ABSTRACT
Total ceramides containing nonbranched and iso-branched C18- and C19-phytosphingosines acylated with non-hydroxylated fatty acids were isolated from a marine sponge Oceanapia sp. The structures of these compounds were determined by HPLC, NMR, MALDI-TOF MS, and GLC-MS of the Me3Si derivatives and by chemical transformations. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2006, vol. 32, no. 3; see also http://www.maik.ru.
Subject(s)
Ceramides/analysis , Porifera/chemistry , Sphingosine/analogs & derivatives , Animals , Ceramides/chemistry , Magnetic Resonance Spectroscopy , Molecular Structure , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Sphingosine/analysis , Sphingosine/chemistryABSTRACT
The transglycosylation reaction catalyzed by endo-1,3-beta-D-glucanase LIV from the marine mollusk Spisula sachalinensis was studied with the goal of preparing p-nitrophenyl (Np) 1,3- and 1,3; 1,6-D-glucooligosides. As donors we used the 1,3;1,6-beta-D-glucans with various content of beta-1, 6-glucoside bonds: laminarians [from Laminaria cichorioides (10%), L. gurjanovae (2%), and Fucus evanescens (35%)] and translam (25%); as acceptor we used the p-nitrophenyl beta-D-glucoside (GNp). The maximal yield of the transglycosylation products was found when using laminaran from Laminaria cichorioides; donors with a lower or higher content of beta-1,6-glucoside bonds were less efficient. The laminaran from F. evanescens and translam gave no Np-laminaribioside. At optimal conditions (10 mg/ml of laminaran from L. cichorioides and 5 mg/ml of GNp), maximal yields of Np-laminaribioside, Np-trioside, Np-tetraoside, and Np-pentaoside were 19, 8, 3, and 1%, respectively. The first two compounds were isolated by chromatography on silica gel, their physicochemical characteristics were obtained, and their structures were established by 13C NMR spectroscopy.
Subject(s)
Glucan Endo-1,3-beta-D-Glucosidase/chemistry , Mollusca/enzymology , Oligosaccharides/chemical synthesis , Animals , Chromatography, Gel , Chromatography, High Pressure Liquid , Glucans/chemistry , Glycosylation , Laminaria/chemistry , Magnetic Resonance Spectroscopy , Nitrophenols/chemistry , Polysaccharides/chemistry , Substrate SpecificityABSTRACT
Biological activity of kurilostatin (KS), an unusual alkaloid from the sea sponge was studied. KS was shown to exert a strong cytostatic effect upon tumor cells and activated lymphocytes by mitogen. However it does not display any antitumoral activity in vivo. KS was found to induce release of free [Ca2+] from the above mentioned cells. This process is probably the basis of the cytostatic effect mechanism of KS.
