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 triterpenoid saponins from the husks of Xanthoceras sorbifolia. Two new oleanane triterpenoid saponins, xanthohuskisides A (1) and B (2), were isolated from the husks of Xanthoceras sorbifolia. The structures of these two compounds were established as 3-O-β-D-glucopyranosyl (1→6)-[β-D-glucopyranosyl (1→2)]-β-D-glucopyranosyl, 28-O-β-D-glucopyranosyl (1→6)-[α-L-rhamnopyranosyl (1→2)]-β-D-glucopyranosyl 16-deoxybarringtogenol C (1) and 3-O-β-D-glucopyranosyl (1→6)-[β-D-glucopyranosyl (1→2)]-β-D-glucopyranosyl, 28-O-β-D-glucopyranosyl (1→6)-β-D-glucopyranosyl 16-deoxybarringtogenol C (2), respectively, based on the analysis on their spectral data including NMR and HR-ESI-MS. The growth inhibitory activities of compounds 1 and 2 were assayed, and 2 showed moderate activity against U937 cell line with the IG(50) value of 82.85 ± 1.58 µM.
{"Chemical": ["xanthohuskisides", "3-O-\u03b2-D-glucopyranosyl (1\u21926)-[\u03b2-D-glucopyranosyl (1\u21922)]-\u03b2-D-glucopyranosyl, 28-O-\u03b2-D-glucopyranosyl (1\u21926)-\u03b2-D-glucopyranosyl 16-deoxybarringtogenol C", "3-O-\u03b2-D-glucopyranosyl (1\u21926)-[\u03b2-D-glucopyranosyl (1\u21922)]-\u03b2-D-glucopyranosyl, 28-O-\u03b2-D-glucopyranosyl (1\u21926)-[\u03b1-L-rhamnopyranosyl (1\u21922)]-\u03b2-D-glucopyranosyl 16-deoxybarringtogenol C", "triterpenoid saponins", "oleanane"]}