Tadao Numata

Interconversion between the Azoxyglycosides by Cycad Emulsin:Studies on Some New Azoxyglycosides of Cycas revoluta Thunb. Part III

glycoside, neocycasin C, is also produced. In this case, it is noteworthy that neocycasin A, containing a ƒÀ-1.3g lucosyl linkage, is predominantly produced from cycasin as substrate, although in the hitherto reported transglucosylation 4, 5) a ƒÀ-1.6 or 1.4 linkage was mainly formed by emulsins obtained from various origins. The cycad emulsin employed here is an acetone-dried preparation obtained from the cycad seeds by the tannic acid precipitation methods 6)

Studies on Some New Azoxy Glycosides of Cycas revoluta Thunb.: Part I. On Neocycasin A, β-Laminaribiosyloxyazoxymethane

The isolation of a new glycoside, named here as neocycasin A, with use of carbon chromatography, is described. It is one of a series of aliphatic azoxy glycosides, found in the seeds of Japanese cycad together with cycasin which is β-glucosyloxyazoxymethane as reported previously. The glycoside monohydrate gives m.p. 162° ~ 163° (decomp.), − 35.1°; its heptaacetylate, m.p. 142° ~ 143°, − 55.5°, from which octaacetyl-β-laminaribiose is isolated. On the basis of examination of the products obtained from partial or complete hydrolysis, and spectroscopic measurements, neocycasin A is concluded to be β-laminaribiosyloxyazoxymethane, i.e. 3-O-β-d-glucopyranosylcycasin.