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Nine new naphthalene related compounds (I, IV, V, VII-XII) together with four known compounds (II, III, VI, XIII) were isolated from the root bark of Oroxylum indicum Vent. (Bignoniaceae), one of the Nepalese crude drugs. Their structures were determined based on chemical and physiocochemical evidence.
We determined the neutralizing activity of 12 ethanolic extracts of plants against the edema-forming, defibrinating and coagulant effects of Bothrops asper venom in Swiss Webster mice. The material used consisted of the leaves and branches of Bixa orellana (Bixaceae), Ficus nymphaeifolia (Moraceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plant of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); rhizomes of Renealmia alpinia (Zingiberaceae), Heliconia curtispatha (Heliconiaceae) and Dracontium croatii (Araceae), and the ripe fruit of Citrus limon (Rutaceae). After preincubation of varying amounts of each extract with either 1.0 microg venom for the edema-forming effect or 2.0 microg venom for the defibrinating effect, the mixture was injected subcutaneously (sc) into the right foot pad or intravenously into the tail, respectively, to groups of four mice (18-20 g). All extracts (6.2-200 microg/mouse) partially neutralized the edema-forming activity of venom in a dose-dependent manner (58-76% inhibition), with B. orellana, S. orbicularis, G. panamensis, B. rosademonte, and D. croatii showing the highest effect. Ten extracts (3.9-2000 microg/mouse) also showed 100% neutralizing ability against the defibrinating effect of venom, and nine prolonged the coagulation time induced by the venom. When the extracts were administered either before or after venom injection, the neutralization of the edema-forming effect was lower than 40% for all extracts, and none of them neutralized the defibrinating effect of venom. When they were administered in situ (sc at the same site 5 min after venom injection), the neutralization of edema increased for six extracts, reaching levels up to 64% for C. limon.
The immature stages of Adelpha malea goyama Schaus are described from the Estação Ecol6gica do Caiuá, Paraná State, Brazil. The species uses the native liana Arrabidaea mutabilis Bur. & K. Schum. (Bignoniaceae) as larval hostplant in the study site. Isolated eggs are laid on leaf tips, and are similar in shape to those described for other species of Adelpha Hübner. Larvae pass through five stadia during 21 days, and first to third instars construct frass chains. Later instars rest on the upper leaf surface, and their body is covered by rigid branched scoli. The general profile of the pupa is elongated, with short head horns projecting laterally and with segment A2 projecting and curved anteriorly. Comparisons with closely related species of Adelpha are not conclusive, and more species in the genus need to be reared before a clear pattern of the variation in immature morphology becomes evident.
We screened ethanol extracts from a total of 134 species of edible Thai plants for their suppressive effects on superoxide (O2(-)) generation using a xanthine (XA)-xanthine oxidase (XOD) assay system. When the extracts were tested at a concentration of 500 &mgr;/g/ml, 28.4% significantly suppressed O2(-) generation. Of these active extracts, it was found that in 17.9% of cases the action was due to XOD inhibition, in 1.5% due to O2(-) scavenging activity, and in 9% due to both XOD inhibition and O2(-) scavenging. In addition, some plant extracts (25 species) which had been known to possibly possess anti-tumor promoting activity were tested for O2(-) and NO generation in cellular systems. In this test, 13 species exhibited strong inhibitory activity toward both O2(-) and NO generation. From the fruit pods of Oroxylum indicum (Bignoniaceae), a traditional vegetable in Thailand, two flavones, oroxylin A and chrysin, and a triterpene carboxylic acid, ursolic acid (UA), were identified as inhibitors of O2(-) generation in XA/XOD system. These compounds also showed marked inhibitory effects on the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced O2(-) generation in dimethylsulfoxide (DMSO)-differentiated HL-60 cells. Our results suggest that, as we have reported earlier, edible Thai plants are promising sources of antioxidants with chemopreventive potential.
In an attempt to identify new antimalarial compounds we studied the blood schizonticide effect of chemically defined natural products which were isolated from plants (Bignoniaceae) or synthesized. Different concentrations of these drugs (up to 20 microM) were incubated in vitro with blood forms of Plasmodium falciparum for 72 h. A total of 12 drugs of the naphthoquinones group were tested. Eight of them were isolated from plants (NP) and 4 synthesized (S). Three of the drugs (2 NP and one S) were very active and completely inhibited parasite growth at the higher concentrations used (20 microM); 5 drugs were partially active (3S and 2NP) and 3 (NP) were totally inactive. Lapachol was among the drugs tested. Although it has been considered a potential antimalarial agent, it exhibited very low activity (20% inhibition of schizogony). The antimalarial activity of our naphthoquinones against drug-resistant strains was superior to that of chloroquine and quinine which were used as controls. Two of the P. falciparum strains used for the tests were strongly chloroquine resistant. If these naphthoquinones prove to be active in vivo and are of low toxicity, they will be promising candidates for treatment of human malaria particularly since they are easily synthesized.
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.
Tecostanine (1) was isolated from Tecoma stans leaves. Its sterochemistry was elucidated as well as its antihyperglycemic activity and its affinity to opioid and nicotinic receptors. The oxalate salt of 1 did not significantly affect blood glucose levels in normoglycaemic and hyperglycaemic rats. It did not appear to interact with opioid receptors (mu type) and showed only moderate affinity to the nicotinic receptor.
Two new 3-deoxyanthocyanidins, 6,7,3',4'-tetrahydroxy-5-methoxyflavylium and 6,7,4'-trihydroxy-5-methoxyflavylium, and the pigment carajurin, which has been previously identified, were isolated from dried leaves of Arrabidaea chica, a creeper native to the American tropics. The structures of the components were elucidated by 1H- and 13C-NMR spectroscopy and HPLC-MS, including X-ray crystallographic analysis for carajurin.
The methanol extract of stems of Catalpa ovata G Don exhibits potent in vivo antifungal activity against Magnaporthe grisea (Hebert) Barr (rice blast) on rice plants, Botrytis cinerea Pers ex Fr (tomato grey mould) and Phytophthora infestans (Mont) de Bary (tomato late blight) on tomato plants, Puccinia recondita Rob ex Desm (wheat leaf rust) on wheat plants and Blumeria graminis (DC) Speer f. sp. hordei Marchal (barley powdery mildew) on barley plants. An antifungal substance was isolated and identified as dehydro-alpha-lapachone from mass and nuclear magnetic resonance spectral data. It completely inhibited the mycelial growth of B. cinerea, Colletotrichum acutatum Simmonds, Colletotrichum gloeosporioides Simmonds, M. grisea and Pythium ultimum Trow over a range of 0.4-33.3 mg litre(-1). It also controlled the development of rice blast, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose (Colletotrichum coccodes (Wallr) S Hughes). The chemical was particularly effective in suppressing red pepper anthracnose by 95% at a concentration of 125 mg litre(-1).
Commelina diffusa and Spathodea campanulata are used as wound-healing agents in Ashanti traditional medicine in Ghana. The methanol extracts of Commelina diffusa herb and Spathodea campanulata bark showed some level of antimicrobial activity with C. diffusa exhibiting selective antifungal activity against Trichophyton species. The extracts reduced the peroxidation of bovine brain extract with an IC(50) value of 1.39 mg/mL and 0.24 mg/mL, respectively. In addition the extracts also exhibited significant antioxidant activity by protecting MRC-5 cells from hydrogen peroxide induced oxidant injury at concentrations between 1 microg/mL and 10 microg/mL. The extracts showed no inhibition of NF-kappaB at 100 microg/mL. The antioxidant activities and antimicrobial activities suggest that the use of the plants in wound healing may be based on antioxidant and antiseptic effects of its constituents.
The flower of Campsis grandiflora K. Schum. was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and H2O. From the EtOAc fraction, seven triterpenoids were isolated through the repeated silica gel, ODS column chromatographies and preparative HPLC. From the result of physico-chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as 3beta-hydroxyolean-12-en-28-oic acid (oleanolic acid, 1), 3beta-hydroxyurs-12-en-28-oic acid (ursolic acid, 2), 3beta-hydroxyurs-12-en-28-al (ursolic aldehyde, 3), 2alpha,3beta-dihydroxyolean-12-en-28-oic acid (maslinic acid, 4), 2alpha,3beta-dihydroxyurs-12-en-28-oic acid (corosolic acid, 5), 3beta,23-dihydroxyurs-12-en-28-oic acid (23-hydroxyursolic acid, 6) and 2alpha,3beta,23-trihydroxyolean-12-en-28-oic acid (arjunolic acid, 7). These teriterpenoids were isolated for the first time from this plant. Also, compounds 4, 5, 6, and 7 revealed relatively high hACAT-1 inhibitory activity with the value of 46.2+/-1.1, 46.7+/-0.9, 41.5+/-1.3 and 60.8+/-1.1% at the concentration of 100 microg/mL, respectively.
Five pentacyclic triterpenoids, oleanolic acid (1), hederagenin (2), ursolic acid (3), tormentic acid (4) and myrianthic acid (5), were isolated from the methanol extract of the leaves of Campsis grandiflora, and structures of the compounds were established by the spectroscopic methods. Compounds 2, 3, 4, and 5 were isolated for the first time from the genus Campsis. All of the compounds (IC50: 45.3, 32.8, 82.6, 42.9 and 46.2 microM respectively) were as equivalently inhibitive as acetylsalicylic acid (IC50: 57.0 microM) on epinephrine induced platelet aggregation.
Under natural conditions gold has low solubility that reduces its bioavailability, a critical factor for phytoextraction. Researchers have found that phytoextraction can be improved by using synthetic chelating agents. Preliminary studies have shown that desert willow (Chilopsis linearis), a common inhabitant of the Chihuahuan Desert, is able to extract gold from a gold-enriched medium. The objective of the present study was to determine the ability of thiocyanate to enhance the gold-uptake capacity of C. linearis. Seedlings of this plant were exposed to the following hydroponics treatment: (1) 5 mg Au L(-1) (2.5x10(-5) mol L(-1)), (2) 5 mg Au L(-1) + 10(-5) mol L(-1) NH4SCN, (3) 5 mg Au L(-1) + 5x10(-5) mol L(-1) NH4SCN, and (4) 5 mg Au L(-1) + 10(-4) mol L(-1) NH4SCN. Each treatment had its respective control. After 2 weeks we determined the effect of the treatment on plant growth and gold content by inductively coupled plasma-optical emission spectroscopy (ICP-OES). No signs of shoot-growth inhibition were observed at any NH4SCN treatment level. The ICP-OES analysis showed that addition of 10(-4) mol L(-1) NH4SCN increased the concentration of gold by about 595, 396, and 467% in roots, stems, and leaves, respectively. X-ray absorption spectroscopy (XAS) studies showed that the oxidation state of gold was Au(0) and that gold nanoparticles were formed inside the plants.
As "exploiters" of plant-pollinator mutualisms, nectar-robbers remove rewards (nectar) without providing pollination services. Though one might expect nectar-robbing to be costly to plants, it may instead benefit plants by indirectly increasing pollen dispersal. I investigated the direct effects of nectar-robbing bees ( Xylocopa californica) on floral rewards and behaviors of pollinators visiting desert willow ( Chilopsis linearis) and indirect effects of robbing on the reproductive success of the plant. Nectar-robbers reduced nectar; while unrobbed and robbed flowers were equally likely to contain nectar, nectar volumes were smaller in robbed flowers with nectar. Apis mellifera (honeybees), ineffective pollinators in terms of pollen deposition, avoided robbed flowers. In contrast, Bombus sonorus (bumblebees), effective pollinators, did not avoid robbed flowers. While bumblebees tended to spend less time in robbed flowers, the time that they spent in flowers was not correlated with pollen deposition. Using powder mimicking pollen, I found that on some days, powder was dispersed farther or to more flowers from robbed flowers, indicating that robbing may sometimes benefit plants by increasing male reproductive success. Powder movement suggested that the effect of robbing on male reproductive success ranged from costly to beneficial. The outcome for flowers that were marked early each morning was a function of prevalence of robbing and abundances of effective pollinators, but not a function of spatial variability among trees in prevalence of robbing or the abundance of ineffective honeybees. Unlike powder dispersal, female reproductive success, measured by fruit set and the number of pollen tubes growing in styles, was not affected by robbing. Thus, robbers did not reduce plants' female reproductive success either directly by damaging flowers or indirectly by reducing pollen deposition by pollinators. Overall, this study indicates that nectar-robbers were not often costly to plants, and sometimes even benefited plants.
Novel ceramides, rel-(3S,4S,5S)-3-[(2R)-2-hydroxycosanoyl-hexacosanoylamino]-4-hydroxy-5-[(4Z)-tetradecane-4-ene]-2,3,4,5-tetrahydrofuran (1a-g), and a new glucoceramide, 1-O-beta-D-glucopyranosyl-(2S,3S,4R,8E)-2-[(2R)-2-hydroxytetracosanoylamino]-1,3,4-octodecanetriol-8-ene (2) were isolated from the aqueous ethanolic extract of the roots of Incarvillea arguta, together with eight known compounds: beta-sitosterol (3), oleanolic acid (4), ursolic acid (5), piperin (6), maslinic acid (7), beta-sitosterol 6'-O-acyl-beta-D-glucopyranoside (8), 8-epideoxyloganic acid (9), and plantarenaloside (10). Their structures were elucidated on the basis of spectral data including IR, MS, NMR [1H NMR, 13C NMR (distortionless enhancement by polarization transfer), 1H-1H COSY, heteronuclear multiple-quantum coherence, and heteronuclear multiple-bond coherence correlations]. The relative configurations were established by nuclear Overhauser effect spectroscopy experiments and by comparison of the NMR spectral data and coupling constants with those already reported in the literature.
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Analytical Milli high-speed counter-current chromatography (HSCCC) was used for the selection and optimization of the two-phase solvent system to separate flavonoids from the extracts of the seeds of Oroxylum indicum. The optimum solvent system obtained from Milli-CCC was also the best solvent system for preparative HSCCC and led to the successful separation of two crude flavonoids from the seeds of O. indicum by Lab/Prep (laboratory preparative) HSCCC using different sized coils. Four flavonoids were isolated by preparative HSCCC: baicalein-7-O-diglucoside (25.0 mg, 92% purity), baicalein-7-o-glucoside (50.4 mg; 95% purity), baicalein (75 mg; purity 98%) and chrysin (100 mg; purity 98%).