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:

Melanogenesis inhibitory daphnane diterpenoids from the flower buds of Daphne genkwa. Two new daphnane-type diterpene esters, daphneresiniferins A (1) and B (2), along with seven known diterpenes, yuanhuacine (3), yuanhuadine (4), yuanhuahine (5), genkwadaphnin (6), genkwanine A (7), genkwanine F (8), and genkwanine H (9), were isolated from the methanol extract of the flower buds of Daphne genkwa. Their structures were elucidated on the basis of spectroscopic methods, especially 2D NMR spectra such as HMQC, HMBC, and NOESY. All the isolates were evaluated for their inhibitory effects of the melanogenesis against α-melanocyte stimulating hormone (α-MSH)-activated B16 melanoma cells.
{"Chemical": ["daphneresiniferins A (1) and B", "genkwanine H", "genkwadaphnin", "yuanhuadine", "yuanhuahine", "methanol", "genkwanine A", "daphnane diterpenoids", "genkwanine F", "yuanhuacine", "diterpenes"]}