Objective To study the secondary metabolites of marine-derived Sulfitobacter sp.(M44).Methods The ethyl acetate(EtOAc) extract of fermentation broth was subjected to chromatography on Sephadex LH-20,ODS C18 reversed-phase column and high-performance liquid chromatography for constituents.The structures of the compounds were elucidated by 1HNMR,13CNMR and MS technologies;MTT method were employed to detect the biological activities of the separated compounds.Results Six cyclodipeptides were obtained from the Sulfitobacter sp.(M44) and their structures were identified as follows: Cyclo(L-Leu-D-val)(1),Cyclo(L-Phe-D-val)(2),Cyclo(L-Phe-L-Leu)(3),Cyclo(L-Leu-L-Ile)(4),Cyclo(D-Phe-L-Ile)(5) and Cyclo(L-Trp-L-Pro)(6).Cytotoxic activities tests showed that compound 2 and 4 can inhibit the growth of HepG2 cell with IC50 values being 88g/mL and 105g/mL respectively,and compound 4 also showed some inhibitory activities against Hep2 cell with IC50 value being 115g/mL.Conclusion All the six compounds were isolated from Sulfitobacter sp.for the first time.The present study provided a basis for further exploiting microorganism of the East China Sea.

A marine bacterium M44 was separated from 30 m deep seawater in the East China Sea (26° 28.3′ N 122° 29.0′ E) in 2006. 16S rDNA gene sequence comparison showed that the strain M44 was a member of the genus Sulfitobacter and highly similar to KMM 3554T. A series of experiments demonstrated that this strain M44 had many distinctive characteristics: its cells were gram-negative and mesophilic; its colonies were slightly yellowish, round, convex, and smooth; and it could grow at 10–28°C, pH 6.0–10.0, and in the presence of 0–12.5% (w/v) NaCl; the optimum growth conditions were 25°C and pH 7.0, and the optimum Na+ concentration was 2.5%. In addition, strain M44 contained 18 : 1 ω7c, 11 methyl 18 : 1 ω7c and 16 : 0 fatty acids as major fatty acids, and the genomic DNA G+C content was 58.04 mol%. According to our results of the secondary metabolites, six cyclodipeptides were isolated from the strain M44, which were Cyclo (Val-Leu), Cyclo (Phe-Val), Cyclo (Phe-Leu), Cyclo (Leu-Ile), Cyclo (Phe-Ile), and Cyclo (Trp-Pro). It is the first study of secondary metabolites isolated from this genus.

East China Sea is one of the four sea areas in China, which possesses peculiar ecological environment and many kinds of living creatures, especially the microorganisms. We established the East China Sea microorganism library (during 2006-2010) for the first time, which stored about 30000 strains that covered most kinds of the species. In this paper, 395 pure strains of East China Sea microorganism library which belong to 33 different genera were mainly introduced. Sulfitobacter, Halomonas, Bacillus, Pseudoalteromonas, and Idiomarina were the most dominant species. On the large-scale biological activity screening of the 395 strains, 100 strains possess different biological activities based on different screening models, of which 11.4% strains have antibacterial activities, 15.9% have cytotoxicity activities, and 6.1% have antioxidation activities. Besides, the secondary metabolites of 6 strains with strong biological activities were studied systematically; diketopiperazines and macrocyclic lactones are the active secondary metabolites. The species and the biological activity of microorganisms diversity, the abundant structure type of the secondary metabolites, and their bioactivities all indicate that East China Sea is a potent marine microorganisms-derived developing resource for drug discovery.

Objective To determine the 16S rDNA sequences of 36 strains of Halomonas sp.isolated from the seawater of the East China Sea and to study their bioactivities.Methods The 16S rDNA sequences of all isolated strains were amplified by PCR,and the obtained sequences were subjected to phylogenetic analyses using MEGA4.1 and multiple sequence alignment with Clustal X1.8 software.MTT assay was applied to assess the cytotoxic activities of their fermentation broth;ABTS and DPPH antioxidant models were applied to test the antioxidation activities of their fermentation broth.The HLE inhibition activities of the fermentation broth were tested by a stable HLE inhibitor screening model.Results Analysis of 16S rDNA sequences showed that the 36 strains had a high affinity(96%-99%) to the Halomonas sp.Fermentation broth of the 36 strains showed different degrees of cytotoxic activities,antioxidation activities,and HLE inhibition activities.Eleven strains inhibited the growth of HepG2 cells,with the inhibition rate ranging(4.40±1.2)% to(24.90±3.5)%;20 strains inhibited the growth of HL-60 cells,with the inhibition rate ranging(1.70±1.1)% to(50.90±4.2)%;7 strains showed ABTS radical scavenging capacity,with the scavenging rate ranging(4.49±2.1)% to(58.43±4.4)%;3 strains showed DPPH radical scavenging capacity,with the scavenging rate ranging(5.68±3.7)% to(59.06±3.2)%,and 3 strains showed HLE inhibition activities,with the inhibition rate ranging(12.71±1.81)% to(71.19±5.62)%.Conclusion All the 36 Halomonas sp.strains show different degrees of cytotoxic effects,antioxidation activities,and HLE inhibition capacities.Several strains with high activities possess the potential for medicinal application.

Three new iridoid glycosides, epiasperuloside (1), epipaederosidic acid (2), and epipaederoside (3), together with 7 known compounds, were isolated from the 85 % ethanol extract of the leaves of Saprosma ternatum Hook. f. Their structures were determined by application of spectroscopic (NMR, MS) and chemical methodologies. The antioxidant activity was evaluated for all isolates in terms of both DPPH and ABTS bioassays. Epiasperuloside (1) showed some antioxidant activity.

Marine fungi have considerable potential to produce new biologically active substances because of their special environment and metabolic mechanism.Recently,more and more new structurally-unique anti-tumor natural products have been isolated from marine fungi that are from sea-water,sea-mud,marine sediments and marine organisms.This paper reviewed new advances in research of anti-tumor natural products from marine fungi in the recent years.

Objective: To identify a strain of bacterium (Numbered P12008) isolated from the seawater of the East China Sea and study its bioactivity. Methods: The strain P12008 was subjected to Gram stain, salt-aggregation test and 16S rDNA sequence analysis to determine its characteristics. The cytotoxic activity of strain P12008 in vitro was tested by MTT method using HepG2 and HL60 cells as the indicators. The antioxidation activity of the ethyl acetate extracts of strain P12008 was tested using DPPH and ABTS models. Results: The strain P12008 was a G~- bacterium and its shape was oval or circle under the microscope. The strain cannot grow with a non-salt medium and its optimum salt concentration was 12.5%. Analysis of the 16S rDNA gene sequence showed high similarity (99%) to the Halomonas sp.MZ0306A1(EU124745.1). The results of bioactivities researches showed that P12008 could inhibit the growth of HepG2 cell with inhibition ratio 17.1%, and eliminate ABTS free radical with elimination radio 40.71%(100μg ·mL~(-1) )and eliminate DPPH free radical with the ratio 59.06%. Conclusion: P12008 was a moderate halophylic Halomonas sp.. The fermentation broth has cytotoxic effect and antioxidation activity. The active metabolites were worth to further study.

Objective:To determine the 16S rDNA sequences of 44 strains of Sulfitobacter sp. obtained from the East China Sea and to study their biological activities. Methods:PCR was used to amplify the 16S rDNA sequences of the 44 strains,and the obtained sequences were subjected to GenBank similarity search.The multiple sequence alignment of the 44 strains was done by Clustal X1.8 and MEGA4.1.The antibacterial activities of Sulfitobacter sp. fermentation broths were tested using the following indicator bacteria:Pyricularia oryzae,Bacillus subtills,and Escherichia coli.The cytotoxic activities of the fermentation broths were tested using HL-60 and HepG2 as the indicator cells.ABTS and DPPH antioxidant models were applied to test the free radical scavenging efficacy of the fermentation broth.Results:Analysis of the 16S rDNA genes of the 44 strains showed high similarity (97%-100%) to Sulfitobacter sp..No fermentation broths of the 44 strains showed evident anti-bacterial activities,and they showed different degrees of cytotoxic activities and free radical scavenging capacities.Nineteen strains inhibited the growth of HepG2 cells,with the inhibition rate ranging 6.8%-42.8%; 18 strains inhibited the growth of HL-60 cells,with the inhibition rate ranging 6.9%-43.6%; 12 strains showed ABTS radical scavenging capacity,with the elimination rate ranging 4.49%-23.08%; and 8 strains showed DPPH radical scavenging capacity,with the elimination rate ranging 1.23%-30.76%.Conclusion:The 44 Sulfitobacter sp.strains possess evident cytotoxic activities and free radical scavenging capacities,making them potential for medicinal application and laying a foundation for further development of these bacteria.