Chemical and biological investigation of the polar constituents of the starfish Luidia clathrata, collected in the Gulf of Mexico.

Ten new [1-10] and three known [11-13] polyhydroxysteroids were isolated, along with four known asterosaponins [14-17], from the starfish Luidia clathrata, collected from the offshore waters of the northern Gulf of Mexico. The EtOH extracts of this starfish showed feeding-deterrent properties against marine fish, and inhibited the settlement of larvae of barnacles and bryozoans, as well as the growth of several bacteria. The structures of the new compounds were determined by interpretation of their nmr spectral data and by comparison with the spectral data of known compounds. The assignment of the configurations of the side-chain stereogenic centers of compounds 1 and 3-10 were based on the comparison of their nmr data with those of the stereoisomeric model compounds after derivatization with the chiral auxiliary MTPA reagent. Larval settlement assays conducted on ten isolated compounds revealed they are all potent inhibitors of settlement. Two of these isolated compounds inhibited the growth of several bacteria.

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.

Estudo do deterioramento intelectual através da relação vocabulário - progressive matrices

Os autores propõem uma maneira objetiva de analisar quantitativamente, pela relação entre os resultados do pogressive matrices de RAVEN e a tese de vocabulário, o dano causado à eficiência intelectual por doenças mentais ou neurológicas. O estudo se baseia na aplicação dessas provas em cerca de 300 sujeitos de idade compreendida entre 20 e 93 anos e de escolaridade diferente (primária, secundária e superior. (AU)