RESUMO
Astragalus is a medicinal plant with obvious rhizosphere effects. At present, there are many Astragalus plants with high application value but low recognition and resource reserves in the northwestern area of Yunnan province, China. In this study, metagenomics was used to analyze the microbial diversity and community structure of rhizosphere soil of A. forrestii, A. acaulis, and A. ernestii plants grown in a special high-cold environment of northwestern Yunnan, China, at different altitudes ranging from 3225 to 4353 m. These microbes were taxonomically annotated to obtain 24 phyla and 501 genera for A. forrestii, 30 phyla and 504 genera for A. acaulis, as well as 39 phyla and 533 genera for A. ernestii. Overall, the dominant bacterial phyla included Proteobacteria, Actinobacteria, and Acidobacteria, while the dominant fungal ones were Ascomycota and Basidiomycota. At the genus level, Bradyrhizobium, Afipia, and Paraburkholderia were the most prevalent bacteria, and Hyaloscypha, Pseudogymnoascus, and Russula were the dominant fungal genera. Some of them are considered biocontrol microbes that could sustain the growth and health of host Astragalus plants. Redundancy analysis revealed that pH, TN, and SOM had a significant impact on the microbial community structures (p < 0.05). Finally, triterpene, flavonoid, polysaccharide, and amino acid metabolisms accounted for a high proportion of the enriched KEGG pathways, which possibly contributed to the synthesis of bioactive constituents in the Astragalus plants.
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Low expression levels of E2F3a and caspase 8-associated protein 2 (CASP8AP2) are associated with poor outcomes in children with acute lymphoblastic leukemia. Our previous study showed that a combined assessment of E2F3a and CASP8AP2 expression was more accurate in predicting relapse in children with acute lymphoblastic leukemia. However, the underlying mechanism remains unclear. In this study, the interaction between E2F3a and CASP8AP2 and its role in the regulation of histone expression, cell proliferation, the cell cycle, and chemosensitivity were investigated. Exogenous E2F3a-GST was coprecipitated with CASP8AP2-FLAG in HEK-293T cells. E2F3a was colocalized with CASP8AP2-GFP in the nucleus. The replication-dependent histones H2A and H2B were significantly upregulated when E2F3a or CASP8AP2 was overexpressed in HEK-293T or 697 cells and downregulated by E2F3a or CASP8AP2 knockdown. E2F3a and CASP8AP2 could collaboratively enhance the transcriptional activity of HIST1H2AG and HIST1H2BK . Both CASP8AP2 and E2F3a are involved in S phase progression. E2F3a and CASP8AP2 also affected the sensitivity of leukemic cells to daunorubicin. Therefore, CASP8AP2 and E2F3a collaboratively regulated replication-dependent histone expression, cell cycle progression, and chemosensitivity of leukemic cells.
Assuntos
Histonas , Leucemia-Linfoma Linfoblástico de Células Precursoras , Criança , Humanos , Proteínas Reguladoras de Apoptose , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas de Ligação ao CálcioRESUMO
Bacteria growing inside biofilms are more resistant to hostile environments, conventional antibiotics, and mechanical stresses than their planktonic counterparts. It is estimated that more than 80% of microbial infections in human patients are biofilm-based, and biofouling induced by the biofilms of some bacteria causes serious ecological and economic problems throughout the world. Therefore, exploring highly effective anti-biofilm compounds has become an urgent demand for the medical and marine industries. Marine microorganisms, a well-documented and prolific source of natural products, provide an array of structurally distinct secondary metabolites with diverse biological activities. However, up to date, only a handful of anti-biofilm natural products derived from marine microorganisms have been reported. Meanwhile, it is worth noting that some promising antifouling (AF) compounds from marine microbes, particularly those that inhibit settlement of fouling invertebrate larvae and algal spores, can be considered as potential anti-biofilm agents owing to the well-known knowledge of the correlations between biofilm formation and the biofouling process of fouling organisms. In this review, a total of 112 anti-biofilm, anti-larval, and anti-algal natural products from marine microbes and 26 of their synthetic analogues are highlighted from 2000 to 2021. These compounds are introduced based on their microbial origins, and then categorized into the following different structural groups: fatty acids, butenolides, terpenoids, steroids, phenols, phenyl ethers, polyketides, alkaloids, flavonoids, amines, nucleosides, and peptides. The preliminary structure-activity relationships (SAR) of some important compounds are also briefly discussed. Finally, current challenges and future research perspectives are proposed based on opinions from many previous reviews.
Assuntos
Organismos Aquáticos/metabolismo , Biofilmes/efeitos dos fármacos , Produtos Biológicos/farmacologia , Animais , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Incrustação Biológica/prevenção & controle , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Humanos , Larva/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Although laparoscopic technology has achieved rapid development in the surgical field, it has not been applied to liver transplantation, primarily because of difficulties associated with laparoscopic vascular anastomosis. In this study, we introduced a new magnetic-assisted vascular anastomosis technique and explored its application in laparoscopic liver transplantation in pigs. METHODS: Two sets of magnetic vascular anastomosis rings (MVARs) with different diameters were developed. One set was used for anastomosis of the suprahepatic vena cava (SHVC) and the other set was used for anastomosis of the infrahepatic vena cava (IHVC) and portal vein (PV). Six laparoscopic orthotopic liver transplantations were performed in pigs. Donor liver was obtained via open surgery. Hepatectomy was performed in the recipients through laparoscopic surgery. Anastomosis of the SHVC was performed using hand-assisted magnetic anastomosis, and the anastomosis of the IHVC and PV was performed by magnetic anastomosis with or without hand assistance. RESULTS: Liver transplants were successfully performed in five of the six cases. Postoperative ultrasonographic examination showed that the portal inflow was smooth. However, PV bending and blood flow obstruction occurred in one case because the MVARs were attached to each other. The durations of loading of MVAR in the laparoscope group and manual assistance group for IHVC and PV were 13 ± 5 vs. 5 ± 1 min (P < 0.01) and 10 ± 2 vs. 4 ± 1 min (P < 0.05), respectively. The durations of MVAR anastomosis in the laparoscope group and manual assistance group for IHVC and PV were 5 ± 1 vs. 1 ± 1 min (P < 0.01), and 5 ± 1 vs. 1 ± 1 min (P < 0.01), respectively. The anhepatic phase was 43 ± 4 min in the laparoscope group and 23 ± 2 min in the manual assistance group (P < 0.01). CONCLUSIONS: Our study showed that magnetic-assisted laparoscopic liver transplantation can be successfully carried out in pigs.
Assuntos
Laparoscopia , Transplante de Fígado , Anastomose Cirúrgica/métodos , Animais , Humanos , Transplante de Fígado/métodos , Doadores Vivos , Fenômenos Magnéticos , Veia Porta/diagnóstico por imagem , Veia Porta/cirurgia , Suínos , Veia Cava Inferior/cirurgiaRESUMO
In this study, liquid chromatography-mass spectrometry(LC-MS) and high performance liquid chromatography(HPLC) were employed for qualitative and quantitative analysis of the steroidal saponins in rhizomes of Paris polyphylla var. yunnanensis from three different habitats cultured in vitro, in an attempt to explore whether the rhizomes of the medicinal herb cultured in vitro can synthesize the steroidal saponins, including polyphyllinsâ , â ¡, and â ¦, the quality markers specified in Chinese Pharmacopoeia(2020 edition). A total of 20 steroidal saponins were identified in the rhizomes from Changxin, Yunlong(S1), Fengyi, Dali(S2), and Niujie, Eryuan(S3): parisyunnanoside A and parisyunnanoside D or E, proto-polyphyllin â ¡, polyphyllins G and H, polyphyllinsâ , â ¡, â ¤, â ¥, and â ¦, dioscin, gracillin, prosapogenin A, Tg, isomer of Th, saponin Th, reclinatoside, proto-pairs D, pseudoproto-dioscin, and 23-O-glc-(23S,25R)-spirost-5-en-3ß,23α,27-triol-3-O-rha-(1â2)-[ara(1â4)]-glc or 27-O-glc-(23S,25R)-spirost-5-en-3ß,27α-diol-3-O-rha-(1â2)-[ara(1â4)]-glc. Among them, polyphyllinsâ , â ¡, and â ¦ were detected in the rhizomes from S1, with the mass fraction of 0.109 1%, 0.165 2%, and 0.051 03%, respectively(total 0.325 3%). Polyphyllins â ¡ and â ¦ were identified in the rhizomes from S2 with the respective mass fraction of 0.192 2% and 0.074 23% and total content of 0.266 5%. Moreover, polyphyllins â ¡ and â ¦ were also found in the rhizomes from S3, which had the mass fraction of 0.207 7% and 0.186 9%, separately, with the total content of 0.394 6%. Thus, steroidal saponins, including the quality makers polyphyllins â , â ¡, and â ¦ recorded in Chinese Pharmacopoeia(2020 edition) can be synthesized in rhizomes of Paris polyphylla var. yunnanensis cultured in vitro, but their total content fails to meet the standard(0.60% in Chinese Pharmacopoeia). Therefore, in vitro culture of the Paris polyphylla var. yunnanensis is feasible, but the culture conditions need to be further improved.
Assuntos
Liliaceae , Melanthiaceae , Saponinas , Cromatografia Líquida de Alta Pressão , RizomaRESUMO
Biofilms formed by methicillin-resistant Staphylococcus aureus (MRSA) are one of the contributing factors to recurrent nosocomial infection in humans. There is currently no specific treatment targeting on biofilms in clinical trials approved by FDA, and antibiotics remain the primary therapeutic strategy. In this study, two anthraquinone compounds isolated from a rare actinobacterial strain Kitasatospora albolonga R62, 3,8-dihydroxy-l-methylanthraquinon-2-carboxylic acid (1) and 3,6,8-trihydroxy-1-methylanthraquinone-2-carboxylic acid (2), together with their 10 commercial analogs 3-12 were evaluated for antibacterial and antibiofilm activities against MRSA, which led to the discovery of two potential antibiofilm anthraquinone compounds anthraquinone-2-carboxlic acid (6) and rhein (12). The structure-activity relationship analysis of these anthraquinones indicated that the hydroxyl group at the C-2 position of the anthraquinone skeleton played an important role in inhibiting biofilm formation at high concentrations, while the carboxyl group at the same C-2 position had a great influence on the antibacterial activity and biofilm eradication activity. The results of crystal violet and methyl thiazolyl tetrazolium staining assays, as well as scanning electron microscope and confocal scanning laser microscopy imaging of compounds 6 and 12 treatment groups showed that both compounds could disrupt preformed MRSA biofilms possibly by killing or dispersing biofilm cells. RNA-Seq was subsequently used for the preliminary elucidation of the mechanism of biofilm eradication, and the results showed upregulation of phosphate transport-related genes in the overlapping differentially expressed genes of both compound treatment groups. Herein, we propose that anthraquinone compounds 6 and 12 could be considered promising candidates for the development of antibiofilm agents.
RESUMO
Di(1H-indol-3-yl)methane (DIM) was previously suggested to be an environmentally friendly antifouling compound, but it was also reported that the compound was highly stable in natural seawater. The present study reported that 3 h DIM treatments at 4 µg mL-1 or higher concentration and 12 h DIM treatments at 2 µg mL-1 or higher concentration induced significant larval mortality and metamorphic abnormality in the bryozoan Bugula neritina. The bioassay results correlated with the dose-dependent up-regulation of HSP family proteins, pro-apoptotic proteins, ubiquitination protein, and the dose-dependent down-regulation of anti-apoptotic genes and developmental genes. Unexpectedly, genes involved in fatty acid biosynthesis and protein synthesis were up-regulated in response to DIM treatment, but, in general, the effects of DIM on B. neritina larvae were comparable to that reported in human cancer cell lines. DIM also induced changes in steroid hormone biosynthesis genes in B. neritina larvae, leading to the concern that DIM might have long-term effects on marine lives. Overall, the present study suggested that application of DIM to the bryozoan larvae would trigger a major transcriptomic response, which might be linked to the observed larval mortality and abnormality. We suggest that application of DIM as an antifouling ingredient should be proceeded with great cautions.
Assuntos
Incrustação Biológica , Briozoários , Animais , Larva , Metano , TranscriptomaRESUMO
Strain XY-J91T, a Gram-stain-negative, reddish orange, non-spore-forming and short-rod-shaped marine bacterium, was isolated from rhizosphere soil of the mangrove plant Kandelia candel (L.) Druce in Mai Po Nature Reserve, Hong Kong. The strain showed growth at 15-50 °C (optimum 40 °C), at pH 5.5-9.5 (optimum 7.0-8.0) and with 0-8â% (w/v) NaCl (optimum 1-2â%). The only respiratory quinone was MK-7 and the major fatty acids were iso-C15â:â0 and iso-C17â:â0 3-OH. The major polar lipids were phosphatidylethanolamine, an unidentified aminolipid and an unidentified phospholipid. The G+C content of strain XY-J91T was 40.4 mol%. Strain XY-J91T exhibited highest 16S rRNA gene sequence similarities to the type strains of Algoriphagus marincola SW-2T (96.66â%), Algoriphagus taiwanensis CC-PR-82T (96.21%), Algoriphagus ornithinivorans JC2052T (96.16%), Algoriphagus confluentis HJM-2T (95.73%) and Algoriphagus zhangzhouensis 12C11T (95.52â%). Based on the phylogenetic, phenotypic and chemotaxonomic evidence presented, strain XY-J91T represents a novel species of the genus Algoriphagus, for which the name Algoriphagus kandeliae sp. nov. is proposed. The type strain is XY-J91T (=MCCC 1K03612T=KCTC 72216T).
Assuntos
Bacteroidetes/classificação , Filogenia , Rhizophoraceae/microbiologia , Rizosfera , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Bacteroidetes/isolamento & purificação , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hong Kong , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMO
A novel perylenequinone-related compound, alternatone A (1), with an unprecedented tricyclo[6.3.1.02,7] dodecane skeleton, together with three known perylenequinones, altertoxin I (2), stemphyperylenol (3), and alterperylenol (4), was isolated from the soft-coral-derived fungus Alternaria alternata L3111'. Their structures including absolute configurations were elucidated on the basis of comprehensive spectroscopic analysis, electronic circular dichroism calculations, and X-ray diffraction data. Compound 4 showed cytotoxicity against A-549, HCT-116, and HeLa cell lines with IC50 values of 2.6, 2.4, and 3.1 µM, respectively. A possible biosynthetic pathway of 1 was proposed.
Assuntos
Alternaria/química , Antozoários/microbiologia , Perileno/análogos & derivados , Quinonas/química , Quinonas/farmacologia , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Perileno/química , Perileno/farmacologia , Difração de Raios XRESUMO
A Gram-negative, rod-shaped and motile bacterium, designated strain J95T, was isolated from the rhizosphere soil of a mangrove plant Kandeliacandel (L.) Druce in Mai Po Nature Reserve, Hong Kong. Growth of strain J95T was observed at pH 5.0-8.5 (optimum, 6.0-7.0), between 10-40 °C (30-37 °C) and in the presence of 0-9â% (w/v) NaCl (0.5-3â%). Chemotaxonomic analysis showed ubiquinone-10 as the predominant respiratory quinone and C18â:â1ω7c and C19â:â0 cycloω8c as the major fatty acids. The major polar lipids were lipid, aminolipid, phospholipid, phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine. The genomic contained a circular chromosome of 5.48 Mb with a DNA G+C content of 65.7 mol%. The genome included 5299 genes. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain J95T belongs to the genus Ruegeria with highest sequence similarity (96.8â%) to the type strain Ruegeria marina ZH17T. The combined phenotypic, chemotaxonomic and phylogenetic data suggested that strain J95T represents a novel species of the genus Ruegeria, for which the name Ruegeria kandeliae sp. nov. is proposed. The type strain is J95T (=MCCC 1K03284T=DSM 104293T).
Assuntos
Filogenia , Rhizophoraceae/microbiologia , Rizosfera , Rhodobacteraceae/classificação , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hong Kong , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Rhodobacteraceae/genética , Rhodobacteraceae/isolamento & purificação , Análise de Sequência de DNA , Ubiquinona/químicaRESUMO
A Gram-stain-negative, non-flagellated, short rod-shaped bacterium, designated XY-R6T, was isolated from the rhizosphere soil of a mangrove plant, Kandelia candel (L.) Druce, in Mai Po Nature Reserve, Hong Kong. Growth of strain XY-R6T was observed at pH 5.0-9.5 (optimum 6.5-8.0), between 8 and 42 °C (optimum 28-34 °C), and in the presence of 0-9.5â% (w/v) NaCl (optimum 1-4â%). The predominant isoprenoid quinone was ubiquinone-10. The major fatty acids were summed feature 8 (C18â:â1ω6c and/or C18â:â1ω7c) (55.61â%), C19â:â0cycloω8c (21.59â%) and C16â:â0 (11.24â%). The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, aminolipid, phosphatidylcholine and diphosphatidylglycerol. The genomic DNA G+C content of strain XY-R6T was 69.3 mol%. Phylogenetic analyses, based on 16S rRNA gene sequences, revealed that strain XY-R6T belonged to the family Rhodobacteraceae of the class Alphaproteobacteria and formed a distinct lineage, showing the highest gene sequence similarities to the members of genus Wenxinia(94.5-94.3â%), followed by the genera Profundibacterium (94.3â%), Defluviimonas(93.8-92.5â%), Oceanicola (93.8â%) and Cereibacter (93.7â%). Similarities to other genera within the family Rhodobacteraceae were below 94.0â%. Based on comprehensive phenotypic, phylogenetic and chemotaxonomic characterization, it is indicated that strain XY-R6T represents a novel species of a new genus in the family Rhodobacteraceae, for which the name Kandeliimicrobium roseum gen. nov., sp. nov. is proposed, with XY-R6T (=MCCC 1K01498T=KCTC 52266T=DSM 104294T) as the type strain.
Assuntos
Filogenia , Rhizophoraceae , Rizosfera , Rhodobacteraceae/classificação , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hong Kong , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Rhodobacteraceae/genética , Rhodobacteraceae/isolamento & purificação , Análise de Sequência de DNA , Ubiquinona/químicaRESUMO
BACKGROUND: Low expression of E2F3a and caspase 8 associated protein 2 (CASP8AP2) are associated with poor prognosis of childhood acute lymphoblastic leukemia (ALL). METHODS: Dual-luciferase reporter assay and wild type as well as four mutated types of reporter plasmids were used to demonstrate the activation of E2F3a on CASP8AP2 transcription. The direct binding of E2F3a with the promoter of CASP8AP2 was shown by Chromatin Immunoprecipitation (ChIP). Cell proliferation activity and cell cycle were determined by MTS and flow cytometry in leukemic cells after treating with common chemotherapeutic drugs vincristine and daunorubicin. RESULTS: In this study, we found that up-regulation of E2F3a in leukemic cells led to increased fraction of cells in S and G2/M phase, accelerated proliferation, and enhanced sensitivity to vincristine and daunorubicin. ChIP and luciferase assay indicated that E2F3a could directly bind to two fragments in the wild type of CASP8AP2 promotor (- 206 to - 69 and - 677 to - 507), and activate its transcription activity which was reduced in mutated promotors. The effect of E2F3a on chemotherapeutic sensitivity of leukemic cells could be reversed by down-regulating CASP8AP2. CONCLUSIONS: E2F3a could promote transcription and expression of CASP8AP2. The effect of E2F3a on chemotherapeutic sensitivity of ALL cells was implemented by regulating CASP8AP2 expression to a great extent.
RESUMO
The aim of this research is to explore the biological and chemical diversity of bacteria associated with a marine flatworm Paraplanocera sp., and to discover the bioactive metabolites from culturable strains. A total of 141 strains of bacteria including 45 strains of actinomycetes and 96 strains of other bacteria were isolated, identified and fermented on a small scale. Bioactive screening (antibacterial and cytotoxic activities) and chemical screening (ultra-performance liquid chromatography-mass spectrometry (UPLC-MS)) yielded several target bacterial strains. Among these strains, the ethyl acetate (EA) crude extract of Streptomyces sp. XY-FW47 fermentation broth showed strong antibacterial activity against methicillin-resistant Staphylococcus aureus ATCC43300 (MRSA ATCC43300) and potent cytotoxic effects on HeLa cells. The UPLC-MS spectral analysis of the crude extract indicated that the strain XY-FW47 could produce a series of geldanamycins (GMs). One new geldanamycin (GM) analog, 4,5-dihydro-17-O-demethylgeldanamycin (1), and three known GMs (2-4) were obtained. All of these compounds were tested for antibacterial, cytotoxic, and antifungal activities, yet only GM (3) showed potent cytotoxic (HeLa cells, EC50 = 1.12 µg/mL) and antifungal (Setosphaeria turcica MIC = 2.40 µg/mL) activities. Their structure-activity relationship (SAR) was also preliminarily discussed in this study.
Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Platelmintos/microbiologia , Actinobacteria/química , Actinobacteria/genética , Animais , Benzoquinonas/metabolismo , Sedimentos Geológicos/microbiologia , Células HeLa , Humanos , Lactamas Macrocíclicas/metabolismo , Biologia Marinha , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Streptomyces/química , Relação Estrutura-AtividadeRESUMO
Biofouling causes huge economic loss and generates serious ecological issues worldwide. Marine coatings incorporated with antifouling (AF) compounds are the most common practices to prevent biofouling. With a ban of organotins and an increase in the restrictions regarding the use of other AF alternatives, exploring effective and environmentally friendly AF compounds has become an urgent demand for marine coating industries. Marine microorganisms, which have the largest biodiversity, represent a rich and important source of bioactive compounds and have many medical and industrial applications. This review summarizes 89 natural products from marine microorganisms and 13 of their synthetic analogs with AF EC50 values ≤ 25 µg/mL from 1995 (the first report about marine microorganism-derived AF compounds) to April 2017. Some compounds with the EC50 values < 5 µg/mL and LC50/EC50 ratios > 50 are highlighted as potential AF compounds, and the preliminary analysis of structure-relationship (SAR) of these compounds is also discussed briefly. In the last part, current challenges and future research perspectives are proposed based on opinions from many previous reviews. To provide clear guidance for the readers, the AF compounds from microorganisms and their synthetic analogs in this review are categorized into ten types, including fatty acids, lactones, terpenes, steroids, benzenoids, phenyl ethers, polyketides, alkaloids, nucleosides and peptides. In addition to the major AF compounds which targets macro-foulers, this review also includes compounds with antibiofilm activity since micro-foulers also contribute significantly to the biofouling communities.
Assuntos
Organismos Aquáticos/química , Incrustação Biológica/prevenção & controle , Produtos Biológicos/química , Biologia Marinha , Relação Estrutura-AtividadeRESUMO
A series of 30 sclerotioramine derivatives (2-31) of the natural compound, (+)-sclerotiorin (1), has been successfully semi-synthesized by a one-step reaction with high yields (up to 80%). The structures of these new derivatives were established by extensive spectroscopic methods and single-crystal X-ray diffraction analysis for 3, 6, and 10. (+)-Sclerotiorin (1) and its semisynthetic derivatives (2-31) were evaluated for their antifouling activity. Most of them except 6, 7, 8, 12, and 28 showed potent antifouling activity against the larval settlement of the barnacle Balanus amphitrite. More interestingly, most of the aromatic amino-derivatives (13-17, 19-21, 23, 25-27, and 29-31) showed strong antifouling activity; however, only two aliphatic amino-derivatives (5 and 10) had the activity.
Assuntos
Benzopiranos/química , Benzopiranos/farmacologia , Incrustação Biológica/prevenção & controle , Thoracica/efeitos dos fármacos , Animais , Benzopiranos/síntese química , Concentração Inibidora 50 , Larva/efeitos dos fármacos , Penicillium/química , Penicillium/crescimento & desenvolvimento , Relação Estrutura-Atividade , Difração de Raios XRESUMO
Marine organism-derived secondary metabolites are promising potential sources for discovering environmentally safe antifouling agents. In present study, 55 marine secondary metabolites and their synthesized derivatives were tested and evaluated for their antifouling activities and security. These compounds include 44 natural products isolated from marine invertebrates and their symbiotic microorganisms collected from the South China Sea and 11 structural modified products derived from the isolated compounds. The natural secondary metabolites, covering phenyl ether derivatives, terpenoids, 9, 11-secosteroids, anthraquinones, alkaloids, nucleoside derivatives and peptides, were isolated from two corals, one sponge and five symbiotic fungi. All of the isolated and synthesized compounds were tested for their antifouling activities against the cyprids of barnacle Balanus (Amphibalanus) amphitrite Darwin. Noticeably, five phenyl ether derivatives (9, 11, 13-15) exhibited potent anti-larval settlement activity with the EC50 values lower than 3.05 µM and the LC50/EC50 ratios higher than 15. The study of structure-activity relationship (SAR) revealed that the introduction of acetoxy groups and bromine atoms to phenyl ether derivatives could significantly improve their antifouling activities. This is the first report on the SAR of phenyl ether derivatives on antifouling activity against barnacle B. amphitrite. The polybrominated diphenyl ether derivative, 2, 4, 6, 2', 4', 6'-hexabromo-diorcinol (13), which displayed excellent antifouling activity, was considered as a promising candidate of environmentally friendly antifouling agents.
RESUMO
Cochliomycin A is a compound with anti-barnacle settlement activity and low toxicity, but the molecular mechanism of the compound is unknown. Here, isobaric tags for the relative or absolute quantitation (iTRAQ) labeling proteomic method were applied to analyze changes in the proteome of Amphibalanus (=Balanus) amphitrite cyprids in response to cochliomycin A treatment. Cochliomycin A affected the cytochrome P450, glutathione S-transferase (GST) and NO/cGMP pathways, among which the NO/cGMP pathway was considered to play a key role in barnacle larval settlement, while the cytochrome P450 and the GST pathways are mainly for detoxification. The results of real-time PCR further suggested the NO/cGMP pathway was activated in response to cochliomycin A. Larval settlement assays revealed that S-methylisothiourea sulfate (SMIS) and 1H-(1,2,4)oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) rescued cyprids from cochliomycin A-induced inhibition of larval settlement. The findings supported the hypothesis that cochliomycin A inhibited barnacle larval settlement by stimulating the NO/cGMP pathway.
Assuntos
Incrustação Biológica/prevenção & controle , Hidroxibenzoatos/farmacologia , Lactonas/farmacologia , Thoracica , Animais , GMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Isotiurônio/análogos & derivados , Isotiurônio/farmacologia , Larva/efeitos dos fármacos , Larva/fisiologia , Óxido Nítrico/metabolismo , Tensoativos/farmacologia , Thoracica/efeitos dos fármacos , Thoracica/fisiologiaRESUMO
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 18.4â 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 1.56â µM for all three compounds).
Assuntos
4-Butirolactona/análogos & derivados , Antibacterianos/química , Aspergillus/química , Esteroides/química , 4-Butirolactona/isolamento & purificação , 4-Butirolactona/farmacologia , Animais , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Incrustação Biológica/prevenção & controle , Humanos , Larva/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Esteroides/isolamento & purificação , Esteroides/farmacologia , Thoracica/efeitos dos fármacosRESUMO
In the present study, eight natural products that belonged to di(1H-indol-3-yl)methane (DIM) family were isolated from Pseudovibrio denitrificans UST4-50 and tested for their antifouling activity against larval settlement (including both attachment and metamorphosis) of the barnacle Balanus (=Amphibalanus) amphitrite and the bryozoan Bugula neritina. All diindol-3-ylmethanes (DIMs) showed moderate to strong inhibitory effects against larval settlement of B. amphitrite with EC50 values ranging from 18.57 to 1.86 µM and could be considered as low-toxicity antifouling compounds since their LC50/EC50 ratios were larger than 15. Furthermore, the DIM- and 4-(di(1H-indol-3-yl)methyl)phenol (DIM-Ph-4-OH)-treated larvae completed normal settlement when they were transferred to clean seawater after being exposed to those compounds for 24 h. DIM also showed comparable antifouling performance to the commercial antifouling biocide Sea-Nine 211(™) in the field test over a period of 5 months, which further confirmed that DIMs can be considered as promising candidates of environmentally friendly antifouling compounds.
Assuntos
Incrustação Biológica/prevenção & controle , Produtos Biológicos/farmacologia , Animais , Briozoários/química , Larva/efeitos dos fármacos , Tiazóis/farmacologia , Thoracica/químicaRESUMO
Three new azaphilone derivatives, pinophilins D-F (1-3), and one new diphenyl ether derivative, hydroxypenicillide (10), together with nine known compounds (4-9, 11-13), were isolated from the gorgonian-derived fungus Penicillium pinophilum XS-20090E18. Their structures including absolute configurations were determined by spectroscopic data, chemical conversions, the ECD exciton chirality method, and ECD calculations. Compounds 10-13 exhibited inhibitory activity against the larval settlement of the barnacle Balanus amphitrite at nontoxic concentrations. Compounds 10 and 11 showed cytotoxicity against Hep-2, RD, and HeLa cell lines.