The most active phenolics in Quercus sideroxyla Humb. & Bonpl. residual bark were identified and ... more The most active phenolics in Quercus sideroxyla Humb. & Bonpl. residual bark were identified and evaluated following a chromatographic fractionation. Bark powder was defatted with hexane and crude extract (CE) was obtained by extraction with aqueous acetone (70%). A liquid partition with ethyl acetate was performed to produce an organic extract (OE), which was subsequently purified by column chromatography (Toyopearl HW-40F, methanol), and resulted in six methanolic fractions (MF1 to MF6) and an oligomeric fraction (OLF) eluted with acetone 67%. Extraction yields, total phenolic and flavanol contents were determined. The antioxidant activity of bark extracts was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), Trolox (6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic-acid)-equivalent antioxidant capacity (TEAC), and ferric ion reducing antioxidant power (FRAP) assays. Their median effective concentration (EC50) data and rate constants for DPPH radical scavenging were also estimate...
Cupressus macrocarpa (Monterey cypress) heartwood has natural durability. The heartwood oil was p... more Cupressus macrocarpa (Monterey cypress) heartwood has natural durability. The heartwood oil was prepared by steam distillation and its anti-fungal activity was tested against four wood decay fungi, i.e. Trametes versicolor, Irpex lacteus, Gloeophyllum trabeum, and Postia placenta with a filter paper disc method. The oil was active against all these fungi at the concentration of 8 mg.mL-1 or greater, but Postia placenta was the most difficult for the oil to inhibit. GC-MS was adopted to analyze the components of the heartwood oil. Two components, 4-terpineol and carvacrol were identified and carvacrol represented 94.428% of the oil. The oil had anti-fungal activity mostly because of carvacrol in the high content
(2015). Volatile terpenoids and tropolones in heartwood extracts of yellow-cedar, Monterey cypres... more (2015). Volatile terpenoids and tropolones in heartwood extracts of yellow-cedar, Monterey cypress, and their hybrid Leyland cypress
In a study of Pacific Northwest plants of the Asteraceae family, a nor-ent-kaurane diterpene and ... more In a study of Pacific Northwest plants of the Asteraceae family, a nor-ent-kaurane diterpene and a known diterpene, both displaying antibacterial activities, were isolated together with scopoletin and sitosterol-3-O-β-glucopyranoside from the aerial parts of Antennaria geyeri. Anaphalis margaritacea afforded two hydroxylactones. The structures were established by one and two dimensional NMR techniques, IR and CIMS.
Two new p-cymene based diphenols (1-2) were isolated from the heartwood of Calocedrus decurrans. ... more Two new p-cymene based diphenols (1-2) were isolated from the heartwood of Calocedrus decurrans. Structures were elucidated by 1D and 2D NMR techniques and HRMS. Libocedroquinone (3) was also isolated as a natural product for the first time. A new system of nomenclature is proposed for description of such oligomeric p-cymene derivatives.
The bark and leaf essential oil of Umbellularia californica (Hook. & Arn.) Nutt. from west centra... more The bark and leaf essential oil of Umbellularia californica (Hook. & Arn.) Nutt. from west central Oregon, USA, was isolated by steam distillation and the chemical composition analyzed by GC-FID and GC-MS. The three major components in bark oil were 1,8-cineole (36.0%), α-santalene (9.3), and α-terpineol (6.9%), while those in leaf oil were umbellulone (41.0%), 1,8-cineole (22.0%) and sabinene (10.2%).
Natural products from Pacific Northwest forest resources can offer alternatives to the use of syn... more Natural products from Pacific Northwest forest resources can offer alternatives to the use of synthetic pesticides for control of arthropods of public health concern and forest microbial pathogens. Tree heartwoods whose extracts showed high toxicity (LC50 <100 ppm) in preliminary brine shrimp bioassays, also were found to be good sources for biocide and repellent compounds. Comparisons were made for the activities of the isolated compounds, derivatives, and extracts from yellow, incense, Port-Orford, and western red cedars, and western juniper against mosquitoes (Aedes aegypti), ticks (Ixodes scapularis), fleas (Xenopsylla cheopis) and the microbe responsible for Sudden Oak Death (Phytophthora ramorum). For example, laboratory bioassays show that hinokitiol from western redcedar, thymoquinone from incense-cedar, and nootkatin from yellow-cedar all exhibit strong antimicrobial activity toward P. ramorum (EC50 = 2.0 to 10.0 ppm). The mode of action for nootkatin is disruption of th...
Abstract Antifungal activities of essential oils have been extensively studied and these material... more Abstract Antifungal activities of essential oils have been extensively studied and these materials have the potential to replace synthetic biocides. In this study, the chemical composition of Leyland cypress (× Cupressocyparis leylandii), Monterey cypress ( ...
The most active phenolics in Quercus sideroxyla Humb. & Bonpl. residual bark were identified and ... more The most active phenolics in Quercus sideroxyla Humb. & Bonpl. residual bark were identified and evaluated following a chromatographic fractionation. Bark powder was defatted with hexane and crude extract (CE) was obtained by extraction with aqueous acetone (70%). A liquid partition with ethyl acetate was performed to produce an organic extract (OE), which was subsequently purified by column chromatography (Toyopearl HW-40F, methanol), and resulted in six methanolic fractions (MF1 to MF6) and an oligomeric fraction (OLF) eluted with acetone 67%. Extraction yields, total phenolic and flavanol contents were determined. The antioxidant activity of bark extracts was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), Trolox (6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic-acid)-equivalent antioxidant capacity (TEAC), and ferric ion reducing antioxidant power (FRAP) assays. Their median effective concentration (EC50) data and rate constants for DPPH radical scavenging were also estimate...
Cupressus macrocarpa (Monterey cypress) heartwood has natural durability. The heartwood oil was p... more Cupressus macrocarpa (Monterey cypress) heartwood has natural durability. The heartwood oil was prepared by steam distillation and its anti-fungal activity was tested against four wood decay fungi, i.e. Trametes versicolor, Irpex lacteus, Gloeophyllum trabeum, and Postia placenta with a filter paper disc method. The oil was active against all these fungi at the concentration of 8 mg.mL-1 or greater, but Postia placenta was the most difficult for the oil to inhibit. GC-MS was adopted to analyze the components of the heartwood oil. Two components, 4-terpineol and carvacrol were identified and carvacrol represented 94.428% of the oil. The oil had anti-fungal activity mostly because of carvacrol in the high content
(2015). Volatile terpenoids and tropolones in heartwood extracts of yellow-cedar, Monterey cypres... more (2015). Volatile terpenoids and tropolones in heartwood extracts of yellow-cedar, Monterey cypress, and their hybrid Leyland cypress
In a study of Pacific Northwest plants of the Asteraceae family, a nor-ent-kaurane diterpene and ... more In a study of Pacific Northwest plants of the Asteraceae family, a nor-ent-kaurane diterpene and a known diterpene, both displaying antibacterial activities, were isolated together with scopoletin and sitosterol-3-O-β-glucopyranoside from the aerial parts of Antennaria geyeri. Anaphalis margaritacea afforded two hydroxylactones. The structures were established by one and two dimensional NMR techniques, IR and CIMS.
Two new p-cymene based diphenols (1-2) were isolated from the heartwood of Calocedrus decurrans. ... more Two new p-cymene based diphenols (1-2) were isolated from the heartwood of Calocedrus decurrans. Structures were elucidated by 1D and 2D NMR techniques and HRMS. Libocedroquinone (3) was also isolated as a natural product for the first time. A new system of nomenclature is proposed for description of such oligomeric p-cymene derivatives.
The bark and leaf essential oil of Umbellularia californica (Hook. & Arn.) Nutt. from west centra... more The bark and leaf essential oil of Umbellularia californica (Hook. & Arn.) Nutt. from west central Oregon, USA, was isolated by steam distillation and the chemical composition analyzed by GC-FID and GC-MS. The three major components in bark oil were 1,8-cineole (36.0%), α-santalene (9.3), and α-terpineol (6.9%), while those in leaf oil were umbellulone (41.0%), 1,8-cineole (22.0%) and sabinene (10.2%).
Natural products from Pacific Northwest forest resources can offer alternatives to the use of syn... more Natural products from Pacific Northwest forest resources can offer alternatives to the use of synthetic pesticides for control of arthropods of public health concern and forest microbial pathogens. Tree heartwoods whose extracts showed high toxicity (LC50 <100 ppm) in preliminary brine shrimp bioassays, also were found to be good sources for biocide and repellent compounds. Comparisons were made for the activities of the isolated compounds, derivatives, and extracts from yellow, incense, Port-Orford, and western red cedars, and western juniper against mosquitoes (Aedes aegypti), ticks (Ixodes scapularis), fleas (Xenopsylla cheopis) and the microbe responsible for Sudden Oak Death (Phytophthora ramorum). For example, laboratory bioassays show that hinokitiol from western redcedar, thymoquinone from incense-cedar, and nootkatin from yellow-cedar all exhibit strong antimicrobial activity toward P. ramorum (EC50 = 2.0 to 10.0 ppm). The mode of action for nootkatin is disruption of th...
Abstract Antifungal activities of essential oils have been extensively studied and these material... more Abstract Antifungal activities of essential oils have been extensively studied and these materials have the potential to replace synthetic biocides. In this study, the chemical composition of Leyland cypress (× Cupressocyparis leylandii), Monterey cypress ( ...
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