D-fructose Dianhydrides from Natural Sources

Di-d-fructose Dianhydrides from Natural Sources 1. Isolation of Di-D-fructose Dianhydrides from Higher Plants 

In 1933, Schlubach and Knoop32 isolated a di-D-fructose dianhydride from Jerusalem artichoke and tentatively identified it as difructose anhydride I [a-D-Fru/-1,2 2,1 - 3-D-Fn / (5)]. Alliuminoside ( -D-fructofuranose- -D-fructofura-nose 2,6 6,2 -dianhydride) was isolated from tubers of Allium sewertzowi by Strepkov33 in 1958. Uchiyama34 has demonstrated the enzymic formation of a-D-Fru/-1,2 2,3 -(3-D-Fru/ [di-D-fructose anhydride III (6)] from inulin by a homogenate of the roots of Lycoris radiata Herbert. 

The biosynthesis and degradation of fructans by microbial organisms has been reviewed in detail recently.35 Additionally, a review of the production of di-D-fructose dianhydrides from inulin and levan by enzymes has been published in Japanese.36 This account is therefore limited to a general overview. 

An extracellular enzyme [levan fructotransferase, (EC 2.4.1.10)] that carries out an intramolecular transfructosylation upon levan to produce (3-D-Fru/-2,6 6,2 -f)-D-Fru/ [difructose anhydride IV (7)] has been identified in A. ure-afaciens.54,55 

An extracellular inulin fructotransferase that results in the formation of a-D-Fru/-1,2 2,1 -(3-D-Fru/ [difructose anhydride I (5)] has been purified from Arthrobacter globiformis S14-3,65,66 from Arthrobacter sp. MCI-249367 and from Streptomyces sp. MCI-2524.68 

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