Determination of hesperetin, cinnamic acid and nicotinic acid in propolis with micellar electrokinetic capillary chromatography

Micellar electrokinetic capillary chromatography (MEKC) has been used to determine hesperetin, cinnamic acid and nicotinic acid in propolis. After systematically study the effect of buffer concentration and pH, micellar concentration, organic modifier, applied voltage and injection time, the analytical conditions were optimized. Under the optimized conditions, the three analytes could be well separated in 20 min. A good linearity between the peak current and the concentration was found in the range of 0.02-0.60 mg/ml, 0.05-1.20 mg/ml and 0.10-1.40 mg/ml with correlation coefficients of 0.9989, 0.9995 and 0.9990 for hesperetin, cinnamic acid and nicotinic acid, respectively. The detection limits were 0.006 mg/ml (hesperetin), 0.017 mg/ml (cinnamic acid) and 0.036 mg/ml (nicotinic acid). The validity of the method was verified by analyzing the three analytes in propolis oral liquids.     

Stimulation of gastric acid secretion and intestinal motility by Vernonia amygdalina extract

Aqueous extract of Vernonia amygdalina infused intragastrically at a dose of 10 mg/ml to rats induced a significant increase in acid output which was reduced by, ranitidine (5 mg/kg b.w.) or atropine (1.2 microMol/kg b.w.). Moreover the extract evoked a dose-dependent contraction of the guinea pig ileum at a dose range of 0.6 mg/ml to 66 mg/ml which was inhibited by atropine (2.4 x 10(-8)-2.4 x 10(-6) M).     

Hemagglutinating activity of Curcuma plants

Crude proteins obtained by Mg/NP-40 extraction from Thai medicinal plants of the Curcuma species exhibited agglutination activity against rabbit erythrocytes. A crude extract from Salingalinthong, a Thai Curcuma specie, exhibited the strongest hemagglutinating activity, 2 x 10(-5) mg/ml.     

Xanthone isolated from Securidaca longependunculata with activity against erectile dysfunction

1,7-Dimethoxy-2-hydroxy-xanthone and 1,4-dihydroxy-7-methoxy-xanthone isolated from Securidaca longependunculata were tested for their activity on rabbit corpus cavernosum in vitro. Only the former relaxed the corpus cavernosum by 63% at 1.8 x 10(-5) mg/ml.     

Intraspecific variation in <Emphasis Type="Italic">Trifolium pratense</Emphasis>: impact on feeding and host location by <Emphasis Type="Italic">Sitona lepidus</Emphasis> (Coleoptera,Curculionidae)

Red clover (Trifolium pratense L.) is becoming increasingly important in grassland systems because of its high productivity, protein content and nitrogen-fixing ability, but its use has been constrained by losses due to pests and diseases, and this contributed to the decline of red clover usage allowing white clover (T. repens L.) to become the dominant legume of UK grasslands. One of the major pests of red clover is the clover root weevil (Sitona lepidus Gyllenhal, Coleoptera, Curculionidae) which attacks both the shoots and roots, particularly the N-fixing root nodules, of clover plants. This current work investigates the feeding preferences of S. lepidus with respect to 11 varieties (Pawera, Kuhn, Astra, Norseman, Norseman low, Norseman high, Marcom, Merviot, Milvus, Britta, Sabtoron) and 5 lines (AA30, AA31, AA4493, AA4494 and AA4495) of red clover in order to identify relationships between the variation in attractiveness of different red clover varieties for both adult and larval stages of the weevil. Of those tested Norseman high showed potential resistance, being less favoured by both adults and larvae of the weevil. This may be attributed to the potentially high phyto-oestrogen levels in this variety.     

树木菌根真菌——美味红菇复合制剂的生物效应*

在探明菌根真菌美味红菇生理活性物质的基础上,为使其实用化,又从该菌的发酵液中提取并研制成真菌复合制剂。除在医学上进行了一系列抗菌活性试验外,同时还在育苗造林上,利用不同树种进行防病保苗促进生长的生物活性试验。本文主要报道应用美味红菇复合制剂对几种亚热带针阔叶树种幼苗和种子进行体内生物活性的试验结果。目的在于观察和研究该复合制剂对促进幼苗生长和提高抗生能力的生物效应,以便进一步开拓美味红菇复合制剂的有效应用范围和途径。     

Tree establishment and growth using forage ground covers in an alley-cropped system in Midwestern USA

The integration of forage crops in an alley-cropped system was examined as a method of encouraging tree planting to increase farm income, improve soil quality, and enhance biodiversity on Midwestern U.S. farms. Crop and tree performance were evaluated in an alley-cropped system using four forage intercrops grown in tree alleyways to simulate a potential hay crop – oat (Avena sativa L.) and red clover (Trifolium pratense L.); oat, red clover, and red fescue (Festuca rubra L.); oat, red clover, and orchardgrass (Dactylis glomerata L.); and oat and hairy vetch (Vicia villosa Roth) – compared to a herbicide, mowing and control (no management) treatment. Five tree species, divided into fast-growing hardwoods of two poplar (Populus spp.) clones [Crandon (P. alba L. × P. grandidentata Michx.) and Eugenei (P. deltoids Bartr. × P. nigra L.)], and silver maple (Acer saccharinum L.) were compared with two high-value, slow-growing hardwoods planted from seed and as seedlings: red oak (Quercus rubra L.) and black walnut (Juglans nigra L.). Tree survival in the first year was greater for the fast-growing species, and by the fourth year, tree height among the four forage treatments was equivalent for all upland locations. The oat/hairy vetch ground cover was associated with the shortest trees in the bottomland site. Herbicide-treated trees were taller than the average of the four forage treatments for all four planting conditions. Tree height in the mowing and the control treatments was not significantly different for all four planting conditions. The nutritive value of the forage crop was excellent in the second year of tree establishment, with crude protein content and digestibility at 17 and 71%, respectively, in the oat/red clover/red fescue treatment, suggesting the viability of forage crops as alternatives to herbicides in alley-cropped systems.     

大肠杆菌表达重组Taq DNA聚合酶的分离和纯化

以插入Taq DNA聚合酶基因的pET-24a表达质粒转化E．coli菌株,表达Taq DNA聚合酶,用反复冻融的方法裂解菌体．表达产物为可溶性蛋白,采用Duo-Flow系统(Bio-Rad)及S柱,Tris缓冲液pH为7．5．以0-1 mol／L盐梯度洗脱方式,收集洗脱峰．透析去盐可得到高纯度的产品．经PCR反应与商品Taq酶的一个活性单位相比较,重组的Taq酶活性有1个单位．用该方法可以从1 L培养液中分离得到5．51 mg产品．     

Anthelmintic activities of three medicinal plants from Nigeria

Aqueous extracts of the leaf, stem bark and root bark from Canna bidentata, Spondias mombin and Commiphora africana were examined for anthelmintic activity against earthworm. All the extracts demonstrated a concentration-dependent activity at tested concentrations of 10-80 mg/ml. Higher activities were observed at the higher concentrations, 40-80 mg/ml for all the plant extracts. C. bidentata with a paralysis time of 3-5 min and death time of 5-18 min at these concentrations for the stem bark, and S. mombin which exhibited comparatively higher efficacy (34-44 min paralysis time and 105 min death time for the leaf) at lower concentrations of 10-20 mg/ml were adjudged the outstanding anthelmintics of plant origin accordingly.     

Allelopathic Interactions Between Herbaceous Species and Trees Grown in Topsoil and Spoil Media

Dried foliage (litter) of several herbaceous species was mixed with either vermiculite or two minesoils (topsoil and spoil) in containers planted with black locust (Robinia pseudoacacia), white ash (Fraxinus americana) or sweetgum (Liquidambar styraciflrua) seedlings in a greenhouse. Also, germinated seed of northern red oak (Quercus rubra) was planted in containers previously seeded with herbaceous species. In vermiculite, black locust growth was inhibited by 12 g litter additions of ranger alfalfa (Medicago sativa), birdsfoot trefoil (Lotus corniculatus), tall fescue (Festuca arundinacea), and Kentucky bluegrass (Poa pratensis), but stimulated by red clover (Trifolium pratense) litter. White ash growth was strongly inhibited by alfalfa and trefoil added to vermiculite at 12 and 18 g levels. In topsoil, sweetgum was strongly inhibited by alfalfa litter. Both sweetgum and red oak grew poorly in spoil, but seeded perennial ryegrass (Lolium perenne), orchardgrass (Dactylis glomerata) and fescue grew well. Some aspects of red oak growth were inhibited if grown in containers seeded with alfalfa, ryegrass, orchardgrass, red clover or fescue. Although isolation and identification of allelopathic compounds was not attempted, these results demonstrate that there may be important allelopathic interactions between herbaceous species and trees planted on minelands.     

APEX model simulation of runoff and sediment losses for grazed pasture watersheds with agroforestry buffers

Buffers have been found to reduce non-point source pollution (NPSP) from watersheds. Hydrologic simulation models assist in predicting the effects of buffers on runoff and sediment losses from small watersheds. The objective of this study was to calibrate, validate and simulate runoff and sediment losses and compare buffer effects on NPSP losses relative to control watersheds (no buffer) for seven years. The experimental design consists of four watersheds under pasture management which were monitored from 2002 through 2008; two with agroforestry buffers (AgB 100 and AgB 300) and two control watersheds (CW 400 and CW 600). Pasture areas included red clover (Trifolium pretense L.) and lespedeza (Kummerowia stipulacea Maxim.) planted into fescue (Festuca arundinacea Schreb.) while the agroforestry buffer area included Eastern cottonwood trees (Populus deltoids Bortr. ex Marsh.) planted into fescue. The APEX model was calibrated from 2002 to 2005 and was validated from 2006 to 2008. The r ² and NSE values for the calibration and validation periods of the runoff varied from 0.52 to 0.78 and 0.50 to 0.74, respectively. The model did not predict sediment loss very well probably due to insufficient number of measured events and low measured sediment loss. The measured runoff was 57% higher for CW watersheds compared to AgB watersheds. The measured sediment loss was 95% higher for CW watersheds compared to AgB watersheds. After calibrating and validating the model, it was run for long-term scenario analyses for 10 years from 1999 to 2008. Simulated buffer width had a significant influence on runoff. Simulated runoff decreased by 24% when the buffer width was doubled compared to losses associated with the measured buffer width. Simulated runoff from the CW watersheds was 11% higher with double stocking density (relative to measured density) compared to AgB watersheds with double stocking density. With half stocking density (relative to measured density), the AgB watershed had 18% lower runoff compared to CW. Results from this study imply that establishment of agroforestry buffers on grazed pasture watersheds reduce runoff and sediment losses compared to control watersheds without buffers.     

Light-energy processing and freezing-tolerance traits in red spruce and black spruce: species and seed-source variation

Red spruce (Picea rubens Sarg.) and black spruce (Picea mariana (Mill.) B.S.P.) are genetically and morphologically similar but ecologically distinct species. We determined intraspecific seed-source and interspecific variation of red spruce and black spruce, from across the near-northern margins of their ranges, for several light-energy processing and freezing-tolerance adaptive traits. Before exposure to low temperature, red spruce had variable fluorescence (Fv) similar to black spruce, but higher photochemical efficiency (Fv/Fm), lower quantum yield, lower chlorophyll fluorescence (%), and higher thermal dissipation efficiency (qN), although the seed-source effect and the seed-source x species interaction were significant only for Fv/Fm. After low-temperature exposure (-40 degrees C), red spruce had significantly lower Fv/Fm, quantum yield and qN than black spruce, but higher chlorophyll fluorescence and relative fluorescence. Species, seed-source effect, and seed-source x species interaction were consistent with predictions based on genetic (e.g., geographic) origins. Multi-temperature exposures (5, -20 and -40 degrees C) often produced significant species and temperature effects, and species x temperature interactions as a result of species-specific responses to temperature exposures. The inherent physiological species-specific adaptations of red spruce and black spruce were largely consistent with a shade-tolerant, late-successional species and an early successional species, respectively. Species differences in physiological adaptations conform to a biological trade-off, probably as a result of natural selection pressure in response to light availability and prevailing temperature gradients.     

Antioxidant activity of polyphenols from solid olive residues of c.v. Coratina

The antioxidant profile of extracts from solid olive residue (SOR) of c.v. Coratina, a cultivar widely diffused in the south of Italy, using both cell-free and cell-based experimental models, was investigated. A total hydroalcoholic extract (polyphenols content 19.7%) and a purified extract (Oleaselecttrade mark) (polyphenols content 35.1%) were tested for their ability to quench the stable free radical DPPH, the peroxyl radicals (ORAC assay), by monitoring the loss in fluorescence of R-phycoerythrin induced by the peroxyl radical generator AAPH and their ability to inhibit the cumene hydroperoxide-induced lysis of rat red blood cells (RBC). The total hydroalcoholic extract showed IC(50) 26.96+/-1.53 microg/ml in the DPPH assay, that 10 microg/ml were equivalent to 2.11+/-0.12 microg/ml Trolox (ORAC assay) and IC(50) 1.7+/-0.20 microg/ml in the RBC hemolysis. The Oleaselect extract was 4 to 5 folds more active than the hydroalcoholic extract in all the experimental models, with IC(50) values of 7.36+/-0.38 microg/ml in the DPPH test and of 0.38+/-0.03 microg/ml in RBC; the antioxidant activity in the ORAC assay was slightly greater than that of Trolox (10 microg/ml equivalent to 11.45+/-0.40 microg/ml). The scavenging effect of the extract in the ORAC assay was compared to that of verbascoside (the main polyphenol component) and of caffeic acid (the basic constituent of verbascoside): the results indicate that caffeic acid (10 microg/ml equivalent to 35.70+/-2.95 microg/ml Trolox) is more potent than verbascoside (10 microg/ml equivalent to 15.42+/-1.21 microg/ml Trolox) in entrapping peroxyl radicals. Finally the antioxidant activity of the Oleaselect extract was confirmed in human umbilical endothelial cells (EC) exposed to the site-specific peroxyl radical inducer AAPH, where a massive lipid peroxidation process (marker the fluorescence probe BODIPY) takes place, paralleled by a marked loss of cell viability (calcein assay). The purified extract (1-20 microg/ml) pre-incubated with EC for 1 h dose-dependently inhibited both the lipid-peroxidation damage and cell death. Taking into account the total polyphenol content, these results clearly indicate a greater antioxidant activity for the purified extract, due to a cooperative antioxidant interaction among its polyphenol constituents.     

浅析木材酸性及其对MDF生产的影响

本文对福州人造板厂生产用木片的ｐＨ值、缓冲性能及其对ＵＦ胶固化时间的影响进行了研究，结果表明：木片的ｐＨ值与缓冲性能是影响ＵＦ胶固化的重要因素，煮沸回流后的木片ｐＨ值与ＵＦ胶的固化时间相关性最大；在ｐＨ值相近的情况下，木粉与胶的混合物固化时间随木材缓冲性能的增加而缩短；树皮对胶固化的阻碍大大超过相同ｐＨ值的木材；作为主要原料的马尾松，其地域不同、ｐＨ值不同而呈现出对ＵＦ胶固化的影响也不同。     

Root morphology and nutritional status of Japanese red cedar saplings subjected to in situ levels of aluminum in forest soil solution

There is little information on the effects of in situ levels of aluminum (Al) in the forest soil solution on the root morphology of Japanese red cedar (Cryptomeria japonica D. Don). We evaluated whether morphological and nutritional changes in the white roots of Japanese red cedar saplings grown in glass-bead culture for 18 weeks occurred in response to Al solutions at five concentrations: 0 (control), 0.05, 0.1, 0.5, and 1.0mM. Branching white roots treated with 0.5 or 1.0mM Al had some stunted, brown, thickened tips. Their mean lengths were significantly shorter than those of roots treated with 0.05 or 0.1mM Al. The maximum diameters of white roots treated with 0.5 or 1.0mM Al were significantly larger than those of the control. Treatment with 0.5 or 1.0mM Al reduced the concentrations of Ca and Mg in the white roots and increased the concentration of Al compared with the control. These results indicate that between 0.1 and 0.5mM Al, a drastic change occurs in the effects of Al on the morphology and nutritional status of white roots of Japanese red cedar saplings, and suggest that the Al levels in Japanese forest soils may induce morphological changes in the white roots.     

Bioactive flavones and biflavones from Selaginella moellendorffii Hieron

Three new flavones named 5-carboxymethyl-4′,7-dihydroxyflavone (1), its ethyl ester (2) and butyl ester (3) were isolated from the herb Selaginella moellendorffii Hieron., together with ten known compounds. Their structures were elucidated on the basis of spectroscopic and chemical analysis. Selected compounds were evaluated for their anti-HBV and cytotoxic activity. Among them, compounds 2 and 3 displayed inhibitory activity in vitro on hepatitis B virus (HBV) surface antigen (HBsAg) secretion of the Hep G2.2.15 cell line with IC₅₀ values of 0.17 mg/ml and 0.46 mg/ml, and on HBV e antigen (HBeAg) secretion with IC₅₀ values of 0.42 mg/ml and 0.42 mg/ml, respectively. Compounds 7, 8, 10 and 12 exhibited selective cytotoxicity against the three human cancer cell lines tested.     

Ecophysiological characteristics of the seed of the tropical forest pioneer Urera caracasana (Urticaceae)

Urera caracasana (Jacq.) Griseb is a small, fast-growing evergreen pioneer tree which colonizes openings in the tropical rain forest of 'Los Tuxtlas', Veracruz, Mèxico. Annual seed production by 10 trees was estimated to range from 0.4 x 10(5) to 1.6 x 10(6) seeds per tree. Fifteen species of resident and migratory birds were observed to visit the plants and disperse the seeds. Most seeds imbibed in petri dishes placed on the forest floor beneath a small opening in the canopy, where the red/far-red ratio of the light was around 1.0, germinated within 2 weeks. Germination beneath the forest canopy, where the red/far-red ratio of the light was approximately 0.2, was much slower and did not exceed 40%. A minimum of 4 h daily exposure to unfiltered natural light was required for rapid germination in the forest. In the laboratory rapid germination at 25 degrees C required a minimum of 4 h white light. However, if temperature during the light period was 35 degrees C, 30 min exposure to white light daily was sufficient to induce germination. Seeds that failed to germinate when imbibed for 60-360 days in petri dishes placed on the forest floor beneath the forest canopy, germinated rapidly in the laboratory when held at 25 degrees C and exposed daily to 12 h white or red light. Seeds imbibed for 120 days or more beneath the forest canopy were also induced to germinate by 12 h daily exposure to far-red light when this was combined with a 35/25 degrees C day/night temperature regime. Seeds buried in vermiculite-filled nylon mesh bags disappeared rapidly with few remaining after 2 months. Seeds that survived remained viable and germinated when incubated in petri dishes at 25 degrees C. Initially, buried seeds required light for germination. However, after 17 months' burial, seeds germinated in darkness when transferred to the laboratory and incubated on agar at 25 degrees C.     

Antibacterial activity of luteoforol from Bridelia crenulata

The methanol extract of Bridelia crenulata stem bark (50-1.5625 mg/ml) and its isolated luteoforol (2-0.25 mg/ml) showed concentration-dependent inhibiting activity against all 10 tested bacteria.     

Antioxidant, anti-hyaluronidase and antifungal activities of Melaleuca leucadendron Linn. leaf oils

The present study examined the chemical composition, in vitro antioxidant, anti-hyaluronidase and antifungal activities of essential oils of Melaleuca leucadendron Linn. from Gundih-Central Java, Indonesia in different plant ages of 5, 10 and 15 years old. The Chemical composition of essential oils were analyzed by GC/MS. Twenty-six components were identified, of which 1,8-cineole (49.22–55.04 %), α-terpineol (8.79–10.70 %), d-limonene (5.58–6.39 %), and β-caryophyllene (5.03–7.64 %) were the main compounds in these oils. The antioxidant assay and anti-hyaluronidase assay showed that M. leucadendron leaf oils possess mild antioxidant activity with IC₅₀ between 7.21 and 9.23 mg/ml and anti-hyaluronidase activity with IC₅₀ between 1.94 and 3.03 mg/ml. The antifungal assay showed the effectiveness of these essential oils against Fomitopsis palustris (IC₅₀ 0.12–3.16 mg/ml), Trametes versicolor (IC₅₀ 0.01–0.06 mg/ml), Cladosporium cladosporioides (IC₅₀ 0.03–0.49 mg/ml), and Chaetomium globosum (IC₅₀ 0.06–0.15 mg/ml).     

Morinda lucida extract induces endothelium-dependent and -independent relaxation of rat aorta

The effect of an aqueous extract of Morinda lucida (ML) on vascular tone was tested using rat aortic rings precontracted with noradrenaline (10(-7) mol/l). Relaxation responses were determined with endothelium-intact, L-NAME-treated, methylene blue-treated and endothelium-denuded tissues. In the concentration range of 0.25-9.0 mg/ml, ML elicited vasorelaxation in noradrenaline-precontracted rings. This relaxation response was partially attenuated by removal of the endothelium, and completely inhibited by pretreatment of rings with L-NAME and methylene blue. Thus, ML-induced relaxation of vascular smooth muscle occurs via endothelium-dependent and -independent mechanisms, the former of which involves the nitric oxide-cGMP pathway.