1-O-Alkylglycerol Ethers from the Marine Sponge Guitarra abbotti and Their Cytotoxic Activity.

The cytotoxicity-bioassay-guided fractionation of the ethanol extract from the marine sponge Guitarra abbotti, whose 1-O-alkyl-sn-glycerol ethers (AGEs) have not been investigated so far, led to the isolation of a complex lipid fraction containing, along with previously known compounds, six new lipids of the AGE type. The composition of the AGE fraction as well as the structures of 6 new and 22 previously known compounds were established using 1H and 13C NMR, GC/MS, and chemical conversion methods. The new AGEs were identified as: 1-O-(Z-docos-15-enyl)-sn-glycerol (1), 1-O-(Z-docos-17-enyl)-sn-glycerol (2), 1-O-(Z-tricos-15-enyl)-sn-glycerol (3), 1-O-(Z-tricos-16-enyl)-sn-glycerol (4), 1-O-(Z-tricos-17-enyl)-sn-glycerol (5), and 1-O-(Z-tetracos-15-enyl)-sn-glycerol (6). The isolated AGEs show weak cytotoxic activity in THP-1, HL-60, HeLa, DLD-1, SNU C4, SK-MEL-28, and MDA-MB-231 human cancer cells. A further cytotoxicity analysis in JB6 P+ Cl41 cells bearing mutated MAP kinase genes revealed that ERK2 and JNK1 play a cytoprotective role in the cellular response to the AGE-induced cytotoxic effects.

Melonoside B and Melonosins A and B, Lipids Containing Multifunctionalized ω-Hydroxy Fatty Acid Amides from the Far Eastern Marine Sponge Melonanchora kobjakovae.

Melonoside B (1) and melonosins B (2) and A (3), new lipids based on polyoxygenated fatty acid amides, and known melonoside A (4) were isolated from two different collections of the marine sponge Melonanchora kobjakovae. The structures of these compounds, including their absolute configurations, were established using detailed analysis of 1D and 2D NMR, ECD, and mass spectra as well as chemical transformations. Melonosins 2 and 3 inhibit AP-1- and NF-kB-dependent transcriptional activities in JB6 Cl41 cells at noncytotoxic concentrations, demonstrating potential cancer preventive activity.

Melonoside A: An ω-Glycosylated Fatty Acid Amide from the Far Eastern Marine Sponge Melonanchora kobjakovae.

Melonoside A (1), the first representative of a new class of ω-glycosylated fatty acid amides, was isolated from the Far Eastern marine sponge Melonanchora kobjakovae. The structure of 1, including absolute configuration, was established using detailed analysis of 1D and 2D NMR, CD, and mass spectra as well as chemical transformations. Compound 1 induces autophagy of human cisplatin-resistant germinal tumor cells NCCIT-R.

Pyridine Nucleosides Neopetrosides A and B from a Marine Neopetrosia sp. Sponge. Synthesis of Neopetroside A and Its ß-Riboside Analogue.

Neopetrosides A (1) and B (2), new naturally occurring ribosides of nicotinic acid with extremely rare α-N-glycoside linkages and residues of p-hydroxybenzoic and pyrrole-2-carboxylic acids attached to C-5', were isolated from a marine Neopetrosia sp. sponge. Structures 1 and 2 were determined by NMR and MS methods and confirmed by the synthesis of 1 and its ß-riboside analogue (3). Neopetroside A (1) upregulates mitochondrial functions in cardiomyocytes.

Glycosides from marine sponges (Porifera, Demospongiae): structures, taxonomical distribution, biological activities and biological roles.

Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed.

New meroterpenoids from the marine sponge Aka coralliphaga.

Three new sulfated meroterpenoids containing sesquiterpene and hydroquinone moieties, namely siphonodictyal A sulfate (1), akadisulfate A (2) and akadisulfate B (3), along with the known siphonodictyal B3 and bis(sulfato)-cyclosiphonodictyol A were isolated from the sponge Aka coralliphaga. Their structures were elucidated on the basis of spectroscopic data. Akadisulfate B and siphonodictyal B3 showed a radical-scavenging activity comparable with that of the known lipophylic antioxidant BHT.

Terpenoid metabolites from Spongia spp. and their effects on nucleic acid biosynthesis in sea urchin eggs.

19-Norspongia-13(16),14-diene-3-one (1) was isolated for the first time from a natural source, along with a series of known spongiane diterpenoids (2-11) and sesquiterpene (12) from two unidentified species belonging to the genus Spongia. The effects of 1, 4, 5, 8-12 on biosynthesis of nucleic acids and embryonic development of the sea urchin Strongylocentrotus intermedius have been studied. All the compounds inhibit sea urchin embryo development at concentration of 20 microg/mL and above and DNA biosynthesis at the dose of 10 microg/mL. The inhibitory effect of diterpenoids at least partly may be explained by the inhibition of thymidine kinase activity.

Occurrence of a silicatein gene in glass sponges (Hexactinellida: Porifera).

Silicatein genes are involved in spicule formation in demosponges (Demospongiae: Porifera). However, numerous attempts to isolate silicatein genes from glass sponges (Hexactinellida: Porifera) resulted in a limited success. In the present investigation, we performed analysis of potential silicatein/cathepsin transcripts in three different species of glass sponges (Pheronema raphanus, Aulosaccus schulzei, and Bathydorus levis). In total, 472 clones of such transcripts have been analyzed. Most of them represent cathepsin transcripts and only three clones have been found to represent transcripts, which can be related to silicateins. Silicatein transcripts were identified in A. schulzei (Hexactinellida; Lyssacinosida; Rosselidae), and the corresponding gene was called AuSil-Hexa. Expression of AuSil-Hexa in A. schulzei was confirmed by real-time PCR. Comparative sequence analysis indicates high sequence identity of the A. schulzei silicatein with demosponge silicateins described previously. A phylogenetic analysis indicates that the AuSil-Hexa protein belongs to silicateins. However, the AuSil-Hexa protein contains a catalytic cysteine instead of the conventional serine.

Monanchocidin: a new apoptosis-inducing polycyclic guanidine alkaloid from the marine sponge Monanchora pulchra.

Monanchocidin (1), a guanidine alkaloid with an unprecedented skeleton system derived from a polyketide precursor, (ω-3)-hydroxy fatty acid, and containing a 2-aminoethyl- and 3-aminopropyl-substituted morpholine hemiketal ring, has been isolated from the sponge Monanhora pulchra. The structure of 1 was assigned on the basis of detailed analysis of 1D and 2D NMR spectra, mass spectrometry, and results of chemical transformations. Compound 1 shows pro-apoptotic and cytoxic activities.

Sesquiterpenoid aminoquinones from the marine sponge Dysidea sp.

Four new sesquiterpenoid arenarone derivatives, 18-aminoarenarone (1), 19-aminoarenarone (2), 18-methylaminoarenarone (3), and 19-methylaminoarenarone (4), and the new dimeric popolohuanone F (5), a derivative of 19-aminoarenarone (2) and arenarol (6), have been isolated from the Australian marine sponge Dysidea sp. together with the known compounds arenarol (6) and popolohuanone A (7). The structures of the new compounds 1-5 were established from extensive NMR spectroscopic data. Popolohuanones A (7) and F (5) and arenarol (6) showed DPPH radical scavenging activity with IC(50) values of 35, 35, and 19 microM, respectively.

Silicatein genes in spicule-forming and nonspicule-forming Pacific demosponges.

Silicatein genes are known to be involved in siliceous spicule formation in marine sponges. Proteins encoded by these genes, silicateins, were recently proposed for nanobiotechnological applications. We studied silicatein genes of marine sponges Latrunculia oparinae collected in the west Pacific region, shelf of Kuril Islands. Five silicatein genes, LoSilA1, LoSilA1a, LoSilA2, and LoSilA3 (silicatein-alpha group), LoSilB (silicatein-beta group), and one cathepsin gene, LoCath, were isolated from the sponge L. oparinae for the first time. The deduced amino acid sequence of L. oparinae silicateins showed high-sequence identity with silicateins described previously. LoCath contains the catalytic triad of amino acid residues Cys-His-Asn characteristic for cathepsins as well as motifs typical for silicateins. A phylogenetic analysis places LoCath between sponge silicateins-beta and L-cathepsins suggesting that the LoCath gene represents an intermediate form between silicatein and cathepsin genes. Additionally, we identified, for the first time, silicatein genes (AcSilA and AcSilB) in nonspicule-forming marine sponge, Acsmall a, Cyrillicnthodendrilla sp. The results suggest that silicateins could participate also in the function(s) unrelated to spiculogenesis.

Aaptamine alkaloids from the Vietnamese sponge Aaptos sp.

A series of aaptamines, including one new alkaloid (1), were isolated from the marine sponge Aaptos sp. collected in Vietnamese waters. The structure of 1 was elucidated using NMR and HRESIMS, as well as by chemical transformation of 1 to the previously known aaptamine and established as 3-N-morpholinyl-9-demethyl(oxy)aaptamine. The isolated compounds showed a potential cancer preventive activity.

Isolation and structures of erylosides from the Carribean sponge Erylus goffrilleri.

Eight new triterpene glycosides, erylosides R ( 1), S ( 2), T ( 3), U ( 4), F 5-F 7 ( 5- 7), and V ( 8), were isolated from the sponge Erylus goffrilleri collected near Arresife-Seko Reef (Cuba). Structures of 1 and 2 were determined as the corresponding monosides having aglycons related to penasterol with additional oxidation and methylation patterns in their side chains. Eryloside T ( 3) was structurally identified as the Delta (7)-isomer of 1, containing an unusual (14-->9)-lactone ring in the tetracyclic aglycon moiety, and eryloside U ( 4) was shown to be the 7,8-epoxide of 3. Erylosides F 5-F 7 ( 5- 7) and V ( 8) contain new variants of carbohydrate chains with two ( 5- 7) and three ( 8) sugar units, respectively.

Spongian diterpenoids from the sponge Spongia (Heterofibria) sp.

Five new (1, 2, 4-6) and one known (3) diterpenoid were isolated from the keratose sponge Spongia (Heterofibria) sp. Structures of these compounds and their absolute configurations were proposed on the basis of X-ray analysis of 1, its CD spectrum, and NMR and MS spectroscopic studies of 1-6. One of the new diterpenoids was shown to be 2(R),3(S),4(S)-3,18-methylene-2-acetoxyspongia-13(16),14-diene (6), possessing a novel carbon skeleton system.

Salegentibacter agarivorans sp. nov., a novel marine bacterium of the family Flavobacteriaceae isolated from the sponge Artemisina sp.

A sponge-associated strain, KMM 7019T, was investigated in a polyphasic taxonomic study. The bacterium was strictly aerobic, heterotrophic, Gram-negative, yellow-pigmented, motile by gliding and oxidase-, catalase-, beta-galactosidase- and alkaline phosphatase-positive. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strain KMM 7019T is closely related to members of the genus Salegentibacter, namely Salegentibacter holothuriorum, Salegentibacter mishustinae and Salegentibacter salegens (97.7-98 % sequence similarities). The DNA-DNA relatedness between the strain studied and Salegentibacter species ranged from 27 to 31 %, clearly demonstrating that KMM 7019T belongs to a novel species of the genus Salegentibacter, for which the name Salegentibacter agarivorans sp. nov. is proposed. The type strain is KMM 7019T (=KCTC 12560T = LMG 23205T).