maximum mussel size recorded in a stomach was 24 mm long. The diet composition of this sea star at M. edulis platensis banks varied according to the seasonal
recruitment and growth of mussels. When young mussels were absent (late fall and
winter), the contribution of cumaceans, other pelecypods and gastropods increased
in the gut contents of A. brasiliensis.
With respect to echinoderms from deeper areas of the ACS, there are only the
faunal inventories of the H.M.S Challenger, Vema and Walther Herwig expeditions (Sladen 1889; Bernasconi 1966b, 1972, 1973b; Bartsch 1982). Recently,
samples taken from a submarine canyon at 365 m depth, around 43°35
0 S and
59°33
0 W, show that echinoderms are diverse and constitute an important part of
the benthic community (18 species, 14 % wet weight). The same species are found
in scallop fishing grounds, with the exception of the brittle star Astrotoma agassizii
(Bremec and Schejter 2010).
11.3.3 Chemical Studies
Secondary metabolites from Echinodermata have been thoroughly investigated for
the past four decades. Members of this phylum contain steroidal and triterpernoidal oligoglycosides and saponins, which are widely diffused in terrestrial plants
but apparently not so common in marine organisms (Burnell and Apsimon 1983;
Minale et al. 1986, 1993, 1995; Stonik and Elyakov 1988; Kalinin et al. 1992,
1996, 2005; D’Auria et al. 1993; Verbist 1993; Stonik et al. 1999; Iorizzi and
Riccio 1999; Kalinin 2000; Iorizzi et al. 2001; Chludil et al. 2002b, 2003a, b;
Maier and Murray 2006; Maier 2008).
Asteroidea
Asterosaponins are steroidal glycosides which share a 3b-O-sulfated,6a-O-glycosylated D
9(11) steroidal skeleton- only one reported structure shows a 12ahydroxy functionality, with different side chains (Yasumoto and Hashimoto 1965).
Twelve asterosaponins have been isolated from four species of sea stars from the
Patagonian coast of Argentina: Luidia ludwigi scotti from SMG, Cosmasterias
lurida and Allostichaster capensis from NG, and Anasterias minuta from SJOG.
Analysis of their chemical structures showed six novel asterosaponins: Cosmasterosides A, B, C and D (from C. lurida) (Roccatagliata et al. 1994) and Anasterosides A (from A. minuta and A. capensis) and B (from A. minuta) (Díaz de
Vivar 2002; Maier et al. 2002) (Fig. 11.5a). The hexaglycoside Anasteroside
A showed antifungal activity against the plant pathogenic fungus Cladosporium
cucumericum. Two additional known saponins were isolated from C. lurida:
Ophidianoside F, previously isolated from Ophidiaster ophidianus (Riccio et al.
1985), as the main component and Forbeside H, previously isolated from Asterias
forbesi (Findlay et al. 1990). Acanthaglycosides B and C, previously isolated from
382
M. I. Brogger et al.
recruitment and growth of mussels. When young mussels were absent (late fall and
winter), the contribution of cumaceans, other pelecypods and gastropods increased
in the gut contents of A. brasiliensis.
With respect to echinoderms from deeper areas of the ACS, there are only the
faunal inventories of the H.M.S Challenger, Vema and Walther Herwig expeditions (Sladen 1889; Bernasconi 1966b, 1972, 1973b; Bartsch 1982). Recently,
samples taken from a submarine canyon at 365 m depth, around 43°35
0 S and
59°33
0 W, show that echinoderms are diverse and constitute an important part of
the benthic community (18 species, 14 % wet weight). The same species are found
in scallop fishing grounds, with the exception of the brittle star Astrotoma agassizii
(Bremec and Schejter 2010).
11.3.3 Chemical Studies
Secondary metabolites from Echinodermata have been thoroughly investigated for
the past four decades. Members of this phylum contain steroidal and triterpernoidal oligoglycosides and saponins, which are widely diffused in terrestrial plants
but apparently not so common in marine organisms (Burnell and Apsimon 1983;
Minale et al. 1986, 1993, 1995; Stonik and Elyakov 1988; Kalinin et al. 1992,
1996, 2005; D’Auria et al. 1993; Verbist 1993; Stonik et al. 1999; Iorizzi and
Riccio 1999; Kalinin 2000; Iorizzi et al. 2001; Chludil et al. 2002b, 2003a, b;
Maier and Murray 2006; Maier 2008).
Asteroidea
Asterosaponins are steroidal glycosides which share a 3b-O-sulfated,6a-O-glycosylated D
9(11) steroidal skeleton- only one reported structure shows a 12ahydroxy functionality, with different side chains (Yasumoto and Hashimoto 1965).
Twelve asterosaponins have been isolated from four species of sea stars from the
Patagonian coast of Argentina: Luidia ludwigi scotti from SMG, Cosmasterias
lurida and Allostichaster capensis from NG, and Anasterias minuta from SJOG.
Analysis of their chemical structures showed six novel asterosaponins: Cosmasterosides A, B, C and D (from C. lurida) (Roccatagliata et al. 1994) and Anasterosides A (from A. minuta and A. capensis) and B (from A. minuta) (Díaz de
Vivar 2002; Maier et al. 2002) (Fig. 11.5a). The hexaglycoside Anasteroside
A showed antifungal activity against the plant pathogenic fungus Cladosporium
cucumericum. Two additional known saponins were isolated from C. lurida:
Ophidianoside F, previously isolated from Ophidiaster ophidianus (Riccio et al.
1985), as the main component and Forbeside H, previously isolated from Asterias
forbesi (Findlay et al. 1990). Acanthaglycosides B and C, previously isolated from
382
M. I. Brogger et al.