Mono 2-ethylhexyl Ester Research Articles

In vitro screening of, antibacterial antifungal and cytotoxicity activities in crude extract of freshwater cyanobacterium Oscillatoria sp.

Cyanobacteria, highly diverse group of prokaryotes are recognized as a potent source of biologically active compounds with antiviral, antibacterial, antifungal, and anticancer properties.The aim of the present study was to screen antibacterial, antifungal and cytotoxic activities of intracellular secondary metabolites of freshwater cyanobacterium Oscillataria sp. Cyanobacterium Oscillatoria sp. was isolated from Senanayaka Samudraya reservoir (7 0 11’ 37.37 0 N 810 31’ 47.13 0 E), Sri Lanka.In vitro antibacterial and antifungal activity of Oscillatoria sp. was screened against Gram-positive Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 25923, Bacillus anthracis and Gram-negative Pseudomonas aeruginosa (ATCC 25853), Salmonella typhi and Escherichia coli (ATCC 25922) and fungi, unicellular Candida albicans (ATCC 60192) and Candida tropicalis using agar disc diffusion method.The Minimum Inhibitory Concentrations (MIC), Minimum Bacteriocidal Concentration (MBC), Minimum Fungicidal Concentrations (MFC) and cytotoxic effects (brine shrimp bioassay) of Oscillatoria crude extract were determined. 10% and 60% of biomass was extracted with hexane and methanol respectively.Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify compounds in the crude extract. The highest antibacterial and antifungal activity of crude extract were detectedin methanol extract against S.aureus (19 ± 2 mm)and C.albicans (10 ± 1 mm) within 24 hours wherein the hexane extract, antibacterial activity was detected only for S. aureus and mean diameter of inhibition zone was 11 ± 1mm within 24 hours.The lowest MIC of methanol extract against S. aureus wasfound as 156.25 µg/ml. The lowest MBC and MFC of methanol extract against S. aureus and C.albicans were 0.63 mg/ml and 1.25mg/ml respectively. Lethal concentration, 50% of the crude extract against brine shrimp was recorded at 2.50 g/l, 1.25 g/l and 0.625 g/l for 6, 12, 24 hrs intervals respectively. GC-MS analysis revealed that the methanol crude extract of Oscillatoria sp. contains important fatty acid namely hexadecanoic acid methyl ester, methyl tetradecane and 13-tetradecanoic acid and n-hexane extract contains Bis (2-ethylhexyl hydroxypyridine oxide, 1 2-benzenedicarboxylic acid mono (2-ethylhexyl) ester, Phthalic acid 6-ethyl-3-Octyl heptyl ester and Phthalic acid dodecyl nonyl ester which may possess antibacterial and antifungal properties. Keywords: Oscillatoria sp., MFC, MIC, MBC, Cytotoxicity

GC-MS ANALYSIS AND ANTIFUNGAL ACTIVITY OF METHANOLIC ROOT EXTRACT OF Chenopodium album AGAINST Sclerotium rolfsii

ABSTRACT Sclerotium rolfsii is a soil-borne fungal plant pathogen that causes diseases in more than 500 plant species. Chemical fungicides used to control this disease cause environmental pollution, therefore, plant derived compounds can be used as alternative to synthetic fungicides to reduce environmental pollution. Chenopodium album is a weed of family Chenopodiaceae that is used as food and also has medicinal importance. In the present study, antifungal activity of methanolic root extract of C. album was evaluated against S. rolfsii using six concentrations viz. 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 g 100 mL-1 amended in malt extract as growth medium. All the root extract concentrations significantly reduced fungal biomass by 15-58% over control. Gas chromatography-mass spectrometry (GC-MS) analysis of the methanolic root extract of C. album was performed. Six compounds were identified in methanolic root extract through GC-MS analysis. The most abundant compound was 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester (58.56%) followed by 9-octadecenoic acid (Z)-, methyl ester (12.75%) and 9-octadecenoic acid (Z)-, methyl ester (10.27%), which might be responsible for antifungal activity of methanolic root extract of C. album.

Characterization of natural products from the peel of Lagenaria siceraria fruit using chromatographic techniques

Herbal products, which comprise a wide variety of bioactive molecules, have been used as remedies for different diseases throughout history. Lagenaria siceraria, a fruit vegetable, is employed in folk medicine as a treatment for various disorders including diabetes, hyperlipidemia, and heart and liver ailments. In the present work, a number of compounds were isolated and characterized from the ethyl acetate fraction of the methanolic extract of its peel, including β-sitosterol, vanillin, quercetin, rutin, 3-tert-butyl-4-hydroxyanisole, stearic acid, 2,4-bis(1,1-dimethylethyl)phenol, 2,2′-methylenebis[6-(1,1-dimethylethyl)-4-methylphenol], 1,2-benzenedicarboxylic acid mono(2-ethylhexyl) ester, hexadecanoic acid and its methyl ester, (Z,Z)-9,12-ocatdecadienoic acid and its ester, and (Z,Z,Z)-9,12,15-ocatdecatrienoic acid methyl ester. Separation of the phytochemicals was done using column and thin-layer chromatography, while gas chromatography–mass spectrometry (GC–MS), liquid chromatography-mass spectrometry (LC–MS), and high-performance liquid chromatography (HPLC) were employed for their identification. These compounds are being reported for the first time from the peel of the fruit of L. siceraria. The results provide a possible chemical rationale for the medicinal applications of this fruit.

Bioactivity of Some Plant Extracts Against Termite Odontotermes obesus (Rambur) (Blattodea: Termitidae)

A study was carried out to determine the chemical constituents of wood extractives from Ashoka, Saraca asoca (Roxb) and Magnolia (Magnolia grandiflora L.) (Southern Magnolia) against Odontotermes Obesus (Rambur) under laboratory conditions in Forman Christian College University (Lahore, Pakistan) in June 2016. Extraction was done by soxhlet apparatus. The analysis of these compounds was performed by Gas Chromatography-Mass Spectrometry (GC-MS). Gas Chromatography-Mass Spectrometry of wood extractives of Saraca asoca detected 4-[(1E)-3-Hydroxy-1-propenyl]-2-methoxyphenol; Hexdecanoic acid, methyl ester; n-Hexadecanoic acid; 5,6-Dimethoxy phthalaldehydic acid; 9,12-Octadecadienoic acid, methyl ester, (E,E)-; 9,12-Octadecadienoic acid (Z,Z)-; Oleic acid; Octadecanoic acid; 1,2-Benzenedicarboxylic acid, mono(2-ethylhexyl) ester. Compounds in wood extractives of Magnolia grandiflora were Cyclopentane carboxylic acid, 2-methyl-4-(phenylmethylene)-, methyl ester; 4-((1E)-3-Hydroxy-1-propenyl)-2- methoxyphenol; n -Hexadecanoic acid; 5,6-Dimethoxy phthalaldehydic acid; 7-(1,3-Dimethylbuta-1,3- dienyl)-1,6,6-trimethyl-3, 8-dioxatricyclo[5.1.0.0(2,4)]; 9,12-Octadecadienoic acid, methyl ester, (E,E)-; Oleic acid; 16-Methyloxacyclohexadeca-3,5-dien-2-one; Germacra-1(10), 4,11(13)-trein-12-oic acid, 6.alpha.- hydroxy-gamma-lactone, (E,E);5,6-Azulenedicarboxaldehyde,1,2,3,3a,8,8a-hexahydro-2,2,8-trimethyl-, (3a.alpha.,8.alpha.,8a.alpha)-(-)-; Aromadendrene oxide-(2); Cedran-diol, 8S, 14-; Cis-Z-.alpha.-Bisabolene epoxide; 2-Dodecen-1-yl(-)succinic anhydride; 3-Buen-2-ol, 2-methyl-4(1,3,3-trimethyl-7- oxabicyclo[4.1.0]hept-2-yl)-.Based on the feeding activity, wood extracts were arranged in descending order of preference; Ashoka > Magnolia. So these could prove useful in developing a soil barrier to block termite activity and serve as a replacement to synthetic chemicals.

Constituents and termiticide potential of some wood extracts against Coptotermes heimi (Wasmann) (Isoptera: Rhinotermitidae)

Wood extractives are one of the main reasons for the resistance of wood to termite attack. A study was carried out to determine the chemical constituents of wood extractives from Pinus roxburghii Sargent , Morus alba L. and Eucalyptus camaldulensis Dehnh against Coptotermes heimi (Wasmann) under laboratory conditions in Forman Christian College University (Lahor, Pakistan) in June 2015. Gas chromatography-mass spectrometry of wood extractives of P. roxburghii detected 1,2 - benzenedicarboxylic acid, mono (2-ethylhexyl) ester and octadecanoic acid (methyl ester). Hexadecanoic acid (methyl ester) and 1-methyl-3-(1-methylethyl)-benzene were present in M. alba in addition to the compounds present in P. roxburghii and in E. camaldulensis 1,2-benzenedicarboxylic acid, mono (2-ethylhexyl) ester and β-phellandrene were also present. Based on the feeding activity, wood extracts were arranged in descending order of preference; P. roxburghii > M. alba >E. camaldulensis . Extracts of P. roxburghii, M. alba and E. camaldulensis proved repellent at higher concentrations, with tunneling activity almost fully inhibited. So these could prove useful in developing a soil barrier to block termite activity and serve as a replacement to synthetic chemicals.

The SRAP based molecular diversity related to antifungal and antioxidant bioactive constituents for biocontrol potentials of Trichoderma against Sclerotium rolfsii Scc.

The study was performed to examine 11 isolates of Trichoderma for their bio-control potentials against Sclerotium rolfsii Sacc. causing stem rot in groundnut. The antagonists Trichoderma were subjected to sequence related amplified polymorphism (SRAP) based molecular diversity analysis and compared with their hardness to S. rolfsii with respect to secretary antifungal and antioxidant profile. T. virens NBAII Tvs 12 evident highest (87.91%) growth inhibition of test pathogen followed by T. koningii MTCC 796 (67.03%) at 7days after inoculation (DAI). Microscopic study confirmed biocontrol mechanism as mycoparasitism for Tvs 12 and antibiosis for MTCC 796. The growth inhibition of test pathogen was significantly negatively correlated with sclerotia formation and lipid peroxidation during antagonism due to release of secretary bioactive antioxidants by antagonists to terminate oxidative burst generated by S. rolfsii and causing inhibition of sclerotium formation. The GC-MS profile identified antifungal and antioxidant constituents hexadecane, 1,2-benzenedicarboxylic acid, mono (2-ethylhexyl) ester, 1-hexadecanesulfonyl chloride, and octadecane in potent antagonists Tvs 12; and nonacosane and octadecane in MTCC 796 along with two novel compounds 1-pentadecene and 1-heneicosyl formate for biocontrol activity. Molecular diversity of Trichoderma isolates associated with antagonistic activity was assessed by SRAP markers. The 115 primer combinations generate total 1328 amplified products of which, 1095 are shared polymorphic and 199 are unique polymorphic. The 15 SRAP combinations produced 18 bands to diagnose best antagonist Tvs 12 and 13 SRAP combinations generated 19 unique bands for identification of MTCC 796. The mycoparasitic antagonist Tvs 12 would be the best antagonist and released unique antifungal and antioxidant constituents to combat pathogen infection. The SRAP based genetic diversity indicates Tvs12 strain clustered with T. viride NBAII Tv23 and shared only 52% similarity with other isolates of Trichoderma. The SRAP similarities explained substantial diversity (19-68%) across Trichoderma isolates.

Removal of p-nonylphenol isomers using nitrifying sludge in a membrane sequencing batch reactor

The aim of this study was to assess p-nonylphenol removal mechanisms under nitrifying conditions in a bioreactor system. The removal of a technical mixture of p-nonylphenol isomers was evaluated in a membrane sequencing batch reactor without the addition of an organic carbon source in enriched nitrifying sludge. The p-nonylphenol concentration was quantified in the liquid and solid phases to accurately differentiate between biodegradation and sorption mechanisms. The predominant removal mechanism was p-nonylphenol biodegradation (62%), followed by sorption, which resulted in a total removal of 96%. In addition, ammonium-oxidizing microorganisms controlled the biodegradation of p-nonylphenol, and 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl)ester was identified as the main intermediary metabolite. These results suggested that co-metabolic biodegradation by heterotrophic microorganisms is necessary to completely mineralize p-NP isomers under nitrifying conditions. This study provides an important contribution to existing knowledge of nonylphenol biodegradation.

Antimicrobial activities of methanolic extract of Carissa opaca roots and its fractions and compounds isolated from the most active ethyl acetate fraction

ObjectiveTo study the antibacterial and antifungal activities of methanolic extract of roots of Carissa opaca and its fractions in hexane, chloroform, ethyl acetate, n-butanol and water, and the isolated compounds. MethodsThe zones of inhibition of the samples against test microorganisms were determined by agar well diffusion method. Minimum inhibitory concentrations of the samples were determined by agar well dilution method. Test microorganisms included four standard bacteria [Bacillus subtilis ATCC 6633 (B. subtilis), Escherichia coli ATCC 8739 (E. coli), Pseudomonas aeruginosa ATCC 9027 (P. aeruginosa), and Staphylococcus aureus ATCC 6538], two standard fungi [Candida albicans ATCC 10231 (C. albicans)] and Aspergillus niger, and six clinical isolates (B. subtilis, E. coli, P. aeruginosa, Staphylococcus aureus, Salmonella typhi and Enterobacter cloacae). The most active fraction was investigated to isolate compounds. The chemical compounds isolated from the ethyl acetate fraction were identified by gas chromatography-mass spectrometer, high performance liquid chromatography and liquid chromatography-mass spectrometer. ResultsE. coli, P. aeruginosa, and C. albicans were the most susceptible. Less polar fractions exhibited stronger efficacy than polar ones, and ethyl acetate fraction proved to be the most potent. Zones of inhibition of hexane, chloroform and ethyl acetate fractions, and amoxil against C. albicans were 19.96, 22.01, 23.10 and 19.20 mm, respectively. Ethyl acetate faction was the most toxic to all the test microorganisms, with minimum inhibitory concentrations of 8.0, 7.8 and 7.78 μg/mL against P. aeruginosa, C. albicans and B. subtilis, respectively. Isolated compounds, limonene, 2'-hydroxyacetophenone, vanillin, naphthalenone, 2,3,3-trimethyl-2-(3-methylbuta-1,3-dienyl)-6-methylenecyclohexanone, 2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester, β-sitosterol, vitamin E, rutin, quercetin, lupeol, epigallocatechin, showed considerable antimicrobial activities against test microorganisms. ConclusionsThe roots of Carissa opaca contain compounds with significant antimicrobial potential.

Solvent Extraction Separation of Trivalent Americium from Curium and the Lanthanides

The sterically constrained, macrocyclic, aqueous soluble ligand N,N′-bis[(6-carboxy-2-pyridyl)methyl]-1,10-diaza-18-crown-6 (H2BP18C6) was investigated for separating americium from curium and all the lanthanides by solvent extraction. Pairing H2BP18C6, which favors complexation of larger f-element cations, with acidic organophosphorus extractants that favor extraction of smaller f-element cations, such as bis-(2-ethylhexyl)phosphoric acid (HDEHP) or (2-ethylhexyl)phosphonic acid mono(2-ethylhexyl) ester (HEH[EHP]), created solvent extraction systems with good Cm/Am selectivity, excellent trans-lanthanide selectivity (Kex,Lu/Kex,La = 108), but poor selectivity for Am against the lightest lanthanides. However, using an organic phase containing both a neutral extractant, N,N,N’,N’-tetra(2-ethylhexyl)diglycolamide (TEHDGA), and HEH[EHP] enabled rejection of the lightest lanthanides during loading of the organic phase from aqueous nitric acid, eliminating their interference in the americium stripping stages. In addition, although it is a macrocyclic ligand, H2BP18C6 does not significantly impede the mass transfer kinetics of the HDEHP solvent extraction system.

Differences of Biochemical Constituents and Contents of Eight Cultivars Flowers of Camellia sinensis

For better use of tea plant (Camellia sinensis) flower resources, biochemical components and contents of eight tea cultivars flowers were investigated. Volatile aromatic compounds were extracted by simultaneous distillation and solvent extraction (SDE) and determined using Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GC-MS). The contents of tea polyphenols, amino acids, caffeine, soluble sugars and soluble proteins was assayed by colorimetric method with ferrous tartrate, ultraviolet spectrophotometric method, anthrone colorimetric method and coomassie brillient blue method, respectively. Among the eight cultivars flowers there were big difference in contents and numbers of volatile aromatic compounds. The greatest numbers of volatile aromatic compounds in flowers was 50, and the least numbers of volatile aromatic compounds in flowers was 9. The major constituents of volatile aromatic compounds in flowers included alkanes, alcohols, esters, ketones, aldehydes and alkenes. Acetophenone and tricosane were found in each cultivar flowers. However, The content of acetophenone, 2-heptanol, (S)-, 1,6-octadien-3-ol, 3,7-dimethyl-, 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester and di-n-octyl phthalate were higher in some flowers. The result also indicated that tea flowers were rich in soluble sugars and soluble proteins.

Isolation of mosquito larvicidal molecule form the leaves of Clausena anista

The vector-borne diseases caused by mosquitoes are one of the major health problems in many countries especially in tropical and sub-tropical countries. The resistance of mosquitoes to synthetic chemicals and environmental toxicity created by the chemicals raised the demand for finding of alternate natural molecules that control mosquito. In the present study, the compound 1, 2-Benzenedicarboxylic acid, mono (2-ethylhexyl) ester was isolated from the ethyl acetate extract of leaves of Clausena anisata and it was identified by various spectral studies. The larvicidal potential of the isolated compound was evaluated against early 4 th instar larvae of Culex quinquefasciatus , Aedes aegypti and Anopheles stephensi. The compound exhibited 100% larval mortality against A. aegypti and A. stephensi at 40 ppm with LC 50 values of 8.944 and 9.230 ppm respectively. The molecule also showed the LC 50 value of 12.067 ppm against C . quinquefasciatus. The molecule isolated from C. anisata can be better explored for the control of mosquito population after toxicological evaluation.

Identification of new phytoconstituents and antimicrobial activity in stem bark of Mangifera indica (L.)

Mangifera indica, commonly called mango or amra belonging to a family of Anacardiaceae, is an important medicinal plant widely used in a variety of Ayurvedic preparations. Extract of its bark, leaves, flowers and kernels are being extensively used for curing various chronic diseases. Mango wood is used in yagya as base fire through which medicated smoke is generated. Three new compounds have been isolated from methanolic and hexane extracts of stem bark: 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl)ester and 9,12-tetradecadiene-1-ol-acetate from the hexane extract and 3-chloro-N-(2-phenylethyl) propanamide from the methanolic extract. These were first separated by thin layer chromatography and later in a silica gel column and identified by characteristic infrared bands corresponding to respective functional groups. The compounds were further confirmed on the basis of GC–MS fragmentation pattern after comparing the data with NIST mass spectral database. All three compounds exhibited antimicrobial activity due to triterpenoids and flavonoids. Elemental analyses by INAA show it to be enriched in essential nutrient elements such as Ca, Fe, K, Mn and Zn which all play an important role in enzymatic processes.

Biocontrol of Lasiodiplodia theobromae, which causes black spot disease of harvested wax apple fruit, using a strain of Brevibacillus brevis FJAT-0809-GLX

A strain of Brevibacillus brevis FJAT-0809-GLX that was isolated from the soil in Yongtai, Fujian Province, PR China, was evaluated for its potential to reduce the black spot decay of wax apple (Syzygium samarangense Merr. et Perry) fruit caused by Lasiodiplodia theobromae using in vitro and in vivo tests. The culture filtrate, unwashed cell suspension (1 × 108 CFU/mL) and washed cell suspension (1 × 108 CFU/mL) significantly suppressed the growth of mycelium in vitro. The culture filtrate was the most effective treatment for controlling wax apple fruit rot in vivo. The incidence of rot in wax apple fruits that were treated with culture filtrate for 8 days at 30 °C was 20% ± 6.67%, which was markedly lower than that of those that were treated with sterile distilled water (control). A better biocontrol was obtained with a longer incubation time of B. brevis. When the incubation time of B. brevis was 72 h, the disease incidence decreased to 14.44% ± 1.93%. Furthermore, the best biocontrol efficacy was obtained when the fruits were inoculated with the culture filtrate of B. brevis before inoculation with the pathogen. The chemical composition of the acetone extract from B. brevis culture filtrate by GC-MS analysis showed that there were three major antifungal compounds: ethylparaben, dibutyl phthalate, and 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester. The in vitro antifungal activities of these major components on L. theobromae showed that ethylparaben was the main antifungal compound. Isolated extracts could be used for the future development of antifungal agents. To the best of our knowledge, this is the first report demonstrating that the bacterium B. brevis could be used as a biocontrol agent against black spot disease by L. theobromae on wax apple fruit.

Thermodynamics and kinetics of thorium extraction from sulfuric acid medium by HEH(EHP)

Solvent extraction of Th(IV) using 2-ethylhexyl phosphoric acid mono 2-ethylhexyl ester (HEH(EHP)) in kerosene from sulfuric acid medium was studied by investigating the dependence of thorium extraction on aqueous acidity and HEH(EHP) concentration. The extraction mechanism was also determined by slope analysis. Th(IV) extraction kinetics was investigated using a constant interfacial cell with a laminar flow, and the data were analyzed based on the principle of pseudo first-order reaction. Some parameters' effect on the mass transfer, including the effect of temperature, Th(IV) concentration, HEH(EHP) concentration and pH was studied, and the rate equation for thorium extraction was obtained through slope analysis. Based on the high activation energy (Ea=45.8kJmol−1), the extraction regime was defined to be an interfacial chemical reaction control. In addition, a mass transfer model with a rate-control step was proposed and it was consistent with the experimental results.

Antagonistic Evaluation of Bioactive Metabolite from Endophytic Fungus, Aspergillus flavipes KF671231

Of the total 40 endophytic fungi isolated from foliar tissues of medicinal plant Stevia rebaudiana Bertoni, a fungal isolate, Aspergillus flavipes, was subjected to bioassay guided fractionation. The fractionation was found active against medicinal plant pathogen Sclerotinia sclerotiorum with an inhibition zone of 29 mm in size. Further the metabolite was extracted which shows 20% growth inhibition in 24 h and 46% after 48 h, respectively. Bioassay guided chemical compound was identified as 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester. On the basis of morphological characters and rDNA sequencing of ITS region the endophyte was identified as Aspergillus flavipes which showed promising plant growth promotory properties.

사군자추출물의 깍지벌레류에 대한 살충활성

Scale insects heavily damaged many agricultural crops and trees in urban and forest areas. This study was conducted to carry out alternative control methods for environmentally friendly control of scale insects. Hot water extract of Quisquali indica produced high mortality against the black pine bast scale, Matsucoccus thunbergianae in previously experiment. Methanol extract obtained from fruit of Q. indica was successively fractionated using hexane, chloroform, ethyl acetate, buthanol and water which were examined by exposing for their insecticidal activity against four Cocoidea species (Eriococcus lagerstroemiae, Ceroplastes japonicus, Crisicoccus pini and Planococcus citri) in laboratory. Hexane fraction gave the highest insecticidal activity against scale insect pest. GC-mass analysis confirmed that the main compounds of Q. indica were alpha-pinene, methyl palmitate, eugenol, methyl myristate, phthalic acid mono(2-ethylhexyl)ester and palmitic acid. Among those compounds, α-pinene was included 10 hexane subfractions. LC of α-pinene was 0.0114 ppm against 2nd instar of E. lagerstroemiae. These results suggest that Q. indica extracts might be used as an alternative control agent of scale insects.

Muscodor tigerii sp. nov.-Volatile antibiotic producing endophytic fungus from the Northeastern Himalayas

Genus Muscodor came into existence with the discovery of Muscodor albus, a sterile endophytic fungus that produces a medley of volatile organic moieties possessing strong antimicrobial activity. The current paper reports Muscodor tigerii as a novel endophytic fungus from the stem internal tissue of Cinnamomum camphora growing in the Tiger Hill area of Darjeeling, West Bengal, India. M. tigerii exhibited distinct morphological, molecular and physiological features than previously reported Muscodor species. The fungus possesses all the morphological features described till date in genus Muscodor making it remarkably unique. The strong fruity smell of the fungus is attributed to 22 volatile organic compounds (VOCs), predominantly 4-Octadecylmorpholine, 1-Tetradecanamine,N,N-dimethyl and 1,2-Benzenedicarboxylic acid, mono(2-ethylhexyl) ester. The in vitro VOC stress assay completely suppressed the growth of Alternaria alternata and Cercospora beticola while growth of other fungal species was inhibited in a range of 10 %-70 %. The growth of Candida albicans in the presence of VOC was reduced by 50 %-65 % while in bacteria 50 %-80 % reduction in growth was observed. Thus, M. tigerii stands as a potential candidate to be further developed into a biocontrol agent.

Separation of high purity gadolinium for reactor application by solvent extraction process

A solvent extraction process for the production of nuclear grade Gd2O3 for its applications in pressurized heavy water reactor (PHWR) from a crude concentrate of rare earths containing ~70 % Gd2O3 has been developed and tested on bench-scale and continuous counter-current operations. The separation of gadolinium from other rare earths with similar chemical properties has been successfully accomplished by adopting a dual cycle solvent extraction employing 2-ethylhexylphosphonic acid, mono-2 ethylhexyl ester (EHEHPA) as an extractant. Taking advantage of the extraction order of rare earths with EHEHPA, in the first cycle, heavy rare earths including Tb, Dy and Y were separated in the product strip solution, while gadolinium was separated in the raffinate solution along with samarium and neodymium. In the second cycle, gadolinium was purified to the extent of >99.5 % with respect to other rare earths. Effects of process variables such as aqueous acidity, phase ratio, metal concentration in the aqueous feed, scrubbing and stripping acidity etc. on separation of terbium and other heavy rare earths in the first cycle and upgrading the purity of Gd2O3 in the second cycle have been investigated. The experimental conditions were optimized using computer simulation and validated by bench scale counter-current operations. Under optimized conditions of process parameters, continuous operations of mixer settler yielded kilogram quantity of nuclear pure Gd2O3 which was subsequently converted to gadolinium nitrate for PHWR application. The overall recovery was found to be >98 %.

The Extraction, Isolation and Identification of Exudates from the Roots of Flaveria bidentis

Large amounts of Flaveria bidentis's root culturing solution were obtained by using DFT (deep flow technique) equipment and these solution which was vacuum concentrated (10, 20 mg mL−1) can have a certain inhibition on Triticum aestivum, Cucumis sativus, Raphanus sativus, Amaranthus retroflexus, Setaria viridis, Chenopodium album, Echinochloa crusgalli and Chloris virgata. This outcome suggested some active compounds in the root exudates of Flaveria bidentis can inhibit the germination, seedling elongation and root length. The dichloromethane extract of root exudates was identificated by GC-MS, and 29 kinds of compounds, including esters, hydrocarbons, ketones, thiazole, amines, etc. were obtained and the phthalate n-octyl ester, phthalate 2-ethylhexyl ester were proved to be allelochemicals. The culturing solution of root exudates was separated through the resin column and silica gel column and a component inhibiting seedling height, root length and fresh weight of wheat was got. There were 6 kinds of organic compounds in this component including dioctyl phthalate, 1,2-phthalate, mono(2-ethylhexyl) ester by GC-MS.

Chemical Constituents and Antimicrobial Activity of Essential Oil of <i>Senna podocarpa</i> (Guill. et Perr.) Lock

The chemistry of essential obtained from the leaves of Senna podocarpa (Guill. Et Perr.) Lock from Nigeria is being reported. The hydrodistilled oil was analyzed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) techniques. The main constituents of the oil were 1,2-benzenedicarboxylic acid, mono (2-ethylhexyl) ester phthalate (26.6%) and β-elemene (27.9%). There were significant amounts of caryophyllene oxide (7.3%) and urs-12-en-24-oic acid, 3-oxo-methyl ester (5.5%). The antimicrobial activity of the essential oil was evaluated against a panel of seven bacteria and two fungal strain using agar diffusion and broth microdilution methods. Results had shown that the oil exhibited moderate to strong antimicrobial activity against the tested microorganisms. The activity zones of inhibition (ZI) ranged between 10.0 ± 0.2 mm and 28.3 ± 2.9 mm while the minimum inhibitory concentrations (MIC) ranged between 0.3 mg/mL 5.0 mg/mL, respectively. The chemical constituents and antimicrobial activity of the essential oil of Senna podocarpa were being reported for the first time.