scholarly journals Coumarinolignans from the Seeds ofAnnona squamosaLinn.

2009 ◽  
Vol 6 (2) ◽  
pp. 518-522 ◽  
Author(s):  
Rakesh Ranjan ◽  
Mahendra Sahai
Keyword(s):  
Spectroscopic Analysis ◽  
Annona Squamosa ◽  
Position Isomer

Phytochemical investigations ofAnnona squamosaseeds have led to the isolation of three lignans consisting of coumarin moiety, cleomiscosin A (1), cleomiscosin B (2) and cleomiscosin C (3). Their structures were arrived at by detailed spectroscopic analysis. Cleomiscosin A and cleomiscosin B are position isomer.

scholarly journals Anthelmintic acetogenin from Annona squamosa L. Seeds

2008 ◽  
Vol 80 (2) ◽  
pp. 271-277 ◽  
Author(s):  
Marta M.C. Souza ◽  
Claudia M.L. Bevilaqua ◽  
Selene M. Morais ◽  
Cícero T.C. Costa ◽  
Ana R.A. Silva ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Haemonchus Contortus ◽  
Spectroscopic Analysis ◽  
Ethyl Acetate Extract ◽  
Anthelmintic Activity ◽  
Northeastern Brazil ◽  
Annona Squamosa ◽  
Egg Hatching

Annona squamosa seeds extracts showed anthelmintic activity against Haemonchus contortus, the main nematode of sheep and goat in Northeastern Brazil. A compound 1 was isolated from ethyl acetate extract and inhibited the egg hatching of H. contortus at 25 mg ml-1. The structure of 1 was determined as a C37 trihydroxy adjacent bistetrahydrofuran acetogenin based on spectroscopic analysis.

scholarly journals Leishmanicidal activity and cytotoxicity of compounds from two Annonacea species cultivated in Northeastern Brazil

2011 ◽  
Vol 44 (5) ◽  
pp. 567-571 ◽  
Author(s):  
Nadja Soares Vila-Nova ◽  
Selen Maia de Morais ◽  
Maria José Cajazeiras Falcão ◽  
Lyeghyna Karla Andrade Machado ◽  
Cláudia Maria Leal Beviláqua ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Spectroscopic Analysis ◽  
Cytotoxicity Assay ◽  
Northeastern Brazil ◽  
Raw 264.7 Cells ◽  
Raw 264.7 ◽  
Annona Muricata ◽  
Annona Squamosa ◽  
Leishmania Chagasi ◽  
Ic50 Values

INTRODUCTION: Visceral leishmaniasis is endemic in 88 countries, with a total of 12 million people infected and 350 million at risk. In the search for new leishmanicidal agents, alkaloids and acetogenins isolated from leaves of Annona squamosa and seeds of Annona muricata were tested against promastigote and amastigote forms of Leishmania chagasi. METHODS: Methanol-water (80:20) extracts of A. squamosa leaves and A. muricata seeds were extracted with 10% phosphoric acid and organic solvents to obtain the alkaloid and acetogenin-rich extracts. These extracts were chromatographed on a silica gel column and eluted with a mixture of several solvents in crescent order of polarity. The compounds were identified by spectroscopic analysis. The isolated compounds were tested against Leishmania chagasi, which is responsible for American visceral leishmaniasis, using the MTT test assay. The cytotoxicity assay was evaluated for all isolated compounds, and for this assay, RAW 264.7 cells were used. RESULTS: O-methylarmepavine, a benzylisoquinolinic alkaloid, and a C37 trihydroxy adjacent bistetrahydrofuran acetogenin were isolated from A. squamosa, while two acetogenins, annonacinone and corossolone, were isolated from A. muricata. Against promastigotes, the alkaloid showed an IC50 of 23.3 µg/mL, and the acetogenins showed an IC50 ranging from 25.9 to 37.6 µg/mL; in the amastigote assay, the IC50 values ranged from 13.5 to 28.7 µg/mL. The cytotoxicity assay showed results ranging from 43.5 to 79.9 µg/mL. CONCLUSIONS: These results characterize A. squamosa and A. muricata as potential sources of leishmanicidal agents. Plants from Annonaceae are rich sources of natural compounds and an important tool in the search for new leishmanicidal therapies.

Characterization of Chemical Impurities in Glutaraldehyde

1975 ◽  
Vol 33 ◽  
pp. 620-621
Author(s):  
B. J. Grenon ◽  
A. J. Tousimis
Keyword(s):  
Glutaric Acid ◽  
Spectroscopic Analysis ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Impurity Component ◽  
Chemical Impurities ◽  
Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

Elemental analysis of human erythrocytes

1989 ◽  
Vol 47 ◽  
pp. 242-243
Author(s):  
S. A. Livesey ◽  
A. A. del Campo ◽  
E. S. Griffey ◽  
D. Ohlmer ◽  
T. Schifani ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Elemental Analysis ◽  
Human Erythrocyte ◽  
Spectroscopic Analysis ◽  
Model System ◽  
Human Erythrocytes ◽  
List Type ◽  
Chemical Fixation ◽  
Ethanol Dehydration ◽  
Lowicryl K4m

The aim of this study is to compare methods of sample preparation for elemental analysis. The model system which is used is the human erythrocyte. Energy dispersive spectroscopic analysis has been previously reported for cryofixed and cryosectioned erythrocytes. Such work represents the reference point for this study. The use of plastic embedded samples for elemental analysis has also been documented. The work which is presented here is based on human erythrocytes which have been either chemically fixed and embedded or cryofixed and subsequently processed by a variety of techniques which culminated in plastic embedded samples.Heparinized and washed erythrocytes were prepared by the following methods for this study :(1). Chemical fixation in 4% paraformaldehyde/0.25% glutaraldehyde/0.2 M sucrose in 0.1 M Na cacodylate, pH 7.3 for 30 min, followed by ethanol dehydration, infiltration and embedding in Lowicryl K4M at -20° C.

Chromatographic and spectroscopic analysis of the fluorescent compounds derived from monosaccharides on HPTLC-NH2plates

2002 ◽  
Vol 15 (6) ◽  
pp. 449-453 ◽  
Author(s):  
G. Grygierczyk ◽  
Walter Fischer ◽  
M. Sajewicz ◽  
P. Kuś ◽  
R. Wrzalik ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Fluorescent Compounds

A Peptoid with Extended Shape in Water

2019 ◽  
Author(s):  
Jumpei Morimoto ◽  
Yasuhiro Fukuda ◽  
Takumu Watanabe ◽  
Daisuke Kuroda ◽  
Kouhei Tsumoto ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Biomolecular Recognition ◽  
Biological Application ◽  
New Class ◽  
Proteolytic Resistance ◽  
Pharmacokinetic Properties ◽  
Optically Pure ◽  
Three Dimensional Space

<div> <div> <div> <p>“Peptoids” was proposed, over decades ago, as a term describing analogs of peptides that exhibit better physicochemical and pharmacokinetic properties than peptides. Oligo-(N-substituted glycines) (oligo-NSG) was previously proposed as a peptoid due to its high proteolytic resistance and membrane permeability. However, oligo-NSG is conformationally flexible and is difficult to achieve a defined shape in water. This conformational flexibility is severely limiting biological application of oligo-NSG. Here, we propose oligo-(N-substituted alanines) (oligo-NSA) as a new peptoid that forms a defined shape in water. A synthetic method established in this study enabled the first isolation and conformational study of optically pure oligo-NSA. Computational simulations, crystallographic studies and spectroscopic analysis demonstrated the well-defined extended shape of oligo-NSA realized by backbone steric effects. The new class of peptoid achieves the constrained conformation without any assistance of N-substituents and serves as an ideal scaffold for displaying functional groups in well-defined three-dimensional space, which leads to effective biomolecular recognition. </p> </div> </div> </div>

Spectroscopic Analysis of NiOx Catalysts for Water Oxidation

2019 ◽  
Author(s):  
Sacha Corby ◽  
James Durrant ◽  
Laia Francas ◽  
Shababa Selim ◽  
Sven Tengeler ◽  
...  
Keyword(s):  
Water Oxidation ◽  
Spectroscopic Analysis
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