- Maslinic acid derivatives induce significant apoptosis in b16f10 murine melanoma cells
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Maslinic acid (2α,3β-dihydroxyolean-12-en-28-oic acid), a natural dihydroxylated pentacyclic triterpene acid isolated from olive-pressing residues, has been investigated together with some of its derivatives regarding the induction of apoptosis in B16F10 melanoma cells. Some of the compounds tested are described in this work, but others come from previous studies. Ten of these derivatives induce over 80% of apoptosis, clearly promoting cell death in B16F10 melanoma. By contrast, the induction cell death through necrosis was very slightly significant with these compounds. These results indicate that maslinic acid derivatives are promising chemopreventive and chemotherapeutic agents.
- Parra, Andres,Rivas, Francisco,Martin-Fonseca, Samuel,Garcia-Granados, Andres,Martinez, Antonio
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experimental part
p. 5991 - 6001
(2012/01/02)
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- Epoxides, cyclic sulfites, and sulfate from natural pentacyclic triterpenoids: Theoretical calculations and chemical transformations
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Several triterpenic derivatives, with the A-ring functionalized, were semisynthesized from oleanolic and maslinic acids. The reactivities of sulfites, sulfate, and epoxides in these triterpene compounds were investigated under different reaction conditions. Moreover, contracted A-ring triterpenes (five-membered rings) were obtained, by different treatments of the sulfate 7. From the epoxide 8, deoxygenated and halohydrin derivatives were semisynthesized with several nucleophiles. Ozonolysis and Beckmann reactions were used to yield 4-aza compounds, from five-membered ring olanediene triterpenes. The X-ray structure of sulfate 7 is given and compared with density functional theory geometries. Theoretical 13C and 1H chemical shifts (gauge-invariant atomic orbital method at the B3LYP/6-31G*//B3LYP/6-31G* level) and 3JH,H coupling constants were calculated for compounds 5-9 and 34-36, identifying the (R)- or (S)-sulfur and α- or β-epoxide configurations together with 4-aza or 3-aza structures.
- Garcia-Granados, Andres,Lopez, Pilar E.,Melguizo, Enrique,Moliz, Juan N.,Parra, Andres,Simeo, Yolanda,Dobado, Jose A.
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p. 4833 - 4844
(2007/10/03)
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- STUDIES ON OXIDATI0N OF TRITERPENOIDS: PART VII. TRANSFORMATION OF OLEANANE AND URSANE SKELETONS TO 11α,12α-OXIDOTRITERPENOIDS WITH HYDROGEN PEROXIDE AND SELENIUM DIOXIDE AND THEIR CARBON-13 NMR DATA.
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Hydrogen peroxide-selenium dioxide in t-butanol has been found to be a good reagent for the preparation of 11α,12α-oxidotriterpenoids of oleanane and ursane skeletons; whereas α-amyrin and β-amyrin acetates furnished 11α,12α-epoxyurs-14-en-3β-yl acetate (4c) and 11α,12α-epoxytaraxer-14-en-3β-yl acetate (4a) respectively, uvaol and ursolic acid/methyl ester gave 11α,12α-epoxyurs-28->13-olide-3β-ol (5d); erythrodiol (3c) and oleanolic acid (3b)/methyl ester (3d) afforded 11α,12α-epoxy-oleanan-28->13-olide-3β-ol (5); olean-12-en-2α,3β,28-yl triacetate (3j) on similar reaction furnished 11α,12α-epoxytaraxer-14-en-3β-ol-2α,28-yl diacetate (4d) and 11α,12α-epoxytaraxer-14-en-2α,3β-diol-28-ylacetate (4e).
- Pradhan, Bhim Prasad,Chakraborty, Satyajit,Weyerstahl, Peter
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p. 4487 - 4496
(2007/10/02)
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