Search results for "Triterpene"
showing 10 items of 164 documents
Cycloartane-type Glycosides from Two Species of Astragalus (Fabaceae)
2009
Three known cycloartane-type glycosides were isolated from the roots of two different species of Astragalus, A. glycyphyllos, A. sempervirens. The identification of these compounds were mainly achieved by 2D NMR spectroscopic techniques and FAB-MS. The results of our studies confirm that triterpene saponins from the cycloartane-type skeleton might be chemotaxonomically significant to the genus Astragalus.
Phytochemistry of Weigela x “kosteriana variegata” (Caprifoliaceae)
2018
One new triterpene glycoside 3- O-β-D-xylopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→3)]-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid, was isolated from Weigela x “kosteriana variegata” (Caprifoliaceae), with three known ones. Their structures were characterized by a combination of mass spectrometry and 1D and 2D NMR spectrocopic techniques including 1H- and 13C NMR, COSY, TOCSY, NOESY, HSQC, and HMBC experiments. The toxicological properties of some glycosides were determined with a zebrafish-based assay. The results show that the most active compounds were toxic to the larvae in the range of 1 μM.
Triterpene Saponins from the Fruits of Phytolacca rugosa (Phytolaccaceae)
2010
Four known serjanic acid glycosides were isolated from the fruits of Phytolacca rugosa and characterized mainly by 2D NMR spectroscopy and mass spectrometry. This aglycon has a chemotaxonomic significance for the genus Phytolacca.
Study of the influencing effect of pigments on the photoageing of terpenoid resins used as pictorial media
2006
Abstract Terpenoid resins have been mainly used as components of pictorial varnishes and binding media from ancient times. In such latest instances, the resin is mixed with pigments affecting its physical and chemical properties. A new procedure based on gas chromatography–mass spectrometry (GC/MS) has been applied, in this work, in combination with Fourier transform infrared spectroscopy (FTIR), with the aim of determining the changes undergone by di- and triterpenoid resins employed as components of binding media. The GC/MS method is based on the derivatisation of these resins using trimethylsilylimidazol. Characterization of the main components of the di- and triterpenoid fractions and t…
Phytochemical Studies on Ptilostemon greuteri Raimondo & Domina (Compositae)
2012
Ptilostemon greuteri Raimondo & Domina is described as a new species and its growth is limited to the area of the province of Trapani. Essential oils of aerial parts of P. greuteri were analized by gas chromatography-mass spectrometry (GC-MS). The analysis of acetonic extract of aerial parts led to identification of triterpenes components: α-amyrin, β-amyrin, α-amyrin acetate, β-amyrin acetate, lupeol, lupeol acetate and taraxasterol. CC and preparative TLC of acetonic extracts has yielded lignan lactone and a sesquiterpene lactone that have been isolated previously from other Ptilostemon species.
New tyrosinase inhibitors selected by atomic linear indices-based classification models.
2005
In the present report, the use of the atom-based linear indices for finding functions that discriminate between the tyrosinase inhibitor compounds and inactive ones is presented. In this sense, discriminant models were applied and globally good classifications of 93.51% and 92.46% were observed for non-stochastic and stochastic linear indices best models, respectively, in the training set. The external prediction sets had accuracies of 91.67% and 89.44%. In addition, these fitted models were used in the screening of new cycloartane compounds isolated from herbal plants. A good behavior is shown between the theoretical and experimental results. These results provide a tool that can be used i…
Synthesis, computational docking and biological evaluation of celastrol derivatives as dual inhibitors of SERCA and P-glycoprotein in cancer therapy.
2021
Abstract A series of eleven celastrol derivatives was designed, synthesized, and evaluated for their in vitro cytotoxic activities against six human cancer cell lines (A549, HepG2, HepAD38, PC3, DLD-1 Bax-Bak WT and DKO) and three human normal cells (LO2, BEAS-2B, CCD19Lu). To our knowledge, six derivatives were the first example of dipeptide celastrol derivatives. Among them, compound 3 was the most promising derivative, as it exhibited a remarkable anti-proliferative activity and improved selectivity in liver cancer HepAD38 versus human normal hepatocytes, LO2. Compound 6 showed higher selectivity in liver cancer cells against human normal lung fibroblasts, CCD19Lu cell line. The Ca2+ mob…
Cucurbitacin R Reduces the Inflammation and Bone Damage Associated with Adjuvant Arthritis in Lewis Rats by Suppression of Tumor Necrosis Factor-α in…
2006
The aim of this study was to investigate the effects of cucurbitacin R on an experimental model of adjuvant-induced arthritis in rats. The treatment of arthritic rats with cucurbitacin R (1 mg/kg p.o. daily) modified the evolution of the clinical symptoms, whereas the histopathology of paws demonstrated a reduction in the signs of arthritis. Compared with the control group, radiography of the tibiotarsal joints of cucurbitacin R-treated rats showed a decrease in joint damage and soft tissue swelling of the footpad. The in vivo study of the expression of proinflammatory enzymes (nitric-oxide synthase-2 and cyclooxygenase-2) with the aid of the Western blot technique, and that of tumor necros…
Cytotoxic Acacic Acid Glycosides from the Roots of Albizia coriaria
2009
Two new oleanane-type saponins, coriariosides A (1) and B (2), along with a known saponin, gummiferaoside C (3), were isolated from the roots of Albizia coriaria. Their structures were established by extensive analysis of 1D and 2D NMR experiments (COSY, ROESY, TOCSY, HSQC, and HMBC) and mass spectrometry. Compounds 1 and 3 when tested for cytotoxicity against two colorectal human cancer cells showed activity against the HCT 116 (IC50 4.2 microM for 1 and 2.7 microM for 3) and HT-29 (IC50 6.7 microM for 1 and 7.9 microM for 3) cell lines.
Arboreasides A−E, Triterpene Saponins from the Bark of Cussonia arborea
2009
Five new triterpene saponins, arboreasides A-E (1-5), and two known saponins, ciwujianoside C(3) and 23-hydroxyursolic acid 28-O-alpha-L-rhamnopyranosyl-(1--4)-beta-D-glucopyranosyl-(1--6)-beta-D-glucopyranosyl ester, were isolated from the bark of Cussonia arborea. The structures were established using extensive 1D and 2D NMR spectroscopic analyses and mass spectrometry.