Composition, in vitro anti-mildew fungal activities of the heartwood essential oil of Chamaecyparis formosensis from Taiwan

Abstract

In this study, anti-mildew fungal activities of the heartwood essential oil, and its constituents from Chamaecyparis formosensis were evaluated in vitro against 7 mildew fungi. The main compounds responsible for the anti-mildew fungal activities were isolated and identified. The heartwood essential oil of C. formosensis was isolated using hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC-MS. The heartwood oil consisted primarily of myrtenol (18.4%), cis-myrtanol (14.0%), α-muurolol (13.8%), αcadinol (12.7%), and chamaecynone (9.8%). The heartwood oil was shown to have excellent anti-mildew fungal activities. Further fractionation of the heartwood oil produced αcadinol, chamaecynone, α-muurolol, τ-cadinol, and τ-muurolol. The 5 compounds exhibited very strong anti-mildew fungal activities. For the anti-mildew fungal activities of the heartwood oil, the active source compounds were determined to be αcadinol, chamaecynone, α-muurolol, τ-cadinol, and τ-muurolol.