Monitoring of Fe,Mn, Cu,Pb and Cd levels in two brown macroalgae from the Bulgarian Black Sea coast

Heavy metal contents (Fe, Mn, Cu, Pb and Cd) were determined in two brown macroalgal species (Cystoseira crinita and Cystoseira barbata). Samples were collected during six seasons from spring 1996 to summer 2000 from five different sites of the Bulgarian Black Sea coastal zone – Tuzlata, Ravda, Sozopol, Ahtopol and Sinemoretz. The local and seasonal metal distribution and their variations were examined.

The data obtained indicate that the two investigated species demonstrate various degrees of metal accumulation and can be used as indicators for the type and quantity of anthropogenic contamination in marine ecosystems.     

The index of ideality of correlation: improvement of models for toxicity to algae

Toxicity to algae is important characteristic of substances from ecologic point of view. The CORAL software (http://www.insilico.eu/coral) gives possibility to build up model of toxicity to algae using data on the molecular architecture and experimental toxicity, without additional data on physicochemical and/or biochemical parameters. Considerable improvement of the model is observed in the case of using the index of ideality of correlation (IIC) in the role of additional criterion of predictive potential. The IIC is calculated with using of the correlation coefficient between experimental and calculated values of endpoint for the calibration set, with taking into account the positive and negative dispersions between experimental and calculated values. The best model calculated with use the IIC is characterized (the validation set) by n?=?50, r²?=?0.947, RMSE?=?0.401 whereas, model calculated without use the IIC is characterized by n?=?50, r²?=?0.805, and RMSE?=?0.539. The suggested models are built up in accordance to five OECD principles.

     

藻类肝毒素的富集提取与分离

采用固相萃取（SPE）和高效液相色谱法（HPLC）对蓝绿藻肝毒素进行富集与分离。以悦目颤藻为研究对象,选择最佳方式破坏其细胞,使其释放出细胞内肝毒素,对肝毒素进行SPE富集提取。用反相HPLC技术,以C18柱作分离术,32%乙腈-水（含0.01mol/L乙酸铵）为流动相,达到了对藻类肝毒素的良好分离。     

大连水云科藻类的研究

大连地区水云科藻类有9属19种,其中前人报道过的2种,本地区新记录17种。在这17种中,有11种是我国首次记录。本文对新记录种的形态、生态与分布作简要描述。     

Luminaolide, a novel metamorphosis-enhancing macrodiolide for scleractinian coral larvae from crustose coralline algae

A new metamorphosis-enhancing macrodiolide, luminaolide (1), was isolated from the crustose coralline algae (CCA) Hydrolithonreinboldii. Its structure was determined by spectroscopic analysis. A fraction (1.30 μg/mL) eluted with 80% aqueous MeOH by ODS gel column chromatography of the same CCA extract induced larval metamorphosis (25.9 ± 7.4%) against Leptastrea purpurea, and its metamorphosis-inducing activity was further enhanced to 92.6 ± 2.9% with the addition of 1 (25.6 ng/mL).     

匐枝马尾藻的化学成分研究

首次报道从中国北海匐枝马尾藻Sargassum polycystcum分离得到3个纯化合物 ，经过MS，IR，~1H NMR，~(13)C NMR（DEPT），HMQC和HMBC等波谱技术鉴定为： 豆甾-3β-羟基-5，23，25-三烯(1)，3-二下五烷氧基-1，2-丙二醇(2)，24ξ-甲 基胆甾-3β，5α，6β，25-四醇-25-乙酸酯(3)，其中化合物1为新化合物。     

网胰藻Hydroclathrus clathratus的化学成分研究

报道从中国南海网胰藻Hydroclathrus clathratus中分离得到3个单体化合物,经过MS,IR,1HNMR,13CNMR(DEPT),HMQC和HMBC等波谱技术鉴定为:(6R,7aS)-6-羟基-4,4,7a-三甲基-2,4,5,6,7,7a-六氢苯并呋喃-2-酮(1),1-(2-脱氧-β-D-呋喃核糖)-5-甲基-1,2,3,4-四氢嘧啶-2,4-二酮(2),尿嘧啶(3),并通过X射线单晶衍射实验确定化合物1的立体结构,其中化合物1是首次从自然界中分离得到.     

New Cytotoxic Laurene‐, Cuparene‐, and Laurokamurene‐Type Sesquiterpenes from the Red Alga Laurencia obtusa

Three new sesquiterpene alcohols, laur‐2‐ene‐3,12‐diol ( 1 ), cuparene‐3,12‐diol ( 2 ), and 8,11‐dihydro‐1‐methoxylaurokamuren‐12‐ol ( 3 ), along with one known diterpene, kahukuen‐10‐ol ( 4 ) have been isolated from the organic extract of the red alga Laurencia obtusa. The chemical structures were elucidated on the basis of spectroscopic analysis. The cytotoxicity of the isolated compounds were evaluated against three cancer cell lines, i.e., KB, HepG2, and MCF‐7. Compound 4 exhibited a wide range of cytotoxic activity against KB, HepG2, and MCF‐7 cell lines with IC₅₀ of 0.100, 0.057, and 0.054 μm, respectively. In addition, 1 showed moderate activities towards KB and MCF‐7 cell lines with IC₅₀ values of 0.171 and 0.184 μM , respectively and 2 exhibited a moderate activity against KB cell line at a concentration of 0.213 μg/ml. On the other hand, compound 3 exhibited no cytotoxic activity against any of the three cell lines.     

Effect of a plant fortifier (Boundary) on pests and predators of greenhouse vegetable crops

Boundary, a plant fortifier composed of extracts of Sophora flavescens Aiton and brown algae, was tested for control of the leaf miner Tuta absoluta (Meyrick) on tomato (three trials) and of the red spider mite Tetranychus urticae Koch on eggplant (one trial) and for side effects on the whitefly predator Macrolophus pygmaeus (Kambur) (two trials) on tomato and on the thrips predators Orius laevigatus (Fieber) and Amblyseius swirskii Athias-Henriot (two trials) on pepper, all in cold greenhouses in South Italy. Control rates for T. absoluta were moderate (40–70%) in the autumn crop but very high and comparable to those for emamectin benzoate in the spring crops (96–100%). Boundary compared well with abamectin against T. urticae, with near complete control. M. pygmaeus was moderately injured in late autumn, but not in early autumn. At the tested application rate and predator population density Boundary was safe for O. laevigatus and A. swirskii.     

High performance liquid chromatographic separation of polar and non-polar chlorophyll pigments from algae using a wide pore polymeric octadecylsilica column

A method employing a wide pore polymeric reversed phase column has been developed for the separation of most of the chlorophylls and related compounds previously described as occurring in marine microalgae. The high selectivity toward molecular shape of this kind of stationary phase has enabled compounds of very similar structure, such as chlorophylls c₁, c₂ and Mg-divinylpheoporphyrin a₅ monomethyl ester, and chlorophyll a and the phytol-substituted chlorophyll c-like pigments, which commonly coelute on monomeric bonded phases, to be resolved in a single run. Some of these pigments, formerly thought to be a single compound, have, in fact, been demonstrated to be groups of two or more. The method has been successfully applied to both algal cultures and natural sea water samples. When visible light absorbance detection was used, the method proved suitable for separation of various carotenoids.