Search results for "triterpene"
showing 10 items of 164 documents
Two New Glycosides from Astragalus caprinus
2001
A new glycoside of flavonol (1) and a new glycoside of a cycloartane-type triterpene (2) were isolated from the leaves and the roots of Astragalus caprinus, respectively. Their structures were elucidated in turn by spectroscopic data interpretation as 3-O-[[beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->6)][beta-D-apiofuranosyl(1-->2)]]-beta-D-galactopyranosyl kaempferol (1) and 3-O-(beta-D-xylopyranosyl)-24-O-(beta-D-glucopyranosyl)-20,25-epoxycycloartane-3beta,6alpha,16beta,24alpha-tetrol (2).
Betulinic acid protects against cerebral ischemia–reperfusion injury in mice by reducing oxidative and nitrosative stress
2011
Increased production of reactive oxygen and nitrogen species following cerebral ischemia-reperfusion is a major cause for neuronal injury. In hypercholesterolemic apolipoprotein E knockout (ApoE-KO) mice, 2h of middle cerebral artery (MCA) occlusion followed by 22h of reperfusion led to an enhanced expression of NADPH oxidase subunits (NOX2, NOX4 and p22phox) and isoforms of nitric oxide synthase (neuronal nNOS and inducible iNOS) in the ischemic hemisphere compared with the non-ischemic contralateral hemisphere. This was associated with elevated levels of 3-nitrotyrosine, an indicator of peroxynitrite-mediated oxidative protein modification. Pre-treatment with betulinic acid (50mg/kg/day f…
Betulinic Acid Protects from Ischemia-Reperfusion Injury in the Mouse Retina
2021
Ischemia/reperfusion (I/R) events are involved in the pathophysiology of numerous ocular diseases. The purpose of this study was to test the hypothesis that betulinic acid protects from I/R injury in the mouse retina. Ocular ischemia was induced in mice by increasing intraocular pressure (IOP) to 110 mm Hg for 45 min, while the fellow eye served as a control. One group of mice received betulinic acid (50 mg/kg/day p.o. once daily) and the other group received the vehicle solution only. Eight days after the I/R event, the animals were killed and the retinal wholemounts and optic nerve cross-sections were prepared and stained with cresyl blue or toluidine blue, respectively, to count cells in…
Betulin binds to gamma-aminobutyric acid receptors and exerts anticonvulsant action in mice.
2007
The lupane type pentacyclic triterpenes: lupeol, betulin, and betulinic acid are widely distributed natural compounds. Recently, pharmaceutical compositions from plant extracts (family Marcgraviaceae) containing betulinic acid, have been patented as anxiolytic remedies. To extend our knowledge of the CNS effects of the triterpenes, we suggest here that the chemically related lupeol, betulin and betulinic acid may interact with the brain neurotransmitter gamma-aminobutyric acid (GABA) receptors in vitro and in vivo. Using radioligand receptor-binding assay, we showed that only betulin bound to the GABA(A)-receptor sites in mice brain in vitro and antagonised the GABA(A)-receptor antagonist b…
Effect of triterpenoids on the inflammation induced by protein kinase C activators, neuronally acting irritants and other agents.
2000
In order to establish the mode of the anti-inflammatory activity of triterpenoids, 11 naturally occurring compounds were assayed on mouse ear oedema induced by the protein kinase C activators, mezerein, 12-O-tetradecanoylphorbol-13-acetate (TPA), two 12-deoxyphorbol-13-monoesters (13-tetradecanoate (DPT) and 13-phenylacetate (DPP)) and bryostatin 1, and by resiniferatoxin, xylene and arachidonic acid. The effects on bradykinin-induced paw oedema and on the rat skin inflammation caused by hydrogen peroxide were also examined. The oedema induced by mezerein and DPT was reduced to different extents by the triterpenoids administered epicutaneously (0.5 mg per ear). Against DPT-induced oedema, l…
Pursaethosides A-E, triterpene saponins from Entada pursaetha.
2005
Five new triterpenoid saponins, pursaethosides A-E (1-5), were isolated from the n-BuOH extract of the seed kernels of Entada pursaetha along with the known phaseoloidin. The structures of 1-5 were elucidated mainly by spectroscopic data interpretation and chemical degradation. Pursaethosides C-E (3-5) possess as a common structural feature entagenic acid as aglycon, which is rare among triterpene saponins. Compounds 2-4 and phaesolidin were found to be not cytotoxic when tested against HCT 116 and HT-29 human colon cancer cells.
Information entropy-based classification of triterpenoids and steroids from Ganoderma
2015
Abstract A set of 71 triterpenoid and steroid compounds from Ganoderma were periodically classified using a procedure based on information entropy with artificial intelligence. Six features were used in hierarchical order to classify the triterpenoids and steroids structurally. The phytochemicals belonging to the same group in the periodic table present similar antioxidant activity, and those compounds belonging to the same period exhibit maximum resemblance. The periodic classification is related to the experimental bioactivity and antioxidant potency data that are available in the literature: a steroid with a three-ketone group conjugated with two carbon–carbon double bonds in the right s…
New Biologically Active Triterpene-Saponins fromRandia dumetorum
1990
Two new triterpene-saponins, 3-O-[O-beta-D-glucopyranosyl-(1----4)-O-beta-D-glucopyranosyl-(1----3)-( beta- D-glucuronopyranosyl)]oleanolic acid (1), 3-O-[O-beta-D-glucopyranosyl-(1----6)-O-beta-D-glucopyranosyl- (1----3)-(beta-D-glucuronopyranosyl)]oleanolic acid (2) together with five known saponins (3-7) were isolated from the methanolic extract of the fruits of Randia dumetorum (Retz) Lam. (Rubiaceae). Their structures were established on the basis of chemical and spectral data. The compounds 1, 3, 4, 5 were found to enhance significantly the proliferation of human lymphocytes in vitro. The crude saponin fraction showed haemolytic, molluscicidal, and immunostimulating activities.
Reciprocal regulation of endothelial nitric-oxide synthase and NADPH oxidase by betulinic acid in human endothelial cells.
2007
Nitric oxide (NO) produced by endothelial NO synthase (eNOS) is a protective principle in the vasculature. Many cardiovascular diseases are associated with reduced NO bioactivity and eNOS uncoupling due to oxidative stress. Compounds that reverse eNOS uncoupling and increase eNOS expression are of therapeutic interest. Zizyphi Spinosi semen (ZSS) is one of the most widely used traditional Chinese herbs with protective effects on the cardiovascular system. In human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 cells, an extract of ZSS increased eNOS promoter activity, eNOS mRNA and protein expression, and NO production in a concentration- and time-dependent manner. Maj…
Ursolic acid from the Chinese herb Danshen (Salvia miltiorrhiza L.) upregulates eNOS and downregulates Nox4 expression in human endothelial cells
2007
Danshen, the dried root of Salvia miltiorrhiza Bunge (Lamiaceae), is one of the most commonly used traditional Chinese medicines for cardiovascular indications. In EA.hy 926 cells, a cell line derived from human umbilical vein endothelial cells (HUVEC), an aqueous extract of danshen, and also a methanol extract of the plant, increased eNOS promoter activity, eNOS mRNA and protein expression, as well as endothelial NO production. A dichloromethane extract, in contrast, did not change eNOS gene expression. Thus, the active danshen constituent(s) responsible for eNOS upregulation is (are) hydrophilic and/or alcohol-soluble. One such compound is ursolic acid that significantly increased eNOS ex…