Xyloglucan derivatives

Various reaction conditions and times have been employed for both acetylation and depolymerization. Acetylation has been performed with pyridine/acetic anhydride for 8 h at 100°C (Kocourek and Ballou, 1969), two days at room temperature (Kooiman, 1961), a combination of ambient and high temperatures (O Neill and Selvendran, 1983) or with the inclusion of dimethyl formamide (Stewart et al., 1968). The xyloglucan from the cell walls of runner bean was acetylated with acetic anhydride-pyridine (1 1 v/v) for 12 h at 20°C followed by 8 h at 100°C (O Neill and Selvendran, 1983). Acetolysis has been carried out in glacial acetic acid/ acetic anhydride/concentrated sulfuric acid (1 1 0.1 v/v) for 13 h at 40°C (Kocourek and Ballou, 1969) or with acetic anhydride/concentrated sulfuric acid for 1 h at 0 C followed by two weeks at 50°C (Kooiman, 1961). Acetolysis of the acetylated xyloglucan derived from runner bean cell walls was performed with acetic anhydride-glacial acetic acidconcentrated sulfuric acid (1 1 0.1 v/v) for 12 h at 37°C, and a number of fragments was characterized (O Neill and Selvendran, 1983). For a discussion of the relative merits of the different procedures for acetolysis, the reader should consult Stewart et al. (1968). 

GA3 gibberellic acid XGOs xyloglucan-derived oligosaccharides... 

Warneck, H.M., Haug, T., and Seitz, H.U. 1996. Activation of cell wall-associated peroxidase isoenzymes in pea epicotyls by a xyloglucan-derived non a saccharide. J. Exp. Bot., 47 1897-1904. 

From tamarind seed xyloglucan, carboxymethyl derivatives with different levels of DS were prepared in isopropanol medium [440]. Swelling power, solubihty and tolerance to organic solvents of the derivatives increased with increasing DS. The interaction properties of the unmodified xyloglucan with calcium chloride and sodiiun tetraborate were found to be reversed upon car-boxymethylation. 

Marry M., Cavalier, D.M., Schnurr, J.K., Netland, J., Yang, Z., Pezeshk, V., York, W.S., Pauly, M. and White, A.R. (2003) Structural characterization of chemically and enzymatically derived standard oligosaccharides isolated from partially purified tamarind xyloglucan. Carbohydrate Polymers 51(3), 347-356. 

Vierhuis, E., York, W. S., Kolli, V S., Vincken, J., Schols, H. A., Van Alebeek, G. W., and Voragen, A. G., Structural analyses of two arabinose containing oligosaccharides derived from olive fruit xyloglucan XXSG and XLSG. Carbohydr Res 2001, 332 (3), 285-97. 

U.S. 2003/ 0022807 01/2003 Wilting et al.l Novozymes North America, Inc. Removing or bleaching soils/stains derived from xyloglucan-containing food or plants, select binding of soils on cellulosic fabrics... 

It was stated earlier that some volatile derivatives may be lost on sample workup. We have found that nonreducing terminal xylose derivatives are underestimated with most of the xyloglucans that we have examined. 

The methods of Valent et al. (1980) and McNeil et al. (1982b) have been applied to the rigorous characterization of a nonasaccharide derived from the enzymic degradation of sycamore cell wall xyloglucan. Following partial acid hydrolysis and workup, 16 alkylated oligosaccharide-alditols were isolated by reverse-phase HPLC, but only 12 were sufficiently pure to be unambiguously characterized. 

Growth-regulating oligosaccharins have been derived principally from two major polymeric sources xyloglucan and pectic polysaccharides. 

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