| dc.description.abstract | L-DOPA is an amino acid that is clinically used to treat Parkinson's disease. Even
though synthetic L-DOPA is effective and in high demand, some severe side effects
have been reported from patients on long-term L-DOPA medication. However, direct
consumption of L-DOPA of rich biomass instead chemically synthesized L-DOPA has
been found to eliminate the side-effect. The objectives of this study were to detect
the presence and measure L-DOPA contents in different microbial groups including
slime molds (Physarum polycephalum), puffballs (Lycoperdon perlatum), Xylaria
(Xylaria polipmorpha and Xylaria sp.) by thin-layer chromatography (TLC) and high performance liquid chromatography (HPLC). The research also initially investigated if
the L-DOPA content of a certain fungus would be different at different stages (fruiting
body and mycelia) in its life cycle.
To initially detect the presence of L-DOPA, the TLC method was applied with the
homogenate obtained from formic acid 2% extraction. Silica gel plate 60 F254 (Merck
PGaA, Germany) activated in methanol at 60oC for 5 minutes was used as the
stationary phase, and the solvent mixture of isopropanol: ethyl acetate: water: glacial
acetic acid (29:19:10:1) was used as the mobile phase. The visualization was done
with ninhydrin dye and heated at 105oC for 5 minutes. Standard L-DOPA was used as
the reference. The obtained results suggested the presence of L-DOPA in all the tested
samples. HPLC-UV quantification found that the L-DOPA contents were different
among the studied species. Specifically, P. polycephalum microplasmodia had the
highest content (1.09 mg/g), followed by the fruiting bodies of L. perlatum (0.34
mg/g) and X. polimorpha (0.22 mg/g). Comparing between different stages of puffball
and Xylaria: the young fruiting bodies of L. perlatum, X. polimorpha and Xylaria sp
contained 0.34 (mg/g), 0.22 (mg/g) and 0.23 (mg/g) respectively; and those of their
mycelial was 0.29 (mg/g), 0.06 (mg/g) and 0.34 (mg/g). These revealed that
different stages in the life cycle would influence the L-DOPA content, but the trend is
largely dependent on each species. Specifically, only the trophic state (mycelia) of
Xylaria sp. produced a higher amount of L-DOPA that that of the reproductive stage
(fruiting body), but the rest is either comparable or lower. | en_US |
