Background: Ganoderma lucidum is a well-known edible mushroom and traditional Chinese
medicine, but there were no comprehensive reports on the extraction, analysis and activities test of
Ganoderma lucidum Amino Acids (GLAA).
Objective: The present study was aimed to optimize the extraction process of GLAA and analyze the
amino acid composition of GLAA, combined with preliminary activity evaluation.
Methods: The hydrochloric acid-hydrolysis method for extraction of GLAA was optimized by Response
Surface Methodology (RSM) with Box-Behnken Design (BBD). The amino acid composition of
GLAA was analyzed by PITC pre-column derivation with HPLC method and amino acid automatic
analyzer. The hypoglycemic and antioxidant activities of GLAA were assayed by inhibitory rate of -
glucosidase and DPPH radical scavenging rate, respectively.
Results: The optimal extraction conditions were obtained: liquid-to-solid ratio 20:1 mL/g, extraction
time 9.5 h, hydrochloric acid concentration 7.0 mol/L, and the yield of GLAA was 4.78 ± 0.21 %. The
result of amino acid automatic analyzer showed that the content of total amino acids in GLAA was 2.94
%, including 18 kinds of amino acids, and the most abundant amino acid was leucine (0.37 %). The
results of activity tests in vitro showed that GLAA exhibited high α-glucosidase inhibitory rate with
IC50 value of 380.62 µg/mL and a certain scavenging DPPH activity with IC50 of 484.54 µg/mL.
Conclusion: The RSM with BBD was successfully implemented for optimization of the extraction parameters
of GLAA. The GLAA was rich in 18 kinds of amino acids and possessed strong hypoglycemic
and antioxidant activities.