Kotaro Nishida

Studies on Cycasin, a New Toxic Glycoside, of Cycas revoluta Thunb: Part V. Quantitative Determination of Cycasin in Cycad Seeds

Quantitative paper chromatography of cycasin is described, where the cycasin and sugars separated on the paper are eluted out and determined, according to the colorimetric micro analysis of sugars by Plumel. The contents of cycasin and free sugars contained in both premature and matured cycad seeds determined by this method are presented.

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.

Studies on Cycasin, a New Toxic Glycoside, of Cycas revoluta Thunb:Part VI. Polarography of Cycasin

The polarographic behaviors and the determination of cycasin, glucosyloxyazoxymethane, are described here. In the whole pH range, cycasin shows a reduction wave, which is considered to be due to the reduction of its aliphatic azoxy group. The polarograms from pH 4 to 7 run in two steps, and two electrode reaction mechanisms may be infered. The following facts are observed on the limiting current at pH 1 or 7: It is controlled by the diffusion process, and its temperature coefficient has a value resembling that of the usual diffusion current. The wave height shows a linear proportionality to the concentration of cycasin. The contents of cycasin in cycad seeds, determined polarographically, are presented, and compared with the results obtained by the paper chromatographic method.

On the Chemical Composition, especially Organic Bases of “Di-Saké”

The chemical composition of the “Di-sake” compared with that of the ordinal “sake” is summarized as follows: (1) In the above experimental results the nitrogenous compounds isolated from 10 litres of “di-sake”, are hypoxanthine-hydrochloride (0.20 g.), arginine nitrate (4.60 g.), cholinechloroaurate (6.75 g.), and ammonia (3.52 g.), while the isolated bases from 25 litres of “sake” by Dr. K. Kurono, are cholinepicrate (3.8 g.), histaminepicrate (0.15 g.), lysinepicrate (0.52 g.) and ammonia (1.3 g.). It is the most great difference that the “di-sake” contains large amount of arginine, which could not be isolated from the “sake”. (2) As regards the general composition, 1 fined great difference between the “di-sake” and the “sake”: in the former, the quantity of reducing sugar (chiefly glucose) and other extractive substances are considerably much more than those of the latter. (3) In the “di-sake”, the amount of non-protein substances is much more than those of the “sake”. (4) The reaction of “di-sake” is almost neutral, but in the “sake” remarkably acidic.