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:

Does Microsecond Sugar Ring Flexing Encode 3D-Shape and Bioactivity in the Heparanome? The biological information encoded in carbohydrate sequences dwarfs that of proteins and nucleic acids. Deciphering structure-function relationships in heparin and heparan sulfate (the heparanome) is further compounded by extreme sequence diversity, experimental difficulties, and the computational cost of rigorous modeling. Here we perform unbiased microsecond dynamics simulations of 11 heparanome oligosaccharides (55 microseconds total) to investigate the effect of sequence on 3D-structure and to underpin a coarse-grained model that is consistent with long-time scale experimentally validated atomic motions in water. Pyranose ring flexing (puckering) in 2-O-sulfo-α-l-iduronic acid, which underlies heparin-mediated anticoagulation, was modulated by polymerization (chain position and adjacent residues), which is supported by previous experiments. Furthermore, in coarse-grained simulations, inclusion of puckering was essential to predict macroscopic hydrodynamic properties of heparan sulfate chains containing hundreds of monosaccharaides. Our structural findings and model enable rational molecular design, and we propose that, in the heparanome, puckering, polymer 3D-shape, and bioactivity are inextricably linked.
{"Chemical": ["Pyranose", "carbohydrate", "2-O-sulfo-\u03b1-l-iduronic acid", "monosaccharaides", "Sugar", "sulfate"]}