抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

介绍了Kirk—Othmer Encyclopedia of Chemical Technology（化工技术百科全书）（第五版）电子图书网络版数据库，并对该数据库使用方法和检索途径作出了说明，且结合实例简单地介绍了该数据库的检索方法。

Kirk-Othmer Encyclopedia of Chemical Technology数据库介绍及实例

Seaweed is more than the wrap that keeps rice together in sushi. Seaweed biomass is already used for a wide range of other products in food, including stabilising agents. Biorefineries with seaweed as feedstock are attracting worldwide interest and include low-volume, high value-added products and vice versa. Scientific research on bioactive compounds in seaweed usually takes place on just a few species and compounds. This paper reviews worldwide research on bioactive compounds, mainly of nine genera or species of seaweed, which are also available in European temperate Atlantic waters, i.e. Laminaria sp., Fucus sp., Ascophyllum nodosum, Chondrus crispus, Porphyra sp., Ulva sp., Sargassum sp., Gracilaria sp. and Palmaria palmata. In addition, Undaria pinnatifida is included in this review as this is globally one of the most commonly produced, investigated and available species. Fewer examples of other species abundant worldwide have also been included. This review will supply fundamental information for biorefineries in Atlantic Europe using seaweed as feedstock. Preliminary selection of one or several candidate seaweed species will be possible based on the summary tables and previous research described in this review. This applies either to the choice of high value-added bioactive products to be exploited in an available species or to the choice of seaweed species when a bioactive compound is desired. Data are presented in tables with species, effect and test organism (if present) with examples of uses to enhance comparisons. In addition, scientific experiments performed on seaweed used as animal feed are presented, and EU, US and Japanese legislation on functional foods is reviewed.

Bioactive compounds in seaweed: functional food applications and legislation

Fatty acids have been used as qualitative markers to trace or confirm predator-prey relationships in the marine environment for more than thirty years. More recently, they have also been used to identify key processes impacting the dynamics of some of the world's major ecosystems. The fatty acid trophic marker (FATM) concept is based on the observation that marine primary producers lay down certain fatty acid patterns that may be transferred conservatively to, and hence can be recognized in, primary consumers. To identify these fatty acid patterns the literature was surveyed and a partial least squares (PLS) regression analysis of the data was performed, validating the specificity of particular microalgal FATM. Microalgal group specific FATM have been traced in various primary consumers, particularly in herbivorous calanoid copepods, which accumulate large lipid reserves, and which dominate the zooplankton biomass in high latitude ecosystems. At higher trophic levels these markers of herbivory are obscured as the degree of carnivory increases, and as the fatty acids originate from a variety of dietary sources. Such differences are highlighted in a PLS regression analysis of fatty acid and fatty alcohol compositional data (the components of wax esters accumulated by many marine organisms) of key Arctic and Antarctic herbivorous, omnivorous and carnivorous copepod species. The analysis emphasizes how calanoid copepods separate from other copepods not only by their content of microalgal group specific FATM, but also by their large content of long-chain monounsaturated fatty acids and alcohols. These monounsaturates have been used to trace and resolve food web relationships in, for example, hyperiid amphipods, euphausiids and fish, which may consume large numbers of calanoid copepods. Results like these are extremely valuable for enabling the discrimination of specific prey species utilized by higher trophic level omnivores and carnivores without the employment of invasive techniques, and thereby for identifying the sources of energetic reserves. A conceptual model of the spatial and temporal dominance of group-specific primary producers, and hence the basic fatty acid patterns available to higher trophic levels is presented. The model is based on stratification, which acts on phytoplankton group dominance through the availability of light and nutrients. It predicts the seasonal and ecosystem specific contribution of diatom and flagellate/microbial loop FATM to food webs as a function of water column stability. Future prospects for the application of FATM in resolving dynamic ecosystem processes are assessed.

Fatty acid trophic markers in the pelagic marine environment.

The present review describes the biological activities of natural halogenated (Cl, Br and I) marine steroids. More than twenty biologically active steroids have shown confirmed anti-tumour, antibacterial, antiviral and other activities. The structures and reported and predicted activities of natural halogenated steroids are available. With the computer programme PASS and based on structure–activity relationships (SAR), some additional activities are also predicted, which point towards new possible applications of these lipids. This review emphasizes the role of natural halogenated steroids as an important source and potential leads for drug discovery and they are of great interest to chemists, physicians, biologists, pharmacologists and the pharmaceutical industry.

https://www.thepharmajournal.com/archives/2017/vol6issue11/PartG/6-11-53-665.pdf

Halogenated (Cl, Br and I) marine steroids and their biological activities: A brief review

Haloperoxidases are ubiquitous metalloenzymes that catalyse a variety of enantioselective oxygen-transfer reactions with hydrogen peroxide or alkylperoxides. Haloperoxidases are enzymes which catalyze the reaction of oxidation, epoxidation and sulfoxidation by hydrogen peroxide. These enzymes usually contain the FeHeme moiety or vanadium as an essential constituent at their active site, however, a few haloperoxidases which lack a metal cofactor are known. This review will examine the reactivity of the different haloperoxidases, particularly the mechanism of oxidation by hydrogen peroxide, and the mechanism of oxidation and sulfoxidation, including the newly reported regioselectivity and enantioselectivity of the haloperoxidases. The structure of chloroperoxidase, the vanadium active site and the role of critical amino acid side chains for catalysis and functional biomimetic systems, with specific relevance to the mechanism of the haloperoxidase enzymes. Advances have recently been made in using them to prepare, under controlled conditions, chiral organic molecules that are valuable for the synthesis of a wide range of useful compounds. The application of biocatalytic methods in asymmetric organic synthesis is of great interest as an alternative to chemical procedures employing chiral auxiliaries. Asymmetric oxidation of prochiral sulfides to yield optically active sulfoxides has been performed by many different techniques yielding varying enantiomeric excess values. Oxygenated metabolites are compounds that are commonly found in nature and they are produced by many different organisms. The oxygen atom is incorporated into organic compounds by enzyme-catalyzed reactions with oxygen ions as the oxygen source. For over 40 years haloperoxidases were thought to be responsible for the incorporation of mainly halogen atoms into organic molecules. However, haloperoxidases lack substrate specificity and regioselectivity, and the connection of haloperoxidases with the in vivo formation of oxygenated as well as halometabolites has been demonstrated. Recently, molecular genetic investigations showed that, at least in bacteria, fungi, and other organisms a different class of halogenases is involved in halo- and oxygenated metabolite formation. These halogenases were found to require FADH2, which can be produced from FAD and NADH by unspecific flavin reductases. The FADH 2 -dependent halogenases and haloperoxidases show substrate specificity and regioselectivity, and their genes have been detected in many halometabolite-producing organisms, suggesting that this type of halogenating enzymes constitutes the major source for halo- and oxygenated metabolite formation in bacteria and also in other organisms. Distribution of haloperoxidases in nature also is demonstrated in this brief review.

/pdf/the-use-haloperoxidases-in-organic-synthesis-selected-29z21lrslv.pdf

The Use Haloperoxidases in Organic Synthesis: Selected Reactions of Oxidation, Epoxydation and Sulfoxidation

The present state of knowledge in the chemistry of mandragora plant is reviewed. Isolations and identifications of the compounds were done from all parts of this plant. Up-to-date more than 80 substances were identified in different species of the genus Mandragora.

Substances Isolated from Mandragora Species

Mononuclear halogenated simple phenol compounds and their derivatives formed from mono- and polyhydroxybenzenes are represented in nature by metabolites of insects, fungi, plants and microorganisms living on land and in water. The structures of a hundred compounds of phenol, quinones and cyclitol types, their metabolism and data on their biological activity are considered in the review.

Natural Halogenated Mononuclear Phenol Compounds and Their Derivatives

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/vjch.201960001

Valery M. Dembitsky

Papers

Halogenated (Cl, Br and I) marine steroids and their biological activities: A brief review

The Use Haloperoxidases in Organic Synthesis: Selected Reactions of Oxidation, Epoxydation and Sulfoxidation

Substances Isolated from Mandragora Species

Natural Halogenated Mononuclear Phenol Compounds and Their Derivatives

Highly oxygenated isoprenoid lipids derived from terrestrial and aquatic sources: Origin, structures and biological activities