161561-86-0Relevant academic research and scientific papers
(-)-Tarchonanthuslactone: Design of New Analogues, Evaluation of their Antiproliferative Activity on Cancer Cell Lines, and Preliminary Mechanistic Studies
Toneto Novaes, Luiz Fernando,Martins Avila, Carolina,Pelizzaro-Rocha, Karin Juliane,Vendramini-Costa, Débora Barbosa,Pereira Dias, Marina,Barbosa Trivella, Daniela Barreto,Ernesto De Carvalho, Jo?o,Ferreira-Halder, Carmen Veríssima,Pilli, Ronaldo Aloise
, p. 1687 - 1699 (2015/10/06)
Natural products containing the α,β-unsaturated δ-lactone skeleton have been shown to possess a variety of biological activities. The natural product (-)-tarchonanthuslactone (1) possessing this privileged scaffold is a popular synthetic target, but its biological activity remains underexplored. Herein, the total syntheses of dihydropyran-2-ones modeled on the structure of 1 were undertaken. These compounds were obtained in overall yields of 17-21 % based on the Keck asymmetric allylation reaction and were evaluated in vitro against eight different cultured human tumor cell lines. We further conducted initial investigation into the mechanism of action of selected analogues. Dihydropyran-2-one 8 [(S,E)-(6-oxo-3,6-dihydro-2H-pyran-2-yl)methyl 3-(3,4-dihydroxyphenyl)acrylate], a simplified analogue of (-)-tarchonanthuslactone (1) bearing an additional electrophilic site and a catechol system, was the most cytotoxic and selective compound against six of the eight cancer cell lines analyzed, including the pancreatic cancer cell line. Preliminary studies on the mechanism of action of compound 8 on pancreatic cancer demonstrated that apoptotic cell death takes place mediated by an increase in the level of reactive oxygen species. It appears as though compound 8, possessing two Michael acceptors and a catechol system, may be a promising scaffold for the selective killing of cancer cells, and thus, it deserves further investigation to determine its potential for cancer therapy. Fighting the big C: We describe the synthesis of a new family of analogues based on the scaffold of the natural product (-)-tarchonanthuslactone; these compounds were evaluated in vitro against tumor cell lines. We further conducted an initial investigation into the mechanism of action, including the inhibition of phosphatases and glutathione-S-transferase and the production of reactive oxygen species.
Coibacins a and b: Total synthesis and stereochemical revision
Carneiro, Vania M. T.,Avila, Carolina M.,Balunas, Marcy J.,Gerwick, William H.,Pilli, Ronaldo A.
, p. 630 - 642 (2014/04/03)
The interface between synthetic organic chemistry and natural products was explored in order to unravel the structure of coibacin A, a metabolite isolated from the marine cyanobacterium cf. Oscillatoria sp. that exhibits selective antileishmanial activity and potent antiinflammatory properties. Our synthetic plan focused on a convergent strategy that allows rapid access to the desired target by coupling of three key fragments involving E-selective Wittig and modified Julia olefinations. CD measurements and comparative HPLC analyses of the natural product and four synthetic stereoisomers led to determination of its absolute configuration, thus correcting the original assignment at C-5 and unambiguously establishing those at C-16 and C-18. Additionally, we synthesized coibacin B on the basis of the assignment of configuration for coibacin A.
A concise and efficient synthesis of spiroketals - Application to the synthesis of SPIKET-P and a spiroketal from bactrocera species
Tomas, Loic,Bourdon, Benjamin,Caille, Jean Claude,Gueyrard, David,Goekjian, Peter G.
, p. 915 - 920 (2013/03/28)
We report the synthesis of spiroketals by sequence of enol ether synthesis and cyclization. The enol ethers were prepared from lactones by a Julia olefination reaction, and the starting chiral lactone was prepared from an industrial intermediate. This route is a concise and efficient way to synthesize naturally occurring and biologically interesting spiroketals. We used this sequence for the preparation of SPIKET-P and a spiroketal from Bactrocera species. Copyright
Role of conformational effects on the regioselectivity of macrocyclic INOC reactions: Two new asymmetric total syntheses of (+)-brefeldin A
Kim, Deukjoon,Lee, Jongkook,Phil, Jong Shim,Joong, Inn Lim,Doi, Takayuki,Kim, Sanghee
, p. 772 - 781 (2007/10/03)
We have gained some insight into the role of conformational effects on the regioselectivity of the macrocyclic intramolecular nitrile oxide cycloaddition observed in our (+)-brefeldin A synthesis. During the course of this regiochemical study, we have developed two novel stereoselective and regioselective schemes for total synthesis of (+)-brefeldin A (i.e. intramolecular nitrile oxide cycloaddition - isomerization and intermolecular nitrile oxide cycloaddition - ring closing metathesis strategies).
