Chemical composition and mosquito larvicidal activity of essential oils from leaves of different Cinnamomum osmophloeum provenances

Chemical compositions of leaf essential oils from eight provenances of indigenous cinnamon (Cinnamomum osmophloeum Kaneh.) were compared. According to GC-MS and cluster analyses, the leaf essential oils of the eight provenances and their relative contents were classified into five chemotypes-cinnamaldehyde type, linalool type, camphor type, cinnamaldehyde/cinnamyl acetate type, and mixed type. The larvicidal activities of leaf essential oils and their constituents from the five chemotypes of indigenous cinnamon trees were evaluated by mosquito larvicidal assay. Results of larvicidal tests demonstrated that the leaf essential oils of cinnamaldehyde type and cinnamaldehyde/cinnamyl acetate type had an excellent inhibitory effect against the fourth-instar larvae of Aedes aegypti. The LC(50) values for cinnamaldehyde type and cinnamaldehyde/cinnamyl acetate type against A. aegypti larvae in 24 h were 36 ppm (LC(90) = 79 ppm) and 44 ppm (LC(90) = 85 ppm), respectively. Results of the 24-h mosquito larvicidal assays also showed that the effective constituents in leaf essential oils were cinnamaldehyde, eugenol, anethole, and cinnamyl acetate and that the LC(50) values of these constituents against A. aegypti larvae were <50 ppm. Cinnamaldehyde had the best mosquito larvicidal activity, with an LC(50) of 29 ppm (LC(90) = 48 ppm) against A. aegypti. Comparisons of mosquito larvicidal activity of cinnamaldehyde congeners revealed that cinnamaldehyde exhibited the strongest mosquito larvicidal activity.     

In vivo antioxidant activities of essential oils and their constituents from leaves of the Taiwanese Cinnamomum osmophloeum

Cinnamomum osmophloeum Kaneh is an indigenous tree species in Taiwan. In this study, phytochemical characteristics and antioxidant activities of the essential oils and key constituents from the leaves of two C. osmophloeum clones were investigated. The two trees possess two chemotypes, which were classified as the cinnamaldehyde type and camphor type. We demonstrated that the essential oils from C. osmophloeum leaves exerted in vivo antioxidant activities in Caenorhabditis elegans. In addition, trans-cinnamaldehyde and D-(+)-camphor, which respectively represent the major compounds in the cinnamaldehyde-type and camphor-type trees, exerted significant in vivo antioxidant activities against juglone-induced oxidative stress in C. elegans. Moreover, expressions of antioxidative-related genes, including superoxide dismutase (SOD) and glutathione S-transferase (GST), were significantly induced by trans-cinnamaldehyde and D-(+)-camphor from C. osmophloeum leaves. Our results showed that the essential oils from C. osmophloeum leaves and their major compounds might have good potential for further development as nutraceuticals or antioxidant remedies.     

加拿大一枝黄花精油熏蒸处理对采后草莓品质和生理的影响

为探究加拿大一枝黄花精油熏蒸处理对采后草莓的保鲜效果,开发一种新型的食品保鲜剂,以红颜草莓为试材,研究在0.1‰精油熏蒸处理12 h条件下,精油对草莓品质和生理代谢的影响。结果表明,该处理能有效降低草莓采后腐烂,维持较高的果实色泽、表面质地、气味等感官指标和整体可接受度,抑制果实失重率的上升和硬度的下降,但对可溶性固形物(TSS)和可滴定酸(TA)含量无显著影响。此外,该处理提高了果实的总抗氧化能力,延迟了果实中过氧化氢(H_2O_2)的积累,降低了超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)和谷胱甘肽还原酶(GR)等抗氧化酶类的活性;但未显著提高果实苯丙氨酸解氨酶(PAL)、β-1,3-葡聚糖酶、几丁质酶等抗病相关酶的活性。可见,加拿大一枝黄花精油熏蒸处理能够减缓采后草莓果实品质的下降,延缓后熟衰老和腐烂发生。本研究结果有利于开发新型果蔬采后保鲜处理方法,为加拿大一枝黄花的高值化利用奠定了基础。     

胜红蓟精油复合微乳液体系构建及其对芦柑保鲜的影响

为更好的资源化利用入侵植物胜红蓟,提高芦柑的保鲜效果,本研究以胜红蓟精油为油相,吐温-80为表面活性剂,乙醇为助表面活性剂,碳酸钠和羧甲基壳聚糖水溶液为水相,采用拟三元相图筛选最优纳米级复合微乳液体系,并检测其在不同浓度(2.5、5.0、10.0和20.0 mg·mL^-1)下对意大利青霉、指状青霉和扩展青霉的抑菌活性和芦柑染菌抑制效果,用最优浓度处理芦柑果实,探究其对芦柑在不同贮藏条件下(25℃和4℃)的保鲜效果。结果表明,最优复合微乳液体系(A₈₀)的配方为胜红蓟精油∶乙醇∶吐温-80∶3%碳酸钠∶0.5%羧甲基壳聚糖=0.13∶0.38∶0.13∶1∶3,其粒径为34.47 nm。复合微乳液体系浓度为20 mg·mL^-1时,对意大利青霉、指状青霉和扩展青霉的抑菌效果最好,抑制率分别为64.86%、60.23%和86.96%,对芦柑的染菌抑制率为76.48%。此浓度复合微乳液A₈₀对4℃贮藏条件的芦柑保鲜效果最好,贮藏30 d后芦柑失重率为22.24%,对照组失重率为26.47%,腐烂率为11.33%,较对照组降低50%。构建的胜红蓟精油复合微乳液体系处理芦柑,不仅可以有效抑菌,延缓芦柑果实水分散失和重量损失,而且能延长芦柑的保鲜期。本研究结果为胜红蓟精油天然保鲜剂的开发和芦柑储藏保鲜提供了一定的理论基础。     

Essential oils from dalmatian sage (Salvia officinalis l.): variations among individuals, plant parts, seasons, and sites.

The factors affecting oil yield and quality of essential oils from Dalmatian sage (Salvia officinalis L.) are analyzed. Distillations of oils from individual plants and GC analyses revealed the presence of three chemotypes with different proportions of alpha- and beta-thujone (alpha/beta 10:1, 1.5:1, and 1:10). Different accessions could also be classified as having high (39-44%), medium (22-28%), or low (9%) total thujone contents. Flowering parts of S. officinalis had higher oil contents (1.6 versus 1.1%) and beta-pinene levels (27 versus 10%) than leaves and lower thujone levels (16 versus 31%). Major seasonal changes were found in the composition of oil distilled from a flowering type of Dalmatian sage, but oil yields from healthy, established plants did not vary greatly. Total thujone levels were lowest (25%) around flowering in spring and summer, so autumn or winter was the best harvest time to obtain oils with high thujone levels.     

Kinetics of Desorption of Heavy Metals from Polluted Soils: Influence of Soil Type and Metal Source

Kinetics of desorption of heavy metal ions (Cd, Cu, Ni and Zn) from the surface (0–15 cm) samples of an acidic soil (Inceptisol) and a neutral soil (Mollisol) spiked with inorganic salts of these metals or through an acidic sludge were studied by the column method. The rate of desorption of soil applied heavy metals was initially rapid and gradually declined with time. In general, the release of heavy metals from soils polluted by inorganic or sludge sources conformed to a multi-site model of first order kinetics; however, the release of Cd and Ni applied through inorganic sources to the neutral soil could be adequately accounted for by single-site model. The double-site model could adequately explain the release of Cd from sludge amended acidic soil and the release of Zn applied though inorganic salt or sludge to the neutral soil. In acidic soil, the apparent desorption rate coefficients of heavy metals applied through inorganic sources were higher than those for the sludge source. In neutral soil, however, the apparent desorption rate coefficients of heavy metals added through sludge were higher than for inorganic sources. Among the heavy metals, the higher apparent desorption coefficient value and percent desorption of Cd indicated a higher potential of this metal for leaching and ground water contamination. The results also suggested that the acidic soil pH might reduce the ability of the soil to naturally sequester heavy metal cations and lead to their leaching.     

油菜叶片衰老相关基因的分离细胞色素P450 cDNA的克隆和序列分析

通过绿叶和衰老叶片cDNA的缩减杂交和差别筛选,富集并分离了缩减cDNA文库中与油菜叶片衰老有关的基因片段.以目的基因片段为探针,通过筛选油菜衰老叶片的cDNA文库,分离了油菜叶片衰老阶段表达增强的全长cDNA LSC46.DNA序列分析结果表明,LSC46可读框架全长由1509个碱基组成,可以编码503个氨基酸残基,它的核苷酸序列及其推导的氨基酸序列与拟南芥菜依赖于单加氧酶的细胞色素P450的相应序列相比,分别有84.23%和83.50%的同源性.     

REVIEW: Variability in Fine Structures of Noncellulosic Cell Wall Polysaccharides from Cereal Grains: Potential Importance in Human Health and Nutrition

Noncellulosic polysaccharides from the cell walls of cereal grains are not digested by human small intestinal enzymes and so contribute to total dietary fiber intake. These polysaccharides are becoming recognized increasingly for their potential to lower the risk of serious diet‐related conditions such as type II diabetes, cardiovascular disease, colorectal cancer, and diverticular disease. The effectiveness of noncellulosic cell wall polysaccharides in improving health outcomes is related to the fine structure and associated physicochemical properties. The two most nutritionally relevant wall polysaccharides of cereal grains are the arabinoxylans and the (1‐3,1‐4)‐β‐d ‐glucans. These polysaccharides have high molecular mass values but are nevertheless soluble in aqueous media, at least in part, where they adopt highly asymmetrical conformations and consequently form high viscosity solutions. Thus, arabinoxylans and (1‐3,1‐4)‐β‐d ‐glucans contribute to the soluble fiber component of human diets. The molecular size, solubility, and viscosity of the polysaccharides vary widely not only between different cereals but also within a single species. The variability in these properties reflects differences in the chemical structure of the polysaccharides, which in turn influences the beneficial effects of arabinoxylans and (1‐3,1‐4)‐β‐d ‐glucans in human diets. Here, we summarize information on the variability of fine structures of the arabinoxylans and (1‐3,1‐4)‐β‐d ‐glucans in common cereals and relate these to solubility, viscosity, and health benefits. The recent identification of genes involved in the biosynthesis of the (1‐3,1‐4)‐β‐d ‐glucans opens the way for the genetic improvement of cereal quality parameters that are important in human health.     

The Use of Leaching Tests to Study the Potential Mobilization of Heavy Metals from Soils and Sediments: A Comparison

In the present study, different leaching tests were applied on well-characterised samples in order to obtain information on the potential mobility of heavy metals and arsenic. The information deduced from the different methods was compared and evaluated. Besides the comparison of heavy metal release in cascade-, column- and pH_stat leaching tests, attention was also paid to the assessment of release kinetics during leaching tests and to the mathematical modelling of leaching behaviour. The aim of this study was to understand the origin of possible discrepancies between the results of different leaching tests. The compatibility of the results of different leaching tests is, besides the inherent differences between methods (single batch tests versus dynamic leaching tests, the duration of the tests, liquid/solid (L/S) ratio,…) to a major extent determined by key-factors such as pH and redox potential. Depending on soil and sediment properties (e.g. acid neutralizing capacity (ANC)) these ‘key-factors’ varied during and at the end of extractions and leaching tests, even when the initial test conditions (e.g. the pH of the reagent) were equal for all test cases. During cascade- and column leaching tests, pH (which is initially 4) will mostly increase, but the extent of this pH-increase mainly depends on the acid neutralizing capacity of the sample. Therefore, measuring the pH of all leachates that are collected during these tests is mandatory for the interpretation of the results. Moreover, the monitoring of other variables such as DOC, anions and major elements can give indications on the reactions that are responsible for the release of elements (e.g. the dissolution of organic matter) and greatly improve the interpretation of the results.     

Sensitivity of Scottish Upland Moorland Podzols Derived from Sandstones and Quartzites to Acidification: the Potential Importance of the Mobile Anion Effect

Soil samples were collected from the main horizons of Scottish upland moorland podzols derived from quartzite or Devonian and Torridonian sandstones. The soils were subjected to routine chemical analysis and the results studied in relation to potential acidification effects of atmospheric deposition. Stronger correlations were observed for soil pH_water than for soil pH in CaCl₂ with wet deposition fluxes of mobile strong-acid anions. Exchangeable Al³⁺ correlated more strongly with wet deposition fluxes of mobile strong-acid anions than with H⁺ deposition flux. It is suggested that the direct effects of mobile anion enhancement upon soil pH_water must be taken into account when assessing damage to, and hence critical loads of, acidification-sensitive mineral soils.     

Characterization of Heavy Metal-Resistant Endophytic Yeast Cryptococcus sp. CBSB78 from Rapes (Brassica chinensis) and Its Potential in Promoting the Growth of Brassica spp. in Metal-Contaminated Soils

A Cd-, Pb-, Zn-, Cu-resistant endophytic yeast CBSB78 was isolated from surface-sterilized rape roots. The isolate was identified as Cryptococcus sp. based on the ITS1?C5.8S?CITS2 sequence analysis. The strain was resistant to 20 mM Cd²⁺, 20 mM Pb²⁺, 10 mM Zn²⁺, and 7 mM Cu²⁺. The yeast CBSB78 was a low indole-3-acetic acid (IAA) producer and possessed low 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. Overall, 29.4?C244 % of survival rates increased and the dry weight of Brassica alboglabra showed a 41.1 % increase when it was inoculated into the seedlings. The inoculation of CBSB78 could also increase the extraction amounts of Cd, Pb, and Zn by B. alboglabra simultaneously in the multi-metal contaminated soils, which showed the potential to improve extraction efficacy of Cd, Pb, Zn by B. alboglabra seedlings in the field.     

Crop uptake of cadmium from phosphorus fertilizers: I. Yield and cadmium content

We investigated the effects of different P fertilizers on the yields and Cd contents of oat (Avena sativa L.), ryegrass (Lolium multiflorum L.), carrot (Daucus carota L.), and spinach (Spinacia oleracea L.). These crops were grown in the greenhouse using soils treated with lime to achieve three pHs ranging from 4.77 to 5.94 for a sandy soil and 4.97 to 6.80 for a loam soil. The crop yields were generally not affected by liming or application of different kinds of P fertilizers, with a few exceptions. Application of Cd-containing NPK fertilizers in all cases tended to increase the Cd concentrations in crops, and the highest Cd concentrations in crops were obtained when the high-Cd NPK fertilizer was applied (adding 12.5 μg Cd kg^?1 soil). Cadmium concentrations in crops in most cases decreased with increasing soil pH. The highest percent recovery of the added Cd by plant species in the sandy soil was found for inorganic Cd-salt and in the loam soil for low-Cd NPK fertilizer. Phosphate rock resulted in the lowest recovery of the added Cd by all the plant species in both soils, but was also an insufficient P-source of its low solubility.     

Nitrous oxide fluxes from grassland in the Netherlands: II. Effects of soil type, nitrogen fertilizer application and grazing

Intensively managed grasslands are potentially a large source of nitrous oxide (N₂O) in the Netherlands because of the large nitrogen (N) input and the fairly wet soil conditions. To quantify the effects of soil type, N-fertilizer application and grazing on total N₂O losses from grassland, fluxes of N₂O were measured weekly from unfertilized and mown, N fertilized and mown, and N fertilized and predominantly grazed grassland on a sand soil, a clay soil, and two peat soils during the growing season of 1992. Total N₂O losses from unfertilized grassland were 2.5–13.5 times more from the peat soils than from the sand and clay soils. Application of calcium ammonium nitrate fertilizer significantly increased N₂O flux on all sites, especially when the soil was wet. The percentage of fertilizer N applied lost to the atmosphere as N₂O during the season ranged from 0.5 on the sand soil to 3.9 on one of the peat soils. Total N₂O losses were 1.5–2.5 times more from grazed grassland than from mown grassland, probably because of the extra N input from urine and dung. From 1.0 to 7.7% of the calculated total amount of N excreted in urine and dung was emitted as N₂O on grazed grassland. The large N₂O losses measured from the peat soils, combined with the large proportion of grassland on peat in the Netherlands, mean that these grasslands contribute significantly to the total emission from the country.     

A stable serine protease, wrightin, from the latex of the plant Wrightia tinctoria (Roxb.) R. Br.: purification and biochemical properties

Today proteases have become an integral part of the food and feed industry, and plant latex could be a potential source of novel proteases with unique substrate specificities and biochemical properties. A new protease named "wrightin" is purified from the latex of the plant Wrightia tinctoria (Family Apocynaceae) by cation-exchange chromatography. The enzyme is a monomer having a molecular mass of 57.9 kDa (MALDI-TOF), an isoelectric point of 6.0, and an extinction coefficient (epsilon1%280) of 36.4. Optimum activity is achieved at a pH of 7.5-10 and a temperature of 70 degrees C. Wrightin hydrolyzes denatured natural substrates such as casein, azoalbumin, and hemoglobin with high specific activity; for example, the Km value is 50 microM for casein as substrate. Wrightin showed weak amidolytic activity toward L-Ala-Ala-p-nitroanilide but completely failed to hydrolyze N-alpha-benzoyl- DL-arginine-p-nitroanilide (BAPNA), a preferred substrate for trypsin-like enzymes. Complete inhibition of enzyme activity by serine protease inhibitors such as PMSF and DFP indicates that the enzyme belongs to the serine protease class. The enzyme was not inhibited by SBTI and resists autodigestion. Wrightin is remarkably thermostable, retaining complete activity at 70 degrees C after 60 min of incubation and 74% of activity after 30 min of incubation at 80 degrees. Besides, the enzyme is very stable over a broad range of pH from 5.0 to 11.5 and remains active in the presence of various denaturants, surfactants, organic solvents, and metal ions. Thus, wrightin might be a potential candidate for various applications in the food and biotechnological industries, especially in operations requiring high temperatures.     

Removal of Iron and Manganese from Water with a High Organic Carbon Loading. Part II: The Effect of Various Adsorbents and Nanofiltration Membranes

This paper describes the second part of an investigation into the removal of iron and manganese from water with a high dissolved organic carbon (DOC) loading. This investigation focused on the use of ferrichloride as coagulant in conjunction with hydrogen peroxide as an oxidant and different physical treatment processes, such as adsorption and nanofiltration, to reduce dissolved iron and manganese in water with a high DOC loading. It was found that nanofiltration employing H₂O₂ is the only treatment capable of producing drinking water within the set requirements of the treatment facility. Both fly ash and powdered activated carbon (PAC) used as adsorbents yielded a low percentage removal of DOC, while all the treatment methods evaluated accomplished high removals of the metallic ions Fe(II) and Mn(II). From the results a staggered treatment approach is recommended to obtain the best results at the lowest cost.     

Using rainfall simulation to guide planning and management of rehabilitated areas: Part II. Computer simulations using parameters from rainfall simulation

This paper reports computer simulations carried out using data from a rainfall simulator study on a steeply sloping revegetated area (a soundbund) at the NorthParkes Mine, near Parkes in New South Wales, Australia. Simulations of slope stability used a combination of daily time‐step models to consider soil water balances and runoff, growth of grass/legume pasture and soil erosion. Simulations indicated that long‐term erosion rates on the soundbund would be low (1·01–1·27 t ha⁻¹ yr⁻¹) due to low runoff rates and good vegetative cover. The simulations highlighted that peak vegetative growth occurred prior to the period of peak erosion hazard, with carry‐over dry matter being crucial for erosion control during the period of peak rainfall erosivity. This, in turn, indicated that grazing during the periods of peak growth and peak erosion hazard should be avoided (to avoid loss of dry matter). It also indicated that there was value in establishing grass species that would give greater growth during summer months, and that may produce dry matter that is more persistent through time. Simulations of stormwater flows in channels draining various lifts on the soundbund compared a range of alternatives with respect to channel length, gradient and roughness. The simulations indicated little effect of channel length on peak flow rates or depths once channel lengths exceeded 250 m and also showed little effect of vegetative roughness on peak flow rates or depths once Manning's n values exceeded 0·05. Implications of these results for design of drainage channels and drop structures on the soundbund are discussed. Copyright © 2000 John Wiley & Sons, Ltd.