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In this study, we focused on evaluating the antimicrobial, antioxidant, and tyrosinase-inhibiting properties of leaf and twig essential oils from Calocedrus macrolepisvar. formosana. Additionally, we determined the major components associated with these effects. The findings revealed that α-pinene (36.4%) and limonene (23.6%) were the dominant components in the leaf essential oil, while α-pinene (36.2%), ferruginol (22.5%), and limonene (13.1%) were the major constituents in the twig essential oil. However, when comparing the biological activities of the 2 essential oils, the twig essential oil demonstrated excellent inhibitory effects against skin pathogens, as well as strong antioxidant and tyrosinase-inhibiting activities, in contrast to the leaf essential oil. The twig essential oil also exhibited excellent antimicrobial activity against 5 skin pathogenic strains, with the strongest inhibitory effect being that against Staphylococcus aureus, S epidermidis, and Candida albicans, which was accompanied by an inhibition zone of 46 to 48 mm, a minimum inhibitory concentration (MIC) of 125 μg/mL, and a minimum bactericidal concentration (MBC) of 250 μg/mL. The inhibitory activity of the twig essential oil against lipid peroxidation was found to be potent, as evidenced by an IC50value of 216 ± 1.9 μg/mL. It also exhibited strong scavenging activity against free radicals, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC50= 121.6 ± 0.5 μg/mL) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (IC50= 136.8 ± 1.6 μg/mL) cation radicals. In addition, it exhibited a high cupric ion reducing–antioxidant capacity (CUPRAC), with the A0.50 value determined to be 186.28 ± 0.5 μg/mL. It also exhibited adequate activity in terms of inhibiting in vitro tyrosinase activity, as evidenced by an IC50value of 168.5 ± 0.6 μg/mL. Further analysis revealed that ferruginol was the active component responsible for the antimicrobial, antioxidative, and tyrosinase-inhibiting activities observed in twig oil. These findings suggest that the twig oil is a promising candidate for further research because of its favorable antimicrobial, antioxidative, and tyrosinase-inhibiting activity.

This study examined the chemical composition and antimicrobial activities of essential oils isolated from the leaves, twigs, and fruits of Neolitsea sericeavar. auratafrom Taiwan. The major compounds responsible for antimicrobial activity were isolated and identified. The leaf, twig, and fruit essential oils were obtained through hydrodistillation in a Clevenger-type apparatus and were characterized through gas chromatography (GC) with flame ionization detection (GC/FID) and GC/mass spectrometry (GC/MS). The major compounds were (E)-β-ocimene (49.3%) and sericenine (31.6%) in the leaf oil; (E)-β-ocimene (73.7%), α-cadinol (6.8%), and α-muurolol (4.0%) in the twig oil; and (E)-β-ocimene (84.7%) in the fruit oil. The twig oil exhibited the strongest antibacterial and antifungal activities. We isolated α-cadinol and α-muurolol, the main components of NTO4 fraction, and used them in antimicrobial tests; the two compounds exhibited excellent antimicrobial activities. The twig essential oil contains α-cadinol and α-muurolol and exhibited excellent antimicrobial activities against food-borne pathogens; thus, they are worthy of further research and development.

In this study, we evaluated the anti-mildew effects of paper treated with essential oils of leaves, twigs, and their main constituents from Cinnamomum micranthum. The main ingredients with the greater anti-mildew effects on paper capability were also purified and identified. Fresh leaves and twigs of C. micranthumwere hydrodistillated in a Clevenger-type apparatus, and the resulting oil characterized using GC-FID and GC-MS instruments. The leaf essential oil consisted principally of n-decanal (50.1%), (E)-β-ocimene (7.9%), (E)-nerolidol (6.5%), and (E)-β-caryophyllene (3.8%), and the twig oil's main components were τ-cadinol (18.3%), (E)-β-ocimene (16.4%), α-cadinol (13.6%), n-decanal (10.6%), and β-selinene (5.8%). Comparing the mildew resistance of the oils on paper exhibited that twig oil was the best anti-mildew activity; at 200 μg/cm2, the twig oil completely inhibited the growth of Aspergillus clavatus, Cladosporium cladosporioides, Chaetonium globosum, Myrothecium verrucaria, and Penicillium citrinum. The twig oil was further divided into 8 fractions (TO1-TO8). TO4 fraction had moderate anti-mildew effects; at the concentration of 200 μg/cm2, all fungi strains were totally inhibited, except A niger, and Trichoderma viride, which were 83.5%, and 93.2% inhibited, respectively. The main ingredients of TO4 fraction were τ-cadinol, and α-cadinol, so we isolated and used the for anti-mildew effect tests; τ-cadinol, and α-cadinol showed moderate anti-mildew activities. Since C. micranthumtwig essential oil, τ-cadinol, and α-cadinol were exhibited a great anti-mildew effects on paper, they are worth further investigations and utilization.

We evaluated the leaf essential oil in whole or fractions of Dysphania ambrosioideswith respect to their resistance to wood decay fungal activities in vitroof 4 fungi. The main ingredients with the greater anti-wood decay capability were also identified. Fresh leaves of D. ambrosioideswere hydrodistillated in a Clevenger-type apparatus and the resulting oil characterized using GC-FID and GC-MS instruments. The essential oil was found to consist of α-terpinene (30.5%), p-cymene (17.3%), carvacrol (16.2%), and ascaridole (15.1%). The oil showed resistance to wood decay activity of Trametes versicolor, Phanerochaete chrysosporium, Phaeolus schweinitzii, and Lenzites sulphureu. The oil had excellent resistance to wood decay fungal activities, and the active compounds were shown to be carvacrol and ascaridole.