scholarly journals Response to Comments on “Urinary Metabolites of Neonicotinoid Insecticides: Levels and Recommendations for Future Biomonitoring Studies in China”

2021 ◽  
Vol 55 (3) ◽  
pp. 2166-2168
Author(s):  
Shiming Song ◽  
Tao Zhang ◽  
Bo Zhang ◽  
Yingyan Huang ◽  
Yuankai Guo ◽  
...  
Keyword(s):  
Urinary Metabolites ◽  
Neonicotinoid Insecticides

Urinary Metabolites of Neonicotinoid Insecticides: Levels and Recommendations for Future Biomonitoring Studies in China

2020 ◽  
Vol 54 (13) ◽  
pp. 8210-8220 ◽  
Author(s):  
Shiming Song ◽  
Tao Zhang ◽  
Yingyan Huang ◽  
Bo Zhang ◽  
Yuankai Guo ◽  
...  
Keyword(s):  
Urinary Metabolites ◽  
Neonicotinoid Insecticides

scholarly journals Correction to “Urinary Metabolites of Neonicotinoid Insecticides: Levels and Recommendations for Future Biomonitoring Studies in China”

2021 ◽  
Vol 55 (9) ◽  
pp. 6521-6523
Author(s):  
Shiming Song ◽  
Tao Zhang ◽  
Yingyan Huang ◽  
Bo Zhang ◽  
Yuankai Guo ◽  
...  
Keyword(s):  
Urinary Metabolites ◽  
Neonicotinoid Insecticides

scholarly journals Comment on “Urinary Metabolites of Neonicotinoid Insecticides: Levels and Recommendations for Future Biomonitoring Studies in China”: Quantification of 5-Hydroxyimidacloprid and Biomonitoring

2021 ◽  
Vol 55 (3) ◽  
pp. 2163-2164
Author(s):  
Heiko U. Käfferlein ◽  
Holger M. Koch ◽  
Daniel Bury ◽  
Sonja A. Wrobel ◽  
Hans-Detlev Gilsing ◽  
...  
Keyword(s):  
Urinary Metabolites ◽  
Neonicotinoid Insecticides

Metabolic Studies of Vitamin K1-14C and Menadione-14C in the Normal and Hepatectomized Rats

1968 ◽  
Vol 19 (03/04) ◽  
pp. 383-388 ◽  
Author(s):  
R Losito ◽  
C. A Owen ◽  
E. V Flock ◽  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Oral Anticoagulants ◽  
Urinary Metabolites ◽  
The Other ◽  
Vitamin K1 ◽  
Vitamin K3 ◽  
Metabolic Studies ◽  
Intact Rats

SummaryThe metabolism of vitamin K1- 14C and menadione-14C (vitamin K3-14C) was studied in normal and hepateetomized rats. After the administration of menadione, about 70% of the 14C was excreted in the urine in 24 hrs in both types of rats. Two urinary metabolites were identified by enzymatic hydrolysis: one a glucuronide and the other a sulfate of reduced menadione. Thus, the liver is not necessary for the metabolism of menadione. In the vitamin K1 studies, the intact rats excreted only 10% of the 14C and the hepatectomized rats excreted less than 0.5%. The retention of vitamin K1 may explain its superiority over menadione as an antidote for overdosages of oral anticoagulants.

PHENOLIC METABOLITES OF DL-NORGESTREL: A METHOD FOR THE REMOVAL OF 1-HYDROXYLATED METABOLITES, POTENTIAL SOURCES OF PHENOLIC ARTIFACTS

1974 ◽  
Vol 76 (4) ◽  
pp. 789-800 ◽  
Author(s):  
Samuel F. Sisenwine ◽  
Ann L. Liu ◽  
Hazel B. Kimmel ◽  
Hans W. Ruelius
Keyword(s):  
Urinary Metabolites ◽  
Ion Exchange Resin ◽  
Gas Chromatography Mass Spectrometry ◽  
Phenolic Metabolites ◽  
Hydroxylated Metabolites ◽  
Analytical Work ◽  
Potential Sources ◽  
Alkaline Conditions ◽  
Artifact Formation ◽  
Work Up

ABSTRACT The identification of 1β-hydroxynorgestrel among the urinary metabolites of dl-norgestrel and the facile transformation of this compound under mild alkaline conditions to a potentially oestrogenic phenol provide an experimental basis for the conclusion advanced by others that the oestrogens present in the urine of subjects treated with synthetic progestens are artifacts formed during analytical work-up. A method has been devised which eliminates 1-hydroxylated metabolites as potential sources of phenolic artifacts. This method is based on the reduction by NaBH4 of the 1-hydroxy-4-en-3-one grouping in the A ring thereby excluding the possibility of aromatization during later fractionation on a basic ion exchange resin that separates neutral from phenolic metabolites. In the urines of women treated with 14C-dl-nogestrel, only 0.17–0.27% of the dose is found to have phenolic properties when this method is used. Two of the phenolic metabolites, 18-homoethynyloestradiol and 16β-hydroxy-18-homoethynyloestradiol, are present in amounts smaller than 0.01 % of the dose. Without the reduction steps the percentages are noticeably higher, indicating artifact formation under alkaline conditions. Similar results were obtained with urines from African Green Monkeys (Cercopithecus Aethiops) that had been dosed with 14C-dl-norgestrel. Radiolabelled 18-homoethynyloestradiol and 16β-hydroxy-18-homoethynyloestradiol were isolated from monkey urine and their identity confirmed by gas chromatography-mass spectrometry.

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