Chemical Components of Fungus Comb from Indo-Malayan Termite Macrotermes gilvus Hagen Mound and Its Bioactivity against Wood-Staining Fungi

Recently, the architectural and physical properties of the fungus comb from subterranean termite Macrotermes gilvus Hagen (Isoptera: Termitidae) mounds had been studied and it is important to determine its chemical profile as well as to evaluate its anti-staining-fungi activity. The results showed that fungus comb of M. gilvus has a high crude ash (30.57%), fiber (25.46%), starch (7.76%), protein (5.80%, 5.53% amino acid), acid-insoluble ash (3.45%), and fat (0.73%). It also contained phenol hydroquinone, steroids, terpenoids, and saponin compounds. Seventeen amino acids were identified via high-performance liquid chromatography analysis, of which arginine, leucine, glutamate, and aspartic acid were the majority. According to gas chromatography-mass spectrometry analysis, the n-hexane extract consists of several types of fatty acid derivatives. Meanwhile, the ethyl acetate (EtOAc) extracts were primarily phenol groups with 1,2,3-propanetriol (glycerol) at the highest relative concentration. Four fungus-comb extracts (n-hexane, EtOAc, MeOH, and water) inhibited the Aspergillus foetidus fungus, with inhibition rates ranging from 24.17% to 100% and EtOAc extract as the most active extract. It appears that EtOAc extracts from the M. gilvus fungus comb can be considered an active ingredient source of novel organic fungicide in preventing wood-staining fungi attacks on susceptible wood.