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:

Polycyclic Hybrid Isoprenoids from a Reed Rhizosphere Soil Derived Streptomyces sp. CHQ-64. Two new hybrid isoprenoids, named indotertine B (2) and drimentine H (3), along with the known analogue drimentine C (4), were isolated from the reed rhizosphere soil derived actinomycete Streptomyces sp. CHQ-64. The structures of these compounds, including absolute configurations, were elucidated by extensive NMR, MS, and CD analyses. Indotertine B (2) exists as a pair of rotamers about the N-C(O) bond with a 2:1 ratio and displays activities against HCT-8 and A549 tumor cell lines with IC50 values of 6.96 and 4.88 μM, respectively.
{"Chemical": ["Isoprenoids", "indotertine B", "isoprenoids", "N-C(O)", "drimentine H", "drimentine C", "Indotertine B"]}