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11.
Antibacterial and antifungal activity of pinosylvin, a constituent of pine   总被引:1,自引:0,他引:1  
Lee SK  Lee HJ  Min HY  Park EJ  Lee KM  Ahn YH  Cho YJ  Pyee JH 《Fitoterapia》2005,76(2):258-260
The antibacterial and antifungal activities of pinosylvin (3,5-dihydroxy-trans-stilbene), a constituent of pine, were studied and compared with those of resveratrol (3,5,4'-trihydroxy-trans-stilbene). Pinosylvin exhibited more potent growth inhibitory activity against Candida albicans and Saccharomyces cerevisiae.  相似文献   
12.
The acaricidal activity of materials derived from rhizome of Atractylodes ovata (Atractylodes macrocephala) toward adult Dermatophagoides farinae and Dermatophagoides pteronyssinus was examined using fabric-circle residual contact and vapor-phase toxicity bioassays. Results were compared with those of the currently used acaricides: benzyl benzoate, dibutyl phthalate, and N,N-diethyl-m-toluamide (Deet). The active principles of A. ovata rhizome were identified as the sesquiterpenoids, atractylenolide III (1) and atractylon (2), by spectroscopic analysis. In fabric-circle residual contact bioassays with adult D. farinae, atractylenolide III (LD50, 103.3 mg/m2) and atractylon (136.2 mg/m2) were five and four times more toxic than Deet and 1.7- and 1.3-fold more active than dibutyl phthalate, respectively, based on 24 h LD50 values. These compounds were less toxic than benzyl benzoate (LD50, 45.8 mg/m2). Against adult D. pteronyssinus, atractylenolide III (LD50, 73.8 mg/m2) and atractylon (72.1 mg/m2) were eight times more active than Deet and 2.5-fold more toxic than dibutyl phthalate. These compounds were slightly less effective than benzyl benzoate (LD50, 46.0 mg/m2). In vapor-phase toxicity tests with both mite species, atractylenolide III and atractylon were effective in closed but not in open containers. These results indicate that the effect of these sesquiterpenoids was largely a result of action in the vapor phase. Naturally occurring atractylenolide III and atractylon merit further study as potential house dust mite control agents or leads because of their great activity as a fumigant.  相似文献   
13.
Newly isolated soil bacterium strain Jin1 was able to grow on both eugenol and isoeugenol each as sole source of carbon and energy. Based on bacterial 16S rDNA analysis, Jin1 belongs to Pseudomonas nitroreducens with a similarity of 98.92% (14/1297). P. nitroreducens Jin1 was found to biotransform eugenol and isoeugenol to vanillin by different pathways. Eugenol was biotransformed to vanillin through coniferyl alcohol and ferulic acid similarly to the pathway shown previously by Pseudomonassp. HR199 and vanillin produced from eugenol was rapidly metabolized to vanillic acid. Contrastively, Pseudomonas nitroreducens Jin1 did not appear to produce metabolic intermediates during the biotransformation of isoeugenol to vanillin which was finally biotransformed to vanillic acid with much slower rate. These results indicate that there seems to be different metabolic regulation systems for the biotransformation of eugenol and isoeugenol by this bacterium. Herein, we report on Pseudomonas nitroreducens Jin1, a novel bacterium that produces vanillin from eugenol and isoeugenol by two different metabolic pathways.  相似文献   
14.
Melatonin affects diverse physiological functions through its receptor and plays an important role in the central nervous system. In the present study, we compared immunoreactivity patterns of arylalkylamine N-acetyltransferase (AANAT), an enzyme essential for melatonin synthesis, and melatonin receptor type 1B (MT2) in the spinal cord of young adult (2~3 years) and aged (10~12 years) beagle dogs using immunohistochemistry and Western blotting. AANAT-specific immunoreactivity was observed in the nuclei of spinal neurons, and was significantly increased in aged dog spinal neurons compared to young adult spinal neurons. MT2-specific immunoreactivity was found in the cytoplasm of spinal neurons, and was predominantly increased in the margin of the neuron cytoplasm in aged spinal cord compared to that in the young adult dogs. These increased levels of AANAT and MT2 immunoreactivity in aged spinal cord might be a feature of normal aging and associated with a feedback mechanism that compensates for decreased production of melatonin during aging.  相似文献   
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This study examined the capability of remotely sensed information gained using the terra moderate resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) and land surface temperature (LST) to explain forest soil moisture. The soil and water assessment tool (SWAT) was used for the analysis. Nine years (2000–2008) of monthly MODIS NDVI and LST data from a 2,694.4 km2 watershed consisting of forest-dominant areas in South Korea were compared with SWAT simulated soil moisture. Before the analysis, the SWAT model was calibrated and verified using 9 years of daily streamflow at three gauging stations and 6 years (2003–2008) of daily measured soil moisture at three locations within the watershed. The average Nash–Sutcliffe model efficiency during the streamflow calibration and validation was 0.72 and 0.70, respectively. The SWAT soil moisture showed a higher correlation with MODIS LST during the forest leaf growing period (March–June) and with MODIS NDVI during the leaf falling period (September–December). Low correlation was observed in the year of frequent rains, regardless of the leaf periods.  相似文献   
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18.
A competitive enzyme-linked immunosorbent assay (ELISA) for the detection of cypermethrin was developed. Two haptens, the trans- and cis-isomers of 3-[(+/-)-cyano-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarbonyloxy]methyl]phenoxyacetic acid, were conjugated with thyroglobulin as immunogens. Four antisera were generated and screened against six different coating antigens. The assay that was the most sensitive for cypermethrin was optimized and characterized. The IC(50) for cypermethrin was 13.5 +/- 4.3 microg/L, and the lower detection limit (LDL) was 1.3 +/- 0.5 microg/L. This ELISA had relatively low cross-reactivities with other major pyrethroids, such as deltamethrin, phenothrin, resmethrin, fluvalinate, and permethrin. Methanol was found to be the best organic cosolvent for this ELISA, with an optimal sensitivity observed at a concentration of 40% (v/v). The assay parameters were unchanged at pH values between 5.0 and 8.0, whereas higher ionic strengths strongly suppressed the absorbances. To increase the sensitivity of the overall method, a C(18) sorbent-based solid-phase extraction was applied to various domestic and environmental water samples. The water samples, fortified with cypermethrin, were analyzed according to this method. Good recoveries and correlation with spike levels were observed.  相似文献   
19.
After far-infrared (FIR) radiation onto rice hull, a methanolic extract was prepared for the determination of antioxidant ability. After 30 min of FIR treatment, the radical scavenging activity and total phenol contents of rice hull extracts increased from 47.74 to 79.63% and from 0.12 to 0.19 mM, respectively, compared to control. Inhibition of lipid peroxidation in extracts was also increased from 41.07 to 47.96%. According to the GC-MS analysis, more phenolic compounds (p-coumaric acid, 3-vinyl-1-oxybenzene, p-hydroxybenzaldehyde, vanillin, p-hydroxybenzoic acid, and 4,7-dihydroxyvanillic acid) were detected in FIR-irradiated rice hull extract. These results indicated that FIR radiation onto rice hull could liberate and activate covalently bound phenolic compounds that have antioxidant activities.  相似文献   
20.
The effect of heat treatment on the antioxidant activity of extracts from Citrus unshiu peels was evaluated. Citrus peels (CP) (5 g) were placed in Pyrex Petri dishes (8.0 cm diameter) and heat-treated at 50, 100, or 150 degrees C for 10, 20, 30, 40, 50, and 60 min in an electric muffle furnace. After heat treatment, 70% ethanol extract (EE) and water extract (WE) (0.1 g/10 mL) of CP were prepared, and total phenol contents (TPC), radical scavenging activity (RSA), and reducing power of the extracts were determined. The antioxidant activities of CP extracts increased as heating temperature increased. For example, heat treatment of CP at 150 degrees C for 60 min increased the TPC, RSA, and reducing power of EE from 71.8 to 171.0 microM, from 29.64 to 64.25%, and from 0.45 to 0.82, respectively, compared to non-heat-treated control. In the case of WE from CP heat-treated at the same conditions (150 degrees C for 60 min), the TPC, RSA, and reducing power also increased from 84.4 to 204.9 microM, from 15.81 to 58.26%, and from 0.27 to 0.96, respectively. Several low molecular weight phenolic compounds such as 2,3-diacetyl-1-phenylnaphthalene, ferulic acid, p-hydroxybenzaldoxime, 5-hydroxyvaleric acid, 2,3-diacetyl-1-phenylnaphthalene, and vanillic acid were newly formed in the CP heated at 150 degrees C for 30 min. These results indicated that the antioxidant activity of CP extracts was significantly affected by heating temperature and duration of treatment on CP and that the heating process can be used as a tool for increasing the antioxidant activity of CP.  相似文献   
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