Sugar beets, araban

Since L-arabinose is a constituent unit of many natural products a number of methylated derivatives of this sugar have been isolated by the hydrolysis of methylated polysaccharides. Thus methylated peanut (Arachis hypogea) araban and sugar beet araban give trimethyl-L-arabofuranose, 2,3-dimethyl-L-arabinose and 2-methyl-L-arabinose in equal proportions.84 From methylated gum arabic trimethyl-L-arabo-furanose and 2,5-dimethyl-L-arabinose have been isolated.85 These same compounds have also been isolated from methylated cherry gum86 and methylated damson gum,87 whereas methylated mesquite gum88 affords 3,5-dimethyl- and 2,3,5-trimethyl-L-arabinose on hydrolysis. 

C10H18O9 282.247 Isol. from partial acid hydrolysates of Virgilia oroboides gum, from stem mucilage of Opuntia ficus-indica (Indian fig) and of sugar beet araban. 

Formed on partial acid hydrolysis of sugar beet araban and certain plant gums, e.g. Acaciapycnantha gum and Rhizophora mangle gum. Md +94 (H2O). Phenylosazone Mp 200°. 

Pectic Substances. Part VIII. The Araban Component of Sugar-beet Pectin, E. L. Hirst and J. K. N. Jones,/. Chem. Soc., (1948) 2311-2313. 

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