Antibacterial Compounds from the Mushroom Ganoderma colossum from Nigeria

Three colossolactones (colossolactone E, colossolactone B and 23‐hydroxycolossolactone E) were isolated and characterized from an n‐hexane:dichloromethane (2:7) extract of Ganoderma colossum using chromatographic techniques. The antimicrobial activity of the three compounds was then tested against Gram‐positive and Gram‐negative bacteria. The activity was evaluated by the thin‐layer chromatography agar overlay method. The results showed that colossolactone E and 23‐hydroxycolossolactone E were active against Bacillus subtilis and Pseudomonas syringae. Colossolactone B was not active against the bacteria. Their structures were elucidated by spectroscopic methods. Potency of the compounds against bacteria tested supports the use of this mushroom in therapeutic medicine.