Microsomal Oxidation and Insecticide Metabolism

Nakatsugawa, Tsutomu; Morelli, M.

doi:10.1007/978-1-4899-2212-0_2

Cited by 49 publications

(26 citation statements)

References 182 publications

(177 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Aquatic insects have been suggested to possess lower capacities for detoxification of lipophilic xenobiotics such as insecticides [21], because there would be lower levels of exposure to lipophilic compounds in an aquatic environment. Reduced levels of xenobiotic-metabolizing enzymes in aquatic insects relative to terrestrial insects would be in agreement with the general trend of increased sensitivity of aquatic insects.…”

Section: Discussionmentioning

confidence: 99%

Comparative toxicity of pyrethroid insecticides to terrestrial and aquatic insects

Siegfried

1993

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

The acute toxicities of three pyrethroid insecticides (permethrin, cypermethrin, and bi‐fenthrin) and one organophosphate insecticide (chlorpyrifos) were compared by topical application and static exposure to a variety of terrestrial and aquatic insects. Mayflies and damselflies were the most susceptible taxa tested by both exposure methods. The aquatic insects were generally more susceptible than the terrestrial insects when compared on a dose per body weight basis, although the differences were smaller than expected, given the extremely low concentrations that produce toxic effects by static exposure.

show abstract

Section: Discussionmentioning

confidence: 99%

Comparative toxicity of pyrethroid insecticides to terrestrial and aquatic insects

Siegfried

1993

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

show abstract

“…1). The dehydrogenation herein described is a unique reaction since all known epoxidations incorporate molecular oxygen into unsaturated compounds (2,4,5,8,16,21,22). We are now searching for the enzyme(s) that converts Hyos-OH to scopolamine by a cis-dehydrogenation reaction.…”

Section: Methodsmentioning

confidence: 99%

Epoxidation in Vivo of Hyoscyamine to Scopolamine Does Not Involve a Dehydration Step

Hashimoto

Kohno²,

Yamada³

1987

Plant Physiol.

View full text Add to dashboard Cite

Hyoscyamine is epoxidized to scopolamine via 6,6-hydroxyhyoscyamine in several solanaceous plants. 6,7-Dehydrohyoscyamine has been proposed to be an intermediate in the conversion of 6#-hydroxyhyoscyamine to scopolamine on the basis of the observation that this unsaturated alkaloid is converted to scopolamine when fed to a Datura scion. To determine whether a dehydration step is involved in scopolamine biosynthesis, 16-'8016j0-hydroxyhyoscyamine was prepared from I-hyoscyamine and '02 using hyoscyamine 6f6-hydroxylase obtained from root cultures of Hyoscyamus niger L. When 16-'8016,-hydroxyhyoscyamine was fed to shoot cultures of Duboisia myoporoides R. BR., the labeled alkaloid was converted to scopolamine which retained "O in the epoxide oxygen. It is concluded that 6,6-hydroxyhyoscyamine is converted in vivo to scopolamine without a dehydration step.Scopolamine, the epoxide of hyoscyamine, is one of the major alkaloids which accumulate in the family Solanaceae (7). The formation of the epoxide bridge in scopolamine begins with the hydroxylation of L-hyoscyamine to Hyos-OH' by a 2-oxoglutarate-dependent dioxygenase, hyoscyamine 6#-hydroxylase (12 De-hyos (scheme 1 in Fig. 1); '"0 should be retained if dehydration is not involved (scheme 2 in Fig. 1). MATERIALS AND METHODSChemicals. '"02 (>99 atom %) was purchased from CEA, France. L-Hyoscyamine hydrobromide and scopolamine hydrobromide were obtained from Nakarai Chemicals, Kyoto. Hyos-OH hydrobromide was prepared using hyoscyamine 6#-hydroxylase from root cultures of Hyoscyamus niger L. (12). De-hyos was synthesized by the method of Sharpless et al. (23). Other chemicals were obtained as described previously (12).Root and Shoot Cultures. Culture conditions for root cultures ofH. niger L. have been reported elesewhere (12). Shoot cultures ofDuboisia myoporoides R. BR. were initiated according to Endo et al. (6) and were subcultured on a Gyrotory shaker (model G 10-21, New Brunswick Scientific, Edison, NJ) at 100 rpm and 25°C under light (2,700-4,500 lux) in 100-ml flasks containing 25 ml of liquid B5 medium (10) supplemented with 3% (w/v) sucrose and 10 Mm 6-BA. In the feeding experiments, alkaloid solutions were neutralized with HCI when necessary and were sterilized by passing through 0.22 Am membrane filters. These were added to 10 ml ofthe above culture medium in 50-ml flasks to a final concentration of0.2 mm. The shoot cultures containing young leaves were inoculated in each flask and cultured under the above conditions.Partial Purification of Hyoscyamine 6,8-Hydroxylase. Hyoscyamine 6t3-hydroxylase was partially purified from root cultures ofH. niger. The hydroxylase in the crude extract was precipitated between 60 and 80% saturation of (NH4)2SO4 and subsequently chromatographed on a DEAE-Toyopearl 650M column. The detailed purification procedure has been reported (13). The partially purified enzyme preparation (about 23-fold in specific activity) was concentrated using Amicon

show abstract

“…The presence of fuel was probably responsible for the increased metabolic rate initially observed. Insects contain a highly developed microsomal oxidase system (Nakatsugawa and Morelli, 1976;and Matsumura, 1975).…”

Section: Effect Of Fuels On Metabolic Ratementioning

confidence: 99%

Comparative Toxicity of Selected Aviation Fuels as Measured by Insect Bioassay

Bombick¹,

Arlian²,

Livingston³

1982

View full text Add to dashboard Cite

NOTICESWhen US Cm. erninelit drti n~lg , spec jficat~ions, Ol other do:t aýre used for any' pLrpo0se other than a definitely related Government procuremnent operationo, the (jovermnoult thercnhý biicuPs no responisibility nor iny obligation whaitsoever, and the fa-ct that the Government na1ýy hanve fornmula ed, fturn ished, or in ,my waiy supplied the said dra1wings, specifications, or other data, is not to be re.garded by imlpllication or otherwise, as in any manner licensing the holder or any other person or corporation, or conveyag a-m rights or permission to manufacture, use, or sell any patented 1nenio thtmy in any waýy be, rein tedi thereto. DISTRIBUTION STATEMENT (of this Report)Approved for public release; distribution unlimited. The acute toxicity of JP-4, JP-8 and JP-9 fuels was evaluated for several terrestrial insects by contact exposure. JP-8 was the most toxic fuel to most of the insect species. Shale derived fuels were more toxic than their petroleum derived counterparts, however, species response varied with each type fuel. The order of decreasing susceptibility to petroleum derived JP-4 was earwigsrice weevilsbflour bettles, lady beetles'ptenebrionid beetlegcockroaches.

show abstract

Microsomal Oxidation and Insecticide Metabolism

Cited by 49 publications

References 182 publications

Comparative toxicity of pyrethroid insecticides to terrestrial and aquatic insects

Comparative toxicity of pyrethroid insecticides to terrestrial and aquatic insects

Epoxidation in Vivo of Hyoscyamine to Scopolamine Does Not Involve a Dehydration Step

Comparative Toxicity of Selected Aviation Fuels as Measured by Insect Bioassay

Contact Info

Product

Resources

About