Antioxidant activity of butane type lignans, secoisolariciresinol, dihydroguaiaretic acid, and 7,7'-oxodihydroguaiaretic acid

The antioxidant activity of butane-type lignans was evaluated. Secoisolariciresinol (SECO) and dihydroguaiaretic acid (DGA) showed higher radical scavenging activity than that of 7,7'-dioxodihydroguaiaretic acid (ODGA). SECO and DGA inhibited the oxidation of unsaturated fatty acid. Both enantiomers of DGA were also lipoxygenase inhibitors, but neither enantiomer of SECO inhibited the lipoxygenase activity.     

A validated bioenergetics model for ruffe Gymnocephalus cernuus and its application to a northern lake

A bioenergetics model was constructed for ruffe Gymnocephalus cernuus , and the model was used to estimate the food consumption of a native G. cernuus stock in Pyhäjärvi, a large mesotrophic lake in south-west Finland. The parameters for the bioenergetics model were determined through laboratory experiments conducted at several temperatures between 5 and 22° C for different sized G. cernuus (from 6 to 27 g). The model was verified and validated with independent laboratory growth experiments. The validated model was applied to field data from Pyhäjärvi to estimate the food consumption of G. cernuus and its effects on the zoobenthos community during the years 2002–2004. The total annual food consumption of the G. cernuus stock ranged from 11·6 to 15·7 g m⁻² (wet mass). Chironomidae was the most abundant prey, 81% of the total consumption. The annual total production of zoobenthos in Pyhäjärvi was 15·2 g m⁻² (wet mass). Therefore, it can be concluded that G. cernuus stock is likely to exert a significant influence on the zoobenthos community in this lake, indicating a potential role of G. cernuus as an influential invasive species in many freshwater ecosystems in Europe and North America.     

6β-Hydroxyursolic acid and other triterpenoids of Enkianthus cernuus

From the leaves of Enkianthus cernuus forma rubens, a new triterpene, 6β-hydroxyursolic acid, was isolated together with several known compounds     

Larvicidal activity of (-)-dihydroguaiaretic acid derivatives against Culex pipiens

The larvicidal activity against Culex pipiens of all stereoisomers of dihydroguaiaretic acid (DGA) and secoisolariciresinol was measured, and these DGAs were found to be potent. Sixteen (-)-DGA derivatives were then newly synthesized to analyze their structure-activity relationship. Two derivatives monohydroxylated at the 3- or 4-position of the 7-phenyl group of DGA induced acute paralytic activity in the mosquitoes. Derivatives with several hydroxyl groups had lower activity than the natural compound, suggesting that hydrophobicity was probably an important factor for their insecticidal activity.     

Antioxidant activities of a new lignan and a neolignan from Saururus chinensis

A new diarylbutane lignan, 2'-hydroxy dihydroguaiaretic acid (4), and a known 8-O-4'-type neolignan, machilin D (5), were isolated from the ethyl acetate extracts of the underground parts of Saururus chinensis. Compounds 4 and 5 exhibited low-density lipoprotein (LDL)-antioxidant activity in the thiobarbituric acid-reactive substances (TBARS) assay (4: IC(50)=3.3 microM and 5: IC(50)=3.8 microM), the lag time of conjugated diene production, the relative electrophoretic mobility (REM) of ox-LDL, the apoB-100 fragmentation on copper-mediated LDL oxidation and the macrophage-mediated LDL oxidation, and radical DPPH scavenging activity.     

An invasion record for the swimbladder nematode Anguillicoloides crassus in European eel Anguilla anguilla in a deep warm-monomictic [corrected] lake, from invasion to steady state

This study is the first account of the establishment and development of the neozoic nematode parasite Anguillicoloides crassus in its host, the European eel Anguilla anguilla, in a deep, warm-monomictic [corrected] lake. A 21 year study of A. crassus took place in Upper Lake Constance (ULC), Europe's second largest pre-alpine lake. The study included two extensive surveys, one in 1991 during the initial parasite invasion phase and the second in 2006 when the infection was well established. The subtropical swimbladder nematode A. crassus was first recorded in A. anguilla in ULC in 1989. Prevalence reached 60% in 1992 and remained at this level until 2007. In 2008, prevalence decreased to 48%. Infection intensity peaked in 1993 at a mean value of 16 adult parasites per host fish. Around 90% of all A. anguilla examined displayed swimbladder lesions, with a significant trend to increasing severity over time. Moreover, heavy swimbladder lesions were seen in c. 10% of A. anguilla ready to migrate to their spawning habitat. Both ruffe Gymnocephalus cernuus and sunfish Lepomis gibbosus serve as paratenic hosts for A. crassus in ULC. Gymnocephalus cernuus seems to be the main vector, and infection is especially frequent in spring possibly caused by reduced immune system efficacy of G. cernuus during winter. In 1991, hypochromic anaemia was prevalent in ULC A. anguilla acutely infected with A. crassus, whereas in 2006 blood values were indicative of chronic infection. The growth and survival rates of A. anguilla during their continental phase were not noticeably altered in infected fish, but damage to the swimbladder probably impairs migration potential and thus the subsequent breeding success of the oceanic phase.     

Feeding of Burbot Lota lota in Modern Conditions of the Kuybyshev Reservoir

Journal of Ichthyology - The feeding of burbot Lota lota was studied in the modern conditions of the Kuibyshev Reservoir. With the decrease in the abundance of ruff Gymnocephalus cernuus in the...     

三白草(三白草科)花部器官发生

In the present study,floral organogenesis of Saururus chinensis was observed and compared with that of 5. cernuus. The two species share essentially similar patterns of floral initiation and stamen development. Their inflorescence produces "common primordia" in acropetal succession on the flanks of the inflorescence meristem. Each primordium bifurcates transversely to form a floral apex above and a bract primordium below. Six stamens arise in three pairs at the floral apex. The median sagittal pair arises first, the lateral distal pair second, and the lateral proximal pair arises last. On the contrary,the initiation of carpels is quite different from each other. In 5. cernuus, the median sagittal pair arises first, and the lateral pair next. In S. chinensis, however, the lateral pair arises first, and the median sagittal pair second. The present study also made a brief generalization using the data obtained from different fields on the relationship of the two species in the genus Saururus, which are dis     

Growth response and tissue accumulation trends of herbaceous wetland plant species exposed to elevated aqueous mercury levels

The impacts of elevated aqueous mercury levels (0, 2, and 4 ppm) on the growth status and mercury tissue concentrations of Eleocharis parvula, Saururus cernuus, Juncus effuses, Typha latifolia, and Panicum hemitomon were determined. Both short-term (net CO2 assimilation) and long-term (biomass) indicators of plant growth status suggest that Eleocharis parvula, Saururus cernuus, and Juncus effuses were relatively unimpacted by elevated mercury levels, whereas Typha latifolia and Panicum hemitomon were somewhat impacted at elevated mercury levels. Eleocharis parvula, Panicum hemitomon, and Typha latifolia generally had the greatest overall belowground tissue concentrations of mercury (2 ppm treatment: 7.21, 7.32, and 9.64 ppm respectively; 4 ppm treatment: 16.23, 18.23, and 13.98 ppm, respectively) and aboveground tissue concentrations of mercury (2 ppm treatment: 0.01, 0.04, 0.02; 4 ppm treatment: 0.26; 0.11; 0.17 ppm, respectively). However, the species investigated in this study demonstrated lower levels of mercury accumulation into tissues when compared with similar investigations of other aquatic plants, suggesting that the above species are not optimal for phytoremediation efforts.     

Structure of the component community of parasites of Gymnocephalus cernuus (Linnaeus, 1758) in different seasons

In the conditions of middle stream of Vychegda River, the species diversity of parasite community associated with Gymnocephalus cernuus was found to be maximal in March and minimal in September. It is shown, that during a year the parasite community passes through the phases of development in December-March, completion in May-June, and destruction in July-September, which form the annual cycle of the community.     

基于5.8SrDNA序列论三白草科的系统发育

三白草科（Saururaceae)是古草本的一个核心类群,它的研究对被子植物起源和早期演化具有重要意义,本文采用最大简约法（maximum parsimony method)和邻接法（neighbor-joining method)等不同的分析方法,对三白草科及其外类群齐头绒（Zippelia begoniaefolia Blume)的5.85rDNA序列进行分析,得到一致的结论：Anemopsis最早从三白草科中分离出来,Saururus chinensis和S.cernuus是一对姐群,由于5.85rDNA序列的变异位点和信息位点相对比较少,Gymnotheca chinensis-G.involucrata-Houttuynia-Saururus之间难以通过5.8SrDNA序列的比较进行分辨。     

Construction and application of a mass spectral and retention time index database generated from plant GC/EI-TOF-MS metabolite profiles

The non-supervised construction of a mass spectral and retention time index data base (MS/RI library) from a set of plant metabolic profiles covering major organs of potato (Solanum tuberosum), tobacco (Nicotiana tabaccum), and Arabidopsis thaliana, was demonstrated. Typically 300-500 mass spectral components with a signal to noise ratio > or =75 were obtained from GC/EI-time-of-flight (TOF)-MS metabolite profiles of methoxyaminated and trimethylsilylated extracts. Profiles from non-sample controls contained approximately 100 mass spectral components. A MS/RI library of 6205 mass spectral components was accumulated and applied to automated identification of the model compounds galactonic acid, a primary metabolite, and 3-caffeoylquinic acid, a secondary metabolite. Neither MS nor RI alone were sufficient for unequivocal identification of unknown mass spectral components. However library searches with single bait mass spectra of the respective reference substance allowed clear identification by mass spectral match and RI window. Moreover, the hit lists of mass spectral searches were demonstrated to comprise candidate components of highly similar chemical nature. The search for the model compound galactonic acid allowed identification of gluconic and gulonic acid among the top scoring mass spectral components. Equally successful was the exemplary search for 3-caffeoylquinic acid, which led to the identification of quinic acid and of the positional isomers, 4-caffeoylquinic acid, 5-caffeoylquinic acid among other still non-identified conjugates of caffeic and quinic acid. All identifications were verified by co-analysis of reference substances. Finally we applied hierarchical clustering to a complete set of pair-wise mass spectral comparisons of unknown components and reference substances with known chemical structure. We demonstrated that the resulting clustering tree depicted the chemical nature of the reference substances and that most of the nearest neighbours represented either identical components, as judged by co-elution, or conformational isomers exhibiting differential retention behaviour. Unknown components could be classified automatically by grouping with the respective branches and sub-branches of the clustering tree.     

Stunted growth of pikeperch Sander lucioperca in Lake Sahajärvi, Finland

Growth of pikeperch Sander lucioperca in the eutrophic and clay-turbid Lake Sahajärvi, Southern Finland, was extremely slow in comparison with other lakes at similar latitudes. The most important food item in July was phantom midge larvae Chaoborus flavicans for all sizes of S. lucioperca (239–423 mm total length L _T), while later, in August and September, the diet of S. lucioperca (149–407 mm L _T) consisted of small (30–100 mm L _T) perch Perca fluviatilis , ruffe Gymnocephalus cernuus and roach Rutilus rutilus .     

Parasite fauna of the perch fishes Percidae in waterbodies of the Kola Region

Results of the parasitological investigation of two species of perch fisches (perch Perca fluviatilis and ruff Gymnocephalus cernuus) from Kola Region are given. 63 species of parasites were found on perch in 16 waterbodies belonging to the White Sea and Barents Sea basins (Myxosporea--3, Pleurostomata--1, Suctoria--2, Peritricha--21, Protozoa incertae sedis--1, Monogenea--2, Cestoda--6, Trematoda--10, Nemadota--8, Acanthocephala--4, Hirudinea--1, Bivalvia--1, Crustacea--3). 33 species of parasites were found on ruff in 5 waterbodies belonging to the White Sea basin (Cyrtostomata--1, Hymenostomata--1, Peritricha--8, Monogenea--2, Cestoda--6, Trematoda--9, Nematoda--2, Acanthospehala--2, Bivalvia--1, Crustacea--1). Data on the infestation of perch and ruff by different parasite species are obtained, occurrence of the parasites in the examined waterbodies is shown.     

Overwinter changes in mass and lipid content of Perca fluviatilis and Gymnocephalus cernuus

The body condition, lipid reserves and mortality of 0 and 1 year‐old perch Perca fluviatilis and ruffe Gymnocephalus cernuus , sampled during the winter in Lake Constance, Germany, were compared. Length‐frequency analyses did not provide evidence for overwinter mortality in either species. The fresh and dry mass of perch as well as their lipid contents decreased during winter, while ruffe were heavier and contained more lipid at the end of the winter. The superior performance of ruffe was mainly attributed to its sensory capabilities, which allowed it to ingest zoobenthos throughout the winter, while the zooplankton feeding of perch was constrained by low light levels. In lakes that undergo a process of re‐oligotrophication, this advantage of ruffe over perch may be even more pronounced, since lower food supply during the growth season and thus lower fish lipid content at the start of winter is probably better tolerated by ruffe than by perch.     

甘肃省丛藓科植物新资料

通过对甘肃省金昌市永昌县境内龙首山及周边湿地苔藓植物进行调查鉴定,报道了甘肃省分布的丛藓科(Pottiaceae)1个新记录属——盐土藓属(Pterygoneurum Jur.)和4个新记录种——卵叶盐土藓[P.ovatum(Hedw.)Dix.]、盐土藓[P.subsessile(Brid.)Jur.]、卷叶墙藓[Tortula atrovirens(Smith)Lindb.]和狭叶链齿藓[Desmatodon cernuus(Hueb.)BruchSchimp.]。标本存放于内蒙古大学植物标本馆(HIMC)。     

Fish community structure in mesotrophic and eutrophic lakes of southern Finland: the relative abundances of percids and cyprinids along a trophic gradient

In 36 south Finnish lakes, the number of species, as well as the cyprinids:percids ratio, was dependent, not only on total phosphorus (TP), but also on lake size. Total fish biomass and cyprinid biomass increased along the TP gradient, whereas the dependence of percid biomass was less evident. Perch Perca fluviatilis and roach Rutilus rutilus strongly dominated mesotrophic lakes; in eutrophic lakes the proportion of other cyprinids and percids, such as white bream Blicca bjoerkna , bream Abramis brama , pikeperch Stizostedion lucioperca and ruffe Gymnocephalus cernuus , increased. Perch biomass was weakly related to abiotic factors but depended on roach biomass. Lake size and fish species composition are essential factors affecting fish community changes in relation to TP, and may be important as well in regulating the responses of a fish community to biomanipulation.     

The effects of food-web management on fish assemblage dynamics in a north temperate lake

There was an intensive trawl fishery in the Enonselkä basin in Lake Vesijärvi (southern Finland) in 1989–1993 and thereafter the fishing intensity declined. The fish assemblage dynamics were studied both during the years of intensive trawling and for 3 years afterwards. Roach Rutilus rutilus dominated the fish assemblage before the mass removal. The intensive trawling effectively diminished the roach stock and the present fishing intensity has been sufficient to prevent its recovery. There were significant decreasing trends in the gillnet cpue (catch per unit effort) of bream Abramis brama (L.) and bleak Alburnus alburnus (L.) while increasing trend was observed in cpue of ruffe Gymnocephalus cernuus (L.) and vendace Coregonus albula (L.). Perch Perca fluviatilis L. and pikeperch Stizostedion lucioperca (L.) showed variations in cpue but no trends existed. The proportion of cyprinids decreased while that of percids and coregonids increased in the catches. The changes in the fish assemblage were induced by the intensive fishing and by the concomitant decline in the ecosystem productivity.