accompanied by the formation of lyso-phosphatidylcholine (lyso-PC) and glycerophospho-choline (GPCh) and was blocked by 5-[2-(2-carboxyethyl)-4-dodecanoyl-3,5-dimethylpyrrol-1-yl]pentano ic acid, …
1H and 13C NMR signal assignment of synthetic (-)-methyl thyrsiflorin B acetate, (-)-thyrsiflorin C and several scopadulane derivatives.
2005
The 1H and 13C NMR signal assignment of the data of 13 scopadulane-type diterpenes is reported. It was based on one- and two- dimensional NMR techniques which included 1H, 13C, DEPT, HMQC and 1D NOE difference spectroscopy. Copyright © 2005 John Wiley & Sons, Ltd.