Impact of Collection Locations and Host Trees on the Bioactive Triterpene Composition and Antioxidant Activity of Four <i>Ganoderma</i> Species: A Chemometric Analysis

This study investigates the influence of host trees and collection sites on the chemical composition and antioxidant properties of four Ganoderma species, namely, G. lucidum, G. adspersum, G. applanatum, and G. resinaceum. Samples were collected from sweetgum, mulberry, walnut, peach, and plum trees and analyzed using HPLC-DAD. Ten key bioactive compounds, including ergosterol peroxide (1), ganoderic acids (2-8), and phenolics, were identified and quantified. Triterpenes were particularly dominant in G. adspersum collected from fruiting trees. The maceration and soxhlet extraction methods significantly increased triterpene yield. Antioxidant activity was evaluated using DPPH, ABTS, CUPRAC, and β-carotene-linoleic acid assays. G. applanatum exhibited the highest DPPH scavenging activity (IC₅₀: 5.78 µg/mL), surpassing α-tocopherol (IC₅₀: 10.34 µg/mL). Similarly, G. adspersum performed potent antioxidant activity in all assays comparable to α-tocopherol. PCA and HCA analyses showed that chemical profiles vary by species, host trees, and extraction methods, with fruiting trees enhancing triterpene richness. Moreover, chemometric analyses revealed that triterpene-rich samples from fruiting trees exhibited enhanced antioxidant properties, aligning with elevated levels of ganoderic acids B (4) and G (3). This study underscores the significant role of environmental and methodological factors in determining the bioactive potential of Ganoderma species and highlights the influence of host tree factors on their bioactive profiles.