Abstract:
In English:
In accord with the proposed objectives, new secondary metabolites from diverse
Antarctic marine organisms were isolated and their chemical structures were
characterized. For these substances we have proposed biogenetic routes,
analyzed the biological activity of the natural products and that of several of
their synthetic derivatives, and carried out structural type-habitat
correlation
... studies.
From the chemical study of Pantoneura plocamioides, a species whose habitat is
exclusively Antarctic and subantarctic, a significant number of halogenated and
poly oxygenated marine monoterpenes representing three new structural types
were isolated. From an initial study of Pantoneura plocamioides, collected at
King George Island, six compounds, pantofuranoids A-F, were characterized. The
study of a further collection of the alga afforded pantopyranoids A-C and
pantoisofuranoids A-C, in addition to polyhydroxylated acyclic monoterpenes
named pantoneurotriols A-B, biogenetic precursors of the pantofuranoids. For
the first time in a species of family Bonnemaisoniaceae, Delisea pulchra (=
fimbriata), substances were found that represent the three carbonated skeletons
characterized from the different genera of the family.
Noteworthy are the fimbrolides, which are halogenated furanones structurally
similar to the N-acyl-homoserine lactones (AHLs or auto inducers I) of a
bacterial origin. AHLs constitute a family of signaling molecules that act as
behavior regulators of a bacterial community in a process known as Quorum
sensing (QS). The natural furanones of D. pulchra act as AHL antagonists and
defend D. pulchra from extensive bacterial colonisation by regulating the
virulence factor required for the infection.
Nematoflustra flagelata is the first Antarctic bryozoan to be chemically
studied. An anthraquinonic-type halogenated metabolite was obtained whose
chemical structure is unusual among the structural models isolated until now
from these organisms.
En Espanol:
De acuerdo con los objetivos planteados se aislaron y caracterizaron las
estructuras quimicas de nuevos metabolitos secundarios de la diversidad marina
antartica. Para estas sustancias hemos propuesto rutas biogeneticas, analizado
la actividad biologica de los productos naturales y de algunos de sus derivados
sinteticos, y efectuado estudios de correlacion habitat-tipos estructurales.
Del estudio quimico de la Pantoneura plocamioides, que es una especie de
habitat exclusivamente antartico y subantartico, se aislaron un numero
importante de monoterpenos marinos halogenados y polioxigenados que representan
tres nuevos tipos estructurales. De un primer estudio de Pantoneura
plocamioides, recolectada en la Isla Rey Jorge, se caracterizaron seis
productos, pantofuranoides A-F. El estudio de una nueva recoleccion del alga
permitio obtener pantopiranoides A-C y pantoisofuranoides A-C, asi como
monoterpenos aciclicos polihidroxilados denominados pantoneurotrioles A-B
precursores biogeneticos de los pantofuranoides.
Por primera vez en una especie de la familia Bonnemaisoniaceae, la Delisea
pulchra (= fimbriata), se encontraron sustancias que representan los tres
esqueletos carbonados caracterizados de los distintos generos de la familia.
Destacan los fimbrolidos que son furanonas halogenadas estructuralmente
similares a las N-acil-homoserina lactonas (AHLs o auto inductor I) de origen
bacteriano. AHLs configuran una familia de moleculas se-ales que actuan como
reguladoras del comportamiento de una comunidad bacteriana in un proceso
denominado Quorum sensing (QS). Las furanonas naturales de D. pulchra actuan
como antagonista de AHL y defienden a la D. pulchra contra una cpolonizacion
bacteriana extensiva mediante la regulacion del factor de virulencia requerido
para la infeccion.
Nematoflustra flagelata es el primer briozoo antartico que se estudia
quimicamente. Obtuvimos un metabolito halogenado de naturaleza antraquinonica
cuya estructura quimica es inusual entre los modelos estructurales hasta ahora
aislados en estos organismos. 
