Lamellarin-S: a New Aromatic Metabolite From an Australian Tunicate, Didemnum sp.

1996 ◽  
Vol 49 (6) ◽  
pp. 711 ◽  
Author(s):  
S Urban ◽  
RJ Capon
Keyword(s):  
Spectroscopic Analysis ◽  
K 12 ◽  
Structure Class

An Australian tunicate Didemnum sp. has yielded a new alkaloid lamellarin-S (1) along with the known compound lamellarin-K (12). Of this structure class, lamellarin-S (1) is the first example that demonstrates atropisomerism , and its structure was secured by spectroscopic analysis.

Alkyl and Alkenyl Resorcinols From an Australian Marine Sponge, Haliclona Sp (Haplosclerida : Haliclonidae)

1991 ◽  
Vol 44 (10) ◽  
pp. 1393 ◽  
Author(s):  
RA Barrow ◽  
RJ Capon
Keyword(s):  
Natural Products ◽  
Marine Sponge ◽  
Spectroscopic Analysis ◽  
Chemical Degradation ◽  
Plant Source ◽  
Marine Plant ◽  
Plant Sources ◽  
Structure Class

Eleven alkyl and alkenyl resorcinols have been isolated from the Australian marine sponge Haliclona sp. Three of these, (3), (5) and (10), have previously been described from Australian terrestrial and marine plant sources. The remaining eight, (13)-(20), are new natural products whose structures have been secured by a combination of spectroscopic analysis and chemical degradation. This report represents the first account of this structure class being isolated from a non-plant source.

Lamellarins O and P: New Aromatic Metabolites From the Australian Marine Sponge Dendrilla cactos

1994 ◽  
Vol 47 (10) ◽  
pp. 1919 ◽  
Author(s):  
S Urban ◽  
MS Butler ◽  
RJ Capon
Keyword(s):  
Marine Sponge ◽  
Spectroscopic Analysis ◽  
Pyrrole Ring ◽  
Ring System ◽  
Aromatic Rings ◽  
Partial Synthesis ◽  
Structure Class

A specimen of Dendrilla cactos collected during trawling operations in Bass Strait, Australia, has yielded two new alkaloids, lamellarin-O (17) and lamellarin-P (18). Both these metabolites are examples of the lamellarin structure class, previously reported from tunicates and a mollusc; however, in these examples the pyrrole ring system is not fused to adjacent aromatic rings. The structures of (17) and (18) were secured by spectroscopic analysis and partial synthesis.

The Bastadins Revisited: New Chemistry From the Australian Marine Sponge Ianthella basta

1991 ◽  
Vol 44 (2) ◽  
pp. 287 ◽  
Author(s):  
MS Butler ◽  
TK Lim ◽  
RJ Capon ◽  
LS Hammond
Keyword(s):  
Great Barrier Reef ◽  
Marine Sponge ◽  
Structure Elucidation ◽  
Spectroscopic Analysis ◽  
Oxidative Cyclization ◽  
Barrier Reef ◽  
Structure Class

A specimen of Ianthella basta, collected from the Great Barrier Reef, Australia, has been found to contain the recently reported tetramer of bromotyrosine , bastadin-9 (6a), along with a new example of this structure class, bastadin-12 (9a). The structure for bastadin-12 (9a) was confirmed by detailed spectroscopic analysis and derivatization, and represents the first reported example of this structure class derived from an alternative oxidative cyclization . As earlier biosynthetic arguments to the structure elucidation of some bastadins were based on the premise that only one cyclization pathway was possible (leading to 13,32-dioxa-4,22-diazabastarane), the discovery of (9a) introduces an added dimension to the identification of new and known bastadins. Also isolated and identified as their methyl ethers were two new dimers of bromotyrosine, hemibastadin-1 (10) and hemibastadin-2 (11).

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.

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