Total Syntheses and Biological Evaluation of the Ganoderma lucidum Alkaloids Lucidimines B and C

Although a range of pharmacologically active compounds has been obtained from the mycelium and fruiting bodies of Ganoderma lucidum, the biological properties of the alkaloids present in this functional food remain unknown. Herein, we report total syntheses of lucidimines B and C, key members of the first family of alkaloids isolated from G. lucidum, and the evaluation of these synthetically derived materials as antioxidants and antiproliferative agents. Lucidimine B proved to be a better antioxidant than congener C. Similarly, lucidimine B exhibited antiproliferative properties toward MCF-7 cells (an EC₅₀ value of 0.27 ± 0.02 μmol/mL), whereas lucidimine C was inactive. The former alkaloid arrested the MCF-7 cell cycle in the S phase by inducing DNA fragmentation, hence reducing the mitochondrial membrane potential. This work thus demonstrates, for the first time, that the alkaloidal constituents derived from G. lucidum are biologically active and may, therefore, contribute to the beneficial health claims made for this nutraceutical.