Figure S1
Zingiberales
Calathea lancifolia
(Marantaceae)
P5
701
P4M
P6
833
P7
759
P4M
1097
800
900
m/z
1000
1100
700
1200
Zingiber officinialis
(Zingiberaceae)
P5
701
745 759
700
800
900
m/z
1000
1100
700
1200
m/z
1000
1100
1200
Musa sp
(Musaceae)
P6
833 877
745
1097
965
891
877
P4U
P8
P
P5U P5M 7
1009 1023
913
891
929
797
832
P8
P6M 1097
P5M
759 781
701
P4U P4M
900
P4M
P6
P7
965
877 891
800
P5
P 5M
P5U
759
745
891
700
P6
833
701
P8
965
P5M
Ctenanthe oppenheiminiana
(Marantaceae)
P5
800
900
m/z
1000
1100
1200
Arecales
P4M
781
759
P5
Rhapis excelsa
(Arecaceae)
P5M
913
930
797
P6M
P5
701
1024 1046
701
700
800
900
913
781
759
891
m/z
1000
1100
1200
Caryota mitis
(Arecaceae)
P5M
P4M
891
930
797
P6M
1024 1046
700
800
900
m/z
1000
1100
1200
Asparagales
P4M
759
781
Ludisia discolor
(Orchidaceae)
P5M
P5U 891
877 913
P4U
P6U P M
6
P4U
759
745 781
10091023
1045
P7U
891
913
877
P7M
P6U
800
900
m/z
1000
1100
1200
P5M
700
800
P4M
759 781
900
929
m/z
1009
1000
m/z
1000
1100
1200
758
780
P7M
1061
1100
P4U
877 P5M
891
700
800
P6U
1009
913
745
1155 1176
1200
Elodea canadensis
(Araceae)
P5U
P4M
P6U
877
800
Clivia miniata
(Amaryllidaceae)
1023
1045
P5U
900
Alismatales
P6M
891
913
P6M
1023
1009 1045
Asparagales
700
P5M
P5U
1155
1141
1177
745
700
P4M
Iris germanica
(Iridaceae)
900
m/z
P6M
1023
1045
1000
1100
1200
Supplementary Fig. S1. MALDI-TOF mass spectrum of the isolated xylo-oligosaccharides
generated by xylanase treatment of the 1 M KOH extracts of AIR from selected monocots. The
[M+Na]+and [M-H+2Na]+ ions corresponding to the most abundant xylo-oligosaccharides in each
mixture are labeled as described in Figure 2 (main text).
Figure S2
Poales
Brachypodium distachyon
(Poaceae)
Terminal
Reducing
β-Xylp
α-Araf
Terminal
Reducing
4Me-α-GlcpA α-Xylp
Terminal
α-GlcpA
2-α-Araf
2,4-β-Xylp
(MG)
3,4-β-Xylp
(Araf)
Panicum virgatum
(Poaceae)
Oryza sativa
(Poaceae)
Miscanthus x giganteus
(Poaceae)
Setaria italica
(Poaceae)
Terminal
4Me-α-GlcpA
Cyperus alternifolius
(Cyperaceae)
2,4-β-Xylp
(MG)
3,4-β-Xylp
(Araf)
Terminal
α-GlcpA
2-α-Araf
Ananus comosus
(Bromeliaceae)
α-Rhap
α-GalpA
β-Xylp
(Rhap)
Tillandsia usneoides
(Bromeliaceae)
5.6
5.5
5.4
5.3
5.2
5.1
4.7
Chemical Shift (ppm)
4.6
4.5
4.4
4.3
Supplementary Fig. S2. Partial 600-MHz 1D 1H NMR spectra of xylo-oligosaccharides of selected
commelinid species.
4.2
Figure S3
Zingiberales
Amomum costatum
(Zingiberaceae)
Terminal
α-Araf
Terminal
4Me-α-GlcpA
Terminal
α-GlcpA
α-GalpA
Reducing
α-Xylp
α-Rhap
Reducing
β-Xylp 3,4-β-Xylp
2,4-β-Xylp
(Araf)
β-Xylp (MG)
(Rhap)
Hedychium coronarium
(Zingiberaceae)
Strelitzia alba
(Streliziaceae)
Commelinales
Tradescantia virginiana
(Commelinaceae
Starch
Sabal etonia
(Arecaceae)
Arecales
2-α-MeGlcpA
(Arap)
Terminal
α-Araf
Cocos nucifera
(Arecaceae)
Howea forsteriana
(Arecaceae)
5.6
5.5
5.4
5.3
5.2
5.1
4.7
Chemical Shift (ppm)
4.6
4.5
4.4
Supplementary Fig. S3. Partial 600-MHz 1D 1H NMR spectra of xylo-oligosaccharides
of selected Zingiberales, Commelinales and Arecales species.
4.3
4.2
Figure S4
Asparagales
Crinum americanum
(Amarylidaceae)
2-α-MeGlcpA
(Arap)
Terminal
Terminal
2-α-GlcpA
α-GlcpA 4Me-α-GlcpA
(Arap)
Reducing
α-Xylp
Terminal
α-Arap Reducing
β-Xylp
2,4-β-Xylp
(Arap)
Agapanthus africanus
(Amarylidaceae)
Allium cepa
(Amarylidaceae)
Asparagus officinalis
(Asparagaceae)
Tip
Asparagus officinalis
(Asparagaceae)
Stem
α-GalpA
α-Rhap
β-Xylp
(Rha)
Agave americana
(Asparagaceae)
5.6
5.5
5.4
5.3
5.2
5.1
4.7
Chemical Shift (ppm)
4.6
4.5
4.4
4.3
Supplementary Fig. S4 Partial 600-MHz 1D 1H NMR spectra of xylo-oligosaccharides isolated
from selected Asparagales (non-commelinid) species.
4.2
Figure S5
Liliales
Alstroemeria sp.
(Alstroemeriaceae)
H1-Terminal
α-GlcpA
α-GalpA
Reducing
α-Xylp α-Rhap
2,4-β-Xylp Reducing
β-Xylp
(GlcA)
β-Xylp
(Rha)
H1-Terminal
4Me-α-GlcpA
Tulip sp.
(Liliaceae)
2,4-β-Xylp
(MeGlcA)
Pandales
Pandanus utilis
(Pandanaceae)
Starch
Dioscorea alata
(Dioscoreaceae)
Dioscoreales
Alismatales
Orontium aquaticum
(Araceae)
2-α-GlcpA
Reducing
Terminal
(Arap)
Terminal
α-GlcpA 4Me-α-GlcpA α-Xylp
2,4-β-Xylp
(Arap)
Terminal Reducing
α-Arap
β-Xylp
Spirodela polyrhiza
(Araceae)
Lemna minor
(Araceae)
Acorus americanus
(Acoraceae)
5.6
5.5
Acorales
5.4
5.3
5.2
5.1
4.7
Chemical Shift (ppm)
4.6
4.5
4.4
4.3
Supplementary Fig. S5 Partial 600-MHz 1D 1H NMR spectra of xylo-oligosaccharides isolated from
selected Liliales, Pandales, Discoreales Alismatales, and Acorales species.
4.2
Figure S6
2,4-β-Xylp
(MeGlcpA-Galp)
Terminal α-Arap
(MeGlcpA)
Terminal β-Galp
(MeGlcpA)
2,4-β-Xylp
(MeGlcpA-Arap)
Terminal
4Me-α-GlcpA
Reducing α-Xylp
Terminal α-GlcpA
2-α-MeGlcpA (Arap)
2-α-MeGlcpA (Galp)
Supplementary Fig. S6 Partial 600-MHz 1D 1H gCOSY NMR
spectra of xylo-oligosaccharides generated from Eucalyptus
grandis wood GX. The labeled cross-peaks correspond to
correlations between vicinal protons of the glycosyl residues in
the sidechains containing GlcA/MeGlcA substituted with α-lArap or β-d-Galp residues.
Figure S7
a
915
P3M-2AB
929
P4M-2AB
1075 1089
P2M-2AB
753
700
959
945
769
800
900
P5M-2AB
1249
1119
1000
m/z
1100
1200
1300
P5 - 2AB
1031
b
P3 - 2AB
711
1003
P4- 2AB
871
857
700
800
P6 - 2AB
1191
P4M-2AB
1089
P3M-2AB
929
900
1061
1000
m/z
1100
1163
P5M-2AB
1249
1200
1300
Supplementary Fig. S7. ESI-MS spectra of the per-O-methylated and 2AB-labeled xylooligosaccharides from Setaria italica. Xylo-oligosaccharides were generated by selectively labeling the
reducing ends of polysaccharides in Setaria italica AIR with 2AB, extracting the labeled
polysaccharides with 1 M KOH, fragmenting the resulting polysaccharides with endo-xylanase,
separating the resulting products into fractions enriched in acidic and neutral oligosaccharides, and perO-methylating the oligosaccharides in each fraction. a Spectrum of the fraction enriched in acidic
oligosaccharides P2M, P3M, P4M, and P5M, which correspond to [M + Na]+ ions at m/z 769, 929, 1089,
and 1249, respectively. b Spectrum of the fraction enriched in neutral oligosaccharides P3, P4, P5, and P6,
which correspond to [M + Na]+ ions at m/z 711, 871, 1031, and 1191,, respectively. Comparable
oligosaccharides were generated from Miscanthus giganteus, Panicum virgatum, Oryza sativa, and
Brachypodium distachyon.
Figure S8
MS2 m/z 929
595
595
755 595
595
XXX2AB
697
M
XX2AB
755   697
P M
929
929
755
755
363
697
697
503
m/z
MS3 m/z 929→755
595
595
XX2AB
523

M
595
XX2AB
523
 
M
755
523
581
363
m/z
Supplementary Fig. S8. ESI-MSn indicates that the reducing-end xylose of Setaria italica GAX is
frequently substituted with GlcA. The precursor ion at m/z 929 (i.e., P3M-2AB) was selected from the
MS1 spectrum (see supplementary Fig. S7a) of the fraction enriched in acidic oligosaccharides and
subjected to ESI-MSn. Possible precursor ion structures and their fragmentation leading to the
generation of Y-ions are shown in each spectrum. The fragmentation pathway (929 – 755 – 595/523) is
consistent with the sequence Xyl-Xyl-(MeGlcA)-Xyl-2AB. The data do not rule out the possibility
that an oligosaccharide with the sequence (Pentose)-Xyl-(MeGlcA)-Xyl-2AB, which corresponds to an
oligosaccharide bearing a pentosyl sidechain, may also be present.
Figure S9
MS2 m/z 1089
915 755 595
915 595
X→X→X→X→2AB
857
M
595
X→X→X→2AB
915   857
P M
915
755
1089
857
897
363
m/z
MS3 m/z 1089 → 915
741 595
595
XXX2AB
  683
M
755 595
XXX2AB
 683
M
595
→X→X→2AB
 683
P M
741 
741
755
915
683
363
m/z
MS4 m/z 1089 → 915 → 755
595
595
XX2AB
523
M
363
523
581
755
m/z
Supplementary Fig. S9. Further evidence that the reducing-end xylose of Setaria italica GAX is
frequently substituted with GlcA. The precursor ion at m/z 1089 (i.e., P4M-2AB) was selected from
the MS1 spectrum (see supplementary Fig. S7a) of the fraction enriched in acidic oligosaccharides
and subjected to ESI-MSn. Fragmentation events leading to the generation of Y ions are indicated in
each spectrum.