A comprehensive review on ethnobotanical,phytochemical and pharmacological aspects of the genus Dorema

The genus Dorema (Apiaceae) comprises 12 accepted species, mainly growing in Asia and, particularly, in Iran, where D. ammoniacum and D. aucheri are the most used species in cuisine and folk medicine. The Dorema species are traditionally applied in the treatment of catarrh, asthma, chronic bronchitis, as carminative, mild diuretic and anthelmintic agents. In general, 42 non-volatile secondary metabolites were isolated from the 6 studied species, namely D. aitchisonii, D. ammoniacum, D. aucheri, D. glabrum, D. hyrcanum, and D. kopetdaghense. Among them, phenolic acid, flavonoid, acetophenone, coumarin, and sesquiterpene derivatives were identified as the predominant phytoconstituents. The leaves are characterized by the highest volatile content, and the sesquiterpenes in both hydrocarbon and oxygenated forms were reported as the most abundant compounds. Most of the studied pharmacological activities were assessed in vivo. Nevertheless, in vitro antiradical and antimicrobial potentials were the main investigated activities. Overall, the evaluation of bioactivities confirmed the ethnopharmacological use of the Dorema species, particularly their anti-inflammatory, antibacterial, and hypolipidemic properties. This study comprehensively overviewed, for the first time, the literature relating to the folk medicinal use and to the available phytochemical and pharmacological data. Considering the genus application and the rare clinical trials, the study of the efficacy and safety of the uninvestigated Dorema species might be an interesting and promising approach for further researches.

     

Cissampelos genus: biological activities,ethnobotanical and phytochemical aspects

Phytochemistry Reviews - Species of Cissampelos (Menispermaceae) are widely used in folk medicine in various cultures, for the treatment of a wide variety of diseases. Several ethnobotanical...     

Common dandelion: a review of its botanical,phytochemical and pharmacological profiles

Phytochemistry Reviews - Phytoalimurgy is a term that derives from Greek and Latin by combination of the words φυτόν, which meaning plant, and alimenta urgentia, indicating...     

Metal ions-induced stability and function of bimetallic human arginase-I,a therapeutically important enzyme

Recent studies have highlighted the therapeutic importance of bimetallic human arginase-I against hyperargininemia and L-arginine auxotrophic cancers. The longer retention of catalytic activity of the Co²⁺-enzyme than that of the Mn²⁺ in human serum is associated with its enhanced therapeutic potential. To understand the basis of this and also to explore the role of a bimetallic center as well as the role of individual metal ions in the stability, we performed a detailed biochemical and biophysical investigation. The thermodynamic and kinetic stabilities of both the holo proteins are found to be significantly higher than the apo form, indicating that an intact bimetallic centre is vital for the enhanced stability of the holo proteins. The Co²⁺-protein is found to be more stable than that of the Mn²⁺, which might explain its longer retention of activity observed in the serum. Mutational studies demonstrated that the metal ions are individually crucial for both the enhanced stability and catalytic activity. Furthermore, we investigated the underlying mechanism for the effect of heat activation on the holo protein for higher catalytic activity, which is not yet known for arginases. Our data reveal that heat activation significantly increases the stability of the holo protein through a metal-induced increase in the helical content leading to the formation of a kinetically competent enzyme. Thus, the present study provides an in-depth insight into the significance of heat activation and the role of metal ions in human arginase, which may be useful for better understanding of its therapeutic use.     

An extended phytochemical survey of Australian species of Acacia: Chemotaxonomic and phylogenetic aspects

An earlier phytochemical survey of the flavonoid content of heartwoods and barks of Acacia species is extended to a much wider range distributed throughout the Australian continent, and representing most sections and subsections of the genus. Flavonoids with pyrogallol (7,8-hydroxy) A-ring nuclei almost exclusively populate the heartwoods of most species constituting subsections of the Plurinerves and Juliflorae, while resorcinol (7-hydroxy) A-ring analogues are similarly represented under the Brunioideae, Uninerves—subsection Racemosae and the Botryocephaleae. Individual representation of both hydroxylation patterns, or their mixtures in heartwoods, are present amongst the Continuae, and under many subsections of the Pungentes, Calamiformes and Uninerves. A small group. A. peuce (Continuae), A. carnei (Pungentes), and A. crombei (Uninerves) show close chemical relationships, being sharply differentiated by the peltogynoid content of their purple heartwoods. This renders them unique amongst the Mimosaceae. Evolutionary trends amongst taxa are discussed on the basis of morphological and chemical correlations.     

Morphological and phytochemical aspects of three alien Opuntia species on Euganean Hills in North-Eastern Italy

In this study, Opuntia stricta, O. engelmannii, and O. humifusa, naturalized alien units in the Euganean Hills (North-Eastern Italy), are investigated. Different morphological and physiological features both in cladodes collected in summer and winter and in fruits arisen from two blooms are reported. The morphological observations showed a different organization in epidermis/hypodermis of cladodes collected in winter and in summer, probably correlated to the individual plant reaction to a stressful factor as low temperature. Scanning electron microscopy observations revealed no differences in the deposition of waxes and stomata distribution in the epidermis of cladodes. The betacyanin analysis showed that cladodes produce these pigments only in the winter season. In all the species, the higher content of betacyanins was reached in the fruits from the second bloom, with O. stricta being the most rich. The amount of betacyanins is comparable to some commercial red beets used as a common source of betacyanins as natural food color.     

The phenolic profile of pea (Pisum sativum): a phytochemical and pharmacological overview

Phytochemistry Reviews - Pisum sativum L., (Fabaceae), commonly known as dry, green or field pea, is one of the most popular and economically important legumes. It enjoys a worldwide culinary,...     

不同氮素水平下入侵种豚草与本地种黄花蒿、蒙古蒿的竞争关系

已有研究表明,土壤氮素增加可提高外来植物的入侵性,降低本地植物的竞争力.为揭示全球氮沉降对入侵种与本地种之间竞争关系的影响,我们于2010年5-8月在中国科学院北京森林生态系统定位研究站温室内,采用取代系列实验方法(standard replacement experiment),研究了3个氮素水平下入侵种豚草(Ambrosia artemisiifolia)与本地种黄花蒿(Artemisia annua)、蒙古蒿(Artemisia mongolica)的生长特征及种内、种间竞争关系的变化.实验采用双因素-随机区组设计,设置了低氮、中氮和高氮3个氮素水平,每一氮素水平分别设置豚草和黄花蒿、豚草和蒙古蒿组成的竞争实验,生长90 d后测量株高和生物量.结果表明:单栽情况下,随氮素水平的增加3个物种的株高均增加,而生物量均无显著变化;混栽情况下,3个物种株高和生物量随氮素水平的增加变化各异,豚草呈极显著增加趋势,而黄花蒿无明显变化,蒙古蒿则先增加后减少.豚草的快速生长使其在竞争中处于优势地位,对本地种黄花蒿和蒙古蒿产生明显的竞争效应.但不同氮素水平下,豚草对本地种的竞争力不同:低氮素水平下,豚草＜两个本地种;中氮素水平下,黄花蒿＜豚草＜蒙古蒿;高氮素水平下,豚草＞两个本地种.氮素添加显著提高了豚草的种间竞争力,改变了豚草与本地种之间的竞争关系,使竞争有利于入侵种.据此推测,在全球变化的背景下,氮沉降的增加将会促进外来种豚草的入侵,增加本地群落的可入侵性.     

Artemisinin: The biosynthetic pathway and its regulation in Artemisia annua, a terpenoid-rich species

Summary Artemisinin is a sesquiterpene lactone isolated from the aerial parts of Artemisia annua L. plants. Besides being currently the best therapeutic against both drug-resistant and cerebral malaria-causing strains of Plasmodium falciparum, the drug has also been shown to be effective against other infections diseases including schistosomiasis and hepatitis. More recently, it has also been shown to be effective against numerous types of tumors. Although chemical synthesis of artemisinin is possible, it is not economically feasible. The relatively low yield (0.01–0.8%) of artemisinin in A. annua is a further serious limitation to the commercialization of the drug. Therffore, the enhanced production of artemisinin either in cell/tissue culture or in the whole plant of A. annua is highly desirable. A better understanding of the biochemical pathway leading to the synthesis of artemisinin and its regulation by both exogenous and endogenous factors is essential for facilitating increased yield. Two genes of the artemisinin biosynthetic pathway have now been identified. This critical review covers recent developments related to the biosynthesis of this important compound and related terpenoids, their regulation, and the production of these compounds both in vitro and in whole plants.     

Community isolation drives lower fish biomass and species richness,but higher functional evenness,in a river metacommunity

1. The flow of individuals among communities and their interactions with local environmental filters are increasingly recognised as determinants of biodiversity patterns in riverine ecosystems. Both incoming dispersers and local conditions are expected to systematically change along connectivity gradients from headwaters to downstream communities. However, the interplay between isolation-centrality gradients and environmental conditions as determinants of biodiversity structure and function has seldom been considered.
2. Here, we represented the dendritic structure of the Negro River basin riverscape (Uruguay) in a directed graph quantifying the isolation-centrality of each river section and evaluated the direct and indirect pathways by which riverscape structure and environmental local drivers determine fish community assembly.
3. Fish communities (n = 58) were sampled following a stratified sampling design that properly represents this isolation-centrality connectivity gradient through the riverscape. In each community, fish abundance, biomass, richness, and functional diversity were estimated, and the direct and indirect hypothesised connections among them were evaluated with structural equation models.
4. We showed that the range of isolation among river sections determines a 2-fold, 5-fold, and 25-fold variation in total fish richness, abundance, and biomass, respectively. Additionally, isolation-centrality was positively associated with local temperature and conductivity, while negatively related to local depth. These variables and taxonomic richness accounted for most of the variation in total fish biomass (81%) herein used as measurement of ecosystem function. Local fish abundance was negatively and positively associated with functional evenness and taxonomic richness, respectively. Furthermore, once the effect of isolation on biomass and richness was accounted for, an effect of diversity on biomass became evident.
5. Our results provide empirical evidence for the role of riverscape structure on taxonomic and functional diversity, biomass, and the relationship between biodiversity and ecosystem function. We emphasise that in the understanding of river biodiversity and its management, local determinants should not be considered without attention to metacommunity processes.

     

Influence of culture age on the phytochemical content and pharmacological activities of five Scenedesmus strains

Five axenic Scenedesmus strains (MACC-411, MACC-422, MACC-493, MACC-720, and MACC-727) were cultured and harvested after 5 and 10 days in culture. Using colorimetric methods, the concentrations of total phenolic, condensed tannin, and iridoids in 50 % methanol extracts from both 5- and 10-day-old cultures were quantified. Different solvent extracts from the strains were also tested for antioxidant, acetylcholinesterase inhibitory (AChEI), and antimicrobial activities using various in vitro test systems. Phenolic content was highest (3.6?±?0.42 mg GAE g^?1 DW) in 10-day-old MACC-727. This was approximately fourfold and significantly higher than in the 5-day-old cultures of MACC-727. Among the tested Scenedesmus strains, 5-day-old MACC-411 had the highest iridoid content (3.4?±?0.3 mg HE g^?1 DW), and this was significantly higher than the level detected in the 10-day-old MACC-411. Scenedesmus strains showed better antioxidant potential in the β-carotene–linoleic acid model compared to the DPPH free radical scavenging assay. The AChEI activity (IC₅₀?μg mL^?1) in all strains (besides MACC-422) was higher in 10-day-old cultures compared to the 5-day-old cultures. Although a broad-spectrum of antibacterial activity was observed, the tested microalgae strains demonstrated varying degrees of antimicrobial potential depending on the harvest time, strain-type, and extracting solvent. Thus, the Scenedesmus strain and time of harvest played a significant role in determining their phytochemical content and resultant pharmacological activity. The promising bioactivity in the tested Scenedesmus strains indicates their potential as possible sources of novel/alternative antioxidants and AChE inhibitors.     

Insights on the evolution of a vegetatively propagated crop species

The opportunity for gene flow between a vegetatively propagated crop and its wild relatives is expected to be much lower than for seed-propagated crops, since sexual reproduction in the crop occurs only infrequently. A study by Duputié and colleagues now demonstrates evidence of sexual reproduction between a vegetatively propagated crop and a closely related wild congener. Working in French Guiana, these workers have documented a hybrid zone arising from introgression between cassava (Manihot esculenta ssp. esculenta, Euphorbiaceae), which is propagated by stem cuttings, and wild Manihot populations growing in close proximity. Patterns of heterozygosity suggest that there are little-to-no barriers to reproduction between the crop and these wild populations. Previous work by these researchers has documented the importance of occasional sexual reproduction for the development of cassava varieties in traditional Amerindian farming systems. Taken together with their previous work, these new findings suggest that gene flow between wild Manihot populations and cassava plants could potentially play a much greater role in the crop's evolution than previously thought.     

Systematic studies on some species of the genus Artemisia: biomolecular analysis

ABSTRACT

The internal transcribed spacers (ITS) of the ribosomal DNA gene of 11 taxa of the genus Artemisia were sequenced and compared with other 14 species taken from GenBank. The aims of this study are to clarify phylogenetic relationships for 25 taxa within the genus Artemisia, and to highlight the phylogenetic position of some species of geobotanical interest from the Alps or from other European areas. The results support the monophyly of the genus Artemisia, and the presence of the five main clades, corresponding to the morphologically based sections, Absinthium, Artemisia, Seriphidium, Dracunculus and Tridentatae. Only A. annua and A. genipi are not classified in the section in which they were traditionally included: A. annua is assigned to Seriphidium and not Artemisia, and A. genipi to Absinthium and not Artemisia. The basal structure of the tree differed in the 45 equally parsimonious MP trees, and thus appeared as a polytomy in the consensus tree. This does not allow us to completely solve the relationships among the clades. The molecular data are complementary with the morphological and biogeographical information and all are essential to draw valid conclusions on the relative closeness of the various taxa.     

Momordica balsamina: phytochemistry and pharmacological potential of a gifted species

Phytochemistry Reviews - Momordica balsamina L. (Cucurbitaceae), frequently named balsam apple, southern balsam pear or African pumpkin, is a vegetable with high nutritional value, being mostly...     

喜马拉雅山东段鸟类多度-垂直分布幅关系:特有种与非特有种的对比

物种多度与分布幅之间的正相关被认为是一种普遍的规律。但近年在热带山地和岛屿的研究发现多度-分布幅关系会出现不相关或负相关的现象;该现象可能是由于当地多度高且分布幅小的特有种比例较高所导致。在喜马拉雅山东段的勒布沟沿海拔2350—4950 m开展研究：1)记录了当地鸟类多度垂直分布格局;2)验证了该区繁殖鸟总体多度-垂直分布幅关系,并对比了特有种和非特有种分组子集多度-垂直分布幅关系、平均多度和垂直分布中心的差异。研究发现勒布沟鸟类多度垂直分布格局为驼峰格局。该区繁殖鸟类与非特有种的多度-垂直分布幅关系均为正相关,但特有种的多度-垂直分布幅关系为不相关。特有种的多度及海拔分布中心位置均高于非特有种。结果表明区域的鸟类特有性对多度-垂直分布幅关系存在着重要的影响;地理隔离导致的区域物种组成差异,是造成多度-分布幅关系模式变化的重要原因之一。     

Removing interactions,rather than species,casts doubt on the high robustness of pollination networks

In the last 15 years, a complex networks perspective has been increasingly used in the robustness assessment of ecological systems. It is therefore crucial to assess the reliability of such tools. Based on the traditional simulation of node (species) removal, mutualistic pollination networks are considered to be relatively robust because of their 1) truncated power‐law degree distribution, 2) redundancy in the number of pollinators per plant and 3) nested interaction pattern. However, species removal is only one of several possible approaches to network robustness assessment. Empirical evidence suggests a decline in abundance prior to the extinction of interacting species, arguing in favour of an interaction removal‐based approach (i.e. interaction disruption), as opposed to traditional species removal. For simulated networks, these two approaches yield radically different conclusions, but no tests are currently available for empirical mutualistic networks. This study compared this new robustness evaluation approach based on interaction extinction versus the traditional species removal approach for 12 alpine and subalpine pollination networks. In comparison with species removal, interaction removal produced higher robustness in the worst‐case extinction scenario but lower robustness in the best‐case extinction scenario. Our results indicate that: 1) these two approaches yield very different conclusions and 2) existing assessments of ecological network robustness could be overly optimistic, at least those based on a disturbance affecting species at random or beginning with the least connected species. Therefore, further empirical study of plant–pollinator interactions in disturbed ecosystems is imperative to understand how pollination networks are disassembled.     

Effects of spatial patterns on the pollination success of a less attractive species

Plant individuals rely on pollinator services for their reproduction and often have to share these services with co‐occurring neighbours, creating complex indirect plant–plant interactions. Many current theoretical models focus on the effect of floral resources’ density on the net outcome of these indirect plant–plant interactions, often neglecting the identity of plant species in the communities and especially the species’ spatial pattern. To fill this gap, we created a spatially explicit model whose goal was to study the interplay between relative densities and spatial distribution patterns of two plant species differing in their attractiveness for pollinators. Since theory predicts that pollinator behaviour strongly governs the outcome of pollination, we allowed the pollinators to systematically change their plant preferences based on their foraging experience. Thus the interplay between density and spatial patterns of plants was tested over a continuum of behaviours from specialists to generalists. Our most striking finding was that reproductive success of the less attractive species was affected in an opposite way by spatial patterns depending on whether the species had relatively low or high densities. Namely, when the less attractive species was highly abundant, its survival was higher when aggregated in large monospecific patches than when uniformly distributed. On the other hand, when the attractive species was more abundant, the less attractive species survived better when uniformly distributed. These results were consistent as long as the scale of the plant spatial aggregation was similar to or larger than the pollinators’ detection range. Our results suggest that aggregated plant spatial patterns manipulate pollinator behaviour by trapping them within monospecific patches. This effect was sufficiently strong to enhance the survival of a competitively inferior species and hence to act in a way similar to the more familiar niche or temporal separation among plant species.