Studies onClaviceps parasitic onPanicum species in India

Panicum repens andP. antidotale were found to be infected withClaviceps sp. This is the first report of ergot onP. repens. The pyrenomycete produced abundant sclerotia on the host plants. The sclerotia contained 0.71 and 0.68 % alkaloids, respectively, which predominantly consisted of chanoclavine, festuclavine and agroclavine. The infected grasses were possibly mycotoxic. Submerged cultures ofClaviceps strain isolated fromPanicum spp produced significant amount of chanoclavine, festuclavine and agroclavine. No pharmaceutically important alkaloid was found in sclerotia or in submerged culture.     

Minor Alkaloids of the Fungus Penicillium roquefortiiThom 1906

New isomers of clavine alkaloids with distinctively low chromatographic mobilities were isolated from the collection and mutant strains of Penicillium roquefortiiThom 1906, in addition to alkaloids roquefortine, 3,12-dihydroroquefortine, isofumigaclavines A and B, festuclavine, and chanoclavine-I, which are characteristic of this species. It was demonstrated that the collection strain produces isomers of agroclavine and epoxyagroclavine, whereas the mutant strain synthesizes isomers of fumigaclavines A and B, festuclavine, and chanoclavine.     

Laboratory production of ergot alkaloids by species of balansia.

Four species of Balansia (clavicipitaceous systemic grass pathogens) isolated from pastures where cattle showed signs of ergot toxicity were grown in culture. Balansia epichlo?, one isolate of B. claviceps, B. henningsiana and two isolates of B. strangulans produced conidia in submerged culture during the first stage of a two-stage fermentation procedure. When tranferred to a glucose/sorbitol/inorganic salts medium during the second stage, these four species produced ergot alkaloids in stationary cultures. The transfer of fungi cultured in the first medium to the second medium was necessary for alkaloid biosynthesis. One isolate of B. claviceps did not produce alkaloids. Balansia epichlo? produced chanoclavine (I), agroclavine, penniclavine, elymoclavine, ergonovine and ergonovinine. Balansia claviceps produced chanoclavine (I), ergonovine and ergonovinine. This is the first report of isolating ergonovine and ergonovinine, two lysergic acid derivatives, from fungi outside the genus Claviceps. Only chanoclavine (I) was identified from extracts of B. strangulans and B. henningsiana. Chanoclavine (I) and ergonovine were identified from smut grass (Sporobolus poiretii) parasitized by B. epichlo?, indicating that this endophyte produces alkaloids both in vivo and in vitro.     

Synthesis of α-mannosylated ergot alkaloids employing α-mannosidase

The ergot alkaloids elymoclavine, ergometrine and chanoclavine were α-mannosylated with α-mannosidase as catalyst. The kinetic reaction with p-nitrophenyl α-mannoside as glycosyl donor gave ca 28 % yield of chanoclavine α-mannoside, whereas the equilibrium reaction with mannose as the glycosyl donor gave ca 11 % yield. However, in the case of elymoclavine and ergometrine, higher yields of α-mannosides were obtained with the equilibrium approach (18 and 13 %).     

Studies on Sphacelia sorghi McRae, an ergot of Sorghum vulgare Pers.

The constituent ergoline alkaloids produced in vitro by a Nigerian strain of Sphacelia sorghi have been identified as dihydroergosine, festuclavine, pyroclavine, dihydroelymoclavine, and chanoclavine. The same alkaloids were present in both the sphacelial stage and the sclerotia when S. sorghi parasitized florets of Sorghum vulgare. The Nigerian fungus appears to be quite different from certain oriental collections bearing the same name, and although forming stromatal initials, failed to develop the sexual stage. Mice successfully raised litters and showed no adverse response when fed on diets containing up to 50% of the ergot sclerotia. The ergot had also no effect on early pregnancy. Some of the alkaloid was excreted in the faeces, but, as injected alkaloid was also shown to be excreted in the faeces, this could have represented alkaloid which had been absorbed from the ingested sclerotia and re-excreted via the bile.     

Influence of temperature on alkaloid levels and fall armyworm performance in endophytic tall fescue and perennial ryegrass

The symbiotic relationships between Neotyphodium endophytes (Clavicipitacea) and certain cool‐season (C3) grasses result in the synthesis of several alkaloids that defend the plant against herbivory. Over a 3 month period we evaluated the effects of temperature on the expression of these alkaloids in tall fescue, Festuca arundinacea Schreb, and perennial ryegrass, Lolium perenne L. (Poaceae). Response surface regression analysis indicated that month, temperature, and their interaction had an impact on the alkaloid levels in both grasses. We aimed to identify the alkaloids most closely associated with enhanced resistance to the fall armyworm, Spodoptera frugiperda JE Smith (Lepidoptera: Noctuidae), and clarify the role of temperature in governing the expression of these alkaloids. The dry weights and survival of fall armyworms feeding on endophyte‐infected tall fescue or perennial ryegrass were significantly lower than for those feeding on uninfected grass, whereas endophyte infection had no significant influence on survival. For tall fescue, a four‐alkaloid model consisting of a plant alkaloid, perloline, and the fungal alkaloids ergonovine chanoclavine, and ergocryptine, explained 47% of the variation in fall armyworm dry weight, whereas a three‐alkaloid model consisting of the plant alkaloid perloline methyl ether and the fungal alkaloids ergonovine and ergocryptine explained 70% of the variation in fall armyworm dry weight on perennial ryegrass. Although temperature had a significant influence on overall alkaloid expression in both grasses, the influence of temperature on individual alkaloids varied over time. The levels of those alkaloids most closely linked to armyworm performance increased linearly or curvilinearly with increasing temperature during the last 2 months of the study. We conclude that the growth temperature of grasses can influence the performance of fall armyworm, and that this effect may be mediated through a set of plant‐ and endophyte‐related alkaloids.     

Glycosylation of ergot alkaloids by free and immobilized cells of Claviceps purpurea

Summary A new strain, Claviceps purpurea 88-EP-47, with high invertase activity was selected. Free and Calginate immobilized cultures of this strain were used for fructosylation of ergot alkaloids. By bioconversion from their aglycones, elymoclavine-O--d-fructofuranosyl(21)-O--d-fructofuranoside, and elymoclavine-O--d-fructoside, the respective fructosides of chanoclavine, lysergol and dihydro-lysergol monofructosides were obtained. These substances are formed by -d-fructofuranosidase present in Claviceps cells. The bioconversion activity of the enzyme system (fructose transfer) is strongly dependent on pH, substrate (sucrose) concentration and the developmental profile of invertase activity. The pH optimum for elymoclavine fructosylation is 6.5, for chanoclavine 5.7, and the optimal sucrose concentration is 75 g/l. Fifteen-day-old production cultures had the best glycosylation activities. Fructosylation of alkaloids can be stimulated in production cultures of C. purpurea or C. fusiformis forming elymoclavine or chanoclavine by a pH shift to 6.5 at the end of the production phase. Glycosylating Claviceps strains producing elymoclavine eliminate the free alkaloid into glycosides. The feedback inhibition of alkaloid synthesis by elymoclavine is then strongly reduced, helping to further improve elymoclavine yields. Elymoclavine can be liberated simply by invertase activity of baker's yeast.Offprint requests to: V. Ken     

Adsorption Behavior of Multicomponent Protein Mixtures Containing α1−Proteinase Inhibitor with the Anion Exchanger, 2-(Diethylamino) ethyl-Spherodex

The equilibrium binding behavior of α₁-proteinase inhibitor (α₁-PI) in the presence of human serum albumin (HSA) has been determined in packed bed systems with the anion exchanger, 2-(diethylamino) ethyl (DEAE) -Spherodex. Experimental data derived for the individual proteins were compared with the corresponding data obtained from batch adsorption studies as well as studies in which mixtures of these two proteins were loaded at different concentration ratios onto columns of the same anion exchange adsorbent. The results confirm that α₁-PI has a greater affinity for the anion exchanger, although competitive adsorption was observed as the inlet concentration of HSA was increased. Under these conditions, decreased binding capacities and lower dynamic adsorption rates were observed for α₁-PI with the DEAE-Spherodex anion exchange adsorbent. The results are discussed in terms of the influence which various contaminants that occur in multicomponent mixtures of proteins from human plasma can have on the equilibrium binding characteristics of a target protein with weak or strong ion exchange adsorbents under conditions approaching concentration overload in preparative chromatographic systems. These investigations have also addressed, as the first part of an iterative approach for the simulation of the adsorption behavior of multicomponent mixtures of human plasma proteins with ion exchange and affinity chromatographic adsorbents, the ability of noncompetitive and competitive Langmuirean models to simulate the adsorption of α₁-PI in the presence of different concentrations of HSA to DEAE-Spherodex.     

Adsorption of Methyl Parathion from Aqueous Solutions Using Mango Kernels: Equilibrium,Kinetic and Thermodynamic Studies

The adsorption of methyl parathion from aqueous solutions by the low-cost and abundant adsorbent mango kernel was studied in a batch adsorption system. The adsorption was studied as a function of pH, contact time, initial pesticide concentration, adsorbent dose, and temperature. A maximum adsorption of 98% ± 1% was achieved. Physicochemical characterization of the adsorbent was carried out by EDXRF, BET, and CHNS analysis. Freundlich, Langmuir, and Dubinin-Radushkevich isotherms were employed to evaluate the adsorption capacity of the adsorbent. Lagergren, Morris-Weber, and Reichenberg equations were employed to study the kinetics of the adsorption process. Thermodynamic parameters Δ H, Δ S, and Δ G were computed. The developed adsorption method was applied to real environmental samples.     

Adsorption of zinc from aqueous solution using chemically treated newspaper pulp

Adsorption of zinc was studied using chemically modified newspaper pulp as an adsorbent in the aqueous medium. Quantitative chemical analysis showed the presence of trace quantities of some inorganic elements along with phosphorous in TNP. The experimental adsorption data fitted reasonably well to both Freundlich and Langmuir isotherm. pHzpc of TNP was 5.1, which indicated that the adsorbent was more potential for cationic adsorption. The adsorption kinetic data followed a pseudo-second order model for zinc. Optimum Zn(2+) loading was 9.20 mg/g for 10.31 mg/l initial zinc concentration at pH 5.80. Zn(2+) loading on TNP was dependent on initial zinc concentration. TNP was a potential adsorbent for the removal of Zn from the effluent of electroplating industry.     

Synergy of clavine alkaloid ‘chanoclavine’ with tetracycline against multi-drug-resistant E. coli

The emergence of multi drug resistance (MDR) in Gram-negative bacteria (GNB) and lack of novel classes of antibacterial agents have raised an immediate need to identify antibacterial agents, which can reverse the phenomenon of MDR. The purpose of present study was to evaluate synergy potential and understanding the drug resistance reversal mechanism of chanoclavine isolated from Ipomoea muricata against the multi-drug-resistant clinical isolate of Escherichia coli (MDREC). Although chanoclavine did not show antibacterial activity of its own, but in combination, it could reduce the minimum inhibitory concentration (MIC) of tetracycline (TET) up to 16-folds. Chanoclavine was found to inhibit the efflux pumps which seem to be ATPase-dependent. In real-time expression analysis, chanoclavine showed down-regulation of different efflux pump genes and decreased the mutation prevention concentration of tetracycline. Further, in silico docking studies revealed significant binding affinity of chanoclavine with different proteins known to be involved in drug resistance. In in silico ADME/toxicity studies, chanoclavine was found safe with good intestinal absorption, aqueous solubility, medium blood–brain barrier (BBB), no CYP 2D6 inhibition, no hepatotoxicity, no skin irritancy, and non-mutagenic indicating towards drug likeliness of this molecule. Based on these observations, it is hypothesized that chanoclavine might be inhibiting the efflux of tetracycline from MDREC and thus enabling the more availability of tetracycline inside the cell for its action.     

Fructosylation of ergot alkaloids by yeast invertase

Summary A method for transfructosylation of ergot alkaloids elymoclavine, chanoclavine, lysergol, 9, 10-dihydrolysergol using commercial yeast -fructofuranosidase and sucrose is described     

Characteristics of PAHs adsorption on inorganic particles and activated sludge in domestic wastewater treatment

The occurrence of polycyclic aromatic hydrocarbons (PAHs) in a domestic wastewater treatment plant (WWTP) was investigated in a 1 year period. In order to understand how PAHs were removed at different stages of the treatment process, adsorption experiments were conducted using quartz sand, kaolinite, and natural clay as inorganic adsorbents and activated sludge as organic adsorbent for adsorbing naphthalene, phenanthrene, and pyrene. As a result, the adsorption of PAHs by the inorganic adsorbents well followed the Langmuir isotherm while that by the activated sludge well followed the Freundlich isotherm. By bridging equilibrium partitioning coefficient with the parameters of adsorption isotherm, a set of mathematical models were developed. Under an assumption that in the primary settler PAHs removal was by adsorption onto inorganic particles and in the biological treatment unit it was by adsorption onto activated sludge, the model calculation results fairly reflected the practical condition in the WWTP.     

Optimization Considerations for the Purification of α1-Antitrypsin Using Silica-Based Ion-Exchange Adsorbents in Packed and Expanded Beds

The influences of the fluid superficial velocity, sample concentration, loading volume, and wash cycle on the recovery and corresponding purification factors for α₁-antitrypsin [syn. α₁-proteinase inhibitor (α₁-PI) ] from crude mixtures of human plasma proteins were investigated using packed and expanded beds of DEAE-Spherodex LS. As part of this study, the effect of fluid superficial velocity on the bed dispersion number (D _v) and dispersion coefficient (D) for this adsorbent in expanded beds was determined with feedstocks containing human serum albumin (HSA), the most abundant of the contaminating proteins in human plasma protein preparations used for the isolation of α₁-PI. When multicomponent protein feedstocks prepared from human plasma were examined with DEAE-Spherodex LS, reduced chromatographic productivity was observed for α₁-PI as the extent of column utilization and the superficial velocity were increased, yet the opposite trend was evident for HSA. In particular, higher adsorption capacities and recoveries were obtained for α₁-PI at lower fluid superficial velocities with both packed and expanded bed conditions. These findings indicate that for process scale purifications of α₁-PI from multicomponent feedstocks with expanded beds containing this silica-based ion-exchange adsorbent, the optimal range of superficial velocities to achieve the highest bed productivity will not be synonymous with maximally fluidized modes of operation. Rather, the results confirm that the adsorbent has an optimum operational performance when fluidization procedures corresponding to plug flow expansion are employed for the capture of α₁-PI. These findings also indicate that advantage can be taken of displacement effects between closely related protein species with packed and expanded bed systems containing the DEAE-Spherodex LS type of ion-exchange porous silicas.     

Effects of clavines, ergot alkaloids, on the membrane potential of an identifiable giant neuron of the African giant snail Achatina fulica Ferussac

The effects of seven clavines, alkaloids of ergot, on the electrical activity of an identifiable giant neurone (TAN, tonically autoactive neurone) of the African giant snail were examined. All the substances examined, lysergine, agroclavine, elymoclavine, festuclavine, chanoclavine, rugulovasine A and rugulovasine B, at 2 X 10(-4) kg/l have no constant effect on TAN, indicating that they have no direct effect on this neurone. However, the substances examined, except for chanoclavine, in the same concentration occasionally caused the transient depression with an augmentation of trans-synaptic influences. This depression may be due to the trans-synaptic influences. The four substances examined, lysergine, agroclavine, elymoclavine and festuclavine, in the same concentration produced TAN abnormal spike discharges, doublet or triplet spikes.     

New skeletons and new concepts in Amaryllidaceae alkaloids

The Amaryllidaceae alkaloids, represent a group of isoquinoline alkaloids, which are produced almost solely by members of the Amaryllidaceae family. The alkaloids of this family have attracted considerable amount of interest due to some important pharmacological activities they were shown to possess. In the last decade, our phytochemical studies on four Galanthus (Amaryllidaceae) species of Turkish origin have yielded quite a number of new alkaloids with diverse structures. Among these alkaloids, gracilines and plicamines constitute two new subgroups for the Amaryllidaceae alkaloids. The gracilines contain an incorporated 10b,4a-ethanoiminodibenzo[b,d]pyrane skeleton. The plicamines are dinitrogenous compounds, where the oxygen atom in position 7 of a tazettine skeleton is replaced by a nitrogen atom substituted by a pendant 4-hydroxyphenethyl moiety. One of the new alkaloids, galanthindole, which possesses a nonfused indole ring, unlike the already known subgroups of Amaryllidaceae alkaloids, may be considered as the prototype of a third new subgroup of the Amaryllidaceae alkaloids. Additionally, two known isoquinoline alkaloids which do not possess one of the established skeletons of the Amaryllidaceae alkaloids, namely ( − )-capnoidine and (+)-bulbocapnine, have been isolated from a Turkish Galanthus species. Totally, 21 new, 20 known alkaloids and 2 known lignans have been characterized. In this review, the isolation and structure elucidation of these compounds with interesting chemical structures are described.     

Determination of Aconitum alkaloids in blood and urine samples: II. Capillary liquid chromatographic–frit fast atom bombardment mass spectrometric analysis

Determination of fourteen alkaloids, toxic Aconitum alkaloids, aconitine, mesaconitine, jesaconitine, hypaconitine and deoxyaconitine, and their hydrolysis products, benzoylaconines and aconines, have been established using capillary liquid chromatography (LC) fast atom bombardment mass spectrometry (FAB-MS) with a frit interface. Protonated molecular ions were observed as base peaks in the FAB-MS for these fourteen alkaloids. All the alkaloids were simultaneously quantified with linear gradient LC elution by solvent mixture of acetonitrile and 0.3% trifluoroacetic acid using selected ion monitoring of the protonated molecular ions. The calibration curves of these alkaloids were linear in injection amounts ranging from 5 to 500 pg, and their detection limits were 1 pg per injection (S/N=3). Solid-phase extraction using Sep-Pak Plus PS-1 was also investigated to clean-up and concentrate alkaloids in blood and urine samples, and showed satisfactory recoveries. This capillary LC–frit-FAB-MS method enables determination of low levels of Aconitum alkaloids in blood and urine samples, coupled with solid-phase extraction.     

A sustainable process for adsorptive removal of methylene blue onto a food grade mucilage: kinetics,thermodynamics, and equilibrium evaluation

Abstract

Adsorption of dyes onto natural materials like polysaccharides is considered a green chemistry approach for remediation of wastewater. In this work, the polysaccharide isolated from the corm of Colocasia esculenta (L.) Schott or taro tuber (CEM) was utilized for removing methylene blue (MB) from aqueous solution by batch adsorption method. The CEM adsorbent was characterized by FTIR spectroscopy, Brunauer–Emmett–Teller (BET), and scanning electron microscopy (SEM). The solution pH and adsorbent dose have been found to have a significant positive correlation with the adsorptive removal efficiency of CEM for MB dye. The removal efficiency of CEM was found to be 72.35% under the optimum conditions; 20?mg/L initial concentration of dye, 120?mg of adsorbent dose, solution pH 8.5, 311.2?K temperature and 80?min contact time. The adsorption of MB onto CEM followed best the Freundlich isotherm and pseudo-second-order kinetics. The adsorption was thermodynamically favorable and was endothermic in nature. The desorption/adsorption data justifiably indicated the reuse capability of CEM adsorbent for MB adsorption. Hence, CEM may be regarded as an eco-friendly and cost-effective natural adsorbent for MB dye removal from aqueous solution.     

Adsorption ofCatharanthus roseus cells on various support particles

Summary Adsorption ofC. roseus cells producing indole alkaloids on various support particles were investigated in an attempt to find a suitable support material for surface culture of plant cells. Five different support particles namely gelatin, agar, alginate, polypropylene and glass beads were tested. Gelatin was found to be the most effective adsorbent resulting in nearly 30% adsorption of cells initially present in suspension. Adsorption isotherm of cells on gelatin beads was represented by a three parameter expression due to sigmoidal shape of the isotherm. The constants of the adsorption isotherm were determined using the experimental data.