Antimildew Effects of Plectranthus amboinicus Leaf Essential Oil on Paper

Abstract

In this study, we evaluated the antimildew effects on paper of Plectranthus amboinicus (Lour.) Spreng leaf essential oil prepared through hydrodistillation. The oil was isolated with a Clevenger-type apparatus and then characterized through gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 43 compounds were identified, representing 99.5% of the oil. The main ingredients were carvacrol (50.0%), γ-terpinene (13.1%), and β-caryophyllene (11.3%). The leaf oil had excellent antimildew effects; its minimum inhibitory concentration (MIC) values against Aspergillus clavatus, A. niger, Cladosporium cladosporioides, Chaetomium globosum, Myrothecium verrucaria, Penicillium citrinum, and Trichoderma viride were 100, 200, 75, 75, 100, 150, and 150 μg/cm2 respectively. The leaf oil was further partitioned into 6 derivative fractions (PO1-PO6). PO2 had excellent antimildew effects on the abovementioned strains; at a concentration of 100 μg/cm2, all were 100% inhibited, except A. niger, which was 75.8% inhibited. Carvacrol, the main ingredient of PO2, was then isolated and used for antimildew tests; carvacrol had excellent antimildew activities. Since both P. amboinicus leaf essential oil and carvacrol were proved to have excellent antimildew effects on paper, they are worth further research and development.

Seasonal Variations of Polyphenols Content, Sun Protection Factor and Antioxidant Activity of Two Lamiaceae Species

“…Scientifically, its endothelium-dependent hypotensive and vasorelaxant effects have been demonstrated [ 11 ], as well as its antimicrobial, antinociceptive [ 12 ], antitumor [ 13 ], anti-inflammatory [ 14 ] and antioxidant activities [ 15 , 16 ]. P. amboinicus is used for the treatment of colds, coughs, asthma, and diseases of the respiratory tract in general, as well as to treat headaches, fever, skin diseases, and gastrointestinal disorders [ 17 , 18 , 19 ]. Thus, because it is a well-known species and used by the population, many studies on its effects already exist and demonstrate its antimicrobial and antiviral activities in vitro [ 20 , 21 ], activity against respiratory and gastrointestinal disorders, anticonvulsant, antitumor [ 22 , 23 ], analgesic, anti-inflammatory, and antioxidant activities [ 24 , 25 ].…”

“…Thus, because it is a well-known species and used by the population, many studies on its effects already exist and demonstrate its antimicrobial and antiviral activities in vitro [ 20 , 21 ], activity against respiratory and gastrointestinal disorders, anticonvulsant, antitumor [ 22 , 23 ], analgesic, anti-inflammatory, and antioxidant activities [ 24 , 25 ]. These two species are also used in culinary as flavorings and in the preparation of some foods [ 17 , 26 ].…”

“…Many of the biological activities presented by M. villosa and P. amboinicus are due to the presence of essential oils that are widely studied and have monoterpenes and sesquiterpenes in their composition [ 17 , 27 ]. However, its nonvolatile extracts also have a large amount of biologically interesting compounds, such as phenolic compounds.…”

Effect of Light Exposure on Secondary Metabolite Production and Bioactivities of Syncephalastrum racemosum Endophyte

“…6 It was reported that essential oil production by P. amboinicus through hydrodistillation yielded only about 0.58 ± 0.03 mL/100 g dry weight of leaves. 7 Additionally, production of secondary metabolites from plant materials is also affected by geographical and environmental conditions, plant genetics and physiology as well as climate. 8 The ability of microbes in synthesising plant secondary metabolites drawn attention of many researchers as an alternative method.…”

Chemical Compositions and In Vitro Antiphytopathogenic Fungi Activities of the Leaf and Cones Essential Oils of Cunninghamia lanceolata From Taiwan

“…Our research team has proven on numerous occasions the antifungal efficacies of various essential oils. 8,9 Cunninghamia lanceolata (Lamb.) Hook.…”