(a)
PCA scores and scree plot(s) for different GAG families. At
least two components are needed to separate the samples into family
groups, indicating that earlier components appear to separate by gross
structure, while later components separate by unique constituents.
(b) Score plot for PC1 versus PC2. Glycosaminoglycan families are
highlighted to show groupings, and the plot is split in half diagonally
to distinguish different glycosidic bond types (β 1–4
upper left vs β 1–3/4 lower right). In all plots, 176
heparins, comprising 69 PMH (dark green), 55 BMH (blue), 33 OMH (orange),
19 BLH (dark blue), 31 HS (orange), 50 chondroitins (including 13
CS-A samples, 16 CS-C samples, and 21 DS (green for monosulfated chondroitin
samples and teal for disulfated chondroitin samples)), 11 HA (purple),
and 6 OSCS (including the OSCS selected for the contamination study
later (aquamarine)) samples, as well as an OSAS and DeS sample, also
used in the contamination study are compared. All five repeats of
each sample are shown, and the polysaccharides selected for the contamination
study are highlighted in lilac. The ellipses are for illustrative
purposes only.