Toxicity and bioaccumulation of xenobiotic organic compounds in the presence of aqueous suspensions of aggregates of nano-C(60)

The potential of C(60)-nanoparticles (Buckminster fullerenes) as contaminant carriers in aqueous systems was studied in a series of toxicity tests with algae (Pseudokirchneriella subcapitata) and crustaceans (Daphnia magna). Four common environmental contaminants (atrazine, methyl parathion, pentachlorophenol (PCP), and phenanthrene) were used as model compounds, representing different physico-chemical properties and toxic modes of action. The aggregates of nano-C(60) formed over 2 months of stirring in water were mixed with model compounds 5 days prior to testing. Uptake and excretion of phenanthrene in 4-days-old D. magna was studied with and without addition of C(60) in aqueous suspensions. It was found that 85% of the added phenanthrene sorbed to C(60)-aggregates >200 nm whereas about 10% sorption was found for atrazine, methyl parathion, and pentachlorophenol. In algal tests, the presence of C(60)-aggregates increased the toxicity of phenanthrene with 60% and decreased toxicity of PCP about 1.9 times. Addition of C(60)-aggregates reduced the toxicity of PCP with 25% in tests with D. magna, whereas a more than 10 times increase in toxicity was observed for phenanthrene when results were expressed as water phase concentrations. Thus, results from both toxicity tests show that phenanthrene sorbed to C(60)-aggregates is available for the organisms. For atrazine and methyl parathion no statistically significant differences in toxicities could be observed in algal and daphnid tests as a result of the presence of C(60)-aggregates. In bioaccumulation studies with phenanthrene in D. magna it was found that the uptake of phenanthrene was faster when C(60) was present in suspension and that a 1.7 times higher steady-state concentration was reached in the animals. However, a very fast clearance took place when animals were transferred to clean water resulting in no accumulation of phenanthrene. This study is the first to demonstrate the influence of C(60)-aggregates on aquatic toxicity and bioaccumulation of other environmentally relevant contaminants. The data provided underline that not only the inherent toxicity of manufactured nanoparticles, but also interactions with other compounds and characterisation of nanoparticles in aqueous suspension are of importance for risk assessment of nanomaterials.     

Single and Combined Effects of Sediment-Associated PAHs on Three Species of Freshwater Macroinvertebrates

Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous pollutants of sediments. Sediment quality criteria often use toxicity data for individual PAHs. However, PAHs always occur in field sediments as a complex mixture of compounds. In this study, the toxicity of phenanthrene (P), fluoranthene (FLA) and benzo(k)fluoranthene (B), alone or in combination, was assessed using monospecific sediment tests of acute toxicity (between 24h and 14 days). The test sediments were spiked formulated sediments. Toxicity of PAHs was determined on a freshwater pelagic organism, Daphnia magna, on an epibenthic organism, Hyalella azteca, and on a benthic organism, Chironomus riparius. The phototoxicity of fluoranthene and phenanthrene was verified. Benzo(k)fluoranthene was not phototoxic and presented no toxicity for the three organisms tested up to 300mg/kg, concentration rarely found in the environment. For all PAHs, the toxicity towards Daphnia magna was two-fold higher in the sediment toxicity tests than in the water-only standard tests, probably due to suspended contaminated particles and contact of daphnids with sediment. For phenanthrene, the LC50s found were 50, 15 and 20mg/kg dry weight sediment, respectively for Daphnia magna, Hyalella azteca and Chironomus riparius. The bioassays on fluoranthene yielded LC50s of 10, 5 and 15mg/kg dw respectively for Daphnia magna, Hyalella azteca and Chironomus riparius. LC50s of the PAHs mixture (1/3 of each compound by weight) were around 10mg/kg dry weight sediment for Hyalella azteca and 20mg/kg for Chironomus riparius. The effects of PAHs in the mixture seemed to be synergistic. This study gives new data about PAH toxicity and showed that the additivity of PAH effects could be inadequate to assess the environmental risk.     

A caridean grass shrimp (Palaemonetes pugio Holthius) as an indicator of sediment quality in Florida coastal areas affected by point and nonpoint source contamination

Grass shrimp are one of the more widely distributed estuarine benthic organisms along the Gulf of Mexico and Atlantic coasts, but they were used infrequently in contaminated sediment assessments. Early‐life stages of caridean grass shrimp, Palaemonetes pugio (Holthius), were used in this baseline survey as indicators of sediment pore water quality for several Florida coastal areas affected by nonpoint and point sources of contamination. Static toxicity tests were conducted using 24 well culture plates assessing embryo and larval survival after 12 days exposure to pore water (interstitial water). Acute toxicity was observed in 28% of pore waters (15 of 53 samples) suggesting that sediment contamination was not widespread in the study area based on the response of this species. When toxicity was observed, grass shrimp pore water toxicity test was usually a more sensitive indicator of contamination than solid‐phase tests conducted with the epibenthic invertebrate, Mysidopsis bahia. P. pugio embryos were more sensitive than larval form and response of different brood stocks usually were similar (P>0.05) when exposed to same pore waters. Based on all considerations, this early‐life stage toxicity test shows promise being useful detecting pore water toxicity. This conclusion is based on availability of a test methodology which requires minimal space and effort, and the test species widespread geographical distribution. However, there are several remaining research needs, including the important issue of its sensitivity relative to that for other pore water test species as well as for species used in solid‐phase toxicity tests. © 2000 John Wiley & Sons, Inc. Environ Toxicol 15: 234–242, 2000     

A marine bioassay test set to assess marine water and sediment quality-its need,the approach and first results

There is a need for establishing a marine bioassay test set to assess marine water and sediment samples in Germany. The selected marine bioassay test set, two tests for the water phase (with the luminescence bacteria Vibrio fischeri and the algae Phaeodactylum tricornutum Bohlin) and a whole sediment test with the marine amphipod Corophium volutator (Pallas) is described and first results are shown.     

Performance of a miniaturized algal bioassay in phytotoxicity screening

A miniaturized and low-cost algal growth-inhibition assay, with Pseudokirchneriella subcapitata, based on the standard ISO 8692 and using 96-well microplates, was tested and optimized in this work, to be used as a useful tool for pollutant phytotoxicity screening. For validation, the performance of the microplate algal growth-inhibition assay was first compared with the standard flask assay for the toxicity testing of five reference toxicants (copper(II) sulfate, zinc sulfate, potassium permanganate, potassium dichromate and 3,5-Dichlorophenol) and six wastewater samples. Statistical evaluation of EC₅₀ results from both methods demonstrated a good agreement between microplate and flask assays either in testing chemicals (r ² = 0.975, p < 0.0017) or environmental samples toxicity (r ² = 0.984, p < 0.0001). In addition, the performance of this algal microplate bioassay was also evaluated in comparison with Lemna test, ISO 20079, for phytotoxicity assessment of 27 wastewater samples from industries and treatment plants. The results showed that the algal test was more sensitive for most of the samples, but a significant agreement between both tests was observed (r ² = 0.644, p < 0.0001). In conclusion, this miniaturized test can be a good tool to include in a battery of tests for phytotoxicity screening of a wide range of chemicals and environmental samples, with the advantage of requiring low sample volumes for the test, allowing large numbers of samples to be tested, and generating low volumes of waste.     

Effects of a pre‐incubation period on the photoinduced toxicity of polycyclic aromatic hydrocarbons to the luminescent bacterium Vibrio fischeri

Irradiation of polycyclic aromatic hydrocarbons (PAHs) in aqueous solution with simulated solar radiation (SSR; a light source with a visible light : UV‐A : UV‐B ratio similar to that of sunlight) can greatly enhance their toxicity. Two microbial toxicity tests with Vibrio fischeri were used to investigate the effect of composition of the growth medium and pre‐incubation on the photoinduced toxicity of PAHs. The assays were a short‐term test (15 min) and long‐term test (18 h). Both assays were carried out in SSR and darkness to examine for photoinduced toxicity of PAHs. For the short‐term toxicity assay, inhibition of bacterial luminescence was measured. For the long‐term toxicity assay, both inhibition of bacterial luminescence and inhibition of growth were recorded. To broaden this test, V. fischeri cells were pre‐incubated with PAHs in medium without a carbon source (minimal medium) for 8 h to facilitate assimilation and photooxidation of the contaminants, and to prevent bacterial growth at the outset of the assay. V. fischeri was more sensitive in minimal medium than in complex medium in both the short‐ and long‐term toxicity assays. Moreover, in the long‐term assay, SSR greatly increased toxicity, especially if there was a pre‐incubation period in minimal medium. This indicates that both assimilation and photooxidation of PAHs are important to their toxicity to V. fischeri. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 277–286, 2001     

Simultaneous determination of quercetin, kaempferol and (E)-cinnamic acid in vegetative organs of Schisandra chinensis Baill. by HPLC

A reversed-phase high-performance liquid chromatographic (RP-HPLC) separation method with UV spectrophotometric detection has been developed for the determination of major components in leaves and caulomas of Schisandra chinensis Baill. The flavonols (quercetin and kaempferol) and (E)-cinnamic acid were analysed after extraction with alcohol from the dry plant material. Identification was based on retention times and UV spectra by comparison with commercial standards. Quercetin, kaempferol and (E)-cinnamic acid were separated within 12 min using acetonitrile–aqueous 0.05% ortho-phosphoric acid (40:60 v/v) mobile phase. The method has been successfully applied for the quantitative analysis of all three major components in several samples from different harvests using propylparaben as the internal standard.     

Effects of Substrate Salinity on Early Seedling Survival and Growth of Scirpus robustus Pursh and Spartina alterniflora Loisel

Rooted aquatic plants are being used increasingly to test the toxicity of sediments. However, effects of naturally occurring substrate constituents on most potential test species are not well understood even though their effects could affect the test results. The objective of this study was to determine the effect of substrate salinity (NaCl) on early seedling survival and growth of the emergent macrophytes, Scirpus robustus Pursh and Spartina alterniflora Loisel. Results of four 21- and 28-day toxicity tests, conducted in an artificial sediment, indicated interspecific differences in NaCl sensitivity when based on changes in shoot, root and whole plant dry-weight biomass. Concentrations of 7.8 g NaCl/ and 19.2 g NaCl/ first reduced early seedling biomass of S. robustus and S. alterniflora (P < 0.05), respectively, when compared to plants grown in sediment containing no measurable salinity. Seedling survival was not affected at average concentrations of 17.5 g NaCl/ or less for S. robustus and 22.3 g NaCl/ or less for S. alterniflora. The results indicate that substrate salinity is an important consideration in the selection of test species for laboratory phytotoxicity tests conducted with estuarine sediments, particularly if determination of chronic toxicity attributable to anthropogenic contamination is the primary objective.     

Inhibition of growth and photosynthesis of selected green microalgae as tools to evaluate toxicity of dodecylethyldimethyl-ammonium bromide

The effect of dodecylethyldimethyl-ammonium bromide (DEAB), a quaternary ammonium, compound widely used as disinfectant, on phytoplankton of inland water systems was analysed by using an experimental model. A toxicity test was based on inhibition of photosynthesis performances (effective quantum yield from photosystem II, Φ_PSII and O₂ production) of the phytoplanktonic species Scenedesmus intermedius and Dictiosphaerium chlorelloides (Chlorophyceae) under growing doses of DEAB. A concentration-dependent toxic response was obtained in both parameters analysed. In addition, this response was almost immediate. Consequently, the measurement of both parameters (Φ_PSII and O₂ production) allows to assess DEAB toxicity with higher standards of precision and repeatability. We propose that this procedure could be used to detect presence of quaternary ammonium pollutants in freshwater.     

Toxicity assessment of wastewaters, river waters, and sediments in Austria using cost-effective microbiotests

The toxicity and chemical quality of surface water and sediment in the River Traun in Austria were studied because of recurrent fish mortality in some alpine rivers over the last few years. The analyses were carried out on samples collected during winter and summer upstream and downstream of two municipal wastewater treatment plants (WWTPs) and on effluents taken at the points of discharge of these two plants. Toxicity tests were performed on 20 samples of surface water, effluent, and sediment pore water. The test battery was composed of microbiotests with protozoans (Protoxkit F), microalgae (Algaltoxkit F), crustaceans (Daphtoxkit F magna and Thamnotoxkit F), and a higher plant (seed germination and root elongation assay on cress). Direct contact tests were performed on whole sediment with crustaceans (Ostracodtoxkit F). The physical-chemical characteristics of the surface water, effluent, and sediment pore water samples analyzed were conductivity, total hardness, pH, O(2), BOD(5), TOC, DOC, AOX, NH(4), NH(3), NO(2), PO(4)--P, Cd, Pb, Cu, and Zn. The toxicity data were expressed as percentage mortality or percentage inhibition, depending on the effect criterion of the respective assay. None of the water samples collected upstream and downstream of the WWTPs showed any significant (short-term) toxicity in either winter or in summer, but the effluents of the first municipal wastewater treatment plant were toxic to some of the test biota. All the sediment pore water samples induced serious inhibition of root growth of cress, and several pore waters were toxic to other test biota as well, particularly at the outlets of the WWTPs. The toxic character of some sediments was confirmed by direct contact tests with the ostracod crustacean. The chemical analyses did not reveal particularly high concentrations of any chemical that is very toxic. As a result no direct causal relationship could be established between the detected toxic effects and the chemical composition of the surface waters or sediment pore waters. The outcome of this preliminary study again highlights the need to complement chemical analyses with toxicity tests to determine the toxic hazard to aquatic environments that may be threatened by contamination. Furthermore, the investigations also confirmed the need to apply a battery of tests for an ecologically meaningful evaluation of the hazards of waters, sediments, and wastewaters. Finally, the results of the 360 bioassays performed show that culture-independent microbiotests are practical and reliable tools for low-cost toxicity monitoring of aquatic environments.     

Physiological response ofLemna species to herbicides and its probable use in toxicity testing

Herbicides such as atrazine, diuron, simazine and glyphosate are of growing concern with respect to ecotoxicity as they are often encountered in outdoor water samples. The present study evaluates the potential damage caused by these xenobiotics on physiology of the aquatic plantLemna sp., thereby proposing its use as a probable bioindicator. Comparative study of a panel of classical endpoints (frond number and relative growth rate) and chlorophyll fluorescence parameters (F_o, F_m, NPQ, F_v/F_m and ETR_max) revealed that diuron caused maximum inhibition of increase in frond number. This coincided with the toxicity ranking obtained on the basis of RGR_area and RGR_FW i.e. diuron>atrazine>simazine>glyphosate. The chlorophyll (chl)a fluorescence parameters revealed a concentration dependent decline in maximal fluorescence (F_m) in the plants exposed to diuron, atrazine and simazine; this decline was negligible in presence of glyphosate. Besides, an EC₅₀ of 0.009 (0.008–0.010) mg/L was recorded in case of F_v/F_m of the diuron exposedLemna sp.; furthermore, the glyphosate exposed plant demonstrated EC₅₀s>16 mg/L. ETR_max ofLemna sp. significantly (p<0.001) declined in presence of diuron, atrazine and simazine, whereas glyphosate did not cause any significant (p>0.05) reduction. A steady concentration-dependent decline in chl a fluorescence parameters ofLemna sp. (specifically F_v/F_m and ETR_max) as compared to the classical endpoints, demonstrated their superiority and sensitivity in detection of herbicides in the aquatic bodies. This study emphasizes on the probable use of chlorophyll fluorescence ofLemna sp. as a tool or bioindicator in evaluation of herbicides.     

Sediment contaminants and microtox toxicity tested in a direct contact exposure test

Limnic and brackish water sediments were tested in a modified contact exposure bioluminescence test, the Microtox test. A variety of chemical constituents were analyzed in the sediments such as metals, chlorinated pesticides, and polychlorinated biphenyls. Sulfur in the common elemental form and pore water hydrogen sulfide were also analyzed. The measured effect in the Microtox toxicity test was correlated with the various chemical parameters to determine the origin of the toxic effect. Based on multivariate data anlaysis, a group of metals including Cu, Zn, Pb, and Cd were correlated positively with the Microtox toxicity tested in the direct contact test. Similarly, but to a lesser extent sulfur, hydrogen sulfide, and the pesticides p,p′-DDT and p,p′-DDD were also correlated. Other pesticides and all the analyzed polychlorinated biphenyls were poorly, if at all, correlated with the toxicity of the samples. In a comparison with the Microtox toxicity of the pure compounds, it was found that, of the analyzed and tested compounds, Zn, Pb, Cu, and elemental sulfur were present in amounts high enough to produce an effect in the test system. This calculation was, however, based on the assumption (unrealistic) that the total amount of a compound in the sediment was available in the test. On the other hand, the metals Cd, Cr, and Ni were found at concentrations of a few percent or less of their EC₅₀ concentrations in the Microtox test of the sediment, γ-Hexachlorocyclohexane and p,p′-DDT were also far less than the concentration required to give an effect in the test system. The pore water content of hydrogen sulfide was also too small to affect the test organism at the EC₅₀ dilution and, similarly, the fraction of the toxicant in the remaining aqueous phase in the sediment after separation of the pore water. Thus only the three metals Zn, Pb, and Cu, and elemental sulfur, were found in concentrations that would give an effect in the test system (0.68–398 times the effect), provided that the substances were available for the organisms. Consequently, elemental sulfur, Zn, Pb, and Cu were indicated as causing the effect in the Microtox test of sediments and not a series of other metal ions, nor tested chloropesticides or chlorinated biphenyls. © 1996 by John Wiley & Sons, Inc.     

Evolution of algal toxicity during (photo)oxidative degradation of diuron

In the aquatic environment and in engineered water treatment systems, organic contaminants can undergo oxidative and photochemical transformations. For an overall risk assessment, the toxicity of the resulting transformation products has to be investigated. In this study, the toxicity of degradation products of diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) formed during its degradation by four (photo)oxidative processes (direct phototransformation, triplet-induced photosensitized oxidation, oxidation by hydroxyl radicals and ozone) was investigated in buffered aqueous solution. The toxicity was evaluated using the combined algae test with Pseudokirchneriella subcapitata that determines both, specific inhibition of photosynthesis and inhibition of the growth rate. The comparison between evolution of toxicity and degradation kinetics indicated that the toxicity during all studied processes was caused predominantly by diuron whereas the formation of degradation products did not contribute to the mixture toxicity. This implies that, if any more toxic transformation products than diuron were formed, their concentration was not sufficiently high to affect the mixture toxicity, which was dominated by the parent compound diuron. On this account, no further studies on identification of degradation products and their toxicity are needed. This study presents an example of a systematic and simple first tier method to assess the toxicity of degradation products.     

Effects of selected PAHs on reproduction and survival of the calanoid copepod <Emphasis Type="Italic">Acartia tonsa</Emphasis>

The effects of selected polycyclic aromatic hydrocarbons on the marine calanoid copepod Acartia tonsa were tested in laboratory short-term toxicity tests in order to facilitate risk assessment of those compounds to the marine pelagic environment. Photo-induced toxicity of pyrene was also investigated under naturally relevant UV light regimes. Lethal and sublethal effects on egg production rate, hatching and potential recruitment rate were evaluated after 48 h exposure to fluoranthene, phenanthrene and pyrene. The 48 h-median lethal concentrations (LC₅₀) reducing survival by 50% were 594, 2,366 and >640 nM for fluoranthene, phenanthrene and pyrene, respectively, whilst lower concentrations induced different sublethal effects. Median effective concentrations (EC₅₀) affecting the egg production rate and the recruitment rate were 433 and 385 (fluoranthene), 1,245 and 1,012 (phenanthrene) and 306 and 295 nM (pyrene), respectively. An increase in toxicity of pyrene was detected after incubation under UV light, resulting in LC₅₀ values of 201 nM (24 h) and 138 nM (48 h) and EC₅₀ values of 79 nM (egg production rate) and 41 nM (recruitment rate). Finally, a comparison between effective concentrations and worst-case environmental concentrations reported in literature indicated that pyrene may pose a threat to A. tonsa from exposure in the field, and that the risk of adverse effects is high for fluoranthene.     

Phytotoxicity assay of crop plants to phenanthrene and pyrene contaminants in acidic soil

Four selected plants (corn, groundnut, cow pea, and mungbean) were tested for their ability to germinate and grow in an acidic soil contaminated with phenanthrene or pyrene, two typical polycyclic aromatic hydrocarbons (PAHs). The growth of corn root was the least sensitive to, but its germination rate was the lowest in the presence of, contaminants. Among the legumes, the growth of groundnut root was better than others. Corn and groundnut were selected to further test their ability to tolerate a mixture of phenanthrene and pyrene in the acidic soil. The presence of both PAHs led to a greater decrease in the lengths of shoot and root of groundnut than phenanthrene or pyrene alone, but the lengths of shoot and root of corn were decreased to a similar extent as when phenanthrene or pyrene was present alone. The growth of corn root was also better than that of groundnut root when they were grown in oil-contaminated soil. Based on these results, we conclude that corn is the most suitable to be grown in PAH-contaminated acidic soil.     

Ecotoxicity assessment of the aquatic environment around Lake Kojima,Japan

To reduce the impact of chemical substances on the aquatic ecosystem, it is essential to understand their ecotoxicological properties in the natural aquatic environment. Consequently, we conducted an ecotoxicological study on the aquatic environment around Lake Kojima, a man-made lake located in the southwest of Japan. Lake Kojima receives its chemical inputs mainly from two rivers that flow through various agricultural and industrial areas. For ecotoxicity screening, surface water and sediment samples were collected 4 times in 1993 from 16 preselected sites. Then, the solutes in the filtered surface water were concentrated by ODS resin, and the organic chemicals in the suspended solids (SS) and sediments were extracted by acetone. A battery of five ecotoxicity tests (agar plate test using bacteria and yeast, algal growth inhibition test, Daphnia magna immobilization test, and root elongation test using lettuce seeds) was used to assess these extracts. The results show that the surface water extracts had a lethal effect on D. magna, the SS extracts suppressed algal growth, and the sediment extracts were inhibitory to the growth of yeast. A significant inhibitory effect by the sediment extracts from 4 lake sites and 3 river sites was detected by these ecotoxicity tests. Attempts also were made to identify the putative ecotoxic chemicals in the collected samples. Elementary sulfur was identified as one of the major toxicants in the sediment extracts that were inhibitory to the yeast growth. Moreover, samples of surface water around Lake Kojima, collected weekly from June to September in 1994, were found to contain three pesticides and were toxic to D. magna. But the concentration of the pesticides detected was too low to cause daphnia immobilization. It is believed that the toxicity of the water extracts was mainly due to the combined toxic effect of natural and man-made components. © 1996 by John Wiley & Sons, Inc.     

Toxicity assessment of reference and natural freshwater sediments with the LuminoTox assay

We examined the possibility of adapting the LuminoTox, a recently-commercialized bioanalytical testing procedure initially developed for aqueous samples, to assess the toxic potential of sediments. This portable fluorescent biosensor uses photosynthetic enzyme complexes (PECs) to rapidly measure photosynthetic efficiency. LuminoTox testing of 14 CRM (Certified Reference Material) sediments was first undertaken with (1) a "solid phase assay" (Lum-SPA) in which PECs are in intimate contact with sediment slurries for a 15 min exposure period and (2) an elutriate assay (Lum-ELU) in which PECs are exposed for 15 min to sediment water elutriates. CRM sediment toxicity data were then compared with those generated with the Microtox Solid Phase Assay (Mic-SPA). A significant correlation (P < 0.05) was shown to exist between Lum-SPA and Mic-SPA, indicating that both tests display a similar toxicity response pattern for CRM sediments having differing contaminant profiles. The sediment elutriate Lum-ELU assay displayed toxicity responses (i.e. measurable IC20s) for eight of the 14 CRM sediments, suggesting that it is capable of determining the presence of sediment contaminants that are readily soluble in an aqueous elutriate. Lum-SPA and Mic-SPA bioassays were further conducted on 12 natural freshwater sediments and their toxicity responses were more weakly, yet significantly, correlated. Finally, Lum-SPA testing undertaken with increasing mixtures of kaolin clay confirmed that its toxicity responses, in a manner similar to those reported for the Mic-SPA assay, are also subject to the influence of grain size. While further studies will be required to more fully understand the relationship between Lum-SPA assay responses and the physicochemical makeup of sediments (e.g., grain size, combined presence of natural and anthropogenic contaminants), these preliminary results suggest that LuminoTox testing could be a useful screen to assess the toxic potential of solid media.     

Seasonal variation in the content of a febrifugine and isofebrifugine alkaloid mixture in aerial parts of <Emphasis Type="Italic">Hydrangea macrophylla</Emphasis> var. <Emphasis Type="Italic">Otaksa</Emphasis>, with special reference to its antimalarial activity

Febrifugine and isofebrifugine alkaloid mixtures extracted from the leaves and buds of Hydrangea macrophylla var. Otaksa, collected during different months, in Japan, were quantified using high-performance liquid chromatography. Leaves collected during the flowering season, namely from June to August, contained 0.16–0.31 mg/g of the alkaloid mixture, whereas those collected from September to December had less than 0.03 mg/g of the mixture. However, extracts of buds harvested from October to February contained a consistently larger amount (more than 0.49 mg/g) of the alkaloids. Hot-water extracts from the leaves and buds collected during different seasons were evaluated for antimalarial activity against Plasmodium yoelii 17XL in mice. The extract of leaves collected in August demonstrated high antimalarial activity, and all mice that received the extract survived the infection. In contrast, the extract of leaves collected in December showed little activity. The extract of buds collected in December cleared parasites, but with subsequent mortality to mouse. The present results show that the amount of antimalarial agent—febrifugine and isofebrifugine mixture—in H. macrophylla var. Otaksa is both part- and season-dependent, suggesting that the choice of plant parts and their harvesting season are important factors worth considering in the pharmacological use of medicinal plants.     

薯蓣属植物中菲类化学成分及其药理活性研究进展

薯蓣属(Dioscorea)植物是中药材的重要来源，山药、穿山龙、粉萆薢、黄山药、绵萆薢等中药皆来源于该属植物。菲类化合物是该属植物中一类重要的化学成分，包括菲单体、二氢菲、四氢菲、菲醌和菲二聚体5种结构类型，具有抗肿瘤、抗炎、抗氧化、降血糖、抗肥胖、抗菌、抗病毒、神经保护等药理活性，其中一些菲类化合物活性多样且作用显著，有较好的开发利用前景。目前未见针对薯蓣属植物中菲类化学成分的系统性综述报道，本文对薯蓣属植物中的菲类化学成分及其药理活性进行综述，旨在为相关研究提供参考，以促进薯蓣属植物的开发利用。