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:

Phospholipases A2: unveiling the secrets of a functionally versatile group of snake venom toxins. Phospholipases A(2) (PLA(2)s) are abundant components of snake venoms, where they play toxic and digestive roles. Despite having a similar three-dimensional structure, venom PLA(2)s exert an amazing variety of toxic and pharmacological effects, which include neurotoxic, myotoxic, hemolytic, edematogenic, hyperalgesic, pro-inflammatory, hypotensive, platelet-aggregation inhibitory, anticoagulant, cytotoxic, and bactericidal activities. Toxinologists have made significant contributions to deciphering the structure, molecular evolution, mechanisms of action, receptors, role of enzymatic activity for toxicity, structural determinants of toxicity and selectivity, and the impact of these enzymes in the overall pathophysiology of snakebite envenoming. The present work highlights some of the most relevant contributions in the study of venom PLA(2)s, including the personal accounts of the authors of these studies.
{"Chemical": []}