Four chlorinated depsidones (two reported for the second time (1 and 2) and two known (3 and 4)) were isolated from a seaweed-derived Aspergillus unguis strain. Their structures were spectroscopically elucidated. Compounds 1, 3 and 4 strongly inhibited methicillin-resistant Staphylococcus aureus (MRSA) with minimum inhibitory concentrations (MICs) of 2, 2 and 4 μg/mL and killed Artemia larva with LC50 of 4.1, 1.7 and 2.8 μg/mL, respectively. Besides, in DNA-damaging test, they also selectively inhibited a DNA repair capacity-defective Escherichia coli strain AB3027(-) (MICs: 2, 32 and 4 μg/mL, respectively) compared with the wild-type strain AB1157(+) (MICs: over 512, over 512 and 256 μg/mL, respectively). Furthermore, compound 1 also strongly inhibited cancer cell line A-549 (IC50: 0.5 μg/mL). The above-mentioned bioactivities were newly reported for compound 1. In contrast, compound 2 did not exhibit significant activity. The structure-activity relationship indicated that a complete lactone ring may be important.

This article described an improved brine shrimp larvae lethality microwell test method. A simply designed connecting vessel with alternative photoperiod was used to culture and collect high yield of active Artemia parthenogenetica nauplii for brine shrimp larvae lethality microwell test. Using this method, pure A. parthenogenetica nauplii suspension was easily cultured and harvested with high density about 100-150 larvae per milliliter and the natural mortality was reduced to near zero by elimination of unnecessary artificial disturbance. And its sensitivity was validated by determination of LC(50)-24 h of different reference toxicants including five antitumor agents, two pesticides, three organic pollutants, and four heavy metals salts, most of which exhibited LC(50)-24 h between 0.07 and 58.43 mg/L except for bleomycin and mitomycin C with LC(50)-24 h over 300 mg/L.

Bioactivity and constituents of 8 common seaweeds from Dalian intertidal zone of northern Yellow Sea were investigated. In the anti-methicillin-resistant Staphylococcus aureus (MRSA) test, Symphyocladia latiuscula and Enteromorpha intestinalis showed obvious activities with MICs much lower than 1.0 mg mL 1 . In the DNA damage repair test (DDRT), Chondrus ocellatu showed selective inhibitory activity against the DNA repair-defective E. coli strain vs. the wild-type E. coli strain; while Sym. latiuscula, Enteromorpha intestinalis and Sar. kjellmanianum showed significant anti-E. coli activity with MICs of 64-128 g mL 1 . In the anti-Pyricularia oryzae test, Sym. latiuscula and Rh. confervoides strongly inhibited the germination of the spores of P. oryzae on agar plate. In the brine shrimp larvicidal test, Sym. latiuscula, Rh. confervoides and Sar. kjellmanianum exhibited potent toxicity against brine shrimp larvae, with LC 50 much lower than 1 mg mL 1 . The HPTLC analysis revealed their diversified secondary metabolites. The HPLC-DAD-MS analysis of the strongest species Sym. latiuscula and database searching showed that it can produce quite diversified metabolites, including halogenated ones, some of which may be new natural products. The results demonstrated the potentials of these seaweeds in the development of new antibiotics, antitumor drugs, agricultural fungicides and pesticides. Macroalgae are important primary producers of marine and coastal ecosystem and are also useful medicine and pesticide resources due to their potentials in accumulating large quantities of bioactive metabolites [1]. As is known to all, algal diversity and biomass depend on the environmental factors such as temperature, light, and nutrition, which can be influenced by human activities (e.g. introducing species and pollutions in the form of heat and eutrophication). Therefore, it is important to investigate and utilize the algal resources in coastal zones. Dalian, an important harbor and industrial city, is located on the tip of the Liaodong Peninsula, between China's inner Bohai Sea and the north Yellow Sea. Its marine ecological environment is influenced by strong sea currents and rivers, which provides diversified habitats for seaweeds and also brings about human influences. In this article, we evaluated the biomass and their biomedical and agrichemical potentials as new antibiotics, antitumor drugs, agricultural fungicides, and pesticides in some common seaweeds from Dalian coastline by determining several bioactivities of them, including anti-methicillin-resistant Staphylococcus aureus (MRSA), anti-Escherichia coli DNA repair-defective/wildtype strains, anti-Pyricularia oryzae, and anti-brine shrimp (Artemia parthenogenetica L.) larvae.

Until recently, little was known about the fungi found in shark gills and their biomedicinal potential. In this article, we described the isolation, bioactivity, diversity, and secondary metabolites of bioactive fungi from the gill of a shark ( Carcharodon carcharias ). A total of 115 isolates were obtained and grown in 12 culture media. Fifty-eight of these isolates demonstrated signifi cant activity in four antimicrobial, pesticidal, and cytotoxic bioassay models. Four randomly selected bioactive isolates inhibited human cancer cell proliferation during re-screening. These active isolates were segregated into 6 genera using the internal transcribed spacer-large subunit (ITS-LSU) rDNA-sequence BLAST comparison. Four genera, Penicillium , Aspergillus , Mucor , and Chaetomium were the dominant taxa. A phylogenic tree illustrated their intergenera and intragenera genetic diversity. HPLC-DAD-HRMS analysis and subsequent database searching revealed that nine representative strains produced diverse bioactive compound profi les. These results detail the broad range of bioactive fungi found in a shark's gills, revealing their biopharmaceutical potential. To the best of our knowledge, this is the fi rst study characterizing shark gill fungi and their bioactivity.

Memory accuracy involves two major processes: pattern separation and pattern completion. Pattern separation refers to the ability to reduce overlap among similar inputs to avoid interference, and pattern completion refers to the ability to retrieve the whole information from partial or degraded cues. Impairments in pattern separation/pattern completion contribute to cognitive deficits in several diseases of the nervous system. Therefore, it is better to evaluate both pattern separation and pattern completion in one apparatus. However, few tools are available to assess pattern separation and pattern completion within the same apparatus for rodents. In this study, we designed a series of images with varying degrees of similarity to the correct image to evaluate pattern separation and pattern completion. First, mice were trained to discriminate between two totally different images, and once the correct percentage reached above 77% for two consecutive days, the images with different degrees of similarity were used to measure pattern separation and pattern completion. The results showed the mice performed progressively worse from S0 to S4 (increasing similarity) when discriminating similar images in pattern separation, and the mice performed progressively worse from C0 to C4 (decreasing cues information) when recalling the correct image according to partial cues in pattern completion, implying a good image similarity-dependent manner for memory accuracy evaluation. In sum, we designed a convenient, effective paradigm to evaluate pattern separation and pattern completion based on a touchscreen pairwise discrimination task, which may provide a new method for the studies of the effects and mechanisms of memory accuracy enhancing drugs.