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:

Two new diterpenes from Caesalpinia minax Hance. Two new cassane-type diterpenes, Caesalpinolide F (1) and Caesalpinolide G (2) were isolated from Caesalpinia minax Hance. Their structures were elucidated on the basis of 1D and 2D NMR, MS and CD analysis. Compounds 1 and 2 were tested against colon carcinoma (HCT-8) and breast cancer (MCF-7) human cancer cell lines, and showed mild cytotoxicity activities.
{"Chemical": ["Caesalpinolide F", "cassane", "diterpenes", "Caesalpinolide G"]}