| Summary: | 博士 === 國立臺灣大學 === 農業化學系 === 81 === This thesis containes two parts. Part 1 is concerned with the
structural, conformational and biological analyses of
polysacch- arides from the broth of Ganoderma tsugae. Part 2
is concerned with the application of piezoelectric quartz
crystal for develop- ment of biosensor in liquid phase. Part 1.
The extracellular polysaccharides were prepared by the
precipitation from the broth of Ganoderma tsugae with ethanol,
after 14 days of shaking culture. The yield of polysaccharides
was about 2.5g/L. Only glucose was found in the acid
hydrolyzate of the polysaccharide by HPLC. The polysaccharide
was submitted to methylation, GLC-MS and 13C NMR analyses and
was identified as a β-1,3-D-glucan having one branch length
was one glucosyl unit. Gel chromatography with Fractogel HW-65(
S) was applied for the fractionation of the β-1,6;1,3-glucan.
One fraction (mw 219,500) was collected when eluented with 0.5%
NaCl, and two fractions (mw 219,500 and 72,500) were collected
with 0.5% NaOH. The thermal conformation was examined by DSC.
One endothermic peak was observed at 131℃, which was assigned
to the conformational tran- sition of the triple-helix into
single chain. That thermal dena- turation of native triple-
helix into the single chains was comp- lete in 10min at 150℃,
had been proved by gel chromatography. These results showed
that the polysaccharide isolated from G. tsugae is similar to
the structur and conformation of schizophy- llan, an antitumor
polysaccharide. Schizophyllan which has marked antitumor
activity in hosts appears to represent host defense
potentiators. The alternative complement pathway was assumed to
be important in the first step of host defense mechanisms. The
activation of human alternative complement pathway by
β-1,6;1,3- D-glucan of G. tsugae was proved by haemolytic
analysis.
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