The cyanobacteria-containing Caribbean sponge, Calyx cf. podatypa, was collected from three sites in the Bahamas. In each of the three collections, a polar solvent partition fraction contained six known compounds including five diketopiperazines [1-4,6] and phenylacetic acid, along with a new diketopiperazine, cyclo-(4-methyl-R-proline-S-norvaline) [5]. Interestingly, all six diketopiperazines are proline-derived cyclic dipeptides. This is the first example for this class of peptide derivative to be isolated from a Calyx sponge. Parallel studies of one of the sponge collections in which the ectosome (cyanobacteria-rich) was separated from the endosome (no cyanobacteria) revealed no significant differences in their content of diketopiperazines.

3403L) during 5-6 h of stirring. The extract was evaporated under vacuum, yielding an oily residue (9 g), which was redissolved in methylene chloride-methanol (191,20 mL) and fractionated on a column (200 mL) of E.M. silica gel 60 (230-400 mesh) packed in hexanemethylene chloride (1:l). Elution of the column was carried out by a step gradient of methylene chloride in hexane yielding partially purified compound in the 80% methylene chloride fractions. After evaporation of the solvent under reduced pressure, the residue (600 mg) was taken up in methanol (4 mL). Upon refrigeration, a precipitate formed which was removed by filtration. The filtrate was further fractionated in two identical runs (2 mL each) on a Rainin Dynamax 60A C1a column (1 in. X 25 cm), eluted with a 15 mL/min gradient of acetonitrile-water (713 to 91) over 40 min. Appropriate fractions were evaporated to dryness, yielding variecolin (95 mg); the homogeneity was verified by HPLC (Whatman Partisil ODs-3) eluted with acetonitrileH20 (3:1, k'5.2) and by TLC on silica gel 60 Fm (E. Merck) (R, 0.40 in CHzClz and R, 0.52 in hexane-acetone, 41) and Whatman KC18 plates (R, 0.43 in ACN-H20, %lo, and R, 0.50 in MeOH-H20, 955).Variecolin (1): [aID -11.5O (c 0.50, ACN); EI-MS mlz 360This paper reports the bioactive constituents of Fascaplysinopsis reticulata collected from the Benga Lagoon of the Fiji islands. The previous literature of this genus includes two aplysinopsins (monomeric tryptophans) from F. reticulata, as well as fascaplysin (Sa) (an apparent tryptophan dimer) and luffariellolide (3) (a seaterterpene) from Fascaplysinopsis sp. Our investigation of F. reticulata has revealed new seaterterpenes isodehydroulTarieUolide (1) and dehydroluffariellolide diacid (2); unique alkaloid-sesterterpene salts fascaplysin A (5b) [fascaplysin cation/dehydroluffariellolide diacid anion] and homofascaplysin A cation/dehydroluffariellolide diacid anion (6); and novel neutral alkaloids homofascaplysin C (7), homofascaplysin B (8), and secofascaplysin A (9). These substances were accompanied by fascaplysin (Sa) and the known alkaloid (+)-&pamine 4. The most important findings in this study are (a) fascaplysin derivative 5b is the first known salt comprised of a complex alkaloid cation and a terpene carboxylate anion, and (b) secofascaplysin A (9) is the first naturally occurring @xrbolinone. An amino acid biogenesis pathway is outlined for each of the above alkaloids. The biological activity profile against the HIV reverse transcriptase is reported for selected metabolites.Nitrogen-containing metabolites are rarely observed from Dictyoceratid sponges as this group is an excellent source of di-or sesterterpenes.'J A few atypical members of the Dictyoceratid family Thorectidae are sources of both sesterterpenes and amino acid derivative^.^^^ In 1985 we collected Fascaplysinopsis reticulata (Thorectidae family, Dictyoceratida order) which were eye-catching because of their massive, globular, and shiny red-brown appearance? This sponge was targeted for further study wh...

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Bengamides, Heterocyclic Anthelminthics from a Jaspidae Marine Sponge Summary: The methanol extract of an undescribed Fiji sponge contains the novel seven-membered ring heterocycles, bengamide A (la) and bengamide B (2a), which are