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Two new flavonol glycosides were isolated from dried leaves of Koelreuteria paniculata Laxm. (Sapindaceae) and characterized as 6,8-dihydroxy-afzelin and afzelin 3"-O-gallate, based on chemical and spectral evidences, in addition to nine known polyphenolic metabolites, including eight isolated for the first time from this species.
A study of the most important polliniferous plants for European and Africanized honeybees (Apis mellifera L.) was made in Quintana Roo state. Comparisons were made between the plants visited by both bee types in order to determine whether there were qualitative or quantitative differences in their choice of plant species. Also some foraging strategies of the honeybees were analysed. Pollen from pollen load samples was acetolysed and mounted on slides. Subsequently the pollen grains were identified, counted and photographed. A total of 206 pollen load samples were collected at Palmas and St. Teresa during two years. The most frequent species in the pollen load samples from European and Africanized honeybees were Cecropia peltata, Metopium brownei, Lonchocarpus sp. 2, Viguiera dentata, Eragrostis sp. 1, Bursera simaruba and Eupatorium albicaule. Both types of honey bees show a high reliance on pollen from only a few species, the first five named above comprised around 50% of all the mean percentage frequencies. Families that contributed with the largest number of pollen species were Fabaceae, Asteraceae, Boraginaceae, Convolvulaceae, Euphorbiaceae, Sapindaceae, Poaceae, Myrtaceae, Sapotaceae and Tiliaceae. C. peltata, Trema micrantha, B. simaruba, Eugenia sp. 1, Thouinia canesceras, Pouteria sp. 1, Mimosa bahamensis and V. dentata, were the pollen species with the largest percentages of occurrence in both European and Africanized bee pollen load samples, and also represent a "long-term" food resources during the year.
In this study, the light energy allocations between photochemical reactions and heat dissipation in the seedlings of three tropical rain forest tree species were investigated under three light regimes (100%, 25% and 8% of full sunlight) by using chlorophyll fluorescence technique. These tree species are Anthocephalus chinensis (Rubiacease), a pioneer species, Pometia tomentosa (Sapindaceae), a canopy climax species, and Horsfieldia tetratepala (Myristicaceae), a sub-canopy climax species. Under the same light levels, A. chinensis had a higher maximum photosynthetic rate (Pmax) and maximum electron transport rate (ETRmax) than P. tomentosa and H. tetratepala. From the light response curves of light energy allocations, all test species had a decreased fraction of light energy allocated to photochemical reactions, while the fraction of light energy allocated to heat dissipation was increased with light intensity. The fractions of light energy allocated to photochemical reactions and heat dissipation were negatively correlated with very high significance. Compared to other two species, A. chinensis allocated more light energy to fractions of photochemical reactions, and had weaker and unsaturated heat dissipation. But, when growing under 100% sunlight, this species had less excess light energy to be used for photosynthesis, so that, it did not suffer from photoinhibition. In contrast, more light energy was allocated to fractions of heat dissipation in both P. tomentosa and H. tetratepala seedlings. Growing under 100% sunlight, these two species received more excess light energy, which caused photoinhibition. Our results support the idea that light requirements for the regeneration of three tropical tree species under different ecological habits are related to their characteristics of light energy utilization and dissipation.
Fifty local medicinal, agricultural and wild growing deciduous plants, representing 49 species, 46 genera and 22 families, were screened as water extracts at 1:1000 concentration for molluscicidal activity against Biomphalaria pfeifferi in Machakos District, Kenya. Forty-seven of the 50 (94%) plants and 106 of the 134 (79%) plant materials (roots, stems, leaves, fruits, flowers and seeds) were molluscicidal. The leaves of Pappea capensis (Sapindaceae), Steganotaenia araliacea (Umbelliferae), Zornia setosa subsp. obvata (Papilionaceae) and Terminalia kilimandscharica (Combretaceae), the flower pods of Hyptis pectinata (Labiatae), the seeds of Acacia nilotica (Mimosaceae) and the fruits and roots of Solanum nigrum (Solanaceae) gave 100% kill. Another 15 species produced mortality rates between 53% and 87%. Plants were evaluated for possible use in local snail control programmes by considering their growing characteristics, habitat requirements, toxicity in non-target organisms, abundance in the study area and competing uses.
Seventy four species of Cerambycidae (Coleoptera) were reared from forty eight host plants found into Yungas, Chaco and Prepuna phytogeografical provinces. The host plants belong Anacardiaceae, Asclepiadaceae, Bignoniaceae, Cactaceae, Cucurbitaceae, Euphorbiaceae, Juglandaceae, Leguminosae sensu lato (Caesalpinaceae, Fabaceae, Mimosaceae), Loranthaceae, Rhamnaceae, Rutaceae, Salicaceae, Sapindaceae, Solanaceae, Ulmaceae and Vitaceae. Some species of Cerambycidae and their host plants show similar distribution patterns: from northeastern Brazil through Paraguay and reach the Argentina at both sides of the Chaco Provine: at the east, along the river systems through Buenos Aires, and the at the west into forests of the Yungas Province or into North Sierra Chaco, a probably relictual community. Others species are restricted to the South America area of Prosopis, that comprise the Chaco, Monte and Espinal biogeographical provinces, and live in host plants of chaquenian lineage mainly Leguminosae sensu lato and Ulmaceae.
New host plants and localities are recorded for 84 species of Cerambycidae of Chaco Province (Chaquenian Dominion) and Paranaense Province (Amazonian Dominion) in northeastern Argentina and Brazil. Host plants belong to Anacardiaceae, Asclepiadaceae, Apocynaceae, Bignoniaceae, Bombacaceae, Cactaceae, Caesalpinaceae, Capparidaceae, Casuarinaceae, Fabaceae, Mimosaceae, Moraceae, Nyctaginaceae, Polygonaceae, Rhamnaceae, Rutaceae, Sapindaceae, Sapotaceae and Ulmaceae. First records for Argentina and host plants: Compsocerus barbicornis Serville 1834, Desmiphora lenkoi (Lane 1959), Neocompsa serrana (Martins 1962) and Trachysomus dromedarius (Voet 1778). First host plants records of rare or uncommon Argentine species of Cerambycidae are Methia tubuliventris Gounelle 1913, Paraleptidea femorata Gounelle 1913 and Oncideres pepotinga Martins 1981.
Plant lectins have insecticidal activity that is probably mediated through their ability to bind carbohydrates. To examine the influence of sugars on the insecticidal activity of a lectin from Talisia esculenta seeds (TEL), the lectin was mixed with mannose, glucose, or mannose plus glucose. Mannose abolished the insecticidal activity. Affinity chromatography showed that TEL bound to midgut proteins of the insect Callosobruchus maculatus. Immunoblotting showed that TEL recognized some proteins, probably glycoproteins, present in the midgut membrane of this insect. The principal proteases responsible for digestive proteolysis in fourth instar larvae of C. maculatus were purified by chromatography on activated thiol-Sepharose. These purified proteases were unable to digest TEL after a 15-h incubation. These results suggest that the insecticidal activity of TEL involves a specific carbohydrate-lectin interaction with glycoconjugates on the surface of digestive tract epithelial cells, as well as binding to assimilatory glycoproteins present in midgut extracts and resistance to enzymatic digestion by cysteine proteinases.
The aim of this study was to compare the efficacy of Venostasin (horse chestnut seed extract) and Pycnogenol (French maritime pine bark extract) in the treatment of chronic venous insufficiency (CVI). In an open, controlled comparative study 40 patients with diagnosed CVI were treated either with 600 mg chestnut seed extract per day or 360 mg Pycnogenol per day over a period of 4 weeks. The following parameters were investigated before the start of treatment and after 2 and 4 weeks of treatment: circumference of the lower legs and rating of subjective symptoms (scores) of pain, cramps, night-time swelling, feeling of "heaviness", and reddening of the skin. In addition, blood levels of cholesterol LDL and HDL were determined before and at the end of treatment. Pycnogenol significantly reduced the circumference of the lower limbs and significantly improved subjective symptoms. Furthermore, Pycnogenol significantly decreased cholesterol and LDL values in the blood, whereas HDL remained unaffected. Venostasin only moderately but not significantly, reduced the circumference of the lower limbs and marginally improved symptoms. Venostasin had no influence on the determined lipid values. Both medications were equally well tolerated. In conclusion, Pycnogenol was found to be more efficacious than Venostasin for the treatment of CVI.
The efficacy of guggulu, the gum resin of Commiphora mukul in regulating hypothyroidism was evaluated in female mice. In addition to estimating serum levels of thyroxine and triiodothyronine, hepatic 5' monodeiodinase, hepatic glucose-6-phospatase and lipid-peroxidation (LPO), the activities of the anti-oxidative enzymes, superoxide dismutase (SOD) and catalase (CAT), were investigated. While 6-n-propyl-2-thiouracil (PTU, 10.00 mg/kg/d for 30 days) induced hypothyroidism in mice, as evidenced by a decrease in thyroid hormone concentration and in hepatic 5'D-I activity, simultaneous administration of guggulu (200 mg/kg/d for 30 days) reversed this effect, indicating its potential to stimulate thyroid function. Although in PTU treated animals a marginal increase in hepatic LPO was observed, when simultaneously treated with guggulu, it was decreased. A parallel increase in the activity of endogenous antioxidants, SOD and CAT, in the latter group indicated the safe and antiperoxidative nature of the drug. These findings suggest the possible use of guggulu in the amelioration of hypothyroidism.
The antioxidant activities of QF808, a steam bark extract of Mangifera indica L., were studied on hydroxyl-mediated oxidation of bovine serum albumin (BSA) and in a hepatic microsome system. The extract was effective in reducing the oxidation of BSA, since its half- maximal inhibition concentration (IC(50)) was 0.0049% w/v in the inhibition of carbonyl group formation and lower than 0.0025% w/v in the inhibition of sulfhydryl group loss. QF808 inhibited lipid peroxidation which was initiated enzymatically by reduced nicotinamide adenine dinucleotide phosphate (NADPH), IC(50)= 0.00075% w/v, or non-enzymatically by ascorbic acid, IC(50) = 0.0126% w/v. The extract tested did not inhibit NADPH-dependent cytochrome P-450 reductase activity, since it had no effect on the oxidation rate of NADPH. These results suggest that QF808 has an antioxidant activity, probably due to its ability to scavenge free radicals involved in microsome lipid peroxidation. In addition, QF808 antioxidant profile in vitro is probably similar to its principal polyphenolic component, mangiferin, a glycosylated xanthone.
This work characterizes differences in selection of Talisia retusa fruits by two sympatric Neotropical primates, Pithecia pithecia (white-faced sakis) and Alouatta seniculus (red howlers). Color appears to be the criterion by which fruits were selected. Greenish fruits were mainly eaten by Pithecia, while yellowish fruits by Alouatta. The characteristics of these primates in relation to seed predation and seed dispersal are discussed in the context of the Talisia retusa fruit color spectrum. Furthermore, a possible differential acquisition of chemical components, like tannins, is hypothetically treated considering the variation in fruit color.
The recent identification of DAD (defender against apoptotic death) gene in plants suggests that the N-linked glycosylation of proteins could be an important control point of plant programmed cell death. In this paper we describe the effects of Tunicamycin, an inhibitor of N-linked protein glycosylation, and Brefeldin A, an inhibitor of protein trafficking from the Golgi apparatus, on sycamore (Acer pseudoplatanus L.) cell cultures. These two chemicals proved able to induce a strong acceleration of the cell death; changes in cell and nucleus morphology; an increase in DNA fragmentation, detectable by a specific immunological reaction; and the presence of oligonucleosomal-size fragments (laddering) in DNA gel electrophoresis. Moreover, Brefeldin A, but not Tunicamycin, strongly stimulated the production of hydrogen peroxide. These results indicate that also in plants chemicals interfering with the activities of endoplasmic reticulum and of Golgi apparatus strongly induce a form of programmed cell death showing apoptotic features.
From the pulp of Euphoria longana (Longan Arillus), three cerebroside molecular species have been isolated. Six known cerebrosides, soyacerebrosides I and II, 1-O-beta-D-glucopyranosyl-(2S,3R,4E,8E)-2-(2'-lignoceroylamino)-4,8-octadecadiene-1,3-diol (longan cerebroside I) and its 8Z isomer (longan cerebroside II), momor-cerebroside I, and phytolacca cerebroside, were identified as major components of these cerebroside molecular species. All the cerebrosides were shown to be a mixture of geometrical isomers (8E and 8Z) of sphingosine-type or phytosphingosine-type glucocerebrosides possessing 2-hydroxy fatty acids. The structures of these cerebrosides have been determined on the basis of chemical and spectroscopic evidence.
Extracts of Cardiospermum halicacabum, medicinal plant, were tested in vitro for their effectiveness against third-stage larvae of Strongyloidesstercoralis. Third-stage larvae of S. stercoralis were isolated from cultures of dog's feces using agar plate culture method. The larvae (1,000 larvae/ml), suspended in phosphate buffer saline solution, pH 7.4, were exposed to aqueous and alcohol extracts (2,000 microg/ml) of C. halicacabum at 37 degrees C with 5% CO2. Ivermectin (250 microg/ml) and piperazine (2,000 microg/ml) were also used as the reference drugs. The survival of Strongyloides larvae based on its motility was determined daily for 7 days. Strongyloides larvae were viable after contact with ivermectin, piperazine and C. halicacabum (aqueous and alcohol) solutions, but most of them were immobilized, after exposure to aqueous and alcohol extracts of C. halicacabum within 72 and 48 h, respectively, while ivermectin took from 72 to 144 h, and piperazine more than 7 days, to achieve the same rate of nonmotility. Clearly, the viability of S. stercoralis larvae was significantly reduced when exposed to extracts of C. halicacabum. Further study is needed on the antiparasitic activity of aqueous and alcohol extracts of C. halicacabum against S. stercoralis.
Diurnal variation in leaf stomatal conductance (gs) of three xerophilous species (Buddleia cordata, Senecio praecox and Dodonaea viscosa) was measured over a 10-month period during the dry and wet seasons in a shrubland that is developing in a lava substratum in Mexico. Averaged stomatal conductances were 147 and 60.2 (B. cordata), 145 and 24.8 (D. viscosa) and 142.8 and 14.1 mmol m(-2) s(-1) (S. praecox) during the wet and dry season respectively. Leaf water potential (Psi) varied in a range of -0.6 to -1.2 (S. praecox), -0.6 to -1.8 (B. cordata) and -0.9 to -3.4 MPa (D. viscosa) during the same measurement periods. Stomata were more sensitive to changes in irradiance, air temperature and leaf-air vapour pressure difference in the rainy season than the dry season. Although stomatal responses to Psi were difficult to distinguish in any season (dry or rainy), data for the entire period of measurement showed a positive correlation, stomata tending to open as Psi increased, but there is strong evidence of isohydric behaviour in S. praecox and B. cordata. A multiplicative model relating gs to environmental variables and to Psi accounted for 79%-83% of the variation of gs in three sites (pooled data); however, the performance of the model was poorer (60%-76%) for individual species from other sites not included in the pooled data.
We investigated whether arbuscular mycorrhizas influenced growth and survival of seedlings in an extremely impoverished and highly disturbed soil. Seedlings of four plants species native to the site were either inoculated with native sporocarpic arbuscular mycorrhizal (AM) fungi or fertilised prior to transplanting, and followed over 86 weeks at the site. One treatment was also irrigated with N-rich leachate from the site. In a laboratory experiment, seedlings were fertilised with excess P for 6 weeks, and location of the P store determined. Growth and survival of AM and fertilised seedlings were similar at the site. Inoculated mycorrhizal fungi and roots appeared to extend into the surrounding soil together. P concentration in leaves of all plants was extremely low. Irrigation with leachate increased growth of seedlings. In the laboratory experiment, significantly more P was stored in roots than shoots. We suggest that successful revegetation of extremely disturbed and impoverished sites requires selection of mycorrhizal fungi and plants to suit the edaphic conditions and methods of out-planting.
Four new ether diglycosides (1-4), named matayosides A-D, were isolated from the root bark of Matayba guianensis, a plant exhibiting in vitro antiplasmodial activity. They were identified as hexadecyl-[O-2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl-(1-->2)]-6-O-palmitoyl-beta-D-glucopyranoside, hexadecyl-[O-2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl-(1-->2)]-4,6-di-O-acetyl-beta-D-glucopyranoside, hexadecyl-[O-2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl-(1-->2)]-3,6-di-O-acetyl-beta-D-glucopyranoside and hexadecyl-[O-2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl-(1-->2)]-6-O-acetyl-beta-D-glucopyranoside, respectively. Their structures were established using one- and two-dimensional NMR techniques, mass spectrometry (MS) and MS/MS experiments. The compounds were found to inhibit the growth of Plasmodium falciparum in vitro with IC50 values ranging from 2.5 to 8.9 microg/mL.
High-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS) analysis revealed the phenolics profile of longan (Dimocarpus longan Lour.) seed. Gallic acid, ellagic acid, monogalloyl-glucose, monogalloyl-diglucose, digalloyl-diglucose, penta- to heptagalloyl-glucose, ellagic acid-pentose conjugate, galloyl-HHDP (Hexahydroxydiphenoyl)-glucopyranose, pentagalloy-HHDP-glucopyranose, procyanidin A-type dimer, procyanidin B2 and quercetin-3-O-rhamnoside were found to be present in longan seed along with a number of, as yet, unknown compounds. The results illustrate the rich array of phenolic compounds in longan seeds which could be utilized as health-beneficial bioactive compounds rather than just discarded as waste.