Publications by authors named "Olga Alvarez Colom"

Annonaceous acetogenins represent a class of bioactive compounds whose primary mode of action is the inhibition of NADH-ubiquinone oxidoreductase (Mitochondrial Complex I). Given the potential pesticidal use of these compounds, we evaluated the effects of seven acetogenins: squamocin (1), molvizarin (2), itrabin (3), almuñequin (4), cherimolin-1 (5), cherimolin-2 (6), and tucumanin (7) isolated from Annona cherimolia Mill. against Ceratitis capitata Wiedemann (Tephritidae).

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Ten acetogenins, one of them new, were isolated from leaves and twigs of a Bolivian collection of Annona montana. The new compound that we named tucupentol (1) is a mono-tetrahydrofuran-pentahydroxy-acetogenin. The inhibitory potency of tucupentol (1) on the mitochondrial complex I was evaluated, and this activity was compared with that of the known acetogenins, annonacin-A, cis-annonacin-10-one, aromin, and gigantetronenin, also isolated from this plant material.

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From an Argentine collection of the tropical tree Rollinia emarginata (Annonaceae), vomifoliol, dehydrovomifoliol, blumenol C, loliolide, 7-epiloliolide, vanillin, dihydroactinolide, as well as other common plant constituents were obtained, and identified by their NMR and MS features compared with authentic samples. Antifeedant and toxic actions were exerted to the polyphagous moth Spodoptera frugiperda by the ethanol extract of the plant, at 250 ppm in the larval diet. Additionally, in greenhouse studies, a 200 ppm aqueous solution of the extract produced a post-emergency herbicidal effect on the annual weed common lambsquarter (Chenopodium album).

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Sixteen plant sesquiterpene lactones, thirteen from four species of the Family Asteraceae, and three from a species of Hepaticae, as well as seven annonaceous acetogenins isolated from the seeds of the tropical tree Annona cherimolia (Family Annonaceae), were evaluated for their ability to inhibit or stimulate the production of biofilm by a strain of Pseudomonas aeruginosa. The tested compounds carry a gamma-lactone moiety in their structures. This structural feature is similar to the lactone moiety present in N-acyl homoserine lactones, compounds that play the important role of "quorum sensors" in the mechanisms of biofilm formation observed in many gram-negative bacteria.

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