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:

Evaluation of antioxidant activities and chemical characterisation of staghorn sumac fruit (Rhus hirta L.). Staghorn sumac (Rhus hirta L.) is a native tree in Eastern Canada whose fruit has been used by aboriginal peoples to treat various illnesses, and has recently been found to be a good source of antioxidants. However, the phytochemical composition of R. hirta is not known. In this study, we used Four highly accepted assays and confirmed its FRAP, ORAC, β-CLAMS and PCL values to be 79.95 μmol AAE/g DW, 1544 μmol TE/g DW, RAA 129% and 4513 μmol TE/g DW, respectively. The antioxidant activities correlated positively to the total polyphenols content, which was higher in the ethanolic extract (81.6 mg GAE/ g DW) compared to the water extract (46.3mg GAE/g DW), suggesting polyphenols play an important role. Quantitative data from UHPLC and qualitative studies using HPLC-DAD-MS showed that in addition to commonly found phenolic acids, flavonoids and anthocyanins, R. hirta fruit contained a novel group of unique anthocyanins with aglycones (anthocyanidins) at 449, 419 and 433 Da. Further studies on the identification and their health beneficial effects are being conducted.
{"Chemical": ["flavonoids", "polyphenols", "anthocyanidins", "anthocyanins", "phenolic acids"]}