74
2. Sterols
investigated by glc and spectral methods and 24f-ethylcholest-7-en-3ß-ol
(26) was the major constituent. Gupta and Scheuer (1968) reported this
sterol as a minor constituent of the echinoderms Acanthaster planci and
Holothuria atra. It was contaminated with some 24-ethylidene-A
7 -cholesterol.
26
4. 24a-ETHYLCHOLESTA-5,22-DiEN-3j8-OL (STIGMASTEROL)
Stigmasterol (27) is an abundant phytosterol readily available from soybeans. Its occurrence as a minor sterol in marine organisms has been demonstrated by Gupta and Scheuer (1968) in the brittlestar Ophiocoma insularia
and in the feather star Antedon sp. Idler et al. (1968) found traces of stigmasterol in some of the red algae that they examined.
/
27
5. 24j3-ETHYLCHOLESTA-5,22-DIEN-3j3-OL (PORIFERASTEROL)
Poriferasterol (28) was first isolated by Valentine and Bergmann (1941)
from the sponges Cliona celata and Spheciospongia vesparia and was considered to be one of the characteristic sterols of the sponges (phylum Porifera).
Lyon and Bergmann (1942) confirmed the proposed structure by Oppenauer
oxidation to an ultraviolet active enone and by ozonization and cleavage
of the side-chain double bond. Again, no recent research has corroborated
either the homogeneity or structure of poriferasterol.
2. Sterols
investigated by glc and spectral methods and 24f-ethylcholest-7-en-3ß-ol
(26) was the major constituent. Gupta and Scheuer (1968) reported this
sterol as a minor constituent of the echinoderms Acanthaster planci and
Holothuria atra. It was contaminated with some 24-ethylidene-A
7 -cholesterol.
26
4. 24a-ETHYLCHOLESTA-5,22-DiEN-3j8-OL (STIGMASTEROL)
Stigmasterol (27) is an abundant phytosterol readily available from soybeans. Its occurrence as a minor sterol in marine organisms has been demonstrated by Gupta and Scheuer (1968) in the brittlestar Ophiocoma insularia
and in the feather star Antedon sp. Idler et al. (1968) found traces of stigmasterol in some of the red algae that they examined.
/
27
5. 24j3-ETHYLCHOLESTA-5,22-DIEN-3j3-OL (PORIFERASTEROL)
Poriferasterol (28) was first isolated by Valentine and Bergmann (1941)
from the sponges Cliona celata and Spheciospongia vesparia and was considered to be one of the characteristic sterols of the sponges (phylum Porifera).
Lyon and Bergmann (1942) confirmed the proposed structure by Oppenauer
oxidation to an ultraviolet active enone and by ozonization and cleavage
of the side-chain double bond. Again, no recent research has corroborated
either the homogeneity or structure of poriferasterol.