27686-35-7Relevant articles and documents
Bismuth triflate-catalyzed Wagner-Meerwein rearrangement in terpenes. Application to the synthesis of the 18α-oleanane core and A-neo-18α-oleanene compounds from lupanes
Salvador, Jorge A. R.,Pinto, Rui M. A.,Santos, Rita C.,Le Roux, Christophe,Beja, Ana Matos,Paixao, Jose A.
, p. 508 - 517 (2009)
The use of bismuth(III) salts as catalysts for the Wagner-Meerwein rearrangement of lupane derivatives with expansion of ring E and formation of an additional O-containing ring is reported. This process has also been extended to other terpenes, such as the sesquiterpene (-)-caryophyllene oxide. When the reaction was performed with oleanonic acid, 28,13β-lactonization occurred, without Wagner-Meerwein rearrangement. Under more vigorous reaction conditions, dehydration of the 3β-hydroxyl group and subsequent additional Wagner-Meerwein rearrangement led to the selective synthesis of A-neo-18α-oleanene compounds, in very high yields. The Royal Society of Chemistry 2009.
Isolation, structural modification, and HIV inhibition of pentacyclic lupane-type triterpenoids from cassine xylocarpa and maytenus cuzcoina
Callies, Oliver,Bedoya, Luis M.,Beltrán, Manuela,Mu?oz, Alejandro,Calderón, Patricia Obregón,Osorio, Alex A.,Jiménez, Ignacio A.,Alcamí, José,Bazzocchi, Isabel L.
, p. 1045 - 1055 (2015/06/02)
As a part of our investigation into new anti-HIV agents, we report herein the isolation, structure elucidation, and biological activity of six new (1-6) and 20 known (7-26) pentacyclic lupane-type triterpenoids from the stem of Cassine xylocarpa and root bark of Maytenus cuzcoina. Their stereostructures were elucidated on the basis of spectroscopic and spectrometric methods, including 1D and 2D NMR techniques. To gain a more complete understanding of the structural requirements for anti-HIV activity, derivatives 27-48 were prepared by chemical modification of the main secondary metabolites. Sixteen compounds from this series displayed inhibitory effects of human immunodeficiency virus type 1 replication with IC50 values in the micromolar range, highlighting compounds 12, 38, and 42 (IC50 4.08, 4.18, and 1.70 μM, respectively) as the most promising anti-HIV agents.
Synthesis, structure and cytotoxic activity of new acetylenic derivatives of betulin
Boryczka, Stanislaw,Bebenek, Ewa,Wietrzyk, Joanna,Kempinska, Katarzyna,Jastrzebska, Maria,Kusz, Joachim,Nowak, Maria
, p. 4526 - 4543 (2013/06/26)
A new series of betulin derivatives containing one or two pharmacophores bearing an acetylenic and carbonyl function at the C-3 and/or C-28 positions has been synthesized and characterized by 1H- and 13C-NMR, IR, MS and elemental analyses. The crystal structure of 28-O-propynoylbetulin was determined by X-ray structural analysis. All new compounds, as well as betulin, were tested in vitro for their antiproliferative activity against human SW707 colorectal, CCRF/CEM leukemia, T47D breast cancer, and against murine P388 leukemia and Balb3T3 normal fibroblasts cell lines. Most of the compounds showed better cytotoxicity than betulin and cisplatin used as reference agent. 28-O-Propynoylbetulin was the most potent derivative, being over 500 times more potent than betulin and about 100 times more cytotoxic than cisplatin against the human leukemia (CCRF/CEM) cell line, with an ID50 value of 0.02 μg/mL.
