Composition of Essential Oils Extracted from the Leaves, Twigs, and Cones of Taxodium distichum (L.) Rich. and the Anti-mildew Property of These Oils on Paper

Objective/Background Taxodium distichum (L.) Rich., a plant of the Cupressaceae family, is known for its leaves and cones rich in essential oils, which are traditionally used in folk medicine. This study employed hydrodistillation to extract essential oils from three parts of T. distichum, namely its leaves, twigs, and cones, and evaluated the yield and composition of these oils as well as their anti-mildew property on paper. Methods The chemical compositions of the essential oils from the three parts were analyzed using gas chromatography with flame ionization detection (GC-FID) and gas chromatography mass spectrometry (GC-MS). The anti-mildew properties were assessed on paper against seven mold fungi, namely Aspergillus clavatus, A. niger, Chaetomium globosum, Cladosporium cladosporioides, Myrothecium verrucaria, Penicillium citrinum, and Trichoderma viride, following standards such as TAPPI T487 cm-93 and CNS 2690. Furthermore, the essential oil demonstrating the strongest anti-mildew properties was selected from the oils extracted from three different parts, underwent column chromatography for isolation, and the main active compounds were identified. Results Among the three parts, cones had the highest essential oil yield (0.53 ± 0.03 mL/100 g), followed by leaves (0.46 ± 0.02 mL/100 g) and twigs (0.06 ± 0.01 mL/100 g). The main components were limonene (39.8%) and α-pinene (37.1%) in leaves; limonene (16.8%), α-pinene (15.8%), and ferruginol (11.0%) in twigs; and ferruginol (43.2%) and caryophyllene oxide (12.5%) in cones. The cone oils exhibited the most effective anti-mildew properties on paper. Furthermore, the cone oils were fractionated into six fractions (CO1–CO6), with the CO4 fraction exhibiting the best activity. CO4's main components were ferruginol, caryophyllene oxide, and β-caryophyllene. Ferruginol showed the best anti-mildew performance, with 100% inhibition at 200 μg/cm² for all strains. Conclusion The study results indicated that essential oils from the cones of T. distichum and ferruginol exhibit promising anti-mildew effects on paper. Therefore, further research and development are highly warranted for their application in inhibiting fungal growth on paper.