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:

Synthesis and antibacterial evaluation of typharin analog: 6,8-dihydroxy-7-methyl-3-styryl-3,4-dihydroisocoumarin. Synthesis of the 6-hydroxy-7-methyl analog of typharin (8-dihydroxy-3-styryl-3,4-dihydroisocoumarin) isolated from the rhizomes of Typha capensis has been described. Direct condensation of 3,5-dimethoxy-4-methylhomophthalic acid (1) with cinnamoyl chloride at elevated temperature under inert conditions afforded 6,8-dihydroxy-7-methyl-3-styrylisocoumarin (2). Hydrolysis of isocoumarin to keto acid (3) followed by reduction and cyclodehydration of hydroxy acid analog (4) afforded ( ± )-6,8-dimethoxy-3-(4-methoxyphenyl)-3,4-dihydroisocoumarin (5). Demethylation of the latter using anhydrous aluminum chloride/ethane thiol furnished the title isocoumarin (6). Compounds (1-6) were screened for in vitro antibacterial activity against a representative panel of Gram-positive and Gram-negative bacteria using levofloxacin as the reference drug.
{"Chemical": ["6-hydroxy-7-methyl", "6,8-dihydroxy-7-methyl-3-styryl-3,4-dihydroisocoumarin", "8-dihydroxy-3-styryl-3,4-dihydroisocoumarin", "cinnamoyl chloride", "6,8-dihydroxy-7-methyl-3-styrylisocoumarin", "(\u00a0\u00b1\u00a0)-6,8-dimethoxy-3-(4-methoxyphenyl)-3,4-dihydroisocoumarin", "aluminum chloride", "ethane thiol", "levofloxacin", "isocoumarin", "hydroxy acid", "3,5-dimethoxy-4-methylhomophthalic acid", "keto acid", "typharin"]}