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 sesquiterpenes from cultures of the basidiomycete Agaricus arvensis. Two new drimane sesquiterpenoids, 11,12-dihydroxy-15-drimeneoic acid (1) and 3α,11,15-trihydroxydrimene (2), were isolated from cultures of the basidiomycete Agaricus arvensis, together with one known compound 3β,11,12-trihydroxydrimene (3). Their structures were established by means of spectroscopic analysis.
{"Chemical": ["3\u03b2,11,12-trihydroxydrimene", "sesquiterpenoids", "3\u03b1,11,15-trihydroxydrimene", "drimane", "sesquiterpenes", "11,12-dihydroxy-15-drimeneoic acid"]}