Filename extension:.sd, .sdf
Internet media type:chemical/x-mdl-sdfile
Type of format:chemical file format
SDF is one of a family of chemical-data file formats developed by MDL; it is intended especially for structural information. "SDF" stands for structure-data file, and SDF files actually wrap the molfile (MDL Molfile) format. Multiple compounds are delimited by lines consisting of four dollar signs ($$$$). A feature of the SDF format is its ability to include associated data.
Associated data items are denoted as follows:
> <Unique_ID> XCA3464366 > <ClogP> 5.825 > <Vendor> Sigma > <Molecular Weight> 499.611
Some programs that can import SDF files (e.g. ISIS/Base) require that the first data field after the molecule data (in the example above, Unique_ID) be a unique identifier for each record.
Multiple data items are permitted on multiple lines.[clarification needed] The MDL SDF-format specification requires that a hard-carriage-return character be inserted into any text field whose content exceeds 200 characters. This requirement is frequently violated in practice, as many SMILES and InChI strings exceed that length.