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Four new (1-4) and 10 known polybrominated diphenyl ethers (5-14) have been isolated from the title sponge. The structures of the new entities were elucidated by interpretation of spectroscopic data and chemical transformations. These metabolites showed potent antimicrobial activity against Bacillus subtilis and moderate/weak cytotoxicity against NBT-T2 rat bladder epithelial cells. The major constituent 14 was treated under debromination conditions to give eight derivatives, which were subjected to a structure-activity relationship study. The results indicated that the presence of two phenolic hydroxyl groups and bromines at C-2 and/or C-5, as in 2, is important for the exhibition of antibacterial activity.

A new catecholate-containing siderophore, labrenzbactin (1), was isolated from the fermentation broth of a coral-associated bacterium Labrenzia sp. The structure and absolute configuration of 1 was determined by spectroscopic methods and Marfey's analysis. Overall, 1 showed antimicrobial activity against Ralstonia solanacearum SUPP1541 and Micrococcus luteus ATCC9341 with MIC values of 25 and 50 µg ml −1 , respectively, and cytotoxicity against P388 murine leukemia cells with an IC 50 of 13 µM. 1234567890();,:1234567890();,:

Extensive investigations on marine natural products have shown that marine sponges are nearly inexhaustible sources of new secondary metabolites.1) From a structural viewpoint, various classes of molecules including macrolides, 2) polypeptides, 3) terpenes, 4) steroids, 5) alkaloids, 6) and others 7) have been isolated, and a number of different modes of biological activity have been reported. The sponges belonging to the genus Haliclona are also prolific sources of unique molecules such as manzamines, 8) haliclonamines, 9) haliclonamides, 10) halipeptins, 11) and others. In our continuing search for new cytotoxic metabolites from Indonesian sponges, 12,13) we collected a small sponge belonging to Haliclona at Baubau, Indonesia. After the 1 H-NMR spectrum of a methanolic extract from the sponge indicated the presence of a unique molecule, we examined the chemical contents. In this note we describe the isolation, structure characterization, and bioactivity of the new compound, which we named halioxepine (1). Results and DiscussionThe sponge (45 g, wet) was soaked in MeOH to provide a crude extract, whose 1 H-NMR spectrum showed the presence of a unique metabolite as one of principal components. The extract was triturated with CH 2 Cl 2 to provide a lipophilic fraction (136.5 mg) followed by purification on silica HPLC to give compound 1 (25.3 mg).Compound 1 Chemical investigations on a sponge Haliclona sp. found a meroditerpene 1 having a new carbon skeleton. By analyzing spectroscopic data, the structure was elucidated to comprise a substituted hydroquinone, a tetrahydrooxepine, and a cyclohexene, and these components were united with C1 and C2 units. Compound 1 showed moderate cytotoxicity against NBT-T2 cells with IC 50 4.8 m mg/ml and also antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC 50 3.2 m mg/ml.

There is no report of diversity, biological properties and bioactive compounds of sponge-associated fungi from Indonesia's mangrove ecosystem to date. This study was designed to isolate sponge-associated fungi from a mangrove ecosystem in Mangkang, to screen the antimicrobial and extracellular enzyme properties of the isolates, characterize the biologically promising isolates using molecular approaches, and profile the secondary metabolites using phytochemical and thin-layer chromatography (TLC) analyses. An unidentified sponge that lived in association with mangrove roots was collected from Mangkang. Total of eight associated fungi were isolated from the sponge. Among all isolates, only two fungi SPMKF 1 and SPMKF 6 produced extracellular amylase, another two fungi SPMKF 4 and 5 showed antibacterial activity against MRSA, and only one fungus SPMKF 8 was able to produce extracellular amylase and show antimicrobial activity against ESBL E. coli, Salmonella enterica ser. Typhi strain MDR and C. albicans, while SPMKF 2, SPMKF 3 and SPMKF 9 did not show any biological properties. The result of genetic

Marine sponge associated fungi are known as potential source of metabolites with various biological activities. Natural pigment is one of metabolite which produced by microorgisms. Several researches reported the antimicrobial activity from natural pigment. Unfortunatelly there are lack of information about marine fungi natural pigment and its producer. The aims of this research were to identify yellow pigmented Indonesian marine sponge-associated fungi, to extract the pigment, and to study the antimicrobial activity of the pigment against clinical MDR bacteria and clinical pathogenic fungi. Sponge associated-fungus isolate MT23 was successfully identified as Trichoderma parareesei. The fungal pigment could be extracted only in methanol with yield 6,22±0,29%. The pigment could inhibitted S. typhi and E. coli MDR strains. The biggest antibacterial activity was shown by concentration 1000µg/mL against S. typhi with inhibition zone was 4.03±0.06 mm.

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Tunicates (Ascidians, sea squirts) are marine protochordates, which live sedentary or sessile in colonial or solitary forms. These invertebrates have to protect themselves against predators and invaders. A most successful strategy, to not being eaten by predators and prevent pathogenic microorganisms to settle, is the usage of chemical molecules for defence. To accomplish this, tunicates take advantage of the specialized metabolites produced by the bacteria associated with them. Therefore, the microbiome of the tunicates can be regarded as a promising bioresource for bacterial strains producing compounds with antibacterial activity. The aim of this study was to test this hypothesis by (i) isolation of tunicate-associated bacteria, (ii) analysis of the antibacterial activities of these strains, and (iii) purification and structure elucidation of an active compound derived from this bioresource. In total, 435 bacterial strains were isolated and thereof 71 (16%) showed antibacterial activity against multidrug resistant (MDR) bacteria. Therefrom, the ethyl acetate crude extracts from liquid fermentations of 25 strains showed activity against MDR Extended-Spectrum Beta-Lactamase (MDR-ESBL) Escherichia coli, MDR Bacillus cereus, Micrococcus luteus, and Bacillus megaterium. Phenotypic analysis based on 16S rDNA sequencing revealed the active strains belonging to different genera and phyla, like Bacillus, Pantoea, Pseudoalteromonas, Salinicola, Streptomyces, Vibrio and Virgibacillus. To obtain first insights into the molecules responsible for the antibacterial activities observed, strain Pseudoalteromonas rubra TKJD 22 was selected for large-scale fermentation and the active compound was isolated. This allowed the purification and structure elucidation of isatin, a compound known for its strong biological effects, thereunder inhibition of Gram-positive and Gram-negative pathogens.