ˈpentəˌsan noun
( -s )
Etymology: International Scientific Vocabulary pentose + -an
: any of a class of polysaccharides (as xylan or araban) that yield only pentoses on hydrolysis and that are widely distributed in plants (as in corncobs, oat hulls, wood, straw, mesquite gum, gum arabic) — compare furfural , hemicellulose