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Four isoprenylated flavones, artoindonesianins Q-T, were isolated from the heartwood of Artocarpus champeden Roxb. The structures of these compounds were elucidated on the basis of their spectroscopic data.
BACKGROUND AND AIMS: To understand the defensive characteristics of interspecies varieties and their responses to herbivory damage, four species of Ficus plants (Ficus altissima, F. auriculata, F. racemosa and F. hispida) were studied. They were similar in life form, but differed in successional stages. Of these, Ficus altissima is a late successional species, F. hispida is a typical pioneer and F. auriculata and F. racemosa are intermediate successional species. We addressed the following questions: (1) What is the difference in plant traits among the four species and are these traits associated with differences in herbivory damage levels? (2) What is the difference in the damage-induced changes among the four species? METHODS: Herbivory damage was measured in the field on randomly planted seedlings of the four species of the same age. Defences to herbivory were also tested by feeding leaves of the four species to larvae of Asota caricae in the laboratory. A total of 14 characters such as water content, thickness, toughness, pubescence density on both sides, leaf expansion time, lifetime and the contents of total carbon (C), nitrogen (N), phosphorous (P), potassium (K), magnesium (Mg) and calcium (Ca) were measured. Leaf calcium oxalate crystal (COC) density, total Ca and N content, leaf toughness and height were measured to investigate induced responses to artificial herbivory among the four species. KEY RESULTS: and conclusions Herbivory damage in the four studied species varied greatly. The pioneer species, F. hispida, suffered the most severe herbivory damage, while the late successional species, F. altissima, showed the least damage. A combination of several characteristics such as high in content of N, Ca and P and low in leaf toughness, lifetime and C : N ratio were associated with increased herbivore damage. The late successional species, F. altissima, might also incorporate induced defence strategies by means of an increase in leaf COC and toughness.
The unusual floral phenology of most monoecious figs, related to their highly specialized pollination mutualism with agaonid wasps, combines pronounced dichogamy at the level of inflorescences and individuals with population-level asynchrony in flowering. This floral phenology ensures that outcrossing strongly predominates. Fig populations may thus be expected to possess deleterious recessive alleles that lead to inbreeding depression when selfing does occur. However, whether monoecious figs are self-compatible and whether selfing results in inbreeding depression have never been investigated. Using wasps as "pollination tools" and exploiting infrequent overlap in male and female phases on the same tree, we conducted controlled selfed and outcrossed pollination experiments in Ficus aurea. Our results show that this species is totally self-compatible. No negative effects of selfing could be demonstrated on syconium retention, number of vacant ovaries, seed set, or seed germination. However, wasp production had a tendency to be higher after self-pollination. While it is possible that inbreeding depression is expressed at later developmental stages, its absence at the early stages we examined is nonetheless surprising for a plant expected to be highly outcrossed. It is likely that selection pressures other than avoidance of inbreeding are responsible for the evolution and maintenance of the unusual floral phenology of figs.
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A lyophilized aqueous leaf extract of Cecropia obtusifolia proved to be antihypertensive when intravenously administrated to conscious spontaneous hypertensive rats. Forty-five minutes after injection, the maximum fall in arterial pressure (-23.5% relative to preinjection values) was seen and recovery was not complete by the end of the 180 min observation period. The extract was also given to pre-hypertensive SHR and normotensive rats. The fall in blood pressure was more conspicuous in the two SHr groups and was not accompanied by changes in cardiac frequency in any group. This would appear to rule out either a direct or indirect involvement of the heart in regard to the observed hypotension.
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The possible diuretic effect of the leaf extract of Cecropia obtusifolia, Bertol; used in Costa Rican traditional medicine, was tested on five Sprague Dawley rats in individual metabolic cages. During the control week, distilled water was administered with an intragastric cannula. During the C.obtusifolia week, the rats were given the aqueous leaf extract in a daily dosage of 500 mg/kg, intragastricly. Although, the urinary flow was increased (p < 0.05) by a 20%, there was no statistically significant difference between the following parameters: excretion in urine of osmoles, sodium and potassium; daily ingestion of food and water. The animal weights decreased when C. obtusifolia was used, but only on the fourth day the decrease was significant (p < 0.05). In conclusion, the aqueous leaf extract of C. obtusifolia has a slight diuretic effect.
Mannose-specific lectins with high sequence similarity to jacalin and the Maclura pomifera agglutinin have been isolated from species belonging to the families Moraceae, Convolvulaceae, Brassicaceae, Asteraceae, Poaceae and Musaceae. Although these novel mannose-specific lectins are undoubtedly related to the galactose-specific Moraceae lectins there are several important differences. Apart from the obvious differences in specificity, the mannose- and galactose-specific jacalin-related lectins differ in what concerns their biosynthesis and processing, intracellular location and degree of oligomerization of the protomers. Taking into consideration that the mannose-specific lectins are widely distributed in higher plants, whereas their galactose-specific counterparts are confined to a subgroup of the Moraceae sp. one can reasonably assume that the galactose-specific Moraceae lectins are a small-side group of the main family. The major change that took place in the structure of the binding site of the diverging Moraceae lectins concerns a proteolytic cleavage close to the N-terminus of the protomer. To corroborate the impact of this change, the specificity of jacalin was re-investigated using surface plasmon resonance analysis. This approach revealed that in addition to galactose and N -acetylgalactosamine, the carbohydrate-binding specificity of jacalin extends to mannose, glucose, N -acetylmuramic acid and N -acetylneuraminic acid. Owing to this broad carbohydrate-binding specificity, jacalin is capable of recognizing complex glycans from plant pathogens or predators.
The floristic composition and structure of a premontane moist forest remnant were studied in the El Rodeo Protected Zone, Central Valley of Costa Rica. Three one-hectare plots were established in the non-disturbed forest, and all trees with a diameter at breast height (dbh) of 10 cm or greater were marked, measured and identified. The plots were located within a radius of 500 m from each other. A total of 106 tree species were recorded in the three plots. Average values: species richness 69.6 species ha-1, abundance 509 individuals ha-1, basal area 36.35 m2 ha-1. Total diversity was 3.54 (Shannon Index, H'), and the species similarity among the plots ranged between S = 0.68 and 0.70 (Sørensen Similarity Index). Most tree species are represented by few individuals (five or less). There is a lack of emergent trees and arborescent palms in the forest canopy. According to the Familial Importance Value, Moraceae, followed by Fabaceae, Lauraceae, and Sapotaceae, largely dominates this forest. Pseudolmedia oxyphillaria (Moraceae) is the dominant species (Importance Value Index), accounting for 25% of all the marked trees in the plots, followed by Clarisia racemosa (Moraceae), Heisteria concinna (Olacaceae), and Brosimum alicastrum (Moraceae). The size class distributions were similar among plots, and in general followed the expected J-inverted shape. Differences in tree abundance, floristic composition, and spatial distribution of some species among the plots suggest heterogeneity of this ecosystem's arborescent vegetation. Moreover, it is an important natural reservoir for the conservation of rare and endangered tree species in a national level. Using these results as a baseline, this study should start a long term monitoring of the structure and composition of this very reduced and fragmented ecosystem.
The diversity and distribution of microfungal assemblages in leaf litter of a tropical Australian forest was assessed using two methods: (1) cultures were isolated using a particle filtration protocol (wet season 2001), and (2) fruit bodies were observed directly on leaf surfaces following incubation in humid chambers (wet and dry season of 2002). Four tree species were studied using both methods, namely Cryptocarya mackinnoniana (Lauraceae), Elaeocarpus angustifolius (Elaeocarpaceae), Ficus pleurocarpa (Moraceae), and Opisthiolepis heterophylla (Proteaceae). An additional two species, Darlingia ferruginea (Proteaceae) and Ficus destruens (Moraceae), were studied using direct observations. In total, fruiting bodies of 185 microfungal species were recorded on leaf surfaces (31-81 species per tree species), and 419 morphotypes were detected among isolates obtained by particle filtration (111-203 morphotypes per tree species). Although the observed microfungal diversity was higher with the particle filtration protocol, both methods concurred with respect to microfungal distributions. The overlap of microfungal species in pair wise comparisons of tree species was low (14-30%), and only 2 and 3% of microfungal species were observed in leaves of all tree species by particle filtration and by direct observations respectively. Multivariate analysis of data from direct observations confirmed the hypothesis that microfungal assemblages are strongly influenced by host phylogeny and are also affected by seasonal and site factors. The importance of host species in shaping microfungal distributions was also supported by the particle filtration data. Several taxa new to science, as well as some widespread saprotrophs, were detected on only one host. The underlying reasons for this affinity remain unclear, but we hypothesise that a number of factors may be involved such as fungal adaptation to plant secondary metabolites or the presence of a biotrophic phase in the fungus' life cycle.
Thirty-one of 75 extracts of plants used by traditional healers for snakebites, had moderate or high neutralizing ability against the haemorrhagic effect of Bothrops atrox venom from Antioquia and Chocó, north-western Colombia. After preincubation of several doses of every extract (7.8-4000 microg/mouse) with six minimum haemorrhagic doses (10 microg) of venom, 12 of them demonstrated 100% neutralizing capacity when the mixture was i.d. injected into mice (18-20 g). These were the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plants of Pleopeltis percussa (Polypodiaceae), Trichomanes elegans (Hymenophyllaceae) and Senna dariensis (Caesalpiniaceae); rhizomes of Heliconia curtispatha (Heliconiaceae); leaves and branches of Bixa orellana (Bixaceae), Philodendron tripartitum (Araceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the ripe fruits of Citrus limon (Rutaceae); leaves, branches and stem of Ficus nymphaeifolia (Moraceae). Extracts of another 19 species showed moderate neutralization (21-72%) at doses up to 4 mg/mouse, e.g. the whole plants of Aristolochia grandiflora (Aristolochiaceae), Columnea kalbreyeriana (Gesneriaceae), Sida acuta (Malvaceae), Selaginella articulata (Selaginellaceae) and Pseudoelephantopus spicatus (Asteraceae); rhizomes of Renealmia alpinia (Zingiberaceae); the stem of Strychnos xinguensis (Loganiaceae); leaves, branches and stems of Hyptis capitata (Lamiaceae), Ipomoea cairica (Convolvulaceae), Neurolaena lobata (Asteraceae), Ocimum micranthum (Lamiaceae), Piper pulchrum (Piperaceae), Siparuna thecaphora (Monimiaceae), Castilla elastica (Moraceae) and Allamanda cathartica (Apocynaceae); the macerated ripe fruits of Capsicum frutescens (Solanaceae); the unripe fruits of Crescentia cujete (Bignoniaceae); leaves and branches of Piper arboreum (Piperaceae) and Passiflora quadrangularis (Passifloraceae). When the extracts were independently administered by oral, i.p. or i.v. route either before or after an i.d. venom injection (10 microg), neutralization of haemorrhage dropped below 25% for all the extracts. Additionally, B. rosademonte and P. percussa extracts were able to inhibit the proteolytic activity of B. atrox venom on casein.
The polyhydroxylated nortropane alkaloids called calystegines occur in many plants of the Convolvulaceae, Solanaceae, and Moraceae families. Certain of these alkaloids exhibit potent inhibitory activities against glycosidases and the recently demonstrated occurrence of calystegines in the leaves, skins, and sprouts of potatoes (Solanum tuberosum), and in the leaves of the eggplant (S. melongena), has raised concerns regarding the safety of these vegetables in the human diet. We have surveyed the occurrence of calystegines in edible fruits and vegetables of the families Convolvulaceae, Solanaceae, and Moraceae by GC-MS. Calystegines A3, B1, B2, and C1 were detected in all the edible fruits and vegetables tested; sweet and chili peppers, potatoes, eggplants, tomatoes, Physalis fruits, sweet potatoes, and mulberries. Calystegines B1 and C1 were potent competitive inhibitors of the bovine, human, and rat beta-glucosidase activities, with Ki values of 150, 10, and 1.9 microM, respectively for B1 and 15, 1.5, and 1 microM, respectively, for C1. Calystegine B2 was a strong competitive inhibitor of the alpha-galactosidase activity in all the livers. Human beta-xylosidase was inhibited by all four nortropanes, with calystegine C1 having a Ki of 0.13 microM. Calystegines A3 and B2 selectively inhibited the rat liver beta-glucosidase activity. The potent inhibition of mammalian beta-glucosidase and alpha-galactosidase activities in vitro raises the possibility of toxicity in humans consuming large amounts of plants that contain these compounds.
Ten xanthones with one or two isoprenoid groups and a prenylated benzophenone isolated from roots of Cudrania cochinchinensis (Moraceae) were tested for their antimicrobial activities against Bacillus subtilis and methicillin-resistant Staphylococcus aureus (MRSA). Among these compounds, gerontoxanthone H exhibited considerable antibacterial activity against B. subtilis (MIC = 1.56 microg/ml). Four xanthones, gerontoxanthone I, toxyloxanthone C, cudraxanthone S, and 1,3,7-trihydroxy-2-prenylxanthone, showed weak antibacterial activity against the bacterium (MICs = 3.13-6.25 microg/ml). These compounds also exhibited similar MIC values against methicillin-sensitive S. aureus, MRSAs, and Micrococcus luteus.
Phytochemical investigation of the MeOH extract of the root barks of Cudrania tricuspidata Bureau (Moraceae), as guided by hepatoprotective activity in vitro, furnished four isoprenylated xanthones, cudratricusxanthone A (1), cudraxanthone L (2), cudratricusxanthone E (3), and macluraxanthone B (4). All of these compounds showed the significant hepatoprotective effect on tacrine-induced cytotoxicity in human liver-derived Hep G2 cells. Compounds 1, 2, and 4 also exhibited the significant hepatoprotective effect on nitrofurantoin-induced cytotoxicity in human liver-derived Hep G2 cells.
This in vitro study aimed at determining the effects of a sublethal concentration of Streblus asper Lour (Moraceae) leaf ethanolic extract on adherence of Candida albicans to human buccal epithelial cells (HBEC). The minimum concentration of Streblus asper leaf ethanolic extract (SAE) that significantly reduced adherence (P<0.05) after a 1-h exposure was 15.6 mg/ml. However, there was a significant reduction (P<0.05) of candidal adhesion to HBEC after 1-min exposure to 125 mg/ml of SAE. Pre-treatment of either Candida or HBEC, or both, with 125 mg/ml of SAE for 1h resulted in reduced adherence. SAE at concentrations of 125 and 250 mg/ml also showed 41 and 61% inhibition of germ tube formation, respectively, which might affect adherence. These findings indicate that the sublethal concentration of SAE may modulate candidal colonization of the oral mucosa thereby suppressing the invasive potential of the pathogen.
Three new species of Veronaea, V. ficina on Ficus hispida L. (Moraceae), V. grewiicola on Grewia asiatica L. (Tiliaceae), and V. hippocratiae on Hippocratia arborea Willd. (Celastraceae), collected from forests of Nepal and the Terai belt of North-Eastern Uttar Pradesh, India, are described, illustrated and compared with related taxa.
Ten xanthones with one or two isoprenoid groups and a prenylated benzophenone isolated from roots of Cudrania cochinchinensis (Moraceae) were tested for their antimicrobial activities against vancomycin-resistant enterococci (VRE). Among these compounds, gerontoxanthone H exhibited considerable antibacterial activity against five VRE strains (VanA, VanB and VanC) (MICs = 1.56 microg/ml). Four xanthones, 1,3,7-trihydroxy-2-prenylxanthone, gerontoxanthone I, alvaxanthone and isoalvaxanthone, showed weaker antibacterial activity against these VREs (MICs = 3.13-6.25 microg/ml). .