Plant Cell Wall, a Challenge for Its Characterisation

The plant cell wall is a complex 3D network composed of polysaccharides, lignin and proteins. The knowledge of the structure and content of each cell wall polymer is a prerequisite to understand their functions during plant development and adaptation but also to optimise their industrial applications. The analysis of cell wall compounds is complicated by their multiple molecular interactions. In this review, we present numerous methods to purify, characterise and quantify proteins, polysaccharides and lignin from the wall. Two kinds of approaches are detailed: the first presents in vitro methods which involve the breakdown of the molecular linkages between polymers thanking to chemical, physical and/or enzymatic treatments. The second approach describes in situ methods that allow the cell wall polymer characterisation thanking to many analytical techniques coupled with microscopy. If microscopy is the common point of all of them, their development is associated with improvement of analytical techniques, increasing their power of resolution.

Synthesis and Cytotoxicity Evaluation of Some Isoquinoline Derivatives Related to 1-Arylnaphthalene Lignans

Two series of novel compounds designed as hybrids of 1-arylnaphthalene lignans with dihydroisoquinolines or isoquinolines were synthesized and evaluated for their cytotoxicities on human tumor cell lines, such as A549, Hela, PC-3 and KB. Some of the synthetic compounds exhibited their IC50 values on selected cell lines at μmol/L scale.

Synthesis of Novel Unsaturated Alkyl Ethers of Racemic Deoxyisopodophyllotoxin as Cytotoxic Agents

A series of isopentenyl-derived unsaturated alkyl ethers 19-31 of racemic deoxyisopodophyllotoxin were designed and synthesized. For comparison, compound 32 with a benzyl group at the same position was also prepared. The cytotoxicities of the synthetic compounds have been screened for six human tumor cell lines such as KB, BEL-7404, A549, Hela, PC-3 and CNE. The results showed that two of them exhibited significant cytotoxicities with their IC50 values on selected cell lines at μmol/L scale.

Pharmacological properties and related constituents of stem bark of Pterocarpus erinaceus Poir.(Fabaceae)

Objective:To sereen methanol and dichloromethane extracts of stem bark of Pterocarpus erinaceus for anti-inflammatory,analgesic.in vitro antioxidant activities and phytochemical analysis.Methods:Anti-inflammatory activity was detcrmined by using carrageenan inducededema of mice paw and croton oil-induced edema of mice ear:analgesic effect was evaluated using acetic acid-induced writhing.Phytochemical screening of extracts was performed by thin layer chromatography.The chromatographic fractionation led to the isolation of main active components as friedelin.lupeol and epicathcchin.The structures were established hy TLC and nuclear magnetic resonance studies.Results:Both methanol and dichloromethane extracts, triedelin.lupeol and epicatechin showed a significant anti—inflammatory effect using croton oil induced—ear edema.Furthermore,the action of dichloroinethane extract was more important. At the doses of 100 and 200 mg/kg.the methanol extract was able to reduce the carrageeuan induced-hind paw edema,while al the doses of 100.200 and 400 mg/kg.it showed an important analgesic effect against writhing induced by acetic acid injection of 38.8%.68.0%and 74.3%, respectively.Antioxidative properties of methanol extract and its dichloromethane and ethyl acetate fractions were assessed by using the 1,1—diphenyl—2—picrylhydrazyl method.The methanol extract showed the stronger radical scavenging activity than dichloromethane and ethyl acetate fractions,with an antiradical power of 5.3.5 and 2 respectively.The main components isolated from these extracts as friedelin,lupeol and epicathechin were responsible of these activities.Conclusions:The results suggest that the stem hark extracts of Pterocarpus erinaceus possessed important anti-inflammatory.analgesie activities and strong antioxidant properties, therefore,they could he used as natural potential ingredients for pharma ceutical industry.

Isolation and characterization of five novel mini-M conotoxins from the venom of mollusk-hunter snail Conus bandanus

Objective:To determine the new M-superfamily conotoxins from molluscivorous snail Conus bandanus in Vietnam.Methods:Conus bandanus venom was fractionated and purified on HPLC system with an analytical reversed-phase C18 column in order to screen small conotoxins.The primary structure of peptide was analyzed by matrix-assisted laser desorption/ionization time of flight tandem mass spectrometry using collision-induced dissociation and confirmed by Edman’s degradation method.Results:Five new conotoxins were biochemically characterized from the crude venom of the mollusk-hunting cone snail Conus bandanus,which were collected at Ke Ga reef of the Nha Trang Bay(Vietnam).Each conotoxin had 15 or 16 amino acid residues and shared the same characteristic cysteine framework V as–CC–C–C–CC–.They were termed as Bn3 b,Bn3 c,Bn3 d,Bn3 e and Bn3 f following the conotoxins nomenclature.Conclusions:The conotoxins Bn3 b,Bn3 e,and Bn3 f are categorized in the mini-M conotoxins of the M1 branch,while conotoxins Bn3 c and Bn3 d are categorized in the mini-M conotoxins of the M2 branch.The homological analysis reveals that these conotoxins could serve as promising probe compounds for voltage-gated sodium channels.

Behaviour of Roofing Materials Facing to Micro-Organisms

An accelerated water-streaming test was used to evaluate several roofing materials regarding their behavior to colonization by algae, by closely reproducing the phenomenon of natural biological soiling. A set of roofing materials with defined physical and chemical characteristics was thus investigated against the colonization by algae. Porosity, roughness and chemical composition showed to be factors of influence in the establishment of those micro-organisms.

Brevipedicelones D and E,Two C-O-C Flavonoid Dimmers from the Leaves of Garcinia brevipedicellata and Anti-onchocercal Activity

A novel isoflavone–chromone flavonoid C–O–C dimmer,brevipedicelone D(1),along with one new C–O–C biflavonoid derivative,brevipedicelone E(2),were isolated from the ethyl acetate extract of the leaves of Garcinia brevipedicellata,a medicinal plant used in folk medicine in parts of Cameroon.Their structures were elucidated by extensive spectroscopic techniques,including 1D-and 2D-NMR,MS experiments,as well as comparing their spectral data with those of known analogues.Anti-onchocercal screening of 1 showed moderate inhibition of adult worm motility of Onchocerca ochengi by 60%at the highest concentration(20 μg/mL)and inhibited motility of both the juvenile worms of O.ochengi and Loa loa by 90%at this same concentration.

Synthesis and Biological Evaluation of a Highly Constrained Analogue of Methylthioadenosine (MTA)

We describe the synthesis and the antibacterial evaluation 2’,N3-cyclonucleoside 3 analogue of MTA that is characterized by the presence of an additional linkage between the heterocyclic ring and the sugar moiety.

Isolation and Spasmolytic Evaluation of New Alkaloids from Dichrostachys cinerea (L.) Wight et Arn. (Fabaceae)

Dichrostachys cinerea (L.) Wight et Arn. (Fabaceae) root bark is used in Ivorian Traditional Medicine to treat asthma, which is a respiratory disorder characterized by inflammation and the restriction of tracheal muscles obstructing the air circulation. The tracheal relaxant effect of a crude aqueous-alcoholic extract of the plant root bark was previously shown. For the present study, alkaloids were isolated from the same extract and investigated ex vivo in C57Bl/6j mice isolated trachea contracted with carbachol 1 μM, in comparison with a reference bronchodilatator, i.e. salbutamol. Two extraction procedures allowed isolating 2 Alkaloids that monodimensional and bi-dimensional nuclear magnetic resonance (NMR) and mass specters allowed identifying a pyrolidine structure type nucleus with a long bi-hydroxyled alkyl chain. Alkaloid 1, carrier of a sugar, is a glycoside of Alkaloid 2. Both alkaloids induced similar spasmolytic effects, but Alkaloid 1 was more effective than Alkaloid 2 at 9 × 10-6 M (p < 0.01), 3 × 10-5 M, and 9 × 10-5 M (p <0.001). Salbutamol induced its spasmolytic effect in a different way, and its maximal effect Emax (less than 30%) was obtained at 9 × 10-6 M, while Emax of both alkaloids (100%) was obtained at 3 × 10-4 M.

New Triterpenoid Isolated from the Roots of Gouania longipetala Hemsl

Gouania longipetala Hemsl. (Rhamnaceae) is a medicinal plant from Côte d’Ivoire used to treat many diseases like malaria, gastrointestinal infections and gout. Scientific research of aerial part revealed the presence of triterpenoid compounds, saponins, phenolic compounds and flavonoids and also mentioned antibacterial, antioxydant and anti-inflammatory activities. Despite the various therapeutic uses of the plant, no scientific research mentions the chemical content of the root. So, this phytochemical investigation is made to identify secondary metabolites present in the hydromethanolic extract of its roots. And the research led to the isolation and characterization of three lupane-type triterpenoid compounds: a novel compound derived from gouanic acid, lupeol (1) and betulin (2), which had been previously reported in the literature. The newly discovered lupane-triterpenoid was identified as 1α-hydroxy-lup-20(29)-en-3-oxo-27,28-dioic acid (3). The structures of these compounds were determined based on analyses of spectroscopic data, including 1D-NMR, 2D-NMR and HR-ESI-MS techniques.

Rim-differentiation vs. mixture of constitutional isomers: A binding study between pillar[5]arene-based glycoclusters and lectins from pathogenic bacteria

Macrocycle-based glycoclusters, on account of their promising anti-adhesive properties against bacteria,are potential therapeutic alternatives to classic antibiotics through the much less explored anti-adhesive strategy. In this study, a series of constitutionally-pure pentavalent glycoclusters was prepared by conjugating assorted azido-carbohydrates onto a penta-propargyl rim-differentiated pillar[5]arene(RD-P[5])scaffold through Cu(I)-catalyzed azide–alkyne cycloaddition “click” reactions. Their binding towards therapeutically relevant bacterial lectins, such as Lec A and Lec B from Pseudomonas aeruginosa and concanavalin A(Con A), were evaluated subsequently by isothermal titration calorimetric studies. Most of these isomerfree RD-P[5] pentavalent glycoclusters, except the fucosylated ones, display good affinities to lectins.Nonetheless, the dissociation constants observed are similar to those displayed by an analogous pentavalent glycocluster consisting of four P[5] constitutional isomers, in which the RD-P[5] component merely accounts for 7% in the mixture. Our results revealed that high constitutional purity is not essential for achieving effective multivalent interactions between P[5]-based glycoclusters and lectins, presumably as a result of the conformationally labile nature of the P[5] scaffold. This information provides valuable design principles for low-cost and facile syntheses of glycosylated P[5]s for biomedical applications.

A Fluorescent Alternative to the Synthetic Strigolactone GR24

Strigolactones have recently been implicated in both above- and below-ground developmental pathways in higher plants. To facilitate the molecular and chemical properties of strigolactones in vitro and in vivo, we have devel- oped a fluorescent strigolactone molecule, CISA-1, synthesized via a novel method which was robust, high-yielding, and used simple starting materials. We demonstrate that CISA-1 has a broad range of known strigolactone activities and further report on an adventitious rooting assay in Arabidopsis which is a highly sensitive and rapid method for testing biological activity of strigolactone analogs. In this rooting assay and the widely used Orobanche germination assay, CISA-1 showed stronger biological activity than the commonly tested GR24. CISA-1 and GR24 were equally effective at inhibiting branching in Arabidopsis inflorescence stems. In both the branching and adventitious rooting assay, we also demonstrated that CISA-1 activity is dependent on the max strigolactone signaling pathway. In water methanol solu- tions, CISA-1 was about threefold more stable than GR24, which may contribute to the increased activity observed in the various biological tests.

New Strigolactone Analogs as Plant Hormones with Low Activities in the Rhizosphere

Strigolactones （SLs） are known not only as plant hormones, but also as rhizosphere signals for establishing symbiotic and parasitic interactions. The design of new specific SL analogs is a challenging goal in understanding the basic plant biology and is also useful to control plant architectures without favoring the development of parasitic plants. Two different molecules （23 （3＇-methyI-GR24）, 31 （thia-3＇-methyl-debranone-like molecule）） already described, and a new one （AR36）, for which the synthesis is presented, are biologically compared with the well-known GR24 and the recently identified CISA-1. These different structures emphasize the wide range of parts attached to the D-ring for the bioactivity as a plant hormone. These new compounds possess a common dimethylbutenolide motif but their structure varies in the ABC part of the molecules： 23 has the same ABC part as GR24, while 31 and AR36 carry, respectively, an aromatic ring and an acyclic carbon chain. Detailed information is given for the bioactivity of such derivatives in strigolactone synthesis or in perception mutant plants （pea rmsl and rms4, Arabidopsis max2 and, max4） for different hormonal functions along with their action in the rhizosphere on arbuscular mycorrhizal hyphal growth and parasitic weed germination.

Ubiquitin is double-phosphorylated by PINK1 for enhanced pH-sensitivity of conformational switch

Dear Editor,Multisite phosphorylation is observed in many signaling proteins,which confers the proteins new functions.A multi­site phosphorylated protein can exhibit switch-like response to cellular stimuli,with the often-clustered phosphorylation sites either unphosphorylated or fully phosphorylated by the same kinase(Kapuy et al..2009).Multisite phosphorylation has also been reported to promote the folding of an intrin­sically disordered protein,and consequently modulate the binding affinity to other proteins(Bah et al.,2015).Here we show that multisite phosphorylation makes a protein a better pH sensor,promptly switching between alternative confor­mational states in response to pH change under physiolog­ical conditions.

Overexpression of the angiogenic tetrapeptide AcSDKP and the prolyl oligopeptidase(POP) is a common feature of cancer

Prolyl oligopeptidase (POP) is a cytosolic enzyme involved in the metabolism of many peptide hormones and neuropeptides (1). It was recently reported that POP is responsible

PHYTOCHEMICAL STUDY OF CITRUS AURANTIUM BERGAMIA: ANALYSIS OF BIOACTIVE COMPOUNDS PRESENT IN JUICE, TISSUES AND ESSENTIAL OIL OF THE FRUIT

Flavonoids are secondary metabolites from aromatic plants and one of the most present classes in the vegetable kingdom.This is thanks to its antioxidant properties but also through its benefits on the human body that these molecules have become the center of interest of many researchers in recent years.They are found in large quantities in citrus species.The aim of this study is

A Phelipanche ramosa KAI2 protein perceives strigolactones and isothiocyanates enzymatically

Phelipanche ramosa is an obligate root-parasitic weed that threatens major crops in central Europe.In order to germinate,it must perceive various structurally divergent host-exuded signals,including isothiocyanates(ITCs)and strigolactones(SLs).However,the receptors involved are still uncharacterized.Here,we identify five putative SL receptors in P.ramosa and show that PrKAI2d3 is involved in the stimulation of seed germination.We demonstrate the high plasticity of PrKAI2d3,which allows it to interact with different chemicals,including ITCs.The SL perception mechanism of PrKAI2d3 is similar to that of endogenous SLs in non-parasitic plants.We provide evidence that PrKAI2d3 enzymatic activity confers hypersensitivity to SLs.Additionally,we demonstrate that methylbutenolide-OH binds PrKAI2d3 and stimulates P.ramosa germination with bioactivity comparable to that of ITCs.This study demonstrates that P.ramosa has extended its signal perception system during evolution,a fact that should be considered for the development of specific and efficient biocontrol methods.

SCREENING OF MEDICINAL PLANTS FROM REUNION ISLAND FOR ANTIMALARIAL ACTIVITY

According to the last World Malaria Report,there were an estimated 584 000 malaria deaths worldwide in 2013.The problem of parasite resistance towards available medicines is increasing.Natural products could play an important role to discover new antimalarial drug.The aim of the study was to highlight the anti-plasmodial properties of plants used in traditional medicine on the Mascarene Islands.85

Preparation of some new arylseleno compounds and application in the oxidation of olefins

Fifteen pyridine and substituted benzene diselenides,seleninic acids and seleninic anhydrides have been synthesized.Among them,4,4'-dipyridinediselenide,bis(2,4-dimethoxyphenyl)diselenide, 2,4-dimethoxyphenyl seleninic acid,2-pyridineseleninic acid,2-pyridineseleninic anhydride,4-pyridine- seleninic anhydride,2-nitrophenyl seleninic anhydride and 4-nitrophenyl seleninic anhydride were new compounds.Their regioselective oxidation or dehydrogenation of β-pinene,3β-benzoyloxycholest- 5-ene and androstan-3-one have been studied and compared.2-Pyridineseleninic anhydride is a more efficient oxidant than the others;most of the substituted benzeneseleno derivatives did not give the expected products.