�ber den Methoxylgehalt des Fichtenholzes

Wacek, A.; Zeisler, F.; Riegelmayer, P.

doi:10.1007/bf00902302

Cited by 6 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As the aromatic methoxyl in lignin has also been accounted for, the presence of unaccounted for methoxyl in alkali-extracted samples, may be due to small amounts of methoxyl present, probably in an alpha-position of the side-chain. Similarly, the methoxyl lost during Klason treatment of Brauns native lignin isolated from spruce was some-what higher (2.8 per cent) than the aromatic methoxyl lost from Freudenberg's dehydrogenation polymer (2.4 percent, Wacek, Zeisler and Riegelmayer 1954); this may also be due to the instability towards acid of aliphatic lignin methoxyl.…”

Section: Alkali-soluble Ligninmentioning

confidence: 92%

“…It can be shown that alkali-soluble lignin is given very closely by the equation: samples and x and y are the percentages (total lignin methoxyl basis) of lignin methoxyl hydrolyzed off as methanol during acid and alkaline treatments, respectively. If the rates of hydrolysis found by Wacek, Zeisler and Riegelmayer (1954) are substituted for x and 3;, equations ι and 2 simplify to: alkali-soluble lignin and a) -1.084 (fie [0.921 g 0.047…”

Section: Alkali-soluble Ligninmentioning

confidence: 99%

“…Methoxyl unaccounted for in alkaliextracted samples, however, considerably exceeds this value in the case of wood samples and may, therefore, Brought to you by | University of Glasgow Library Authenticated Download Date | 6/29/15 5:54 AM be derived from wood itself. It seems unlikely to come from the polysaccharides, since uronic acids have been fully accounted for and methylated sugars, such as 3-O-methylglucose, are easily demethylated by alkali (Wacek, Zeisler and Riegelmayer 1954).…”

Section: Alkali-soluble Ligninmentioning

confidence: 99%

See 2 more Smart Citations

Determination of Total Lignin, Extraneous Substances and Polysaccharides in Bark and Wood ofAcacia penninervis.I. Lignin and Extraneous Substances

Smelstorius¹,

Stewart²

1974

Holzforschung

View full text Add to dashboard Cite

Section: Alkali-soluble Ligninmentioning

confidence: 92%

Section: Alkali-soluble Ligninmentioning

confidence: 99%

Section: Alkali-soluble Ligninmentioning

confidence: 99%

See 1 more Smart Citation

Determination of Total Lignin, Extraneous Substances and Polysaccharides in Bark and Wood ofAcacia penninervis.I. Lignin and Extraneous Substances

Smelstorius¹,

Stewart²

1974

Holzforschung

View full text Add to dashboard Cite

“…Inzwischen erschienen mehrere Arbeiten verschiedener Autoren (28)(29)(30)(31)(32)(33)(34), in denen der Gesamturonidgehalt ausländischer Hölzer und anderer Pflanzenstoffe meist nach der CO 2 -Abspaltungsmethode bestimmt wurde. T i m eil (35) Meier (50,51) untersuchte die Verteilung der Polysaccharide in den Wandschichten der KiefernhdlzTracheiden und fand wechselnde Mengen Galakturonsäure in der Nullschicht und Methylglucuronsäure in den tieferen Zellwandschichten.…”

Section: Introductionunclassified

Über den Polyuronid-Gehalt einiger deutscher Hölzer und daraus hergestellter Holo- und Hemi-Cellulosen

Jayme¹,

Hahn²

1960

Holzforschung

View full text Add to dashboard Cite

“…So wurde beispielsweise von v. Wacek (1952) (v. Wacek u. Däubner-Rettenbacher 1950) und mit -Hydroxy-propiophenon (v. Wacek u. Zeisler 1952) beobachtet worden, und es ist daher noch unsicher, ob sich das Lignin ebenso verhält. Das Ergebnis schließt jedoch die gleichzeitige Beteiligung anderer C-Atome des Lignins nicht aus.…”

unclassified

Kondensationsreaktionen des Lignins. Umsetzung von Lignin-Modellsubstanzen mit Resorcin und Salzsäure

Nimz¹

1969

Holzforschung

View full text Add to dashboard Cite

Specimens of sapwood and heartwood of green Pinus radiata D. Don were dehydrated in successive changes of ethanol and then embedded in a mixture of methyl and butyl methacrylates. Sections were cut at a thickness of 2 microns, mounted in glycerol and photographed with a Cooke, Troughton and Simms ultraviolet microscope at wavelength 254 nm.It can be seen in Figure that, by comparison with the adjacent and axial tracheids, the ray parenchyma cell walls are non-absorbing to ultraviolet light in the sapwood. In the heartwood (Fig. 2) the ray parenchyma cells walls appear to absorb ultraviolet light as strongly as the adjacent tracheids. From these observations it can be concluded that lignin is absent from the ray parenchyma cell walls of the sapwood. P. radiata belongs to the Diploxylon section of the genus Pinus. These results therefore confirm the observations of Balatinecz and Kennedy (i9 6 ?) * n respect to the absence of lignin from the ray parenchyma cell walls of the sapwood species from this group. The presence in the heartwood of a strongly ultraviolet absorbing material supports the positive tests for lignin obtained by them using standard histological procedures.Kondensationsreaktionen des Lignins Umsetzung von Lignin-Modellsubstanzen mit Resorcin und Salzsäure Zusammenfassung Die Dilignole I, III und VIII reagieren mit Resorcin und n/io HC1 bei 80° C leicht zu Kondensationsprodukten, die je ein Mol Resorcin gebunden enthalten. Die neu gebildete C-C-Bindung geht ausschließlich vom Benzyl-C-Atom des Dilignols aus. In den Dilignolen I und VIII erfolgt zuerst die Spaltung der cyclischen Benzylätherbindungen. Die Bildung von Cumaronstrukturen wird unter den hier gewählten Bedingungen nicht beobachtet. Die Modellversuche zeigen, daß auch im Lignin unter der Einwirkung von Mineralsäuren mit der Bildung von Benzylkationen zu rechnen ist, die für die bekannten Kondensationsreaktionen des Lignins im sauren Milieu verantwortlich zu machen sind. Condensation Reactions of Lignin Reaction of Lignin Model Compounds with Resorcinol and Hydrochloric Acid SummaryThe dilignols I, III and VIII react easily with resorcinol and n/io HC1 at 80° C to condensation products, each of which contains one mole of resorcinol. The newly formed C-C-bond originates only from the benzyl carbon atom of the dilignol. In the dilignols I and VIII at first a splitting of the cyclic benzyl ether bonds takes place. The formation of cumaron structures is not observed under the chosen conditions. These experiments with model compounds show that the formation of benzyl cations, under the influence of mineral acids, takes place in lignin also. The benzyl cations are very probably responsible for the known condensation reactions of lignin with acids.

show abstract

�ber den Methoxylgehalt des Fichtenholzes

Cited by 6 publications

References 0 publications

Determination of Total Lignin, Extraneous Substances and Polysaccharides in Bark and Wood ofAcacia penninervis.I. Lignin and Extraneous Substances

Determination of Total Lignin, Extraneous Substances and Polysaccharides in Bark and Wood ofAcacia penninervis.I. Lignin and Extraneous Substances

Über den Polyuronid-Gehalt einiger deutscher Hölzer und daraus hergestellter Holo- und Hemi-Cellulosen

Kondensationsreaktionen des Lignins. Umsetzung von Lignin-Modellsubstanzen mit Resorcin und Salzsäure

Contact Info

Product

Resources

About