目前处于临床研究的抗肿瘤活性海洋天然产物

人们从海洋生物中分离出数万种包括萜类、甾类、多肽、聚醚类、大环内酯类、生物碱类等具有活性的化合物,目前有近二十种抗肿瘤活性化合物正处于临床研究。     

海洋放线菌的研究现状及未来展望

【背景】放线菌具有丰富的遗传和功能多样性,其次级代谢产物活性广泛,在临床医疗、农业生产和污染防治等领域都发挥着重要的作用。海洋放线菌由于其特殊的代谢途径,能产生独特的活性天然产物而受到广泛关注。【目的】探究国内外海洋放线菌领域研究的热点和趋势,为后续研究提供参考。【方法】以“marine actinomycetes or marine actinobacteria”为关键词,在Web of Science中检索海洋放线菌领域的文章进行计量分析,使用VOSviewer软件对其关键词、国家、机构、作者、发表时间进行可视化分析。【结果】海洋放线菌领域的文章发表数量总体呈逐年上升趋势,主要集中在微生物学及药学领域,中美两国在论文数量和引用频次上远超其他国家,海洋放线菌领域的研究集中在菌株的分离鉴定、活性天然产物挖掘以及生物信息学等方面。【结论】海洋放线菌在全球范围内愈发受到重视,国内外机构应当加强合作,运用生物信息学技术进一步挖掘活性次级代谢产物,推动海洋放线菌领域进一步发展。     

Chemistry and biology of maculalactone A from the marine cyanobacterium <Emphasis Type="Italic">Kyrtuthrix maculans</Emphasis>

Maculalactone A is the most abundant secondary metabolite in Kyrtuthrix maculans, a marine cyanobacterium found in the mid-high shore of moderately exposed to sheltered rocky shores in Hong Kong and South East Asia. This species appears to survive as pure colonies forming distinct black zones on the rock. Maculalactone A may provide K. maculans with a chemical defense against several marine organisms, including the common grazer, Chlorostoma argyrostoma and settlement by larvae of the barnacles, Tetraclita japonica, Balanus amphitrite and Ibla cumingii. The natural concentration of maculalactone A varied with season and also with tidal height on the shore and although a strong positive linear correlation was observed between maculalactone A concentration and herbivore grazing pressure, manipulative experiments demonstrated that grazing pressure was not directly responsible for inducing the biosynthesis of this metabolite. The potential of maculalactone A as a natural marine anti-fouling agent (i.e. as an alternative to environmentally-damaging copper- and tin-based anti-fouling paints) was investigated after achieving a gram-scale synthesis of this compound. Preliminary field trials with anti-fouling paints which contained synthetic maculalactone A as the active principle have confirmed that this compound seems to have a specific activity against molluscan settlers.     

Biosynthesis of marine natural products: isolation and characterization of a myrcene synthase from cultured tissues of the marine red alga Ochtodes secundiramea

The acyclic monoterpene myrcene is the likely progenitor of the unusual cytotoxic halogenated monoterpenes that are found in marine algae and that function as feeding deterrents to herbivores. Myrcene synthase was isolated from suspension cultures of the marine red alga Ochtodes secundiramea, representing the first enzyme of this type from a marine organism. The algal myrcene synthase produces exclusively myrcene from the natural substrate geranyl diphosphate (GDP), utilizes Mg(+2) as the required divalent metal ion cofactor, has a molecular mass of about 69 kDa, and exhibits a pH optimum near 7.2. These features are similar to those of monoterpene synthases from terrestrial organisms. When incubated with neryl diphosphate (the cis-isomer of GDP), the O. secundiramea myrcene synthase produces the cyclic monoterpene limonene, whereas incubation with (+/-)linalyl diphosphate (the tertiary allylic isomer of geranyl diphosphate) yields both acyclic and cyclic monoterpenes. These results suggest that the enzyme is incapable of isomerizing geranyl diphosphate to linalyl diphosphate, a feature common to all monoterpene cyclases from terrestrial sources. The limited catalytic capability of the myrcene synthase may reflect the ancient evolutionary origin of the producing organism. The ability to assay this enzyme in cultured algae, grown under strictly defined conditions, provides an unparalleled opportunity to delineate factors eliciting the biosynthesis of this class of secondary metabolites, to investigate the metabolic pathway leading to the halogenated monoterpenes, and to determine their role in the chemical ecology of marine algae.     

海洋天然产物的研究与开发

人们已从海藻、腔肠动物、海绵、海鞘、苔藓虫、软体动物、鱼类等海洋生物中分离到大量化学结构独特、生理活性强烈的物质。这些物质的化学结构可分为:聚醚类、大环内酯、萜类、生物碱、环肽、甾醇、多糖和不饱和脂肪酸等。其中,许多具有抗菌、抗真菌、抗肿瘤、抗病毒和心脑血管活性等作用,有的已进入临床试验阶段,可望发展成新药。     

Plant polyphenols—secondary metabolism and chemical defence: Some observations

Secondary metabolism and theories of plant-animal co-evolution are briefly discussed. Current ideas concerning the role of polyphenols as mediators of a general form of chemical defence in plants are outlined. Studies are described of the association of a group of biosynthetically inter-related polyphenols based on gallic acid and D-glucose with the protein bovine serum albumin. The results are interpreted in terms of structure-activity relationships in protein-polyphenol complexation and are used to comment on the co-evolution theory and the position of plant polyphenols in higher plant secondary metabolism and defence.     

炭角菌属真菌化学成分与生物活性研究进展

炭角菌属真菌广泛分布于温带、热带和亚热带地区,主要含有萜类、生物碱、甾醇和聚酮等次级代谢产物,具有抗氧化、抑菌和抗肿瘤等药理活性。本文综述了近10年来国内外有关炭角菌属真菌的研究情况,对其次级代谢产物进行了归纳,总结了相关代谢产物的抗氧化、抑菌和抗肿瘤等生物活性。     

白僵菌天然产物及其药理活性和生物合成研究进展

白僵菌是重要的昆虫病原真菌,能产生多肽类、聚酮类、生物碱类、苯丙素类、萜类、核苷类等多种结构类型的天然产物,其中很多天然产物显示出优良的抗肿瘤、抗菌、抗病毒和杀虫等活性,具有极大的应用开发潜力。随着白僵菌基因组测序的完成,白僵菌素、白僵菌交酯、球孢交酯、卵孢素及纤细素等活性分子的生物合成基因簇及其生物合成机制已得到阐明,这些研究将大大促进白僵菌来源的新结构活性天然产物的基因组挖掘和发现以及已知重要活性分子的开发应用。本文对已知白僵菌产生的天然产物、药理活性及重要活性分子的生物合成途径进行了概括总结,为系统开发白僵菌天然产物资源提供参考。     

Intricenyne and related halogenated compounds from Laurencia intricata

A total of eleven C₁₅ nonterpenoid halogenated compounds were isolated and characterized to varying degrees from the marine red alga Laurencia intricata. Based on IR, UV, NMR, MS and chemical data, a structure is proposed for one of these compounds which was assigned the name intricenyne.