Avocado, heptose from

H. H. Sephton and N. K. Richtmyer, The isolation of a second octulose and of a heptose from the Avocado D-g/ycero-L-ga/acto-octulose and D-g/ycero-D-ga/acto-heptose, J. Org. Chem., 28 (1963) 1691-1694. 

Heptoses and higher sugars may similarly be separated, and the identity of D-erythro-c-galacto-nonulose in avocado was determined by comparison of its gas-chromatographic behavior with that of a synthetic sample.336 Higher sugars have been separated, and identified, from avocado,151 Pichi,337 opium poppy,338 and bacterial lipopoly-saccharides.339... 

The ketose has been synthesized from D-manno-D-(/ala-heptose by the Lobry de Bruyn enolization reaction. The presence of both perseitol and the ketoheptose in the avocado fruit in the free state, and the absence of any fermentable sugar, seem to indicate that the carbohydrate metabolism of this tree is of a type not recognized previously. 

Occurrence and preparation. In the first report of its occurrence,248 D-glycero-L-galacto-octulose (63) was obtained from the pulp of ripe avocados (Calavo, Hass variety) by extraction and chromatography (see under D-g/ycero-D-ga/acto-heptose). The octulose was also isolated from the dried roots of Primula officinalis Jacq. 

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