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From the lipopolysaccharide of Escherichia coli U41/14 (serotype 03 :K2ab(L) : H2) an unusual amino sugar was isolated. By sequential oxidation with periodate and hypoiodite and by oxidation with periodate, followed by detection of acetaldehyde formed, the ammo sugar was characterized as a 2-amino- dideoxyaldose. The hydrochloride of the amino sugar, in comparison to those of 2-amino-2, 6-dideoxy-D-glucose, 2-amino-2,6-dideoxy-L-galactose, 2-amino-2, 6-dideoxy-D-mannose, 2-amino-2, 6-di- deoxy-D-allose, and 2-amino-2, 6-dideoxy-D-gulose, was studied with aid of ion exchange column chromatography. The N-acetylated amino sugar was compared with the N-acetylated reference amino sugars with regard to their relative mobihties in paper chromatography. The ammo sugar alcohols and reference amino sugar alcohols were studied using paper electrophoresis in molybdate buffer. On the basis of the results obtained the unknown amino sugar was identified as 2-amino- 2,6-dideoxymannose (rhamnosamine). Its optical rotation showed it to be of the L-configuration. This is the first report on the natural occurrence of L-rhamnosamine. [ABSTRACT FROM AUTHOR]

The ethanolic extract of 8-week-old parsley plants was chromatographed on Dowex-1×2 with a concave gradient using the buffer system of Hurlbert. After further purification on carboncelite columns, paper chromatography and high-voltage electrophoresis, 120 μmoles of a homogeneous UDP­sugar fraction were obtained. The sugars present in this fraction were identified after acid or enzymatic hydrolysis (Crotalus adamanteus venom, acid phosphatase) by various chemical and enzymatic tests. A modified Dische test which is specific for apiose and a quantitative deterruination of D­xylose with D­glucose—oxidase were developed. According to the analytical investigations the UDP­sugar fraction had the following composition (μmol): UDP-D-glucose (84), UDP-D-galactose (27), UDP-D-xylose (4), UDP-L-arabinose (2), UDP­fructose (0.42), UDP-L-rhamnose (2.4), and UDP­apiose (0.18). The presence of UDP­apiose in parsley strongly corroborates the proposed biosynthetic pathway for the formation of D-apiose via DDP-D-glucuronic acid. [ABSTRACT FROM AUTHOR]