Search results for "Acetogenin"
showing 10 items of 23 documents
10-Oximeguanacone, the First Nitrogenated Acetogenin Derivative Found To Be a Potent Inhibitor of Mitochondrial Complex I
1998
A new 10-keto bis-tetrahydrofuran acetogenin, guanacone (1), has been isolated from a cytotoxic extract of Annona aff. spraguei seeds. The 10-oximeguanacone derivative 1f is the first bioactive nitrogenated acetogenin found to be a very potent inhibitor of complex I. In addition, a SAR study of guanacone analogues is reported based on the titration of the NADH oxidase and NADH:ubiquinone oxidoreductase activities.
New method for the determination of the absolute stereochemistry in antitumoral annonaceous acetogenins
1998
Abstract The absolute configurations at the carbinol centers in several acetogenins were determined through p-bromophenylurethane derivatives and subsequent Mosher ester methodology. This method has been applied on α,α′-dihydroxylated adjacent bis-THF acetogenins with a threo/cis/threo/cis/erythro relative configuration membrarollin (1), a new acetogenin isolated from Rollinia membranacea seeds, rollimembrin (2), membranacin (3) and rolliniastatin-1 (4), and a threo/trans/threo/translerythro relative configuration motrilin (5), squamocin (6), and desacetyluvaricin (7). 1 was found to be the most potent inhibitor of the mammalian mitochondrial complex I.
Tripoxyrollin, a New Epoxy Acetogenin from the Seeds ofRollinia membranacea1
1993
Abstract A new epoxy acetogenin, tripoxyrollin (1), has been isolated from the seeds of the Colombian Annonaceae, Rollinia membranacea. Its structure was elucidated on the basis of spectral data. Biomimetic synthesis of isodesacetyluvaricin (2) from tripoxyrollin (1) suggests its key role in the biogenesis of the adjacent bis-tetrahydrofuran acetogenins.
Guanaconetins, new antitumoral acetogenins, mitochondrial complex I and tumor cell growth inhibitors
2005
The antitumoral activity of a series of acetylated bis-tetrahydrofuranic acetogenins with a threo/trans/threo/trans/erythro relative configuration was characterized by four new natural and two semisynthetic, 15,24,30-trioxygenated acetogenins that were found to inhibit mitochondrial complex I enzyme as well as growth of several tumor cell lines. Placement of acetyl groups along the alkyl chain modulated the potency of the bis-tetrahydrofuranic acetogenins and could be important for future utilization of these compounds as chemotherapeutic agents.
Cherimolin-1, New Selective Inhibitor of the First Energy-Coupling Site of the NADH:Ubiquinone Oxidoreductase (Complex I)
1997
The mechanism linking electron transport to proton translocation in the NADH:ubiquinone oxidoreductase (complex I of the mitochondrial respiratory chain) is still unclear. Inhibitors acting at different sites of the enzyme are powerful tools to clarify this mechanism. Up to now, a unique inhibitor, the Annonaceous acetogenin rolliniastatin-2, selectively blocks the most internal proton-translocation site. This study introduces cherimolin-1, a new acetogenin that inhibits the complex I with this special mode of action, which is more easily available from the plant material. Moreover, the mode of action of this scarce type of complex I inhibitor is further characterized.
Tucumanin, a β-hydroxy-γ-lactone bistetrahydrofuranic acetogenin from Annona cherimolia, is a potent inhibitor of mitochondrial complex I
2004
A new β-hydroxy-γ-methyl-γ-lactone bistetrahydrofuranic acetogenin, tucumanin, with the infrequent symmetrical threo/trans/threo/trans/ threo relative configuration at the tetrahydrofuran rings was isolated from Annona cherimolia (Annonaceae) seeds. The inhibitory potency on the mitochondrial complex I of acetogenins with this relative configuration (tucumanin and asimicin) was compared with that shown by the corresponding pairs with an asymmetrical threo/trans/threo/trans/erythro relative configuration (laherradurin/rolliniastatin-2, and itrabin/molvizarin). All these compounds act as selective inhibitors of mitochondrial complex 1 in the 0.18 - 1.55 nM range. Fil: Barrachina, Isabel. Univ…
Kinetic characterization of mitochondrial complex I inhibitors using annonaceous acetogenins
1999
The NADH:ubiquinone oxidoreductase (complex I) of the mitochondrial respiratory chain is by far the largest and most complicated of the proton-translocating enzymes involved in the oxidative phosphorylation. Many clues regarding the electron pathways from matrix NADH to membrane ubiquinone and the links of this process with the translocation of protons are highly controversial. Different types of inhibitors become valuable tools to dissect the electron and proton pathways of this complex enzyme. Therefore, further knowledge of the mode of action of complex I inhibitors is needed to understand the underlying mechanism of energy conservation. This study presents for the first time a detailed …
Nuevos fármacos inspirados en Annonáceas
2014
Los metabolitos secundarios activos (MSA) juegan un papel importante en el descubrimiento de nuevos medicamentos. Moléculas naturales con esqueletos complejos, tales como las estatinas aisladas de Aspergillus terreus, o las acetogeninas específicas de la familia Annonaceae, no hubieran podido ser inventadas en ningún laboratorio. Los MSA aislados en Annonaceae, especialmente las acetogeninas y los alcaloides isoquinoleínicos, pueden ser considerados como fuente constante de inspiración para químicos, farmacólogos y para todos los investigadores interesados en el descubrimiento de una nueva familia de medicamentos. Active secondary metabolites (ASM) play a highly significant role in the drug…
Natural acetogenins from annonaceae, synthesis and mechanisms of action
1998
The search concerning Annonaceous acetogenins has increased in the last two years. The goal of the present review is to summarize the knowledge about new isolated acetogenins as well as the advances in synthesis, biological activity and mechanism of action.
Acetogenins from Annonaceae
1997
In 1982, Jolad et al. isolated uvaricin, a new antitumor agent, from the roots of Uvaria acuminata (Annonaceae), a bis-tetrahydrofuranoid fatty acid lactone (1) related to polyketides or acetogenins. However, it contained a number of original structural characteristics, particularly a linear acetogenin, a bis-tetrahydrofuran pattern flanked by hydroxyls and a terminal unsaturated lactone. Two years later, Dabrah and Sneden (2, 3 and Cortes et al. (4) described four new products presenting the same structural characteristics. Because these products formed a new class of natural compounds, and are only found in species belonging to the family of Annonaceae, they are commonly called acetogenin…