New cytotoxic beta-carboline alkaloids from the marine bryozoan, Cribricellina cribraria.

Bioactivity-directed separations led to the isolation of the new alkaloid, 1-vinyl-8-hydroxy-beta-carboline [1], as the major cytotoxic component of the marine bryozoan Cribricellina cribraria. Another new beta-carboline alkaloid 2 with the novel sulfone structure was isolated, together with a number of known beta-carboline compounds. Cytotoxicity and antimicrobial effects are reported for these compounds and for other synthesized beta-carbolines.

Seasonally occurring lectins from the bryozoan Bugula neritina.

Two different lectins (termed BnA-I and BnA-II) with distinct carbohydrate specificities were identified and subsequently isolated from the marine bryozoan Bugula neritina. BnA-I hemagglutinating activity was inhibited by N-acetylated hexosamines, their polymers, and glycoproteins rich in these moieties. BnA-II-induced hemagglutination was not blocked by any simple sugars but could be inhibited by several complex glycoproteins (e.g., thyroglobulin and orosomucoid). Both lectins required the presence of Ca(+)+ for reactivity and were purified by affinity chromatographic procedures. Purified BnA-I was determined to have a native molecular weight of 240 Kd and appeared to be a hexameric homopolymer while BnA-II was shown to be a 65-70 Kd monomer. Both lectins showed seasonality in expression, BnA-I appearing in animal extracts prepared in the spring and fall while BnA-II was expressed only during the summer and winter.

[Anti-tumor natural products isolated from marine organisms].

Marine organisms comprise over half a million species. Due to their unusual living environment as compared with terrestrial organisms, marine organisms produce a variety of metabolic substances which often have various unprecedented chemical structures. In recent years, an increasing number of marine natural products have been reported to exhibit various biological activities such as antimicrobial, physiological, and pharmacological ones. Some metabolites have also been noted by their significant toxicities. The effort to find out anti-tumor substances from marine organisms has been also undertaken in recent years, and several novel compounds (e.g. peptide, polyether, alkaloid, prostanoid etc.), with anti-tumor activities, have been isolated from marine sponges, octocorals, marine algae, tunicates, nudibranchs, bryozoans, and so on. In this article, those chemically clarified anti-tumor compounds isolated from marine organisms were reviewed.

Diagnostic positive and negative ion fast atom bombardment mass spectrometry of low-molecular-weight ammonium compounds of marine origin.

Five ammonium compounds--betaine, taurine, homarine, trigonelline and tetramethylammonium chloride--were investigated by positive and negative ion fast atom bombardment (FAB) mass spectrometry. Observation of the parent cation [M + H]+ together with series of clusters (e.g. [nM + H]+, n = 2-5) and fragmentation patterns in the positive FAB mode may be used diagnostically as a fingerprint of the compound. The shifts in mass and relative intensity by addition of trichloroacetic acid and metal salts offer corroborating information of the identity of a compound in a mixture. The FAB negative ion spectra were characterized by clusters incorporating the anion (e.g. [M + Cl]-) but are generally less informative than the spectra obtained in the positive mode.