You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

A high throughput assay for the glucuronidation of 7-hydroxy-4-trifluoromethylcoumarin by recombinant human UDP-glucuronosyltransferases and liver microsomes. Abstract 1.  UDP-glucuronosyltransferases (UGTs) are versatile and important conjugation enzymes in the metabolism of drugs and other xenobiotics. 2.  We have developed a convenient quantitative multi-well plate assay to measure the glucuronidation rate of 7-hydroxy-4-trifluoromethylcoumarin (HFC) for several UGTs. 3.  We have used this method to screen 11 recombinant human UGTs for HFC glucuronidation activity and studied the reaction kinetics with the most active enzymes. We have also examined the HFC glucuronidation activity of liver microsomes from human, pig, rabbit and rat. 4.  At a substrate concentration of 20 µM, the most active HFC glucuronidation catalysts were UGT1A10 followed by UGT1A6 >UGT1A7 >UGT2A1, whereas at 300 µM UGT1A6 was about 10 times better catalyst than the other recombinant UGTs. The activities of UGTs 1A3, 1A8, 1A9, 2B4 and 2B7 were low, whereas UGT1A1 and UGT2B17 exhibited no HFC glucuronidation activity. UGT1A6 exhibited a significantly higher Vmax and Km values toward both HFC and UDP-glucuronic acid than the other UGTs. 5.  Human, pig and rabbit, but not rat liver microsomes, catalyzed HFC glucuronidation at high rates. 6.  This new method is particularly suitable for fast activity screenings of UGTs 1A6, 1A7, 1A10 and 2A1 and HFC glucuronidation activity determination from various samples.
{"Chemical": ["UDP", "glucuronic acid", "HFC", "7-hydroxy-4-trifluoromethylcoumarin"]}