Acaricidal activity of butylidenephthalide identified in Cnidium officinale rhizome against dermatophagoides farinae and dermatophagoides pteronyssinus (Acari: Pyroglyphidae)

The acaricidal activity of materials derived from the rhizome of Cnidium officinale against adults of Dermatophagoides farinae and Dermatophagoides pteronyssinus was examined using direct contact application and fumigation methods and compared with that of benzyl benzoate and N,N-diethyl-m-toluamide (DEET). The active constituent of the Cnidium rhizome was identified as butylidenephthalide by spectroscopic analyses. Responses varied with dose. On the basis of 24-h LD(50) values, the acaricidal activity of butylidenephthalide (6.77 microg/cm(2)) against D. farinae adults was comparable to that of benzyl benzoate (8.54 microg/cm(2)). Very low activity was observed with DEET (37.59 microg/cm(2)). Against D. pteronyssinus adults, butylidenephthalide (6.46 microg/cm(2)) and benzyl benzoate (6.68 microg/cm(2)) were equitoxic. DEET (17.98 microg/cm(2)) was relatively inactive. The typical poisoning symptom of butylidenephthalide was lethargy of treated mites, leading to death without knockdown, whereas benzyl benzoate and DEET caused death following uncoordinated behavior. In a fumigation test with both mite species, butylidenephthalide was much more effective in closed containers than open ones. Naturally occurring C. officinale rhizome-derived materials merit further study as potential house dust mite control agents or lead compounds.     

Acaricidal activity of Paeonia suffruticosa root bark-derived compounds against Dermatophagoides farinae and Dermatophagoides pteronyssinus (Acari: Pyroglyphidae)

The acaricidal activities of materials derived from the root bark of Paeonia suffruticosa against adults of Dermatophagoides farinae and Dermatophagoides pteronyssinus were examined using direct contact and fumigation bioassays and compared with those of benzyl benzoate, dibutyl phthalate, and N,N-diethyl-m-toluamide (deet), widely used acaricides. The active constituents of Paeonia root bark were identified as paeonol and benzoic acid by spectroscopic analyses. On the basis of 24-h LD50 values, the acaricidal activities of paeonol (7.82 microg/cm3) and benzoic acid (6.58 microg/cm3) against adult D. farinae were comparable to that of benzyl benzoate (7.72 microg/cm3) but higher than those of deet (36.34 microg/cm3) and dibutyl phthalate (33.92 microg/cm3). Against adult D. pteronyssinus, the acaricidal activities of paeonol (7.08 microg/cm3) and benzyl benzoate (7.22 microg/cm3) were comparable to that of benzyl benzoate (7.14 microg/cm3). Deet and dibutyl phthalate were less effective. In fumigation tests with both mite species, paeonol and benzoic acid were much more effective in closed containers than open ones, indicating that the effect of these compounds was largely a result of action in the vapor phase. Neither benzyl benzoate, deet, nor dibutyl phthalate exhibited fumigant toxicity. Paeonia root bark-derived materials, particularly paeonol and benzoic acid, merit further study as potential acaricides or lead compounds for the control of D. farinae and D. pteronyssinus.     

Acaricidal activities of apiol and its derivatives from Petroselinum sativum seeds against Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Tyrophagus putrescentiae

The acaricidal effects of an active constituent derived from Petroselinum sativum seeds and its derivatives were determined using impregnated fabric disk bioassay against Dermatophagoides farinae , Dermatophagoides pteronyssinus , and Tyrophagus putrescentiae and compared with that of synthetic acaricide. The acaricidal constituent of P. sativum was isolated by various chromatographic techniques and identified as apiol. On the basis of LD(50) values against D. farinae and D. pteronyssinus, apiol (0.81 and 0.94 μg/cm(2)) was 12.4 and 10.2 times more toxic than benzyl benzoate (10.0 and 9.58 μg/cm(2)), respectively. In acaricidal studies of apiol derivatives, 3,4-methylenedioxybenzonitrile (0.04, 0.03, and 0.59 μg/cm(2)) was 250, 319, and 20.7 times more toxic than benzyl benzoate (10.0, 9.58, and 12.2 μg/cm(2)) against D. farinae, D. pteronyssinus, and T. putrescentiae. In structure-activity relationships, the acaricidal activities of apiol derivatives could be related to allyl (-C(3)H(5)) and methoxy (-OCH(3)) functional groups. Furthermore, apiol and its derivatives could be useful for natural acaricides against these three mite species.     

Acaricidal activity of constituents identified in Foeniculum vulgare fruit oil against Dermatophagoides spp. (Acari: Pyroglyphidae)

Acaricidal activities of components derived from Foeniculum vulgare fruit oil against Dermatophagoides farinae and Dermatophagoides pteronyssinus were examined using direct contact application and compared with that of the commercial repellent benzyl benzoate. The major biologically active constituent of Foeniculum fruit oil was characterized as (+)-fenchone by spectroscopic analyses. On the basis of LD(50) values, the compound most toxic to D. farinae was p-anisaldehyde (11.3 mg/m(2)) followed by (+)-fenchone (38.9 mg/m(2)), (-)-fenchone (41.8 mg/m(2)), benzyl benzoate (89.2 mg/m(2)), thymol (90.3 mg/m(2)), and estragol (413.3 mg/m(2)). Against D. pteronyssinus, p-anisaldehyde (10.1 mg/m(2)) was much more effective than benzyl benzoate (67.5 mg/m(2)), thymol (68.5 mg/m(2)), and estragol (389.9 mg/m(2)). These results indicate that the acaricidal activity of F. vulgare fruit oil likely results from (+)-fenchone and p-anisaldehyde. (+)-Fenchone was 20.3 times more abundant in the oil than p-anisaldehyde. (+)-Fenchone and p-anisaldehyde merit further study as potential house dust mite control agents or as lead compounds.     

Acaricidal activity of active constituent isolated in Chamaecyparis obtusa leaves against Dermatophagoides spp

Acaricidal activities of materials derived from Chamaecyparis obtusa leaves against Dermatophagoides farinae and Dermatophagoides pteronyssinus were examined using the dry film method and compared with that of commercial benzyl benzoate and N,N-diethyl-m-toluamide (DEET). The active constituent of the C. obtusa leaves was identified as beta-thujaplicin (C10H12(O2)) by spectroscopic analyses. Responses varied with dose. On the basis of a 24 h LC50 value, acaricidal activity against D. farinaewas more pronounced with beta-thujaplicin (72.2 mg/m2) than benzyl benzoate (89.9 mg/m2) and DEET (377 mg/m2). Acaricidal activity against D. pteronyssinus was more pronounced in beta-thujaplicin (62.1 mg/m2) than benzyl benzoate (72.4 mg/m2) and DEET (193 mg/m2). These results indicate that acaricidal activity of C. obtusa leaves likely results from by beta-thujaplicin. Beta-thujaplicin merits further study as potential house dust mite control agents or lead compounds.     

Acaricidal toxicity of 2'-hydroxy-4'-methylacetophenone isolated from Angelicae koreana roots and structure-activity relationships of its derivatives

The acaricidal activities of 2'-hydroxy-4'-methylacetophenone derived from Angelica koreana roots and its derivatives against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Tyrophagus putrescentiae were examined by vapor phase and contact toxicity bioassays. In the vapor phase toxicity bioassay, 2'-methylacetophenone (1.25 μg/cm(2)) was 8.0 times more toxic against D. farinae than benzyl benzoate (10.00 μg/cm(2)), followed by 3'-methylacetophenone (1.26 μg/cm(2)), 4'-methylacetophenone (1.29 μg/cm(2)), 2'-hydroxy-4'-methylacetophenone (1.75 μg/cm(2)), and 2'-hydroxy-5'-methylacetophenone (1.96 μg/cm(2)). In the contact toxicity bioassay, 3'-methylacetophenone (0.58 μg/cm(2)) was 17.24 times more effective against D. farinae than benzyl benzoate (7.52 μg/cm(2)), followed by 2'-methylacetophenone (0.64 μg/cm(2)), 2'-hydroxy-4'-methylacetophenone (0.76 μg/cm(2)), 4'-methylacetophenone (0.77 μg/cm(2)), and 2'-hydroxy-5'-methylacetophenone (1.16 μg/cm(2)). The acaricidal activities of 2'-hydroxy-4'-methylacetophenone derivatives against D. pteronyssinus and T. putrescentiae were similar to those against D. farinae. In terms of structure-activity relationships, acaricidal activity against the three mite species changed with the introduction of hydroxyl and methyl functional groups onto the acetophenone skeleton. Furthermore, some of 2'-hydroxy-4'-methylacetophenone derivatives could be useful for natural acaricides against three mite species.     

Acaricidal constituents isolated from Sinapis alba L. seeds and structure-activity relationships

Allyl isothiocyanate (AITC) and phenethyl isothiocyanate (PEITC) were isolated from Sinapis alba L. seeds and their effects against Dermatophagoides farinae and D. pteronyssinus were evaluated using the impregnated fabric disk method. The LD 50 values of their compounds and derivatives were then compared with those of a commercial acaricide, benzyl benzoate. On the basis of the LD 50 values against D. farinae, PEITC (0.21 microg/cm(2)) was the most toxic, followed by benzyl isothiocyanate (0.55 microg/cm(2)), phenyl isothiocyanate (1.09 microg/cm(2)), butyl isothiocyanate (1.24 microg/cm(2)), and AITC (1.36 microg/cm(2)); acetyl isothiocyanate (195.01 microg/cm(2)) was the least toxic. In addition, the acaricidal effects of AITC and PEITC against D. farinae were 7.4- and 47.8-fold greater than those of benzyl benzoate, respectively. Against D. pteronyssinus, PEITC was the most toxic (0.19 microg/cm(2)), followed by benzyl isothiocyanate (0.77 microg/cm(2)), phenyl isothiocyanate (1.37 microg/cm(2)), butyl isothiocyanate (1.50 microg/cm(2)), and AITC (2.88 microg/cm(2)); acetyl isothiocyanate (168.82 microg/cm(2)) was the least toxic. AITC and PEITC were 3.3- and 50.4-fold more active than benzyl benzoate against D. pteronyssinus, respectively. Taken together, these findings indicate that AITC, PEITC, and partial derivatives may be useful as preventive agents against dust mites. In addition, these results indicate that structure-activity is related to the aromatic structure, the number of carbon atoms, and the compounds hydrophobicity.     

Toxicity of atractylon and atractylenolide III Identified in Atractylodes ovata rhizome to Dermatophagoides farinae and Dermatophagoides pteronyssinus

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.     

Ovicidal and adulticidal effects of Eugenia caryophyllata bud and leaf oil compounds on Pediculus capitis

The toxicity of Eugenia caryophyllata bud and leaf oil-derived compounds (acetyleugenol, beta-caryophyllene, eugenol, alpha-humulene, and methyl salicylate) and congeners of eugenol (isoeugenol and methyleugenol) against eggs and females of Pediculus capitis was examined using direct contact application and fumigation methods and compared with those of the widely used delta-phenothrin and pyrethrum. In a filter paper diffusion bioassay with female P. capitis, the pediculicidal activity of the Eugenia bud and leaf oils was comparable to those of delta-phenothrin and pyrethrum on the basis of LT(50) values at 0.25 mg/cm(2). At 0.25 mg/cm(2), the compound most toxic to female P. capitis was eugenol followed by methyl salicylate. Acetyleugenol, beta-caryophyllene, alpha-humulene, isoeugenol, and methyleugenol were not effective. Eugenol at 0.25 mg/cm(2) was as potent as delta-phenothrin and pyrethrum but was slightly less effective than the pyrethroids at 0.125 mg/cm(2). Against P. capitis eggs, methyl salicylate and eugenol were highly effective at 0.25 and 1.0 mg/cm(2), respectively, whereas little or no activity at 5 mg/cm(2) was observed with the other test compounds as well as with delta-phenothrin and pyrethrum. In fumigation tests with female P. capitis at 0.25 mg/cm(2), eugenol and methyl salicylate were more effective in closed cups than in open ones, indicating that the effect of the compounds was largely due to action in the vapor phase. Neither delta-phenothrin nor pyrethrum exhibited fumigant toxicity. The Eugenia bud and leaf essential oils, particularly eugenol and methyl salicylate, merit further study as potential P. capitis control agents or lead compounds.     

Quantification of flavor-related compounds in the unburned contents of bidi and clove cigarettes

Bidi cigarettes, small hand-rolled cigarettes produced primarily in India, are sold in the United States in a wide variety of candy-like flavors (e.g. dewberry, chocolate, clove) and are popular with adolescents. Many flavored bidis contain high concentrations of compounds such as eugenol, anethole, methyleugenol, pulegone, and estragole; several of these compounds have known toxic or carcinogenic properties. Clove cigarettes, or kreteks, are another highly flavored tobacco product with high levels of eugenol due to clove buds present in the tobacco filler. In this study, compounds in the burnable portion-the filler and wrapper material actually consumed during the smoking of bidis, kreteks, and U.S. cigarettes-were analyzed. Flavor-related compounds were solvent extracted from the burnable portion of each cigarette with methanol. An aliquot of the methanol extract was heated, and the sample headspace was sampled with a solid-phase microextraction fiber and introduced into a gas chromatograph-mass spectrometer for analysis in selected-ion monitoring mode. High levels of eugenol were detected in five clove-flavored bidi brands ranging from 78.6 to 7130 microg/cigarette (microg/cig), whereas diphenyl ether (128-3550 microg/cig) and methyl anthranilate (154-2360 microg/cig) were found in one grape-flavored bidi brand. A nontobacco herbal bidi brand contained the greatest variety of compounds, including anethole (489-665 microg/cig), eugenol (1670-2470 microg/cig), methyleugenol (27.7-36.6 microg/cig), safrole (32.4-34.4 microg/cig), myristicin (170-247 microg/cig), and elemicin (101-109 microg/cig). Filler from kreteks was found to contain high levels of eugenol, anethole, and coumarin. Flavored bidis and clove cigarettes contain a number of compounds that are present at levels far exceeding those reported in U.S. cigarette tobacco. Research is underway to determine the levels of these compounds delivered in smoke. It is not known what effect inhalation of these compounds has on smokers.     

Insect antifeedants from tropical plants II: structure of zumsin

A novel A-seco limonoid was isolated from methanolic extract of Croton jatrophoides and designated as zumsin. This compound showed potent antifeedant activity against two lepidopteran larvae, pink bollworm, Pectinophora gossypiella (PC(50) = 1 microg/cm(2), PC(95) = 8 microg/cm(2)), and fall armyworm, Spodoptera frugiperda (PC(50) = 2 microg/cm(2), PC(95) = 16 microg/cm(2)). The structure of zumsin was determined as 1 using a variety of spectroscopic methods including nuclear magnetic resonance, mass spectrometry, and circular dichroism. The structure consists of an A'-B trans-fused ring while dumsin (2), a constituent of the same source, maintains an A'-B cis-fused ring, and suggests two unique biosynthetic processes after A ring oxidative expansion.     

Quantitation of flavor-related alkenylbenzenes in tobacco smoke particulate by selected ion monitoring gas chromatography-mass spectrometry

Little is known about the possible health effects associated with inhaling alkenylbenzenes through cigarette smoking, even though these flavor-related compounds have known toxic effects in animals. We developed a rapid and sensitive solid-phase extraction (SPE) method to quantify seven alkenylbenzenes and piperonal in mainstream cigarette smoke particulate. The smoke particulate fraction of a single cigarette was collected on Cambridge filter pads, solvent extracted, concentrated, purified with SPE, and analyzed by selected ion monitoring gas chromatography-mass spectrometry. We positively identified and quantified five alkenylbenzenes compounds (eugenol, isoeugenol, methyleugenol myristicin, and elemicin) and piperonal in the smoke particulate from eight U.S. brands with mean levels (measured in triplicate) ranging from 6.6 to 4210 ng per cigarette. Additionally, complete blocking of nearly invisible ventilation holes in the cigarette filter increased 2- to 7-fold the percent transfer of alkenylbenzenes from tobacco to the particulate fraction of mainstream smoke.     

Antioxidant properties of aroma compounds isolated from soybeans and mung beans

Aroma compounds contained in the extracts of soybean and mung bean that possess antioxidant activity were identified by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The major aroma constituents of soybeans were 1-octen-3-ol (13.699 ppm), maltol (1.662 ppm), phenylethyl alcohol (1.474 ppm), hexanol (1.430 ppm), and gamma-butyrolactone (1.370 ppm). The major aroma constituents of mung beans were hexanol (3.234 ppm), benzyl alcohol (2.060 ppm), gamma-butyrolactone (1.857 ppm), 2-methyl-2-propenal (1. 633 ppm), and pentanol (1.363 ppm). The major aroma chemicals of soybeans and mung beans were examined for antioxidative activities in two different assays. Eugenol, maltol, benzyl alcohol, and 1-octen-3-ol showed potent antioxidative activities in two different assays. Eugenol, maltol, benzyl alcohol, and 1-octen-3-ol inhibited the oxidation of hexanal by 100%, 93%, 84%, and 32%, respectively, for a period of 40 days at the 500 microg/mL level. Eugenol, maltol, benzyl alcohol, and 1-octen-3-ol inhibited malonaldehyde (MA) formation from cod liver oil by 91%, 78%, 78%, and 78%, respectively, at the 160 microg/mL level. The antioxidative activity of eugenol was comparable to that of the natural antioxidant alpha-tocopherol (vitamin E).     

Antioxidant capacity and cytotoxicity of essential oil and methanol extract of Aniba canelilla (H.B.K.) Mez

The leaves and fine stems, bark, and trunk wood oils of Aniba canelilla showed yields ranging from 0.2 to 1.3%. The main volatile constituent identified in the oils was 1-nitro -2-phenylethane (70.2-92.1%), as expected. The mean of DPPH radical scavenging activity (EC 50) of the oils (198.17 +/- 1.95 microg mL(-1)) was low in comparison with that of wood methanol extracts (4.41 +/- 0.12 microg mL(-1)), the value of which was equivalent to that of Trolox (4.67 +/- 0.35 microg mL(-1)), used as antioxidant standard. The mean amount of total phenolics (TP) (710.53 +/- 23.16 mg of GAE/g) and this value calculated as Trolox equivalent antioxidant capacity (TEAC) (899.50 +/- 6.50 mg of TE/g) of the wood methanol extracts confirmed the high antioxidant activity of the species. On the other hand, in the brine shrimp bioassay the values of lethal concentration (LC50) for the oils (21.61 +/- 1.21 microg mL(-1)) and 1-nitro-2-phenylethane (20.37 +/- 0.99 microg mL(-1)) were lower than that of the wood methanol extracts (91.38 +/- 7.20 microg mL(-1)), showing significant biological activities.     

Quantitative gas chromatography-olfactometry carried out at different dilutions of an extract. Key differences in the odor profiles of four high-quality Spanish aged red wines

Four Spanish aged red wines made in different wine-making areas have been extracted, and the extracts and their 1:5, 1:50, and 1:500 dilutions have been analyzed by a gas chromatography-olfactometry (GC-O) approach in which three judges evaluated odor intensity on a four-point scale. Sixty-nine different odor regions were detected in the GC-O profiles of wines, 63 of which could be identified. GC-O data have been processed to calculate averaged flavor dilution factors (FD). Different ANOVA strategies have been further applied on FD and on intensity data to check for significant differences among wines and to assess the effects of dilution and the judge. Data show that FD and the average intensity of the odorants are strongly correlated (r(2) = 0.892). However, the measurement of intensity represents a quantitative advantage in terms of detecting differences. For some odorants, dilution exerts a critical role in the detection of differences. Significant differences among wines have been found in 30 of the 69 odorants detected in the experiment. Most of these differences are introduced by grape compounds such as methyl benzoate and terpenols, by compounds released by the wood, such as furfural, (Z)-whiskey lactone, Furaneol, 4-propylguaiacol, eugenol, 4-ethylphenol, 2,6-dimethoxyphenol, isoeugenol, and ethyl vanillate, by compounds formed by lactic acid bacteria, such as 2,3-butanedione and acetoine, or by compounds formed during the oxidative storage of wines, such as methional, sotolon, o-aminoacetophenone, and phenylacetic acid. The most important differences from a quantitative point of view are due to 2-methyl-3-mercaptofuran, 4-propylguaiacol, 2,6-dimethoxyphenol, and isoeugenol.     

Effect of high-pressure treatment on the carotenoid composition and the radical scavenging activity of persimmon fruit purees

The carotenoid composition of persimmon fruit purees of two cultivars, cvs. Rojo Brillante and Sharon, grown in Spain was determined by HPLC to assess the effects of high-pressure processing on some sensory (carotenoids), nutritional (provitamin A value), and health-related (radical-scavenging capacity) parameters. Total carotenoid content was higher in untreated Rojo Brillante puree (22. 11 microg g(-)(1)) than in untreated Sharon puree (15.22 microg g(-)(1)). Purees of both untreated cultivars showed similar carotenoid patterns after saponification with beta-cryptoxanthin, beta-carotene, and zeaxanthin as the main pigments. A high content of lycopene was quantified in Rojo Brillante (5.34 microg g(-)(1)), whereas only traces were detected in Sharon. The provitamin A value, reported as retinol equivalents (RE), was in untreated Rojo Brillante puree (77 RE/100 g) similar to that of Sharon (75 RE/100 g). Scavenging free radical capacity, measured as antiradical efficiency (AE), showed in untreated Rojo Brillante puree a value (12.14 x 10(-)(3)) 8.5 times higher than that in untreated Sharon (1. 42 x 10(-)(3)). Nonuniform behavior of high-pressure treatment was detected. Pressure treatments at 50 and 300 MPa/15 min/25 degrees C for Rojo Brillante and at 50 and 400 MPa/15 min/25 degrees C for Sharon increased the amount of extractable carotenoids (9-27%), which are related with the increase of vitamin A value (75-87 RE/100 g). No correlation with the increase of AE (from 1.42 x 10(-)(3) to 16.73 x 10(-)(3) and 19.58 x 10(-)(3)) after some pressure treatments (150 and 300 MPa/15 min/25 degrees C) was found.     

Natural occurrence of fumonisins in corn from Iran

Corn collected in the Mazandaran and Isfahan Provinces of Iran was analyzed for fumonisin B(1) (FB(1)), fumonisin B(2) (FB(2)), and fumonisin B(3) (FB(3)). The samples from Mazandaran Province, situated on the Caspian littoral of Iran, were random samples from farmers' corn lots collected in September 1998, whereas those from Isfahan Province, situated further south in the center of Iran, were bought as corn cobs in the local retail market during October 1998. All 11 samples from Mazandaran showed high levels of fumonisin contamination with FB(1) levels between 1.270 and 3.980 microg/g, FB(2) levels between 0.190 and 1.175 microg/g, and FB(3) levels between 0.155 and 0.960 microg/g. Samples from Isfahan showed lower levels of contamination with eight of eight samples having detectable FB(1) (0.010-0.590 microg/g), two of eight samples having detectable FB(2) (0.050-0.075 microg/g), and two of eight samples having detectable FB(3) (0.050-0.075 microg/g). This is the first report of fumonisin contamination of corn from Iran, in which samples from the area of high esophageal cancer on the Caspian littoral have been shown to contain high levels of fumonisins.     

Metabolism of metamitron in goat following a single oral administration of a nontoxic dose level: a continued study

Disposition kinetic behavior and metabolism studies of metamitron and its metabolite in terms of the parent compound were carried out in black Bengal goats after a single oral administration of a nontoxic oral dose at 30 mg kg(-1) of body weight. Metamitron was detected in the blood sample at 5 min (2.23 +/- 0.04 microg mL(-1)), maximum at 1 h (3.43 +/- 0.02 microg mL(-1)) and minimum at 12 h (0.41 +/- 0.01 microg mL(-1)), after a single oral administration. Metabolite [3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one] in terms of the parent compound was detected in the blood sample at 5 min (0.47 +/- 0.006 microg mL(-1)), maximum at 6 h (5.12 +/- 0.02 microg mL(-1)) and minimum at 96 h (1.06 +/- 0.016 microg mL(-1)), after a single oral administration. The t(1/2 K) and Cl(B) values of metamitron were 3.63 +/- 0.05 h and 1.36 +/- 0.016 L kg(-1) h(-1), respectively, whereas the t(1/2K)(m) and Cl(B)(m) values of the metabolite were 38.15 +/- 0.37 h and 0.091 +/- 0.001 L kg(-1) h(-1), respectively, which suggested long persistence of the metabolite in blood and tissues of goat. Metamitron was excreted through feces and urine for up to 48 and 72 h, whereas the metabolite was excreted for up to 168 and 144 h, respectively. Metabolite alone contributed to 96 and 67% of combined recovery percentage of metamitron and metabolite against the administered dose in feces and urine of goat, respectively. All of the goat tissues except lung, adrenal gland, ovary, testis, and mammary gland retained the metabolite residue for up to 6 days after administration.     

Vitamin D2 formation from post-harvest UV-B treatment of mushrooms (Agaricus bisporus) and retention during storage

The objectives of this research were to study the effects of high intensity (0.5, 0.75, and 1.0 mW/cm (2)), dose (0.5, 1.0, and 1.5 J/cm (2)), and postharvest time (1 and 4 days) on the vitamin D 2 formation in Portabella mushrooms ( Agaricus bisporus) as a result of UV-B exposure, as well as the vitamin D 2 degradation in treated mushrooms during storage. Within each intensity application, dose had the largest effect where more exposure converted more vitamin D 2 from ergosterol. Similar dose across each intensity application resulted in similar vitamin D 2 concentration. Practical commercial production requires as short a treatment time as possible, and intensity was a major factor from this standpoint where the time it took to achieve a similar vitamin D 2 concentration for similar dose exposure was significantly reduced as intensity increased. By using an intensity of 1.0 mW/cm (2) at a dose of 0.5 J/cm (2), the concentration of vitamin D 2 produced was 3.83 microg/g dry solids of mushrooms in 8 min, whereas using an intensity of 0.5 mW/cm (2) at a dose of 0.5 J/cm (2), the concentration of vitamin D 2 produced was 3.75microg/g dry solids of mushrooms in 18 min. Also, postharvest time did not have a significant effect on vitamin D 2 formation in mushrooms that were treated 1 and 4 days after harvest. Vitamin D 2 degraded in treated mushrooms during storage by apparent first-order kinetics, where the degradation rate constant was 0.025 h (-1). The information provided in this study will help mushroom producers develop commercial-scale UV treatment processes to add value to their crop while improving consumer health.     

Ovicidal and adulticidal activity of Eucalyptus globulus leaf oil terpenoids against Pediculus humanus capitis (Anoplura: Pediculidae)

The toxic effects of Eucalyptus globulus leaf oil-derived monoterpenoids [1,8-cineole, l-phellandrene, (-)-alpha-pinene, 2-beta-pinene, trans-pinocarveol, gamma-terpinene, and 1-alpha-terpineol] and the known Eucalyptusleaf oil terpenoids (beta-eudesmol and geranyl acetate) on eggs and females of the human head louse, Pediculus humanus capitis, were examined using direct contact and fumigation bioassays and compared with the lethal activity of delta-phenothrin and pyrethrum, two commonly used pediculicides. In a filter paper contact bioassay with female P. h. capitis, the pediculicidal activity was more pronounced with Eucalyptus leaf oil than with either delta-phenothrin or pyrethrum on the basis of LT(50) values (0.125 vs 0.25 mg/cm(2)). 1,8-Cineole was 2.2- and 2.3-fold more toxic than either delta-phenothrin or pyrethrum, respectively. The pediculicidal activities of (-)-alpha-pinene, 2-beta-pinene, and (E)-pinocarveol were comparable to those of delta-phenothrin and pyrethrum. l-Phellandrene, gamma-terpinene, and 1-alpha-terpineol were relatively less active than delta-phenothrin and pyrethrum. beta-Eudesmol and geranyl acetate were ineffective. 1-alpha-Terpineol and (E)-pinocaveol were highly effective at 0.5 and 1.0 mg/cm(2), respectively, against P. h. capitis eggs. At 1.0 mg/cm(2), (-)-alpha-pinene, 2-beta-pinene, and gamma-terpinene exhibited moderate ovicidal activity, whereas little or no ovicidal activity was observed with the other terpenoids and with delta-phenothrin and pyrethrum. In fumigation tests with female P. h. capitis at 0.25 mg/cm(2), 1,8-cineole, (-)-alpha-pinene, (E)-pinocarveol, and 1-alpha-terpineol were more effective in closed cups than in open ones, indicating that the effect of the monoterpenoids was largely due to action in the vapor phase. Neither delta-phenothrin nor pyrethrum exhibited fumigant toxicity. Eucalyptus leaf oil, particularly 1,8-cineole, 1-alpha-terpineol, and (E)-pinocaveol, merits further study as potential pediculicides or lead compounds for the control of P. h. capitis.