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Biomedical subjects

L Minale

Publications and source records attributed to L Minale.

At least 37 records · Page 2Linked to original sources

Starfish saponins, Part 51. Steroidal oligoglycosides from the starfish Distolasterias nipon.

A reinvestigation of the extracts from the starfish Distolasterias nipon, collected at Mutsu Bay, Japan, has led to the isolation of six glycosides of polyhydroxysteroids and six asterosaponins. Four steroidal glycosides have been identified as distolasterosides D1 [1] and D2 [2] (previously isolated from the same organism), and pycnopodioside C [5] and pisasteroside A [6], previously found in the related species Pycnopodia helianthoides and Pisaster ochraceus (family Asteridae), respectively. Two asterosaponins have been identified as the common versicoside A [7] and thornasteroside A [7a]. The two remaining glycosides of polyhydroxysteroids, named distolasterosides D4 [3] and D5 [4], and four asterosaponins designated nipoglycosides A [8], B [9], C [10], and D [11] are new compounds, and their structures have been elucidated mainly by interpretation of spectral data and comparison with known compounds.

Animals↗

Starfish saponins, 52. Chemical constituents from the starfish Echinaster brasiliensis.

This paper reports an analysis of the chemical constituents from the Caribbean starfish Echinaster brasiliensis collected at Grand Bahama Island. This species is completely devoid of cyclic steroidal glycosides, previously isolated from two species of the genus Echinaster in place of the more common penta- and hexa-glycoside steroidal sulfates ("asterosaponins"). Two typical "asterosaponins" and ten glycosides of polyhydroxysteroids were instead isolated in relatively large amounts from E. brasiliensis. The asterosaponins include the known marthasteroside A1 [1] and the new brasiliensoside [2], while the glycosides of polyhydroxysteroids include seven new compounds (six monoglycosides and one diglycoside). The known echinasteroside A, previously found in Echinaster sepositus and in the related Henricia laeviuscula (both belonging to the family Echinasteridae), and laeviusculosides C and I from H. laeviuscula were also isolated. Most of the glycosides from E. brasiliensis are 3-O-beta-xylopyranosides of delta 4-3 beta,6 beta,8,15 alpha,16 beta pentahydroxysteroid aglycones, having different side chains and sometimes a sulfate group at C-15, structural features which are typical of steroidal glycosides from starfishes of the family Echinasteridae. Continuing the analysis of the constituents of E. brasiliensis, we have also isolated a series of anthraquinones, known animal pigments found only in echinoderms and particularly in Crinoidea and in the Echinasteridae family of Asteroidea.

Animals↗

Starfish saponins, 48. Isolation of fifteen sterol constituents (six glycosides and nine polyhydroxysteroids) from the starfish Solaster borealis.

This paper reports a complete steroid glycoside and polyhydroxysteroid analysis of the starfish Solaster borealis, collected at Mutsu Bay, Japan. The glycosides include a new pentaglycoside steroid sulfate ("asterosaponin"), designated solasteroside A [1], two new sulfated 24-O-diglycosides, both with the common 5 alpha-cholesta-3 beta,6 alpha,8,15 alpha, 24-pentaol aglycone, borealosides A [2] and B [3], two new 24-O-(3-O-methyl)xylosides, borealosides C [4] and D [5], having the same aglycone with an additional hydroxy group at 4 beta-position in 5, and the known amurensoside B, previously isolated from Asterias amurensis. Among the polyhydroxysteroid constituents, four (7-10) are new, and five (11-15) have previously been isolated from starfishes.

Animals↗

Biological activity of saponins and saponin-like compounds from starfish and brittle-stars.

Twenty-four saponins and saponin-like compounds, isolated from starfish and brittle-stars, have been tested in four in vitro tests, based upon bacterial and cell tissue cultures. Saponin-like compounds from brittle-stars have previously not been tested for biological activity. In an antibacterial test based on an agar diffusion test, the Gram positive bacterium S. aureus was affected by the polyhydroxylated steroidal glycosides, polyhydroxylated sterols and disulfated sterols. However, none of the 21 compounds tested were active against the Gram negative bacterium E. coli. In a cytotoxicity test all 21 compounds tested influenced the cells at a concentration of 100 micrograms/ml, while the cells were unaffected at 1 microgram/ml. In an antitumor test, 16 compounds were tested on two lymphoma cell lines. Inhibition of cell growth, at a concentration of 5 ng/ml, was seen for three polyhydroxylated sterols, in one cell line. Weak activity was seen in an antiviral test at a concentration of 10 micrograms/ml.

Animals↗

The formation of -cyclohexyl-fatty acids from shikimate in an acidophilic thermophilic bacillus. A new biosynthetic pathway.

Labelled acetate, phenylalanine and shikimic acid were fed to Bacillus acidocaldarius. A high proportion of the (14)C incorporated from acetate and shikimate was recovered in methyl esters from the cell lipids, but such recovery of (14)C from phenylalanine was low. Only the (14)C from shikimate was selectively incorporated into 11-cyclohexylundecanoate and 13-cyclohexyltridecanoate. Degradation of these cyclohexyl-fatty acids showed that shikimate was incorporated as an intact C(7) unit.

Acetates↗