Chemical studies of the Proteaceae. I. Grevillea robusta A. Cunn, and Orites excelsa R. Br

1965 ◽  
Vol 18 (12) ◽  
pp. 2015 ◽  
Author(s):  
E Ritchie ◽  
WC Taylor ◽  
STK Vautin
Keyword(s):  
Chemical Degradation ◽  
High Yield ◽  
Spectroscopic Methods ◽  
Grevillea Robusta ◽  
Chemical Studies

From the wood of Grevillea robusta a new phenol, grevillol, was isolated in high yield, together with sitosterol. The structure of grevillol was established as 5-n-tridecylresorcinol by spectroscopic methods, chemical degradation, and synthesis. The wood of Orites excelsa yielded only sitosterol.

Chemical studies of the Proteaceae. IV. The structures of the major phenols of Grevillea striata; a group of novel cyclophanes

1970 ◽  
Vol 23 (1) ◽  
pp. 147 ◽  
Author(s):  
DD Ridley ◽  
E Ritchie ◽  
WC Taylor
Keyword(s):  
Double Bond ◽  
Structure Determination ◽  
Ring System ◽  
Chemical Degradation ◽  
Aliphatic Chain ◽  
Spectroscopic Methods ◽  
Ether Extract ◽  
Phenolic Fraction ◽  
Saturated Chain ◽  
Chemical Studies

Attempts to separate the major constituents of the phenolic fraction of the ether extract of the wood of Grevillea striata R.Br. were unsuccessful, but by chemical degradation and spectroscopic methods the structures of four of the components were deduced. They were mono- and di-methyl ethers of 17,19,22,24- tetrahydroxy(l4-p-0-o)cyclophane with a double bond at either of two positions in the aliphatic chain. The new ring system was given the trivial name "turriane". Evidence that a fifth and a sixth component were derivatives with a saturated chain, and a seventh was a derivative of a double homologue of turriane, was obtained. Synthetic experiments connected with the structure determination, and on the synthesis of tetrahydroxyturriane are described. Possible biogenetic routes to striatol and the cyclophanes are discussed.

Chemical studies of the Proteaceae. II. Some further constituents of Grevillea robusta A. Cunn.; Experiments on the synthesis of 5-n-Tridecylresorcinol (grevillol) and related substances

1968 ◽  
Vol 21 (12) ◽  
pp. 2979 ◽  
Author(s):  
DD Ridley ◽  
E Ritchie ◽  
WC Taylor
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Potassium Hydroxide ◽  
Dimethyl Sulphate ◽  
Chemical Degradation ◽  
Grevillea Robusta ◽  
Aqueous Methanol ◽  
Related Substances ◽  
Chemical Studies

By mass spectrometry, gas chromatography, and chemical degradation it was shown that crude grevillol from the wood of Grevillea robusta contains small amounts of 5-n-pentadecylresorcinol, 5-pentadec-8-enylresorcinol, and 5-pentadec-10-enyl-resorcinol. The first of these substances was synthesized; grevillol has been synthesized by three new routes. Xethylation of resorcinol derivatives by dimethyl sulphate-potassium hydroxide-aqueous methanol resulted in some nuclear methylation as well as the predominant O-methylation.

The Siderophores of Pseudomonas fluorescens 18.1 and the Importance of Cyclopeptidic Substructures for the Recognition at the Cell Surface

2000 ◽  
Vol 55 (9-10) ◽  
pp. 671-680 ◽  
Author(s):  
Cordula Amann ◽  
Kambiz Taraz ◽  
Herbert Budzikiewicz ◽  
Jean-Marie Meyer
Keyword(s):  
Cell Surface ◽  
Pseudomonas Fluorescens ◽  
Mutual Recognition ◽  
Chemical Degradation ◽  
Spectroscopic Methods

Abstract The structure of the pyoverdin siderophore of Pseudomonas fluorescens 18.1 was elucidated by spectroscopic methods and chemical degradation. By cross feeding studies structurally closely related pyoverdins containing a C-terminal cyclopeptidic substructure were tested regarding the mutual recognition by the producing strains. Partial recognition of foreign pyoverdins was observed.

A Pyoverdin from the Antarctica Strain 51W of Pseudomonas fluorescens

1999 ◽  
Vol 54 (3-4) ◽  
pp. 156-162 ◽  
Author(s):  
Jessica Voss ◽  
Kambiz Taraz ◽  
Herbert Budzikiewicz
Keyword(s):  
Amino Acids ◽  
Pseudomonas Fluorescens ◽  
Binding Sites ◽  
Chemical Shifts ◽  
Chemical Degradation ◽  
Spectroscopic Methods ◽  
Extreme Conditions ◽  
Structural Elements ◽  
Nmr Data ◽  
Schirmacher Oasis

From the strain 51W of Pseudomonas fluorescens living under extreme conditions at the Schirmacher Oasis (Antarctica) a pyoverdin was obtained. Its structure was elucidated by chemical degradation and spectroscopic methods. The NMR data of the pyoverdin and of its Ga(III) complex were compared. Appreciable influences of the metal on the chemical shifts of the atoms at its binding sites were observed. Thus the structural elements involved in the complexation can be identified and coinciding signals of amino acids occurring more than once in the peptide chain can be separated.

scholarly journals Electrochemical Detection of 4-Nitrophenol by Using Graphene Based Nanocomposite Modified Glassy Carbon Electrodes: A Mini Review

2021 ◽  
pp. 61-87
Author(s):  
E. Prabakaran ◽  
Kriveshini Pillay
Keyword(s):  
Graphene Oxide ◽  
Glassy Carbon ◽  
Metallic Nanoparticles ◽  
Agricultural Sector ◽  
Chemical Degradation ◽  
High Yield ◽  
Functionalized Graphene ◽  
Agricultural Field ◽  
Functionalized Graphene Oxide ◽  
Phenolic Pollutants

This article describes the fabrication of electrochemical devices for the detection of a key environmental pollutant, 4-Nitrophenol (4-NPh). 4-NPh is a requirement for the synthesis of organophosphate pesticides. These pesticides are mostly used in the agricultural sector to obtain a high yield of agricultural products. The use of 4-NPh in the agricultural field results in poisonous levels of this compound in the soil and water. Different techniques have been used for its transformation by biological and chemical degradation. However, these strategies not only created highly toxic pollutant but also need fast operation and time consuming processes. In this background, we have reported a broad and efficient review of the electrochemical reduction of 4-NPh as a feasible alternate method. In this review paper, graphene oxide (GO), reduced graphene oxide (rGO), N-doped graphene oxide, functionalized graphene oxide, metallic nanoparticles coated graphene oxide, metal oxides covered on rGO, polymer functionalized graphene oxide and hybrids materials functionalized with graphene oxide (hydroxyl apatite and β-cyclodextrin) which have been fabricated on a glassy carbon electrode (GCE) to enhance the electrocatalytic reduction and increase the sensor activity of 4-NPh are discussed. We have also described the effects of a few interfering phenolic pollutants such as aminophenol, hydroquinone, o-nitrophenol (o-NPh), trinitrotoluene, trinitrophenol, 2, 4-dinitrophenol (4-DNPh) and nitrobenzene. In the paper, easy and more effective electrochemical methods for the detection of 4-NPh with graphene- based nanocomposites modified on GCE for 4-NPh detection are summarized and discussed.

Structure Elucidation of Azotobactin 87, Isolated from Azotobacter vinelandii ATCC 12837*, **

1996 ◽  
Vol 51 (3-4) ◽  
pp. 139-150 ◽  
Author(s):  
E. M. Schaffner ◽  
R. Hartmann ◽  
K. Taraz ◽  
H. Budzikiewicz
Keyword(s):  
Structure Elucidation ◽  
Culture Medium ◽  
Azotobacter Vinelandii ◽  
2D Nmr ◽  
Chemical Degradation ◽  
Spectroscopic Methods ◽  
Hydroxybutyric Acid ◽  
Iron Deficient ◽  
N Terminus ◽  
Sequential Information

Abstract Chromopeptide siderophores (azotobactin 87-1 and -II) were isolated from an iron deficient culture medium of Azotobacter vinelandii ATCC 12837 (=DSM 87). Their structures were elu­ cidated by chemical degradation studies and spectroscopic methods, especially 2D-NMR-tech-niques. Total assignments of 1H-, 13C-, and 15N-resonances based on 2D-HOHAHA-, 1H/13C-HMQC-, 1H /13C-HMBC-, 1H /15N-HMQC/TOCSY-, and 1H/15N-HMBC-experiments are given as well as sequential information derived from 1H/1H-NOESY-, 1H /13C-HMBC-and 1H/ 13N-HMBC-experiments. Both Az 87-1 and Az 87-11 consist of a tetracyclic chromophore -(1S)8,9-dihydroxy-4-oxo-2,3,4,5-tetrahydro-1H,10cH-3a,5,10b-triazaacephenantrylene-1-carb-oxylic acid -and a decapeptide chain linked with the N-terminus to the carboxy group of the chromophore containing also modified, non-proteinogenic amino acids. The sequence L-Ser-D-Ser-L-Hse-Gly-D-threo-OHAsp-Hse-Hse-Hse-D-N5OH-N5-R-Hbu-Om-L-Hse was determined for Az 87-1, while Az 87-11 contains a C-terminal L-Hse-lactone instead. Iron is chelated by the catecholic group of the chromophore, the β-hydroxy aspartic acid, and the hydroxamate function formed by N5-hydroxyornithine and R-β-hydroxybutyric acid.

Cepaciachelin, A New Catecholate Siderophore From Burkholderia (Pseudomonas) Cepacia ***

1996 ◽  
Vol 51 (9-10) ◽  
pp. 627-630 ◽  
Author(s):  
I. Barelmann ◽  
J.-M. Meyer ◽  
K. Taraz ◽  
H. Budzikiewicz
Keyword(s):  
Chemical Degradation ◽  
Pseudomonas Cepacia ◽  
Spectroscopic Methods ◽  
First Case ◽  
Hydroxamate Siderophores

In addition to the known hydroxamate siderophores ornibactin C6 and C8 a catecholate siderophore named cepaciachelin, 1-N-[2-N′,6-N′-di(2,3-dihydroxybenzoyl)-ʟ-lysyl]-1,4-diaminobutane, was isolated from a Burkholderia (Pseudomonas) cepacia PHP7 culture and its structure elucidated by chemical degradation and spectroscopic methods. This is the first case of a member of the Pseudomonas group which produces both hydroxamate and catecholate siderophores

The chemical constituents of Australian Flindersia species. XIX. Triterpenoids from the leaves of F. bourjotiana F. Muell

1966 ◽  
Vol 19 (3) ◽  
pp. 455 ◽  
Author(s):  
GJW Breen ◽  
E Ritchie ◽  
WTL Sidwell ◽  
WC Taylor
Keyword(s):  
Chemical Constituents ◽  
Chemical Degradation ◽  
Spectroscopic Methods ◽  
The Absolute ◽  
Absolute Stereochemistry

From the leaves of Flindersia bourjotinna F. Muell. there were isolated sitosterol, triacontanol, lupeol, germanicol, germanicone, and four new triterpenoids, the bourjotinolones A, B, and C, and bourjotone. By chemical degradation and spectroscopic methods, the structures of these substances were shown to be 21,24-epoxy-23,25-dihydroxytirucall-7-en-3one, 23,24-dihydroxytirucalla-7,25-dien- 3-one, 25-chloro-23,24-dihydroxytirucall-7-en-3-one, and 25,26,27-trisnortirucall-7- ene-3,23-dione, respectively. Bourjotinolone C is almost certainly an artefact but bourjotinolone B and bourjotone are less likely to be. From biogenetic and N.M.R. spectral considerations, the absolute stereochemistry of the new triterpenes may be deduced.

scholarly journals Food vs. Wood: Dynamic Choices for Kenyan Smallholders

2016 ◽  
Vol 5 (1) ◽  
pp. 97 ◽  
Author(s):  
Alexandra Peralta ◽  
Scott M. Swinton
Keyword(s):  
Tree Species ◽  
Building Materials ◽  
Programming Model ◽  
Smallholder Farmers ◽  
High Yield ◽  
Food Crops ◽  
Grevillea Robusta ◽  
Annual Crops ◽  
Short Rotation ◽  
Exotic Tree

<p>Smallholder farmers in many areas of the semiarid tropics are planting exotic tree species that provide alternative income sources, fuel, and building materials. While providing other benefits, these trees often occupy land that could produce annual food crops. This study uses a polyperiod, linear programming model, to explore the opportunity cost of planting <em>Eucalyptus grandis</em> and <em>Grevillea robusta</em> trees compared to crops in the Nyando watershed of western Kenya. Results of the ten-year period wealth maximization model suggest that a representative farmer’s decisions on farm resource allocation are sensitive to changes in the relative prices of short rotation tree products and annual crops. The model also suggests that there are economic tradeoffs between planting trees and crops, as well as between planting different tree species. Timber production is not likely to replace food crops for two main reasons: (1) the high cost of meeting household subsistence requirements from marketed grains, (2) household cash flow needs met by annual crops. Farmers plant eucalyptus for commercial purposes because they can obtain timber products within four years; however if the prices of these short rotation products go down, farmers will prefer to grow timber from high yield grevillea.</p>

scholarly journals A 2-(2’-pyridyl)quinoline ruthenium(II) complex as an active catalyst for the transfer hydrogenation of ketones

2016 ◽  
Vol 14 (1) ◽  
pp. 308-315 ◽  
Author(s):  
Nikolaos Zacharopoulos ◽  
Konstantinos Koukoulakis ◽  
Evangelos Bakeas ◽  
Athanassios I. Philippopoulos
Keyword(s):  
Catalytic Activity ◽  
Active Catalyst ◽  
Mass Spectrometric ◽  
Transfer Hydrogenation ◽  
High Yield ◽  
Spectrometric Analysis ◽  
Spectroscopic Methods ◽  
Conductivity Measurements ◽  
Octahedral Environment ◽  
Ft Ir

AbstractThe ruthenium(II) complex cis-[RuCl2(PPh3)2(L1)] (1) where L1 = 2-(2’-pyridyl)quinoline was obtained in high yield from the reaction of [RuCl2(PPh3)3] with L1. The new compound was characterized by different spectroscopic methods including FT-IR, UV-Vis, NMR (1H, 31P) spectroscopy along with a mass spectrometric analysis (ESI-MS) and conductivity measurements. 31P NMR spectroscopy provided evidence that the two PPh3 ligands are orientated trans to each other in an octahedral environment. Complex (1) was tested in the transfer hydrogenation of various ketones in 2-propanol at 82 oC. The catalytic activity of (1) displayed quantitative conversions for benzophenone and 4-chloroacetophenone.

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