Search results for "TERPENES"
showing 10 items of 470 documents
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.
Stereoselective Synthesis and Cytoselective Toxicity of Monoterpene-Fused 2-Imino-1,3-thiazines
2014
Starting from pinane-, apopinane- and carane-based 1,3-amino alcohols obtained from monoterpene-based β-amino acids, a library of monoterpene-fused 2-imino-1,3-thiazines as main products and 2-thioxo-1,3-oxazines as side-products were prepared via two- or three-step syntheses. When thiourea adducts prepared from 1,3-amino alcohols and aryl isothiocyanates were reacted with CDI under mild conditions, O-imidazolylcarbonyl intermediates were isolated which could be transformed to the desired 1,3-thiazines under microwave conditions. 1,3-Thiazines and 2-thioxo-1,3-oxazine side-products could also be prepared in one-step reactions through the application of CDI and microwave irradiation. The rin…
The Antigerminative Activity of Twenty-Seven Monoterpenes
2010
Made available in DSpace on 2013-08-28T14:11:28Z (GMT). No. of bitstreams: 1 WOS000282221100055.pdf: 183420 bytes, checksum: 31d5a1904cd2424113da7989e2e65f14 (MD5) Made available in DSpace on 2013-09-30T18:36:29Z (GMT). No. of bitstreams: 2 WOS000282221100055.pdf: 183420 bytes, checksum: 31d5a1904cd2424113da7989e2e65f14 (MD5) WOS000282221100055.pdf.txt: 26866 bytes, checksum: 653cedb4f682463998ef7f37cae8dd63 (MD5) Previous issue date: 2010-09-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:48:46Z No. of bitstreams: 2 WOS000282221100055.pdf: 183420 bytes, checksum: 31d5a1904cd2424113da7989e2e65f14 (MD5) WOS000282221100055.pdf.txt: 26866 bytes, ch…
Inhibition of human sPLA2 and 5-lipoxygenase activities by two neo-clerodane diterpenoids
1999
Abstract The inhibitory effect of two neo -clerodane diterpenoids, E -isolinaridial (EI) and its methylketone derivative (EIM), isolated from Linaria saxatilis var. glutinosa , on PLA2 and other enzyme activities involved in the inflammatory process was studied. Both compounds inhibited human synovial sPLA 2 in a concentration-dependent manner with IC 50 values of 0.20 and 0.49 μM, respectively, similar to scalaradial. Besides, these compounds decreased the cell-free 5-lipoxygenase activity and A23187-induced neutrophil LTB 4 biosynthesis. Another function of human neutrophils, such as receptor-mediated degranulation, was also significantly reduced. In contrast, none of the compounds affect…
Cycloamphilectenes, a new type of potent marine diterpenes: inhibition of nitric oxide production in murine macrophages.
2003
The inhibitory effect of a series of 6 cycloamphilectenes, novel marine diterpenes based on amphilectene skeletons and isolated from the Vanuatu sponge Axinella sp., on NO, PGE(2) and TNFalpha production in murine peritoneal macrophages was studied. These compounds reduced potently nitric oxide production in a concentration-dependent manner with IC(50) values in the submicromolar range (0.1-4.3 microM). Studies on intact cells and Western blot analysis showed that the more potent cycloamphilectenes reduced the expression of inducible nitric oxide synthase without affecting cyclo-oxygenase-2 expression. Among them cycloamphilectene 2, the unique compound bearing an exocyclic methylene group,…
Diterpenoids from Tetraclinis articulata that Inhibit Various Human Leukocyte Functions
2003
Ten new compounds, eight of them pimarane derivatives (1-8), together with a menthane dimer (9) and a totarane diterpenoid (10), were isolated from the leaves and wood of Tetraclinis articulata. The structures of 1-10 were established by using spectroscopic techniques, including 2D NMR spectra. Pimaranes 1-5 were found to possess an unusual cis interannular union of the B and C rings, which, from a biogenetic perspective, could be derived from the hydration of a carbocation at C-8. Compounds 4-6 and a mixture of 7 and 11 modulated different human leukocyte functions at a concentration of 10 microM, mainly the degranulation process measured as myeloperoxidase release and, to a lesser extent,…
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…
Dysidotronic acid, a new sesquiterpenoid, inhibits cytokine production and the expression of nitric oxide synthase.
2001
In a previous study, we reported a new bioactive sesquiterpenoid, named dysidotronic acid, to be a potent, selective human synovial phospholipase A(2) inhibitor. Dysidotronic acid is a novel, non-complex manoalide analogue lacking the pyranofuranone ring. We now investigate the effect of this compound on cytokine, nitric oxide and prostanoid generation on the mouse macrophage cell line RAW 264.7, where it showed a dose-dependent inhibition with inhibitory concentration 50% values in the micromolar range. This effect was also confirmed in the mouse air pouch injected with zymosan. Dysidotronic acid inhibited the production of tumor necrosis factor alpha and interleukin-1 beta as well as the …