Sponge Stylotella Research Articles

Antibacterial Activity of Marine Sponge (Stylotella sp.)

Sponges are marine biota that makes up coral reefs that live on the bottom of the waters and have an important role in marine ecosystems. Sponges have bioactive components that have not been widely used by the community. This study aimed to analyze the content of secondary metabolites and the antibacterial activity of the sponge Stylotella sp. antibacterial activity test against Gram-negative (-) Escherichia coli and Gram-positive (+) Staphylococcus aureus was carried out using the good diffusion method. The results of antibacterial testing with various concentrations of 50, 100, and 150 ppm of the isolates showed that the zone of inhibition against E. coli was 11.3; 12; and 13 mm while for S. aureus was 12.3; 13; and 14 mm. The results of antibacterial testing with a concentration of 600 ppm of sponge extract showed an inhibition zone on E. coli and S. aureus in the amount of 13.3 and 14 mm, respectively. The test results showed that the sponge extract and isolate were in the intermediate category and were resistant to E. Coli bacteria. and S. Aureus

Purification and molecular docking study of angiotensin I-converting enzyme (ACE) inhibitory peptides from hydrolysates of marine sponge Stylotella aurantium

Abstract Angioteinsin I-converting enzyme (ACE) inhibitory peptide was isolated from marine sponge (Stylotella aurantium) hydrolysate prepared by various hydrolysis enzymes. The peptic hydrolysate exhibited highest ACE inhibitory activity among them and was fractionated into three ranges of molecular weight. The below 5 kDa fraction showed the highest ACE inhibitory activity and was used for subsequent purification steps. The amino acid sequences of the purified peptides were identified to be Tyr-Arg (337.2 Da), and Ile-Arg (287.2 Da). The purified peptides from marine sponge had an IC50 value of 237.2 μM and 306.4 μM, respectively. The molecular docking study revealed that ACE inhibitory activity of the purified peptides was mainly attributed to the hydrogen bond interactions and Pi interaction between the dipeptides and ACE. The results suggest that marine sponge, S. aurantium would be an attractive raw material for the manufacture of anti-hypertensive nutraceutical ingredients.

Antimicrobial and Antioxidant Activities of Bacterial Extracts from Marine Bacteria Associated with Sponge <i>Stylotella</i> sp.

Sponge-associated bacteria have great potential in developing marine pharmaceutical industry since they are capable of synthesizing numerous bioactive metabolite compounds. This study aimed to isolate, characterize and investigate potential antimicrobial, toxicity and antioxidant of bioactive compounds of bacteria associated with sponge Stylotella sp. A total of 138 bacteria were selected. During screening stage, 45 isolates (32%) produced a wide spectrum and species specific bioactive compound against microbial test strains (Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Eschericia coli ATCC 8739, Enteropathogenic Escherichia coli (EPEC) and Candida albicans). Crude extract of five selected potential bacteria were extracted using ethyl acetate solvent. They were identified to have a wide spectrum inhibition capability against microbial test strains. The extracts toxicity were examined using the Brine Shrimp Lethality Test (BSLT) method. All extracts showed toxicity of LC50 in the range of 35.89-484.17 µg mL-1 against Artemia salina. By using Cupric Reducing Antioxidant Capacity (CUPRAC) radical reduction test revealed all the extracts showed potential antioxidant activites, ranging from 445.33 to 1610.00 µmol trolox/g extract. Based on 16S rRNA sequence analysis revealed that isolates STIL 33, STIL 37, STIL 44, STIL 55 and STIL 9 were closely related with Pseudoalteromonas flavipulchra strain NCIMB 2033, Serratia marcescens strain NBRC 102204, Catenococcus thiocycli strain TG 5-3, Vibrio natriegens strain ATCC 14048 and Bacillus subtilis strain JCM 1465, respectively.

Study on the absolute configuration of (−)-palau’amine

The absolute stereochemistry of the immunosuppressive pyrrole–imidazole alkaloid (−)-palau’amine from the marine sponge Stylotella aurantium is analyzed by CD spectroscopy. With the help of a series of model compounds it is shown that the CD spectrum of (−)-palau’amine can be explained based on the assumption that the pyrrolopyrazinone partial structure is planar in 2,2,2-trifluoroethanol (TFE). Surprisingly, the natural product (−)-dibromophakellin shows the opposite Cotton effect, despite exhibiting the same absolute configuration.

FINALLY, PALAU’AMINE

WITH THE HELP of a daring cyclization reaction, a team led by Phil S. Baran at Scripps Research Institute has completed the first total synthesis of palau’amine, a marine natural product that has captivated synthetic chemistry groups around the globe ( Angew. Chem. Int. Ed. , DOI:10.1002/ anie.200907112). Isolated from the sponge Stylotella agminata in waters near the Republic of Palau in the Pacific Ocean, palau’amine is a dauntingly complex alkaloid. It has eight contiguous stereogenic centers and a preponderance of reactive nitrogen-containing moieties. It is also highly polar, which can make it nightmarishly difficult to manipulate synthetic intermediates. The challenge of making such a complex structure has intrigued chemists for more than a decade. Until now, “palau’amine’s unprecedented hexacyclic ring system and its nasty physical properties had undermined total synthesis endeavors in leading laboratories worldwide,” says Larry E. Overman, an organic chemist at the University of California, Irvine...

Stylopeptide 2, a Proline-Rich Cyclodecapeptide from the Sponge Stylotella sp.

A new proline-rich cyclodecapeptide, designated stylopeptide 2, has been isolated from a cytotoxic extract of the Papua New Guinea marine sponge Stylotella sp. and found to correspond to structure 1. The structural assignment was based on HRMS collision-induced dissociation tandem mass spectrometry (CID MS/MS), NMR spectroscopic data, and amino acid analysis, which led to assignment of the absolute configuration.

Revised Structure of Palau′amine.

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Revised structure of palau’amine

The structure of palau’amine, a bioactive hexacyclic pyrrole–imidazole alkaloid, from the sponge Stylotella aurantium was revised by detailed analysis of its 2D ROESY and 1D NOESY data.

Challenge Palauamine: Current Standings

The marine natural product (-)-palauamine from the sponge Stylotella aurantium represents one of the toughest challenges to total synthesis. It possesses a strained hexacyclic skeleton which leads current methods of organic synthesis to their limit. Recently, several research groups have undertaken independent approaches, focussing on possibly biomimetic approaches involving the underlying biogenetic key metabolite oroidin. Oroidin is the parent compound of the pyrrole-imidazole alkaloids. In this review, recent developments in the field since 2003 are discussed, outlining progress on the dimerization of 4(5)-alkenylimidazoles, total syntheses of non-cyclized pyrrole-imidazole alkaloids, of dibromophakellstatin, agelastatin, and an update on hymenialdisine. Although palauamine has not yet been synthesized, there are original approaches to the system which have afforded biologically active, smaller pyrrole-imidazole alkaloids such as dibromophakellstatin and agelastatin A. Keywords: natural products, pyrrole-imidazole alkaloid, konbu'acidin, axinellamine a, intramolecular thermal cycloaddition, sceptrin

Biosynthetic pathways to dichloroimines; precursor incorporation studies on terpene metabolites in the tropical marine sponge Stylotella aurantium.

The biosynthetic origin of the dichloroimine functional group in the marine sponge terpene metabolites stylotellanes A (3) and B (4) was probed by the use of [(14)C]-labelled precursor experiments. Incubation of the sponge Stylotella aurantium with [(14)C]-labelled cyanide or thiocyanate resulted in radioactive terpenes in which the radiolabel was shown by hydrolytic chemical degradation to be associated specifically with the dichloroimine carbons. Additionally, label from both precursors was incorporated into farnesyl isothiocyanate (2). A time course experiment with [(14)C]-cyanide revealed that the specific activity for farnesyl isothiocyanate decreases over time, but increases for stylotellane B (4), consistent with the rapid formation of farnesyl isothiocyanate (2) from inorganic precursors followed by a slower conversion to stylotellane B (4). The advanced precursors farnesyl isothiocyanate (2) and farnesyl isocyanide (5) were supplied to S. aurantium, and shown to be incorporated efficiently into stylotellane A (3) and B (4). Feeding of [(14)C]-farnesyl isothiocyanate (2) resulted in a higher incorporation of label than with [(14)C]-farnesyl isocyanide (5). Farnesyl isocyanide was incorporated into farnesyl isothiocyanate in agreement with labelling studies in other marine sponges. Both farnesyl isocyanide and isothiocyanate were further incorporated into axinyssamide A (11) as well as the cyclized dichloroimines (12)-(14), (16) that represent more advanced biosynthetic products of this pathway. These results identify the likely biosynthetic pathway leading to the major metabolites of S. aurantium.

Two Distinct Conformers of the Cyclic Heptapeptide Phakellistatin 2 Isolated from the Fijian Marine Sponge Stylotella aurantium.

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Advanced Precursors in Marine Biosynthetic Study. Part 3. The Biosynthesis of Dichloroimines in the Tropical Marine Sponge Stylotella aurantium.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Advanced precursors in marine biosynthetic study. Part 3: The biosynthesis of dichloroimines in the tropical marine sponge Stylotella aurantium

The biosynthetic origins of the dichloroimine group in the stylotellanes A and B 1 , 2 have been investigated by incorporation of [ 14C]-labeled farnesyl isocyanide 7 and farnesyl isothiocyanate 3 into the sponge Stylotella aurantium.

Optimizing the formation of in vitro sponge primmorphs from the Chinese sponge Stylotella agminata (Ridley)

The establishment and optimization of in vitro primmorph formation from a Chinese sponge, Stylotella agminata (Ridley), collected from the South China Sea, were investigated. Our aims were to identify the key factors affecting primmorph formation in this species and to optimize the technique for developing an in vitro primmorph culture system. The size of dissociated cells from S. agminata is relatively small, in the range between 5 and 10 μm. Round-shaped primmorphs of less than 100 μm were formed 3 days after transferring the dissociated cells into seawater containing Ca 2+ and Mg 2+. The effect of various cell dissociation conditions, inoculum cell density, concentration of antibiotics, pH, and temperature was further investigated upon the formation of primmorphs. The time required for primmorph formation, primmorph size distribution, and the proliferating capability were microscopically documented. Healthy sponge S. agminata, inoculum cell density and culture temperature play a critical role for the successful formation of primmorphs and that the microbial contamination will have to be controlled.

Two distinct conformers of the cyclic heptapeptide phakellistatin 2 isolated from the fijian marine sponge stylotellaaurantium.

The isolation, structure determination, and solution conformation of two conformers of the cyclic heptapeptide phakellistatin 2 (cyclo-[Phe1-cis-Pro2-Ile3-Ile4-cis-Pro5-Tyr6-cis-Pro7]) isolated from the Fijian marine sponge Stylotella aurantium are reported. The conformers can be isolated separately by HPLC and are stable in methanol solution over a period of weeks as determined by NMR. Their NMR spectra and mass spectral fragmentation patterns differ significantly. Their solution conformations were determined by NOE-restrained molecular dynamics calculations and indicated that the two conformers had different folds, hydrogen bonding patterns, and solvent accessible surfaces. These factors may contribute to the independent stability of the two conformers, and may explain the variable biological activity previously reported for phakellistatin 2.

Axinellin C, a proline-rich cyclic octapeptide isolated from the Fijian marine sponge Stylotella aurantium

The structure of a new cyclic octapeptide, axinellin C, (cyclo[Thr 1-Val 2-Pro 3-Trp 4-Pro 5-Phe 6-Pro 7-Leu 8]), with all- trans peptide bond geometry, was elucidated by a combination of 2D NMR methods and tandem mass spectrometry. The solution state conformation was determined by ROE restrained molecular dynamics calculations. The structural features were found to be similar to those of the crystal structure of the cyclic decapeptide, phakellistatin 8, despite differing peptide sequences.

Bioactive compounds from coral reef invertebrates

Abstract Manzamine A (1) known as a cytotoxin exhibited potent antimalarial activity with 40% recovery 60 days after single intraperitoneal (i.p.) injection against mice infected with the malaria parasite Plasmodium berghei. Pachastrisamine (6), a simple derivative of a sphingosine, isolated from a sponge, Pachastrissa sp. showed a high level of cytotoxicity. New sesquiterpene carbonimidic dichlorides and related aldehydes (8­12) have been isolated as cytotoxic constituents of the sponge Stylotella aurantium and shown to have moderate cytotoxicity. Cyclic undecapeptides, barangamides A­D (13­16), have been isolated from the sponge Theonella swinhoei. Their structures were established by spectroscopic analysis and chemical reaction.

New sesquiterpene carbonimidic dichlorides and related compounds from the sponge Stylotella aurantium.

Five new sesquiterpenes (1-5) having a carbonimidic dichloride or an aldehyde function have been isolated, together with seven known related compounds (6-12), from the sponge Stylotella aurantium. The structures of the new compounds were elucidated from spectral data. The absolute stereochemistry of the previously reported reticulidin A (10) was determined. Four of the new compounds showed cytotoxicity with a range of IC(50) values of 0.1-1 microg/mL against several tumor cell lines.

ChemInform Abstract: Palau′amine and Its Congeners: A Family of Bioactive Bisguanidines from the Marine Sponge Stylotella aurantium.

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Palau'amine and Its Congeners: A Family of Bioactive Bisguanidines from the Marine Sponge Stylotella aurantium1

The strongly cytotoxic, antibiotic, and immunosuppressive palau'amine was isolated from the Belau sponge Stylotella aurantium, along with less active 4-bromo and 4,5-dibromo derivatives. Three corresponding isomeric compounds, all less active, were also isolated, and full details of the isolation and all structure proofs are provided.