Biomarkers
Materials and methods
Sponges were collected by hand along the Senegalese coast, on the seashore at low tide (Pseudosuherites sp., A, and Suberites massa, B) or by
scuba diving at depths of 15-35 m (Suberites sp 1 , C, Suberites sp 2 , D, and
Rhizaxinella elongata, E) ( 1987-1997). Sterols were isolated during lipid
class separation (lipid extraction with chloroform-methanol) from
enriched chromatographic fractions eluted by dichloromethane and
purified by crystallization from methanol. The sterol mixtures were
analysed by GC (OV-1, OV-17) and by GC/MS, in free form, or as acetates.
In GC/MS experiments, a non-polar HP-1 column was used (12 m,
0.2 mm i.d., 0.3.3 mm phase thickness). Temperature was programmed
in increments of 7°C.min
-1 from 150 to 300°C. Unusual 24-methyl
sterols were isolated and purified by HPLC (RP-18 column, methanol)
and studied by
1 H-NMR (Bruker AMX-500).
Results and discussion
It should be first noted that all sponge species from borh families were
unreported along the West African coast. Several samples have been
studied at different times of year. As shown below, a number of genera
have not yet been investigated in both families.
Subclass
Order
Family
Tetractinomorpha
Hadromerida
Suberitidae
Aaptos* Caulospongia Cometella Laxosuherites
Poterion Protosuberites Pseudosuherites Rhizaxinella
Suberites Terpios*
Ceractinomorpha
Halichondrida
Halichondriidae
Amorphinopsis Axinyssa Ciocalypta Collocalypta Didiscus
Epipolasus Halichondria Hymeniacidon* Petronica
Pseudaxynissa* Spongosorites Topsentia
* Data available on sterol composition. Sponge classification: Hooper, 1997.
It should be noted rhat all other sponge families investigated to date
(Tetillidae, Axinellidae, Desmoxyidae, Euryponidae, Tedaniidae, Myxillidae) in the same collection sites (1987-1997) had usual sterol compositions, with 15-20 common Δ5 3β-hydroxysterols including cholesterol, brassicasterol, campesterol, poriferasterol and clionasterol as
major components (Barnathan et al., 1992; Barnathan et al., unpublished
results, 1993-1997).
Suberitidae sponge sterols
As shown in table 1, the most striking feature was the great proportion of saturated ring sterols, namely 5α-stanols.
89
Materials and methods
Sponges were collected by hand along the Senegalese coast, on the seashore at low tide (Pseudosuherites sp., A, and Suberites massa, B) or by
scuba diving at depths of 15-35 m (Suberites sp 1 , C, Suberites sp 2 , D, and
Rhizaxinella elongata, E) ( 1987-1997). Sterols were isolated during lipid
class separation (lipid extraction with chloroform-methanol) from
enriched chromatographic fractions eluted by dichloromethane and
purified by crystallization from methanol. The sterol mixtures were
analysed by GC (OV-1, OV-17) and by GC/MS, in free form, or as acetates.
In GC/MS experiments, a non-polar HP-1 column was used (12 m,
0.2 mm i.d., 0.3.3 mm phase thickness). Temperature was programmed
in increments of 7°C.min
-1 from 150 to 300°C. Unusual 24-methyl
sterols were isolated and purified by HPLC (RP-18 column, methanol)
and studied by
1 H-NMR (Bruker AMX-500).
Results and discussion
It should be first noted that all sponge species from borh families were
unreported along the West African coast. Several samples have been
studied at different times of year. As shown below, a number of genera
have not yet been investigated in both families.
Subclass
Order
Family
Tetractinomorpha
Hadromerida
Suberitidae
Aaptos* Caulospongia Cometella Laxosuherites
Poterion Protosuberites Pseudosuherites Rhizaxinella
Suberites Terpios*
Ceractinomorpha
Halichondrida
Halichondriidae
Amorphinopsis Axinyssa Ciocalypta Collocalypta Didiscus
Epipolasus Halichondria Hymeniacidon* Petronica
Pseudaxynissa* Spongosorites Topsentia
* Data available on sterol composition. Sponge classification: Hooper, 1997.
It should be noted rhat all other sponge families investigated to date
(Tetillidae, Axinellidae, Desmoxyidae, Euryponidae, Tedaniidae, Myxillidae) in the same collection sites (1987-1997) had usual sterol compositions, with 15-20 common Δ5 3β-hydroxysterols including cholesterol, brassicasterol, campesterol, poriferasterol and clionasterol as
major components (Barnathan et al., 1992; Barnathan et al., unpublished
results, 1993-1997).
Suberitidae sponge sterols
As shown in table 1, the most striking feature was the great proportion of saturated ring sterols, namely 5α-stanols.
89