Studies on a Galactan from Tension Wood of Beech (Fagus silvatica L.).

Meier, Hans; Dahlén, Monica; Frisell, Christer

doi:10.3891/acta.chem.scand.16-2275

Cited by 52 publications

(15 citation statements)

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“…The galactose yield remained low in this context (Figure 3a), which implied the presence of glucomannan in the lsW (Melvin and Stewart 1969). The presence of galactan was not indicated in the RW in the present study (Meier 1962;Kuo and Timell 1969;Altaner et al 2007).…”

Section: Reaction Wood Ligninmentioning

confidence: 60%

Characteristics of guaiacyl-syringyl lignin in reaction wood in the gymnosperm Gnetum gnemon L.

Nawawi¹,

Syafii

Akiyama³

et al. 2016

Holzforschung

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Gnetum gnemon L. is a unique gymnosperm species showing angiosperm-like features in terms of its morphology and chemical composition of the cell wall. Xylan is the main hemicellulose component, and its lignin is primarily composed of syringyl (S) and guaiacyl (G) units and small amounts of p-hydroxyphenyl (H) units. In the present study, in addition to branch, root, bark, and leaf samples, the reaction wood (RW) taken from the leaning stem of G. gnemon, was investigated mainly by alkaline nitrobenzene oxidation, ozonation and NMR spectroscopy. The leaning stem was wider on the lower side of the wood stem (lsW) than on the upper side (usW), similar to the case for compression wood (CW) in gymnosperms. The usW contained lignin with a higher S/G ratio, and β-O-4 structure had a higher erythro/threo ratio, while both ratios decreased around the periphery of the stem towards the lsW. The lignin content was higher towards the lsW. Overall, the lignin composition in the RW of this tree was similar to that in the tension wood of angiosperms. The H-units were minor components in the lignin, but the content was higher towards the lsW, which resembles the distribution of the H-units in a gymnosperm CW.

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Section: Reaction Wood Ligninmentioning

confidence: 60%

Characteristics of guaiacyl-syringyl lignin in reaction wood in the gymnosperm Gnetum gnemon L.

Nawawi¹,

Syafii

Akiyama³

et al. 2016

Holzforschung

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“…I t is known, however, that the primary wall and middle lamella in xvood cells are rich in galacturonic acid, galactose, and arabinose residues (12,(28)(29)(30). An a-(1 -+ 2)-linked-D-galacturonosyl rhamnose has been isolated from pine (31,32) and beech (33) woods. The presence in wood of pectic material similar to that found in the fir bark is therefore quite likely.…”

Section: Discussionmentioning

confidence: 99%

A Study of the Pectin Present in the Bark of Amabilis Fir (Abies Amabilis)

Bhattacharjee¹,

Timell²

1965

Can. J. Chem.

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X pectic material has bee11 isolated frorn the bark of Abies anzabilis (Do~rgl.) F~r b e s in a yield of 2y0. On hydrolysis it yielded D-galact~ironic acid, ~-galactose, and L-arab~nose in a ratio of S5:4:ll, and also traces of rhanlllose. The product, when submitted to several conventional fractionation methods, a p p p r e d homogeneous. Further resolution could b e effected by acidihcation of an aqueous solut~on of the pectin, followed by ultracentrifugat~on. 'The insoluble portion (50y0) was an electrophoretically hon~ogeneous galactzrronan with [ a ]~ +246'. The material remaining in solution (30y0), here referred to as a pectic acid, had [ a ]~ +225" and on hydrolysis gave D-galacturonic acid, D-galactose, and L-arbabinose in a ratio of 74:7:19, as well as traces of rhamnose.The structure of the galacturonan was established by partial hydrolysis and methylatio~~. I t consisted of a-D-galacturonic acid residues linked together by ( I --t 4)-glycosidic bonds t o a linear macromolecule. T h e same techniques were applied to the pectic acid. While a unique str~rctural formula could not bc assigned in this case, one probable alternative involved a framework of (1 + 4)-linked a-D-galacturoIIic acid residues together with a few residues of 1,2,4-linlced L-rhamnose. Some of the galacturollrc acid units carried a t C-2 and C-3 side chains which were terminated by D-galactopyranose and L-arabinofuranose residues. A few of the latter also occurred as inner units, probably in the side chains. This appears to be the hrst t i~u e a pectic material has been resolved into a galacturonan and a pectlc a c~d containing the four sugar residues usually found in pectitls. I t is probable that the pectin occurring to a limited extent in wood has a similar composltlon.In previous investigations several polysaccharides were isolated from the bark of amabilis fir (Abies amabilis) ( I ) , namely a cellulose (2), a galactoglucoinannan (3), a gluco~nannan (4), and a xylan (5). The present study is concerned with the pectic substances also present in this bark. Pectin has previously been isolated from both wood and bark by Anderson and his co-worlters (6-9). Painter and Purves (10) obtained pectin in a yield of 770 froln white spruce inner bark. Similarly, inner bark of white birch has yielded a pectin in a yield of 3-4y0 (11). During the early stages of cell differentiation, the primary wall and the middle lamella consist largely of pectin. The pectic substances of cell walls in the phloem, cambial, sapwood, and heartwood regions have recently been studied by Thornber and Northcote (12).The pectic group of polysaccharides is based on residues of D-galacturonic acid, Dgalactose, L-arabinose, and L-rhamnose, with the galacturonic acid usually, albeit not always, predominating. A polymer containing only D-galacturonic acid residues (a galacturonan) seems to have been isolated only on one occasion, namely from sunflower heads (13). Lately, it has become evident that most of the so-called pectic acids probably also contain neutral...

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“…The complex galactans built mainly from β-(14)-galactose were found in tension wood fibers in 60-ties of the XX th century [79,80], though the linkage with the RG I backbone was not proved at that time. The content of galactose was even suggested as an indicator of the extent of the G-layer development [81].…”

Section: Matrix Polysaccharides In Cellulosic Fibersmentioning

confidence: 99%