Study of the long-term action of a Ginkgo biloba extract on vigilance and mental performance as determined by means of quantitative pharmaco-EEG and psychometric measurements.

In: Arzneimittelforschung (1985) 35(9):1459-65

Gonda R Takeda K Shimizu N Tomoda M

Characterization of a neutral polysaccharide having activity on the reticuloendothelial system from the rhizome of Curcuma longa.

In: Chem Pharm Bull (Tokyo) (1992 Jan) 40(1):185-8

A neutral polysaccharide, named ukonan D, was isolated from the rhizome of Curcuma longa L. It produced a single band on electrophoresis and a single peak on gel chromatography, and its molecular mass was estimated to be 28, 000. It showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test. Ukonan D is composed of L-arabinose: D-galactose: D- glucose: D-mannose in the molar ratio of 1:1:12:0.2, in addition to small amounts of peptide moiety. Methylation analysis, carbon-13 nuclear magnetic resonance and enzymic degradation studies indicated that its structural features include mainly both alpha-1, 5-linked L- arabino-beta-3, 6-branched D-galactan type and alpha-4, 6-branched D- glucan type structural units. The influence of degradation with alpha- amylase followed by the elimination of glucan side chains on its immunological activity was discussed.

Gonda R Tomoda M Ohara N Takada K

Arabinogalactan core structure and immunological activities of ukonan C, an acidic polysaccharide from the rhizome of Curcuma longa.

In: Biol Pharm Bull (1993 Mar) 16(3):235-8

Controlled Smith degradation of ukonan C, a phagocytosis-activating polysaccharide isolated from the rhizome of Curcuma longa L., was performed. The reticuloendothelial system-potentiating, anti- complementary and alkaline phosphatase-inducing activities of ukonan C and its degradation products were investigated. Methylation analyses of the primary and secondary Smith degradation products and of a de-arabinosylated product indicated that structural features of the arabinogalactan core of ukonan C include a backbone chain composed of beta-1, 3-linked D-galactose and beta-1, 4-linked D-xylose. All of the galactose units in the backbone carry side chains composed of beta-1, 6-linked D-galactosyl residues with or without terminal alpha-L-arabinose units at position 3. Ukonan C showed remarkable effects on both reticuloendothelial system-potentiating and alkaline phosphatase-inducing activities. Periodate oxidation caused a decrease in or disappearance of the immunological activities, but the controlled Smith degradation product having the arabinogalactan core structure of polysaccharide showed a pronounced effect on anti- complementary activity.

Gonda R Tomoda M Takada K Ohara N Shimizu N

The core structure of ukonan A, a phagocytosis-activating polysaccharide from the rhizome of Curcuma longa, and immunological activities of degradation products.

In: Chem Pharm Bull (Tokyo) (1992 Apr) 40(4):990-3

The controlled Smith degradation of ukonan A, a phagocytosis- activating polysaccharide isolated from the rhizome of Curcuma longa L., was performed. The reticuloendothelial system-potentiating, anti- complementary and alkaline phosphatase-inducing activities of ukonan A and its degradation products were investigated. Methylation analyses of both the primary and the secondary Smith degradation products indicated that the core structural features of ukonan A include a backbone chain mainly composed of beta-1, 3-linked D- galactose, beta-1, 4-linked D-xylose and alpha-1, 2-linked L-rhamnose residues. All of the galactose units in the backbone carry side chains composed of alpha-L-arabino-beta-D-galactosyl or beta-D- galactosyl residues at position 6. Ukonan A has a remarkable effect on each of the three kinds of immunological activities. Periodate oxidation caused pronounced decrease or disappearance of the activities, but the controlled Smith degradation product having the core structure of polysaccharide showed considerable restoration of these activities.