Studies on Lignin and Related Compounds. XXXIV. Acetovanillone and Acetosyringone as Degradation Products of Lignin Sulfonic Acids

1938 ◽  
Vol 60 (3) ◽  
pp. 565-567 ◽  
Author(s):  
Frank Leger ◽  
Harold Hibbert
Keyword(s):  
Degradation Products ◽  
Sulfonic Acids ◽  
Related Compounds

scholarly journals Separation and Quantitation of Alkylphosphocholines and Analogues of Different Liposome Formulations by HPTLC

2001 ◽  
Vol 84 (4) ◽  
pp. 1277-1282 ◽  
Author(s):  
Hannelore Ratz ◽  
Horst Schnell ◽  
Matthias Rischer ◽  
Hans-Jörg Eibl
Keyword(s):  
Quality Control ◽  
Oral Administration ◽  
Thin Layer ◽  
High Performance ◽  
Degradation Products ◽  
Cytostatic Activity ◽  
Chromatographic System ◽  
Liposomal Formulations ◽  
Mobile Phases ◽  
Related Compounds

Abstract High-performance thin-layer chromatographic (HPTLC) analysis of non UV-active phospholipids in biological matrixes is a common method for separation, detection, and quantitation. Liposomes containing new alkylphosphocholines and analogues with enhanced cytostatic activity had been prepared. The liposomal formulations were designed to enable the intravenous application of the alkylphosphocholines and analogues and to reduce dose-limiting toxicities observed after oral administration. For quality control the liposomes were analyzed by HPTLC for content of 1,2-dipalmitoyl-sn-glycero-3-phosphoglycerol (DPPG), cholesterol, alkylphosphocholines, and analogues and their related compounds (main degradation products). Due to the differences in lipophily of the compounds, different mobile phases were necessary to achieve separation. Automated Multiple Development was used to reduce the number of plates and to improve the selectivity and the capacity of the chromatographic system to separate the described alkylphosphocholines and analogues from DPPG and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine in one chromatographic system.

Enterolactone and Other Lignan Metabolites as Taxon-Specifi c Markers in Modern and Ancient Woodrat Middens

2013 ◽  
Vol 68 (7-8) ◽  
pp. 327-335
Author(s):  
David A. Zinniker ◽  
Camille A. Holmgren ◽  
Bernd R. T. Simoneit
Keyword(s):  
Natural Products ◽  
Microbial Communities ◽  
Degradation Products ◽  
Nordihydroguaiaretic Acid ◽  
Structural Elements ◽  
Creosote Bush ◽  
Higher Plant ◽  
Plant Source ◽  
Related Compounds ◽  
Plant Lignans

Diversely sourced degradation products of higher plant lignans were identifi ed in modern and ancient woodrat (Neotoma) middens. The markers indicate extensive chemical modifi cation by intestinal microbial communities of mammals. The observed defunctionalized phenols represent a group of natural products, and their structural elements reveal information about the plant source. The phenols are derived mainly from two precursor types: (1) enterolactone and derivatives from conifer lignans, and (2) 2,3-bis(3’-hydroxybenzyl)butane and related compounds from lignans such as nordihydroguaiaretic acid common in Larrea sp. (e.g. creosote bush)

Lignin and related compounds. VI. A study of variables affecting the hydrogenolysis of spruce wood lignin using a rhodium-on-charcoal catalyst

1978 ◽  
Vol 56 (7) ◽  
pp. 899-902 ◽  
Author(s):  
James M. Pepper ◽  
Punsri Supathna
Keyword(s):  
Degradation Products ◽  
Initial Pressure ◽  
Alkaline Media ◽  
Reaction Conditions ◽  
Spruce Wood ◽  
The Media ◽  
Relative Abundances ◽  
Related Compounds

The effect of reaction conditions on the hydrogenolysis of spruce wood lignin over a rhodium-on-charcoal catalyst has been studied and monitored by the yields of the three major degradation products, 1, 2, and 5. Variables included: initial pressure of hydrogen, amount of catalyst, and acidity–basicity of the media. Little variation occurred under moderate acidic or basic conditions with yields of 18–20% of lignin recovered as monomers. Under strongly acidic or basic conditions both yields and relative abundances changed appreciably. Initial hydrogen pressures less than 500 psig resulted in slightly decreased yields in some cases. In strongly alkaline media similar results were obtained with or without added hydrogen provided the catalyst were present.

Lignin and related compounds. I. A comparative study of catalysts for lignin hydrogenolysis

1969 ◽  
Vol 47 (5) ◽  
pp. 723-727 ◽  
Author(s):  
J. M. Pepper ◽  
Y. W. Lee
Keyword(s):  
Comparative Study ◽  
Raney Nickel ◽  
Lignin Degradation ◽  
Soluble Fraction ◽  
Degradation Products ◽  
Quantitative Estimation ◽  
Liquid Chromatographic Separation ◽  
Lignin Degradation Products ◽  
Liquid Chromatographic ◽  
Related Compounds

A detailed comparative study has been made of the effectiveness of various catalysts for the hydrogenolysis of spruce wood lignin. The catalysts studied were Raney nickel, 10% palladium–charcoal, 5% rhodium–charcoal, 5% rhodium–alumina, 5% ruthenium–charcoal, and 5% ruthenium–alumina. Lignin degradation products were obtained initially as a chloroform-soluble fraction which was then divided and studied as diethyl ether-soluble and -insoluble fractions. Gas–liquid chromatographic separation of the ether-soluble fraction made possible the characterization and quantitative estimation of many of the lower molecular weight lignin degradation products.The data indicate that rhodium, palladium, and a limited amount of Raney nickel produce similar results as do ruthenium and an excess of Raney nickel; however, with the latter catalysts the degradation is more severe. In particular, rhodium–charcoal and palladium–charcoal appear to offer interesting advantages as catalysts for lignin hydrogenolysis.

scholarly journals Development and Validation of RP-UPLC Method for the Determination of Iloperidone, Its Related Compounds and Degradation Products in Bulk and Dosage Form

2014 ◽  
Vol 05 (14) ◽  
pp. 969-981 ◽  
Author(s):  
Shashikant B. Landge ◽  
Sanjay A. Jadhav ◽  
Shrihari P. Vishwambar ◽  
Pavankumar V. Solanki ◽  
Saroj R. Bembalkar ◽  
...  
Keyword(s):  
Dosage Form ◽  
Degradation Products ◽  
Development And Validation ◽  
Related Compounds

Reactivity of triformylmethane. I. Reactions of triformylmethane with selected types of amino compounds

1991 ◽  
Vol 56 (5) ◽  
pp. 1019-1031 ◽  
Author(s):  
Zdeněk Arnold ◽  
Miloš Buděšínský ◽  
Magdalena Pánková
Keyword(s):  
Lewis Acids ◽  
Secondary Amines ◽  
Primary Amines ◽  
Carbamic Acid ◽  
Sulfonic Acids ◽  
Primary Products ◽  
Amino Compounds ◽  
Related Compounds

Reactions of triformylmethane with various types of amino compounds were investigated. Besides with ammonia, triformylmethane reacts spontaneously with primary amines, aminoacids and their esters, urea and related compounds including carbamic acid derivatives. Reactions with amides of carboxylic and sulfonic acids require catalysis with Lewis acids. Primary products are aminomethylenemalonaldehyde derivatives IIIa-IIIv. Reactions of triformylmethane with excess of selected primary amines and two secondary amines (dimethylamine and morpholine) were also studied.

scholarly journals Microbial degradation products from biphenyl-related compounds.

1986 ◽  
Vol 50 (3) ◽  
pp. 681-686 ◽  
Author(s):  
Ichiro TAKASE ◽  
Toshio OMORI ◽  
Yasuji MINODA
Keyword(s):  
Microbial Degradation ◽  
Degradation Products ◽  
Related Compounds
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