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:

Novel Pyridinone Derivatives As Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) with High Potency against NNRTI-Resistant HIV-1 Strains. Novel 6-substituted-4-cycloalkyloxy-pyridin-2(1H)-ones were synthesized as non-nucleoside reverse transcriptase inhibitors (NNRTIs), and their biological activity was evaluated. Most of the compounds, especially 26 and 22, bearing a 3-isopropyl and 3-iodine group, respectively, exhibited highly potent activity against wild-type HIV-1 strains and those resistant to reverse transcriptase inhibitors (RTIs). The diastereoisomers of 26-trans and 26-cis were synthesized separately and confirmed with HPLC and NOESY spectra. The 26-trans isomers had an activity about 400-fold more potent than that of 26-cis. The pair of 26-trans enantiomers, one of the most potent inhibitors with EC50 of 4 nM and selectivity index (SI) of 75000, was highly effective against a panel of RTIs-resistant strains with single (Y181C and K103N) or double (A17) mutations in reverse transcriptase. The results suggest that these novel pyridinone derivatives have the potential to be further developed as new antiretroviral drugs with improved antiviral efficacy and drug resistance profile.
{"Chemical": ["nucleoside", "Pyridinone", "6-substituted-4-cycloalkyloxy-pyridin-2(1H)-ones", "3-iodine", "3-isopropyl", "pyridinone", "Nucleoside"]}