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:

Lipophilic components from Fructus Viticis Negundo and their anti-tumor activities. Two new triterpenoids, (24R/S)-24-hydroxy-3α 10α-epoxy-9-eip-cucurbita-25-ene (1a, b), as well as six known compounds (3-8), were isolated from the extraction of Fructus Viticis Negundo. Their structures were established on the basis of spectral analysis. In addition, all the compounds were tested for inhibitory effect against K-562 and A-549 cell lines.
{"Chemical": ["triterpenoids", "(24R/S)-24-hydroxy-3\u03b1 10\u03b1-epoxy-9-eip-cucurbita-25-ene"]}