Settlement Of Barnacle Balanus Amphitrite Research Articles

Bioactive steroid derivatives and butyrolactone derivatives from a gorgonian-derived Aspergillus sp. fungus.

Six steroid derivatives, 1-6, and five butyrolactone derivatives, 7-11, were isolated from the fermentation broth of a gorgonian-derived Aspergillus sp. fungus. Their structures were elucidated on the basis of NMR and MS spectral data. Compound 1 is a new, highly conjugated steroid. The NMR and MS data of 7 and 8 are reported for the first time, as their structures were listed in SciFinder Scholar with no associated reference. Compounds 1, 4, 5, and 8-11 inhibited the larval settlement of barnacle Balanus amphitrite with EC50 values ranging from 0.63 to 18.4 μg ml(-1) . Butyrolactone derivatives 7 and 8 showed pronounced antibacterial activities against Staphylococcus aureus with the same MIC values as the positive control ciprofloxacin (MIC 1.56 μM for all three compounds).

Potent Antifouling Marine Dihydroquinolin-2(1H)-one-Containing Alkaloids from the Gorgonian Coral-Derived Fungus Scopulariopsis sp.

Marine biofouling has a major economic impact, especially when it occurs on ship hulls or aquaculture facilities. Since the International Maritime Organization (IMO) treaty to ban the application of organotin-based paints to ships went into effect in 2008, there is an urgent demand for the development of efficient and environmentally friendly antifouling agents. Marine microorganisms have proved to be a potential source of antifouling natural compounds. In this study, six dihydroquinolin-2-one-containing alkaloids, three monoterpenoids combined with a 4-phenyl-3,4-dihydroquinolin-2(1H)-one (1-3) and three 4-phenyl-3,4-dihydroquinolin-2(1H)-one alkaloids (4-6), were isolated from the gorgonian coral-derived fungus Scopulariopsis sp. collected in the South China Sea. These dihydroquinolin-2-one-containing alkaloids were evaluated against the larval settlement of barnacle Balanus amphitrite, and antifouling activity was detected for the first time for this class of metabolites. All of them except 6 showed strong antifouling activity. Compounds 1 and 2 were discovered to be the most promising non-toxic antilarval settlement candidates. Especially, compound 1 is the strongest antifouling compound in nature until now which showed highly potent activity with picomolar level (EC50 17.5 pM) and a very safety and high therapeutic ratio (LC50/EC50 1200). This represents an effective non-toxic, anti-larval settlement structural class of promising antifouling lead compound.

Pavidolides A–E, new cembranoids from the soft coral Sinularia pavida

Five new cembrane-based diterpenoids, namely pavidolides A–E (1–5) were isolated from the marine soft coral Sinularia pavida, together with sarcophytin and chatancin. The structures of new compounds were determined on the basis of extensive spectroscopic data analysis. Pavidolide B (2) possesses an unprecedented 6,5,7-tricarbocyclic nucleus, whereas pavidolide C (3) is characteristic of an unusual C-5 and C-9 conjuncted cembranoid. Pavidolides C and D showed moderate antifouling activity against the larval settlement of barnacle Balanus amphitrite, while pavidolides B and C exhibited inhibitory activity against the human leukemia cell line HL-60.

Anthogorgienes A–O, New Guaiazulene-Derived Terpenoids from a Chinese Gorgonian Anthogorgia Species, and Their Antifouling and Antibiotic Activities

Fifteen new guaiazulene-based terpenoids designated anthogorgienes A-O (1-15) were isolated from a Chinese gorgonian Anthogorgia sp., together with eight known analogues (16-23). The structural patterns were classified into monomers, dimers, and trimers, which were supposed to be generated from a precursor guaiazulene and followed by side-chain and nucleus oxidation and oxidative rearrangement. The structures of new compounds were elucidated on the basis of extensive spectroscopic (IR, MS, and 1D and 2D NMR) data analysis. A possible biogenetic relationship of the isolated compounds was postulated. Some of the compounds showed potent antifouling activities against the larval settlement of barnacle Balanus amphitrite , whereas their antibiotic activities were also evaluated.

Chemical constituents of soft coral Sarcophyton infundibuliforme from the South China Sea

Chemical investigation on soft coral Sarcophyton infundibuliforme collected from the South China Sea led to the isolation and identification of 14 secondary metabolites, including ten cembrene diterpenoids (1–10), one α-tocopheryl quinone derivative (11), one prostaglandin (12), one lipid (13) and one carotinoid (14). Their structures were determined by extensive analysis of their spectroscopic data. All of these metabolites were isolated from this species for the first time. Diterpenoids 1, 2, 7 and 10 showed potent antifouling activity against the larval settlement of barnacle Balanus amphitrite.

Potent Antifouling Resorcylic Acid Lactones from the Gorgonian-Derived Fungus Cochliobolus lunatus

Three new 14-membered resorcylic acid lactones, two with a rare natural acetonide group and one with a 5-chloro-substituted lactone, named cochliomycins A-C (1-3), together with four known analogues, zeaenol (4), LL-Z1640-1 (5), LL-Z1640-2 (6), and paecilomycin F (7), were isolated from the culture broth of Cochliobolus lunatus, a fungus obtained from the gorgonian Dichotella gemmacea collected in the South China Sea. Their structures and the relative configurations of 1-3 were elucidated using comprehensive spectroscopic methods including NOESY spectra and chemical conversions. A transetherification reaction was also observed in which cochliomycin B (2) in a solution of CDCl(3) slowly rearranged to give cochliomycin A (1) at room temperature. These resorcylic acid lactones were evaluated against the larval settlement of barnacle Balanus amphitrite, and antifouling activity was detected for the first time for this class of metabolites. The antibacterial and cytotoxic activities of these compounds were also examined.

Antibacterial and antilarval compounds from marine bacteriumPseudomonas rhizosphaerae

In order to obtain non-toxic, antifouling natural products from marine organisms, we studied on the marine bacterium Pseudomonas rhizosphaerae isolated from deep sea sediment. Bioassay-guided column chromatography techniques were used to separate and purify compounds. Extensive spectral analyses including 1D NMR spectra and GC-MS were employed for structure elucidation of the compounds. Antibacterial activity of the isolated compounds towards eight marine bacterial strains was measures by optical density, while antilarval activity was evaluated in settlement inhibition assays with laboratory-reared Balanus amphitrite and Bugula neritina larvae. In total, nine compounds including six diketopiperazine were obtained. Among them, cyclo-(Tyr-Pro), cyclo-(Tyr-Ile), cyclo-(Phe-Pro), cyclo-(Val-Pro), 3-phenyl-2-propenoic acid, and uracil had various antibacterial activities towards five marine fouling bacteria, furthermore, bis(2-ethylhexyl)phthalate, cyclo-(Tyr-Ile), cyclo-(Phe-Pro), cyclo-(Val-Pro), and 3-phenyl-2-propenoic acid showed antilarval effect on larval settlement of barnacle Balanus amphitrite and bryozoan Bugula neritina. The results suggested that marine bacterium Pseudomonas rhizosphaerae could produce potent antibacterial and antilarval diketopiperazine and benzene-type secondary metabolites.

Antifeedant and antifouling briaranes from the South China Sea gorgonian Junceella juncea

A new briarane diterpene, juncin ZII (1), along with three known briaranes (2-4), was isolated from the EtOH/CH2Cl2 extracts of the South China Sea gorgonian Junceella juncea. The structure of 1 was established by extensive spectroscopic analysis, including 1D and 2D NMR data. For compounds 1-4 and eight other briaranes (5-12) isolated from J. juncea previously, the antifeedant activity against second-instar larvae of Spodoptera litura and cytotoxicity against S. litura cells were investigated, and it was observed that they all exhibit medium antifeedant activity. Compounds 1, 8, 9, and 12 also showed potent antifouling activity against the larval settlement of barnacle Balanus amphitrite at nontoxic concentrations with EC50 values of 0.004, 0.005, 2.82, and 0.447 mu g/mL, respectively, while all compounds did not show obvious cytotoxicity against tumor cell lines K562, A549, Hela, and Hep-2. Their structure-activity relationship was discussed.

Ten new antifouling briarane diterpenoids from the South China Sea gorgonian Junceella juncea

Ten new antifouling briarane diterpenoids, juncins R–ZI ( 1– 10) were isolated from the South China Sea gorgonian coral Junceella juncea. The structures of these new compounds were established by extensive spectroscopic analysis, including 1D and 2D NMR data. Compounds 1– 10 all showed potent antifouling activities against the larval settlement of barnacle Balanus amphitrite at nontoxic concentrations with EC 50 values of 0.004, 0.34, 2.65, 1.61, 3.77, 21.06, 0.004, 0.14, 1.47, and 0.51 μg mL −1. The structure–activity relationship was discussed.