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:

Alkaloids from Microcos paniculata with cytotoxic and nicotinic receptor antagonistic activities.
Microcos paniculata is a large shrub or small tree that grows in several countries in South and Southeast Asia. In the present study, three new piperidine alkaloids, microgrewiapines A-C (1-3), as well as three known compounds, inclusive of microcosamine A (4), 7'-(3',4'-dihydroxyphenyl)-N-[4-methoxyphenyl)ethyl]propenamide (5), and liriodenine (6), were isolated from cytotoxic fractions of the separate chloroform-soluble extracts of the stem bark, branches, and leaves of M. paniculata. Compounds 1-6 and 1a (microgrewiapine A 3-acetate) showed a range of cytotoxicity values against the HT-29 human colon cancer cell line. When evaluated for their effects on human α3β4 or α4β2 nicotinic acetylcholine receptors (nAChRs), several of these compounds were shown to be active as nAChR antagonists. As a result of this study, microgrewiapine A (1) was found to be a selective cytotoxic agent for colon cancer cells over normal colon cells and to exhibit nicotinic receptor antagonistic activity for both the hα3β4 and hα4β2 receptor subtypes.
{"Chemical": ["chloroform", "microcosamine A", "liriodenine", "piperidine alkaloids", "microgrewiapine A", "acetylcholine", "microgrewiapine A 3-acetate", "microgrewiapines A-C", "7\u0027-(3\u0027,4\u0027-dihydroxyphenyl)-N-[4-methoxyphenyl)ethyl]propenamide"], "Protein": ["nicotinic receptor", "nAChRs", "h\u03b13\u03b24 and h\u03b14\u03b22 receptor", "nAChR", "human \u03b13\u03b24 or \u03b14\u03b22 nicotinic acetylcholine receptors"]}