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:

Triterpene saponins from Clethra barbinervis and their hyaluronidase inhibitory activities. An extract of Clethra barbinervis with an inhibitory effect on hyaluronidase activity was fractionated guided by the results of an assay. From the active fractions, seven new triterpene saponins (1-4, 6-8) and a new lignan glycoside (14) were isolated together with 14 known compounds (5, 9-13, 15-22). Some of the saponins (2, 3, 9) were revealed as hyaluronidase inhibitors similar to epicatechin (17).
{"Chemical": ["triterpene saponins", "saponins", "lignan glycoside", "epicatechin", "Triterpene saponins"]}