Bioactive Bromotyrosine Derivatives from the Pacific Marine Sponge Suberea clavata (Pulitzer-Finali, 1982)

Chemical investigation of the South-Pacific marine sponge Suberea clavata led to the isolation of eight new bromotyrosine metabolites named subereins 1–8 (2–9) along with twelve known co-isolated congeners. The detailed configuration determination of the first representative major compound of this family 11-epi-fistularin-3 (11R,17S) (1) is described. Their chemical characterization was achieved by HRMS and integrated 1D and 2D NMR (nuclear magnetic resonance) spectroscopic studies and extensive comparison with literature data. For the first time, a complete assignment of the absolute configurations for stereogenic centers C-11/17 of the known members (11R,17S) 11-epi-fistularin-3 (1) and 17-deoxyfistularin-3 (10) was determined by a combination of chemical modifications, Mosher’s technology, and ECD spectroscopy. Consequently, the absolute configurations of all our new isolated compounds 2–9 were determined by the combination of NMR, Mosher’s method, ECD comparison, and chemical modifications. Interestingly, compounds 2–7 were obtained by chemical transformation of the major compound 11-epi-fistularin-3 (1). Evaluation for acetylcholinesterase inhibition (AChE), DNA methyltransferase 1 (DNMT1) modulating activity and antifouling activities using marine bacterial strains are also presented.     

大连海区海藻和无脊椎动物附生细菌对养殖网笼污损细菌的拮抗活性

以从养殖网笼上分离的6株污损细菌为指示菌,采用双层琼脂扩散法对从藻类表面分离出的192株和从无脊椎动物表面分离出的127株附生细菌进行筛选,从中获得有拮抗活性的菌株分别为60株和49株,占其测试菌株的31.3%和38.6%。从不同海藻和无脊椎动物附生细菌中可以筛选出不同得率的活性菌株,其抗菌谱和活性强度各不相同,将抗菌谱和活性强度两个参数结合,设置活性指数Index(I),经计算可知,P31、HE426和AU4111的活性最高,其I值(≥2.00)最大。研究结果表明,海藻和无脊椎动物附生细菌可能帮助宿主阻止污损细菌等污损生物的附着。     

空心莲子草中抗污损活性皂苷成分的研究

海洋污损生物危害水产养殖,为发现抗污损的天然资源,对入侵植物空心莲子草(Alternantheraphiloxeroides)进行了抗污损活性化学成分研究。分离鉴定了3个皂苷类化合物,分别为3-O-β-D-吡喃葡萄糖醛酸基齐墩果酸-28-O-β-D-吡喃葡萄糖酯(1)、3-O-β-D-吡喃葡萄糖醛酸甲酯基齐墩果酸-28-O-β-D-吡喃葡萄糖酯(2)、3-O-β-D-吡喃葡萄糖醛酸基-30-去甲基-12,20(29)-二烯齐墩果酸-28-O-β-D-吡喃葡萄糖酯(3),其中化合物2为首次从该植物中分离得到。初步的抗污损结果表明,皂苷3具有明显的杀灭污损生物藤壶的作用,活性与阳性对照CuSO4相近,但是对卤虫的毒性则远低于相同剂量的CuSO4;部分皂苷混合物也具有一定的选择性杀灭藤壶的作用。     

Inhibition of Bacterial Quorum Sensing by Extracts from Aquatic Fungi: First Report from Marine Endophytes

In our search for quorum-sensing (QS) disrupting molecules, 75 fungal isolates were recovered from reef organisms (endophytes), saline lakes and mangrove rhizosphere. Their QS inhibitory activity was evaluated in Chromobacterium violaceum CVO26. Four strains of endophytic fungi stood out for their potent activity at concentrations from 500 to 50 μg mL⁻¹. The molecular characterization, based on the internal transcribed spacer (ITS) region sequences (ITS1, 5.8S and ITS2) between the rRNA of 18S and 28S, identified these strains as belonging to four genera: Sarocladium (LAEE06), Fusarium (LAEE13), Epicoccum (LAEE14), and Khuskia (LAEE21). Interestingly, three came from coral species and two of them came from the same organism, the coral Diploria strigosa. Metabolic profiles obtained by Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS) suggest that a combination of fungal secondary metabolites and fatty acids could be the responsible for the observed activities. The LC-HRMS analysis also revealed the presence of potentially new secondary metabolites. This is, to the best of our knowledge, the first report of QS inhibition by marine endophytic fungi.     

银川市地下水防污性能研究

银川市地下水资源较丰富,但地下水污染日益严重,不仅加剧了水资源危机和供需矛盾,而且直接影响了工农业生产,破坏了生态环境,甚至威胁到城乡居民的日常饮用水安全．对银川市地下水污染进行调查和取样分析,采用DRASTIC模型,对地下水防污性能进行分析和研究,并对地下水的防污性能进行评价和分区．     

辣素防污涂料在海洋网箱网衣材料中的应用

以辣素作为海洋附着生物防污剂,研究了3种辣素防污涂料对海水养殖网衣材料的防污效果。试验于2003年4～10月进行,分别将网片涂上辣素防污涂料（5^#）、辣素-聚四氟乙烯（PTFE）（4^#）、辣素-硅酸盐防污涂料（8^#）,对照组网片无涂料（9^#）,吊挂在试验海区的生产网箱之间,网片吊挂深度为2～3m,间距为1．5m左右。试验中,每月吊挂一块新的无涂料网片,用于调查不同季节附着生物的种类和附着情况;每月测量1次海水的温度及透明度,并对网衣进行拍照、称重,计算被污损生物附着的网片占总面积的百分比。结果表明,涂有3种辣素防污涂料的网衣增重比无涂料的对照网衣的增重要小得多,说明防污涂料的防污效果都比较好,尤其是辣素一硅酸盐防污涂料（8^#）的防污效果最佳。     

Anti-Larval and Anti-Algal Natural Products from Marine Microorganisms as Sources of Anti-Biofilm Agents

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.     

海水网箱网衣碱性硅酸盐防污涂料的初步研究

本文以碱性硅酸盐为主防污剂,开发了一种防污期长、无毒、环保且高效的海水网箱网衣防污涂料：涂有该种防污涂料的试验网衣于2002年4月开始进行浅海挂网试验．为期七个月;每月一次定期对试验网片进行附着情况检查、拍照及称重。结果证明．与对照组相比,涂有硅酸盐防污涂料的网衣材料的网片增重及被附着的面积百分比均有大幅度的降低;实拍照片也证明涂有防污涂料的网片具有极佳的防污效果：根据试验结果,讨论了影响防污涂料防污效果的诸多因素。     

Marine Microbial-Derived Antibiotics and Biosurfactants as Potential New Agents against Catheter-Associated Urinary Tract Infections

Catheter-associated urinary tract infections (CAUTIs) are among the leading nosocomial infections in the world and have led to the extensive study of various strategies to prevent infection. However, despite an abundance of anti-infection materials having been studied over the last forty-five years, only a few types have come into clinical use, providing an insignificant reduction in CAUTIs. In recent decades, marine resources have emerged as an unexplored area of opportunity offering huge potential in discovering novel bioactive materials to combat human diseases. Some of these materials, such as antimicrobial compounds and biosurfactants synthesized by marine microorganisms, exhibit potent antimicrobial, antiadhesive and antibiofilm activity against a broad spectrum of uropathogens (including multidrug-resistant pathogens) that could be potentially used in urinary catheters to eradicate CAUTIs. This paper summarizes information on the most relevant materials that have been obtained from marine-derived microorganisms over the last decade and discusses their potential as new agents against CAUTIs, providing a prospective proposal for researchers.     

Isolation of antifouling substances from the Palauan sponge Protophlitaspongia aga

ABSTRACT: Fouling organisms cause serious problems by settling on ships' hulls, and other marine infrastructures. Organotin compounds have been developed as effective antifoulants. However, environmental problems are associated with these compounds. It is necessary to find antifouling substances that exhibit a lower toxicity than those substances currently used. A new pyrimidine derivative, 3,4,5,6-tetrahydro-6-hydroxymethyl-3,6-dimethyl-4-pyrimidinecarboxylic acid, (compound 1) and zooanemonin (compound 2) were isolated from the marine sponge Protophlitaspongia aga as antifouling substances against the barnacle Balanus amphitrite . We also found that α-nicotinamide ribose (compound 3) inhibited germination and the attachment of Ulva spores.