A study of lipid- and water-soluble arsenic species in liver of Northeast Arctic cod (Gadus morhua) containing high levels of total arsenic

In the present study liver samples (n = 26) of Northeast Arctic cod (Gadus morhua), ranging in total arsenic concentrations from 2.1 to 240 mg/kg liver wet weight (ww), were analysed for their content of total arsenic and arsenic species in the lipid-soluble and water-soluble fractions. The arsenic concentrations in the lipid fractions ranged from 1.8 to 16.4 mg As/kg oil of liver, and a linear correlation (r² = 0.80, p < 0.001) was observed between the total arsenic concentrations in liver and the total arsenic concentrations in the respective lipid fractions of the same livers. The relative proportion of arsenolipids was considerably lower in liver samples with high total arsenic levels (33–240 mg/kg ww), which contained from 3 to 7% of the total arsenic in the lipid-soluble fraction. In contrast liver samples with low arsenic concentrations (2.1–33 mg/kg ww) contained up to 50% of the total arsenic as lipid-soluble species. Arsenic speciation analysis of the lipid-soluble fractions of the livers, using reversed-phase high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC–ICP-MS), revealed the presence of several arsenolipids. Three major arsenic-containing hydrocarbons (C₁₇H₃₉AsO, C₁₉H₄₁AsO and C₂₃H₃₇AsO) and five arsenic-containing fatty acids (C₁₇H₃₅AsO₃, C₁₉H₃₉AO₃, C₁₉H₃₇AsO₃, C₂₃H₃₇AsO₃ and C₂₄H₃₇AsO₃) were identified using HPLC coupled to quadrupole time-of-flight mass spectrometry (qTOF-MS). Arsenobetaine was the major arsenic species in the water-soluble fraction of the livers, while dimethylarsinate, arsenocholine and inorganic arsenic were minor constituents. Inorganic arsenic accounted for less than 0.1% of the total arsenic in the liver samples.     

砷对土壤脲酶活性影响的研究

采用模拟方法对As污染土壤脲酶特征进行了研究．结果表明,土壤中As浓度在0～200mg·kg^-1浓度范围内,反应初期脲酶活性变化无明显规律;一年后砷激活土壤脲酶活性,二者达到显著或极显著正相关．随As浓度增加,土壤脲酶Km值基本不变或略有增加,Vmax增大,从机制上揭示出As加速脲酶-尿素复合物的解离．厩肥和无肥土样脲酶对As的反应类似,只是变化幅度有所差异．     

Effect of reverse photoperiod on in vitro regeneration and piperine production in Piper nigrum L.

In this study, a novel approach for in vitro regeneration of Piper nigrum L. has been applied in order to increase healthy biomass, phytochemicals and piperine production via reverse photoperiod (16hD/8hL). Leaf portions of the seed-derived plants were placed on an MS-medium fortified with different PGRs. Under 16hD/8hL, thidiazuron (TDZ; 4.0 mg L⁻¹) and BA (1.5 mg L⁻¹) was found to be the most effective (< 90%) in callus induction. Two concentrations (1.5, 2.0 mg L⁻¹) of the IBA produced > 80% shoots from callus cultures. Healthy shoots were transferred to rooting medium and higher percentage of rooting (< 90%) was observed on IBA (1.5 mg L⁻¹). These in vitro tissues were subjected to amino acid analysis, spectrophotometry, and HPLC. ARG, SER, THR, and TYR were the most abundant components out of 17 amino acids. Higher amino acid production was observed under normal photoperiod (16hL/8hD) than under reverse photoperiod (16hD/8hL). The highest total phenolic content (TPC; 9.91 mg/g-DW) and flavonoid content (7.38 mg/g-DW) were observed in callus cultures incubated under 16hL/8hD than other tissues incubated under 16hD/8hL photoperiod. Higher DPPH and PoMo activities were observed in tissues incubated under 16hL/8hD photoperiod, while ABTS and Fe²⁺ chelating activities were found higher in tissues incubated under reverse photoperiod. Significant quantities of piperine content were observed in all tissues except callus cultures. These results suggest that reverse photoperiod is a promising approach for callus induction, phytochemicals and piperine production for commercial applications.     

砷形态对黑藻和竹叶眼子菜有机酸含量的影响

采用室内溶液培养法,运用气相色谱-质谱联用(Gas chromatography-mass spectrometry,GC-MS)技术测定在As(Ⅲ)、As(Ⅴ)和二甲基胂酸(Dimethylarsinic acid,DMA)3种形态砷(浓度0—5.0 mg/L)胁迫下,砷超富集植物黑藻(Hydrilla verticillata(Linn.f.)Royle.)和非砷超富集植物竹叶眼子菜(Potamogeton malaianus Miq.)体内生成和体外分泌的7种有机酸的含量。结果表明,黑藻体内草酸、丙二酸、柠檬酸、苹果酸和棕榈酸都显著高于竹叶眼子菜(P<0.05)。在As(Ⅲ)处理时,黑藻体内柠檬酸、苹果酸、棕榈酸、亚麻酸和总有机酸显著下降,竹叶眼子菜棕榈酸显著下降;在As(Ⅴ)处理时,黑藻棕榈酸和总有机酸显著下降,竹叶眼子菜棕榈酸显著下降;在DMA处理时,黑藻草酸、柠檬酸和苹果酸显著下降,竹叶眼子菜棕榈酸、亚麻酸和总有机酸显著下降。黑藻在As(Ⅲ)处理下棕榈酸、亚麻酸、总有机酸和As(Ⅴ)处理下草酸含量与体内As含量呈显著负相关(P<0.05),而竹叶眼子菜在As(Ⅲ)或DMA处理下棕榈酸、亚麻酸、总有机酸含量以及在DMA处理下柠檬酸含量与体内As含量均呈显著负相关(P<0.05)。两种植物根系分泌物中均检测出草酸、丙二酸、琥珀酸和棕榈酸,但只有在As(Ⅲ)或As(Ⅴ)处理时黑藻分泌的草酸与体内As含量呈显著正相关。本研究表明As(Ⅲ)或As(Ⅴ)胁迫下黑藻向体外分泌草酸是其超富集砷的一种重要机制。     

The alkaloid contents of sixty Nicotiana species

The alkaloid content (nicotine, nornicotine, anabasine, and anatabine) in leaves and roots of 60 Nicotiana species were analyzed by GC. All species contained alkaloids, the amounts varying with the species. There was no clearcut correlation between alkaloid amounts and subgeneric or sectional classification. The alkaloid content in the floral parts and immature and mature fruits of Nicotiana tabacum were also analyzed.     

Variation in icariin and flavonoid contents of barrenwort accessions native to Guizhou,China

Flavonoid and icariin contents of 87 samples drawn from 21 accessions of seven species native to Guizhou, China, of the genus Epimedium were determined by means of ultraviolet and high-performance liquid chromatography. The contents differed significantly among the species and accessions. E. acuminatum, E. yinjiangense, E. myrianthum, E. wushanense, and E. simplicifloum had greater amounts of flavonoids and icariin than E. letorrhizum and E. luodianense.     

Effect of vitamin E supplementation on arsenic induced alteration in blood biochemical profile,oxidant/antioxidant status,serum cortisol level and retention of arsenic and selenium in goats

Arsenic (As) exerts oxidative stress with depletion of body selenium in monogastric animals. But in ruminants this fact is not yet verified. Vitamin E is an effective dietary antioxidant. Thus, in this experiment, the protective effect of vitamin E against arsenic toxicity induced by sodium arsenite (60 mg As/kg diet) was investigated in goat kids. For this, 21 male kids were divided into three equal groups and fed either basal diet as such (control), or supplemented with 60 mg As/kg diet and 60 mg As/kg diet + 250 IU vitamin E/kg diet for 180 days. Vitamin E supplementation alleviated the toxic effects caused by arsenic on serum alanine aminotransferase and aspartate aminotransferase and lipid peroxidation. It also prevented the depletion of reduced glutathione content and reduction in activity of catalase, superoxide dismutase and glutathione-s-transferase in erythrocytes resulted from arsenic intoxication. The elevated levels of arsenic and reduced levels of selenium in the serum and tissues in arsenic treated animals were attenuated by vitamin E supplementation, though not completely. However, serum cortisol level was not affected by arsenic. It was concluded that arsenic exerts cortisol independent stressor mechanism and supplementation of vitamin E at a level of 250 IU/kg diet was partially effective in reducing tissue accumulation of arsenic in the body and protect the kids from oxidative stress induced by arsenic.     

Phenolic compounds in Hypericum species from the Trigynobrathys section

Phenolic compounds of thirteen Hypericum species growing in South Brazil were investigated aiming to evaluate the usefulness of their distribution as a taxonomic character. The HPLC analysis of the methanolic fractions displayed similar chemical profile and significant contents variation among the investigated taxa, being chlorogenic acid the main metabolite quantified in most of the species (ranging from traces to 16.65 mg% of extract), followed by hyperoside (between 0.27 and 11.48 mg%), quercitrin (0.09 and 13.34 mg%), guaijaverin (0.14 and 2.91 mg%) and isoquercitrin (0.14 and 6.97 mg%), whereas rutin and the xanthone mangiferin were not detected.     

Impact of solar ultraviolet-B radiation on the antioxidant defense system in soybean lines differing in flavonoid contents

Exposure to ultraviolet-B (UV-B) radiation can lead to oxidative damage in plants. However, plants possess a number of UV-protection mechanisms including screening of potentially damaging UV-B and increased production or activities of antioxidants. The balance or trade-off between these two mechanisms has rarely been studied and is poorly understood. Two isolines of soybean (Glycine max [L.] Merr.) Clark cultivar, the normal line with moderate levels of flavonoids and the magenta line with reduced flavonoids levels, were grown in the field with or without natural levels of UV-B. Leaflet blades of the first trifoliate leaf were harvested after 4–12 days of exposure to the experimental conditions for analysis of active oxygen species (AOS) and antioxidant levels. Solar UV-B radiation caused oxidative stress in both lines and altered AOS metabolism primarily by decreasing superoxide dismutase activity and increasing the activities of ascorbate peroxidase, catalase and glutathione reductase. This resulted in decreased ascorbic acid content and increased dehydroascorbate content. The magenta line had greater oxidative stress than the normal line in spite of its enhanced oxidative defense capacity as compared to the normal line, even under UV-B exclusion. These results indicate enhanced sensitivity in the magenta line, especially under UV-B exclusion that was likely due to the absence of flavonoid epidermal screening compounds and subsequent increased penetration of solar ultraviolet radiation into the leaf.     

Taxonomic significance of flavonoid variation in temperate species of Nothofagus

Forty-two flavonoids and a stilbene (pinosylvin) were identified in the leaf exudates of 11 temperate species of Nothofagus from South America, Australia and New Zealand. The flavonoid profiles demonstrate significant taxonomic value at the subgeneric level. Most species of subgenus Fuscospora are characterized by the presence of pinosylvin, galangin and galangin methyl ethers. Kaempferol-type flavonols are abundant in subgenus Lophozonia while these flavonols are largely absent from species of subgenus Fuscospora. The flavonoid patterns are largely in agreement with a recent subgeneric classification of Nothofagus.     

Biological implications of flavonoid chemistry in Baptisia and Thermopsis

An analysis of flavonoid distributional data from detailed biochemical systematic investigations of Baptisia and Thermopsis species supports the contention that the two genera are closely related with Baptisia being the more advanced evolutionarily and exhibiting greater evolutionary vigor. B. megacarpa may represent an ancestral complex which gave rise to several major Baptisia lines. Enzymes involved in methoxylation and 4′-glucosylation of flavonoids in Thermopsis have higher substrate specificities than those involved in 7-glucosylation.     

Quantitative flavonoid variation in Lupinus sericeus

One hundred and eighty-one plants representing 32 individual populations of Lupinus sericeus were collected from throughout the range of the species. Quantitative analyses of flavonoid derivatives were performed using high performance liquid chromatography. Peak height data were subjected to multivariate analysis. Principal components analysis suggested the existence of a north-south cline based upon differences in orientin concentration. Canonical variates analysis suggested that southerly, central and northerly populations were distinguishable. Simple statistical tests on orientin concentration, the major flavonoid seen in the study, clearly distinguished southerly populations from all others. Seeds were collected from representative populations from the range of L. sericeus and the plants obtained therefrom were grown under uniform conditions. Analysis of orientin concentration in these plants showed no significant differences between populations. We conclude from these studies that all L. sericeus plants appear to have similar capacities to accumulate orientin, and that differences in concentration of this compound seen in naturally occurring plants are a reflection of environmental influences and cannot be used as support for any infrageneric taxonomic distinctions.     

A new flavonoid from the bark of Ulmus pumila L

A new flavonoid (6), together with eight (1–5 and 7–9) known flavonoids, were isolated from the n-butyl alcohol soluble portion of the EtOH extract of Ulmus pumila L. The chemical structures of the compounds were determined by using spectroscopic methods and further supported by comparison with previously literature values. Among them, flavonoids 4, 6 and 9 were isolated for the first time from the family Ulmaceae. Furthermore, the chemotaxonomic significance of the isolates was also discussed.     

The accumulation,distribution, and toxicological effects of dietary arsenic exposure in lake whitefish (Coregonus clupeaformis) and lake trout (Salvelinus namaycush)

A 20-day experiment was conducted to compare the accumulation, distribution, and toxicological effects of dietary As, as arsenate, in lake whitefish (LWF, Coregonusclupeaformis) and lake trout (LT, Salvelinus namaycush). Results of this experiment were used to design an experiment of longer duration in which one of the fish species was selected and exposed three times per week to lower dietary As doses. In the present study each treatment group was exposed to a combination of one of three doses of As (0, 100, or 1000 μg As/g) and one of two types of diet, no brine shrimp (NS) or with brine shrimp (WS) for a total of eight dosing events. Brine shrimp were added to determine whether their presence enhanced consumption of As-contaminated food. Modified feeding behavior occurred in both fish species fed As contaminated diets, with the exception of the 100 μg As/g NS food. Brine shrimp addition did not affect feed consumption of the As contaminated diets. Significant As accumulation occurred in stomach, pyloric caeca, intestine, liver, kidney, and gallbladder, but not in bile or muscle. As exposure did not have a significant effect on hepatic and renal metallothionein concentrations. Concentrations of lipid peroxides were only significantly elevated in the plasma of LT fed the 1000 μg As/g WS food. Liver somatic indices decreased significantly in both species, whereas hematological parameters were not affected in either species. Histological lesions occurred in gallbladder, liver, kidney, pyloric caeca and intestine from LWF. These lesions were not observed in LT; however, gallbladders were not examined in this species. Weight gain was lower in both species fed As contaminated diets, however, condition factors were not affected.     

Modification of flavonoid biosynthesis in crop plants

Flavonoids comprise the most common group of polyphenolic plant secondary metabolites. In plants, flavonoids play an important role in biological processes. Beside their function as pigments in flowers and fruits, to attract pollinators and seed dispersers, flavonoids are involved in UV-scavenging, fertility and disease resistance. Since they are present in a wide range of fruits and vegetables, flavonoids form an integral part of the human diet. Currently there is broad interest in the effects of dietary polyphenols on human health. In addition to the potent antioxidant activity of many of these compounds in vitro, an inverse correlation between the intake of certain polyphenols and the risk of cardiovascular disease, cancer and other age related diseases has been observed in epidemiological studies. The potential nutritional effects of these molecules make them an attractive target for genetic engineering strategies aimed at producing plants with increased nutritional value. This review describes the current knowledge of the molecular regulation of the flavonoid pathway and the state of the art with respect to metabolic engineering of this pathway in crop plants.     

磷对土壤中砷吸附的影响

在黄壤、红壤和褐土中进行As的等温吸附实验表明,在不添加P的情况下,3种土壤对As的吸附能力随土壤pH的升高而降低,随土壤粘粒含量的降低而减弱,3种土壤吸附能力为黄壤>红壤>褐土,As在土壤中的吸附受P存在的影响,60mg·kg^-1的P可以降低黄壤和红壤对As最大吸附量．吸附质中P：As的比例不同,P对土壤吸附As的影响差异很大：吸附质中P：As=1：2时,土壤对As的吸附能力均强于P：As=1：1和P：As=2：1,后两者差异不显著,表明土壤中的吸附点位对As和P的亲和性具有一定的差异,Languir方程能很好地拟合所测得的土壤平衡溶液中As浓度。     

An HPLC study of flavones from some Spanish Sideritis species

Nine flavone aglycones were identified from the ether extracts of fifteen Sideritis species by means of HPLC techniques.     

Modulatory role of Emblica officinalis fruit extract against arsenic induced oxidative stress in Swiss albino mice

Arsenic, an important human toxin, is naturally occurring in groundwater and its accumulation in plants and animals have assumed a menacing proportion in a large part of the world, particularly Asia. Epidemiological studies have shown a strong association between chronic arsenic exposure and various adverse health effects, including cardiovascular diseases, neurological defects and cancer of lung, skin, bladder, liver and kidney. The protective role of the fruits of Emblica officinalis (500 mg/kg b.wt.) was studied in adult Swiss albino mice against arsenic induced hepatopathy. Arsenic treated group (NaAsO₂, 4 mg/kg b.wt.) had a significant increase in serum transaminases and lipid peroxidation (LPO) content in liver, whereas significant decrease was recorded in hepatic superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST) and serum alkaline phosphatase activity. Combined treatment of Emblica and arsenic (pre and post) declined the serum transaminases and LPO content in liver whereas significant increase was noticed in SOD, CAT, GST and serum alkaline phosphatase activities. Liver histopathology showed that Emblica fruit extract had reduced karyolysis, karyorrhexis, necrosis and cytoplasmic vacuolization induced by NaAsO₂ intoxication. Thus it can be concluded that pre- and post-supplementation of E. officinalis fruit extract significantly reduced arsenic induced oxidative stress in liver.     

On-line reversed-phase liquid chromatography hydride generation emission spectrometry: speciation of arsenic in urine of patients intravenously treated with As2O3

Hydride generation inductively coupled plasma–atomic emission spectrometry (HG ICP–AES) was used as a continuous detection system for the determination of arsenic in the eluate from a high-performance liquid chromatographic (HPLC) system. Four arsenic species [arsenite As(III), arsenate As(V), monomethylarsonate (MMA), and dimethylarsinate (DMA)] present in the urine samples of patients treated intravenously with arsenite, were analyzed separately by HPLC–HG-ICP–AES using a non-polar C₁₈ column. This analytical method allowed the sensitive determination of the arsenic species in the submicrogram per liter range. Urine samples collected on different days after arsenite administration were found to contain arsenite predominantly – monomethylarsonate and dimethylarsinate were also detected.