Comparison of Chemical Composition of Spore Lipids Extracted from Two Species of Ganoderma

Abstract

Ganoderma, commonly referred to as “Lingzhi” in Chinese, “Reizhi” in Japanese, and “Youngzhi” in Korean, is a family of medicinal mushrooms employed to maintain human vitality and to promote longevity in traditional Chinese medicine for over 2000 years [1]. To date, Ganoderma has been used as remedy for the treatment of various diseases such as migraine and headache, hypertension, arthritis, hepatitis, cardiovascular problems, and cancer. It has been shown to contain a variety of bioactive ingredients including trierpenes, polysaccharides, nucleosides, steroids, fatty acids, alkaloids, proteins, peptides, amino acids, and inorganic elements [2]. Recently, Ganoderma spores gained considerable attention owning to their possible higher bioactivity [3]. However, spores have extremely hard and resilient bilayer walls, thus making them difficult to break open, and their bioactive lipid is stored between the inner and outer walls and is difficult to extract [4]. The difficulty above could be overcome by using superfine grinding technology through breaking the sporoderm and removing plant cellulose barriers [5]. Furthermore, it was reported that alcohol extracts from sporoderm-broken spores were more cytotoxic against tumor cells than that from sporoderm-nonbroken spores [6]. Super CO2 fluid extraction (SFE), a well-known extract technology, was established to extract liposoluble materials, which presented some advantages such as being nontoxic, high-efficiently, and less-deteriorating compared with the conventional methods viz. hydrodistillation, steam distillation, or solvent extraction [7]. In our current work, spores from Ganoderma duropora Lloyd (G. duropora) and Ganoderma lucidum (Leyss.ex Fr.) Karst. (G. lucidum) were superfine pulverized prior to extraction by SFE. The chemical composition of DSL (G. duropora spores lipids) and LSL (G. lucidum spores lipids) were then determined and compared by GC-MS. The results showed that spore lipids from G. duropora and G. lucidum obtained by SFE gave an average yield of 14.14% and 20.66% on a dry weight basis, respectively. As given in Table 1, GC-MS analyses revealed the presence of 22 and 10 compounds whose total relative contents were 74.04% and 88.58% in DSL and LSL, respectively. Aliphatic compounds were the main constituents in these two spore lipids, except for naphthalene and ergosterol belonging to aromatics and steroids, respectively. The chromatographic profile showed that both contained eight compounds and high levels of n-hexadecanoic acid and oleic acid (9.52%, 61.19% in DSL and 7.99%, 80.01% in LSL, as shown in Table 1). Nevertheless, 1-nonadecene (0.02%) and 2,3-dihydroxypropyl elaidate (0.07%) were detected in LSL but not in DSL. According to the above-mentioned results, it was concluded that the components from two spore lipids resembled each other. From this point of view, G. duropora in high production amounts might be developed as an alternative to Ganoderma.