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: ["Protein", "Chemical"].

Please return the output as a JSON object of the format: {"Chemical" : ["Dexamethasone", ...], "Protein" : ["BRCA-1", ...]}. 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:

Synthesis and cytotoxicity of 3-aryl acrylic amide derivatives of the simplified saframycin-ecteinascidin skeleton prepared from l-dopa.
Twenty four compounds with diversified 3-aryl acrylic amide side chains of the simplified saframycin-ecteinascidin pentacyclic skeleton were synthesized via a 14-step stereospecific route starting from l-dopa. The cytotoxicities of these compounds were tested against eight human tumor cell lines including HCT-8, BEL-7402, BGC-803, A549, A2780, MCF-7, MX-1, and MDA-MB-231. Most of these compounds exhibited potent antitumor activity, and a preliminary structure-activity relationship (SAR) was discussed. Compound 28 with 3-thiophenyl acrylic amide side chain exhibited selective cytotoxicity against MDA-MB-231 cell line with the IC50 value of 50 nM.
{"Chemical": ["saframycin", "3-thiophenyl acrylic amide", "3-aryl acrylic amide", "l-dopa", "ecteinascidin"], "Protein": []}