Glycan drawing/mass calculation for glycosylceramides

This tool takes a glycosylceramide glycan sequence as input and generates all possible intermediates, starting from glucosyl-ceramide. The reported exact mass of each intermediate corresponds to the glycan portion minus a molecule of water.

The "level" parameter is set at 20 by default, but may be changed to a smaller integer to restrict the number of displayed structures based on the number of glycans removed from the input sequence.
The input may be the LM_ID of a generic glycosylceramide (ending in "00", e.g. "LMSP0504BO00"), a SpingoMap ID present in LMSD (e.g. "193") or a full glycan name using the glycan symbol nomenclature (e.g."Galbeta1-3GlcNAcbeta1-3(GlcNAcbeta1-6)Galbeta1-3GlcNAcbeta1-3Galbeta1-4Glcbeta-Cer").
The full glycan name must be in the following format: <sugar1><linkage1><sugar2><linkage2>...Glcbeta-Cer
Maximum number of branches, designated by parentheses: 3
Allowed Sugars (maximum glycan length=20):'Fuc' (L-Fucose), 'Glc' (D-Glucose), 'Gal' (D-Galactose), 'Man' (D-Mannose), 'GlcNAc' (N-Acetyl-D-glucosamine), 'GalNAc' (N-Acetyl-D-galactosamine), 'KDN' (2-Keto-3-deoxy-nononic acid), 'NeuAc' (N-Acetylneuraminic acid) and 'NeuGc' (N-Glycolylneuraminic acid).
Allowed Linkages: alpha1-2, alpha1-3, alpha1-4, alpha1-6, alpha2-3, alpha2-6, alpha2-8, beta1-2, beta1-3, beta1-4, beta1-5, beta1-6, beta2-3 and beta2-6.