Marine invertebrates are a promising source of novel natural products with biological activities. The phylum Bryozoa is relatively under-investigated in this context, although a number of compounds with medical potential has been discovered in recent years. Here, we report on the novel group of brominated metabolites from the bryozoan Terminoflustra membranaceatruncata, including analysis of biological activities of the tribrominated terminoflustrindole A (Cm-1) and the structures of the related dibrominated variants terminoflustrindoles B and C. Terminoflustrindole A was previously shown to have fungicidal properties. Although they vary by just one bromine group in each case from terminoflustrindole A, in this study, we report that terminoflustrindoles B and C exhibit no antimicrobial activity in the same assays. In addition to displaying antifungal activity, Terminoflustrindole A was also found to exhibit potent cytotoxic activity when tested against tumour cell lines. The gradient distribution of this compound within the bryozoan colony was demonstrated using LC-MS-analysis.

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Bryozoans are typical modular organisms. They consist of repetitive structural units, the zooids. Bryozoan colonies grow by zooidal budding, with the distribution pattern of the budding loci underlying the diversity of colony forms. Budding is usually restricted to the colony periphery, where a "growing edge" or local terminal growth zones are formed. Non budding parts of the colony can be functionally subdivided, too. In many species colonies consist of regular, often repetitive zones of feeding and non feeding modules, associated with a periodical degeneration and regeneration of the polypide retractile tentacle crown with a gut and the accompanying musculature. The mechanisms of functional differentiation in bryozoan colonies are unknown. Presumably, budding and/or polypide recycling are induced or inhibited by certain determi nants of functional specialization in different colony parts. An effective tool of their identification is the com parison of proteomes in functionally different zones. Here we report the results of proteomic analysis of three bryozoan species from the White Sea with a different colony form: Flustrellidra hispida, Terminoflus tra membranaceotruncata and Securiflustra securifrons. Using differential two dimensional electrophoresis (2D DIGE), we compared proteomes of the growing edge, the zone with polypides and the zone without polypides. We assessed the general level of differences between the zones and revealed proteins whose relative abundance changed gradually along the proximal distal colony axis. These proteins might be involved in the determination of the functional differentiation of the colony.

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