Weissella confusa VTT E-90392 is an efficient producer of a dextran that is mainly composed of α-(1→6)-linked d-glucosyl units and very few α-(1→3) branch linkages. A mixture of the Chaetomium erraticum endodextranase and the Aspergillus niger α-glucosidase was used to hydrolyze W. confusa dextran to glucose and a set of enzyme-resistant isomaltooligosaccharides. Two of the oligosaccharides (tetra- and hexasaccharide) were isolated in pure form and their structures elucidated. The tetrasaccharide had a nonreducing end terminal α-(1→3)-linked glucosyl unit (α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc), whereas the hexasaccharide had an α-(1→3)-linked isomaltosyl side group (α-D-Glcp-(1→6)[α-D-Glcp-(1→6)-α-D-Glcp-(1→3)]-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc). A mixture of two isomeric oligosaccharides was also obtained in the pentasaccharide fraction, which were identified as (α-D-Glcp-(1→6)-α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc) and (α-D-Glcp-(1→6)[α-D-Glcp-(1→3)]-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc). The structures of the oligosaccharides indicated that W. confusa dextran contains both terminal and elongated α-(1→3)-branches. This is the first report evidencing the presence of elongated branches in W. confusa dextran. The 1H and 13C NMR spectroscopic data on the enzyme-resistant isomaltooligosaccharides with α-(1→3)-linked glucosyl and isomaltosyl groups are published here for the first time.

Weissella confusa, isomaltooligosaccharide

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
6,6,3	aDGlcp	100.5	72.8	74.2	70.6	73.0	61.5
6,6	aDGlcp	99.1	73.0	81.1	70.8	72.9	61.5
6	aDGlcp	99.1	72.8	74.6	70.8	71.4	66.5
	aDGlcp	97.5	75.4	77.3	70.8	75.6	67.0


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
6,6,3	aDGlcp	5.35	3.57	3.75	3.45	4.02	3.75-3.85
6,6	aDGlcp	4.97	3.66	3.85	3.65	3.74	3.75-3.85
6	aDGlcp	4.97	3.58	3.73	3.54	3.93	3.75
	aDGlcp	5.24	3.54	3.71	3.51	4.02	3.71


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
6,6,3	aDGlcp	100.5/5.35	72.8/3.57	74.2/3.75	70.6/3.45	73.0/4.02	61.5/3.75-3.85
6,6	aDGlcp	99.1/4.97	73.0/3.66	81.1/3.85	70.8/3.65	72.9/3.74	61.5/3.75-3.85
6	aDGlcp	99.1/4.97	72.8/3.58	74.6/3.73	70.8/3.54	71.4/3.93	66.5/3.75
	aDGlcp	97.5/5.24	75.4/3.54	77.3/3.71	70.8/3.51	75.6/4.02	67.0/3.71

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

OC[C@H]1O[C@H](O[C@@H]2[C@@H](O)[C@@H](OC[C@H]3O[C@H](OC[C@H]4O[C@H](O)[C@H](O)[C@@H](O)[C@@H]4O)[C@H](O)[C@@H](O)[C@@H]3O)O[C@H](CO)[C@H]2O)[C@H](O)[C@@H](O)[C@@H]1O

666.579 g/mol (C₂₄H₄₂O₂₁)

Weissella confusa VTT E-90392 is an efficient producer of a dextran that is mainly composed of α-(1→6)-linked d-glucosyl units and very few α-(1→3) branch linkages. A mixture of the Chaetomium erraticum endodextranase and the Aspergillus niger α-glucosidase was used to hydrolyze W. confusa dextran to glucose and a set of enzyme-resistant isomaltooligosaccharides. Two of the oligosaccharides (tetra- and hexasaccharide) were isolated in pure form and their structures elucidated. The tetrasaccharide had a nonreducing end terminal α-(1→3)-linked glucosyl unit (α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc), whereas the hexasaccharide had an α-(1→3)-linked isomaltosyl side group (α-D-Glcp-(1→6)[α-D-Glcp-(1→6)-α-D-Glcp-(1→3)]-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc). A mixture of two isomeric oligosaccharides was also obtained in the pentasaccharide fraction, which were identified as (α-D-Glcp-(1→6)-α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc) and (α-D-Glcp-(1→6)[α-D-Glcp-(1→3)]-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc). The structures of the oligosaccharides indicated that W. confusa dextran contains both terminal and elongated α-(1→3)-branches. This is the first report evidencing the presence of elongated branches in W. confusa dextran. The 1H and 13C NMR spectroscopic data on the enzyme-resistant isomaltooligosaccharides with α-(1→3)-linked glucosyl and isomaltosyl groups are published here for the first time.

Weissella confusa, isomaltooligosaccharide

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

OC[C@H]1O[C@H](OC[C@H]2O[C@H](OC[C@H]3O[C@H](OC[C@H]4O[C@H](O)[C@H](O)[C@@H](O)[C@@H]4O)[C@H](O)[C@@H](O)[C@@H]3O)[C@H](O)[C@@H](O[C@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@H]3O)[C@@H]2O)[C@H](O)[C@@H](O)[C@@H]1O

828.72 g/mol (C₃₀H₅₂O₂₆)

Weissella confusa VTT E-90392 is an efficient producer of a dextran that is mainly composed of α-(1→6)-linked d-glucosyl units and very few α-(1→3) branch linkages. A mixture of the Chaetomium erraticum endodextranase and the Aspergillus niger α-glucosidase was used to hydrolyze W. confusa dextran to glucose and a set of enzyme-resistant isomaltooligosaccharides. Two of the oligosaccharides (tetra- and hexasaccharide) were isolated in pure form and their structures elucidated. The tetrasaccharide had a nonreducing end terminal α-(1→3)-linked glucosyl unit (α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc), whereas the hexasaccharide had an α-(1→3)-linked isomaltosyl side group (α-D-Glcp-(1→6)[α-D-Glcp-(1→6)-α-D-Glcp-(1→3)]-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc). A mixture of two isomeric oligosaccharides was also obtained in the pentasaccharide fraction, which were identified as (α-D-Glcp-(1→6)-α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc) and (α-D-Glcp-(1→6)[α-D-Glcp-(1→3)]-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc). The structures of the oligosaccharides indicated that W. confusa dextran contains both terminal and elongated α-(1→3)-branches. This is the first report evidencing the presence of elongated branches in W. confusa dextran. The 1H and 13C NMR spectroscopic data on the enzyme-resistant isomaltooligosaccharides with α-(1→3)-linked glucosyl and isomaltosyl groups are published here for the first time.

Weissella confusa, isomaltooligosaccharide

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

OC[C@H]1O[C@H](OC[C@H]2O[C@H](O[C@@H]3[C@@H](O)[C@@H](OC[C@H]4O[C@H](OC[C@H]5O[C@H](O)[C@H](O)[C@@H](O)[C@@H]5O)[C@H](O)[C@@H](O)[C@@H]4O)O[C@H](CO)[C@H]3O)[C@H](O)[C@@H](O)[C@@H]2O)[C@H](O)[C@@H](O)[C@@H]1O

828.72 g/mol (C₃₀H₅₂O₂₆)

Weissella confusa VTT E-90392 is an efficient producer of a dextran that is mainly composed of α-(1→6)-linked d-glucosyl units and very few α-(1→3) branch linkages. A mixture of the Chaetomium erraticum endodextranase and the Aspergillus niger α-glucosidase was used to hydrolyze W. confusa dextran to glucose and a set of enzyme-resistant isomaltooligosaccharides. Two of the oligosaccharides (tetra- and hexasaccharide) were isolated in pure form and their structures elucidated. The tetrasaccharide had a nonreducing end terminal α-(1→3)-linked glucosyl unit (α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc), whereas the hexasaccharide had an α-(1→3)-linked isomaltosyl side group (α-D-Glcp-(1→6)[α-D-Glcp-(1→6)-α-D-Glcp-(1→3)]-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc). A mixture of two isomeric oligosaccharides was also obtained in the pentasaccharide fraction, which were identified as (α-D-Glcp-(1→6)-α-D-Glcp-(1→3)-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc) and (α-D-Glcp-(1→6)[α-D-Glcp-(1→3)]-α-D-Glcp-(1→6)-α-D-Glcp-(1→6)-α-D-Glc). The structures of the oligosaccharides indicated that W. confusa dextran contains both terminal and elongated α-(1→3)-branches. This is the first report evidencing the presence of elongated branches in W. confusa dextran. The 1H and 13C NMR spectroscopic data on the enzyme-resistant isomaltooligosaccharides with α-(1→3)-linked glucosyl and isomaltosyl groups are published here for the first time.

Weissella confusa, isomaltooligosaccharide

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
6,6,3,6	aDGlcp	99.1	72.9	74.4	70.7	73.2	61.6
6,6,3	aDGlcp	100.9	72.9	74.4	70.6	71.6	66.5
6,6,6	aDGlcp	99.1	72.9	74.4	70.7	73.2	61.6
6,6	aDGlcp	99.0	71.4	82.3	71.3	71.2	66.7
6	aDGlcp	99.3	72.8	74.8	?	?	66.7
	aDGlcp	97.5	75.4	77.3	70.8	75.6	66.9


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
6,6,3,6	aDGlcp	4.96	3.55	3.72	3.42	3.73	3.85
6,6,3	aDGlcp	5.32	3.59	3.73	3.56	4.20	3.68
6,6,6	aDGlcp	4.96	3.55	3.72	3.42	3.73	3.85
6,6	aDGlcp	4.99	3.68	3.82	3.77	3.93	?
6	aDGlcp	4.99	3.59	3.73	3.54	?	?
	aDGlcp	5.24	3.54	3.71	3.52	4.02	3.71


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
6,6,3,6	aDGlcp	99.1/4.96	72.9/3.55	74.4/3.72	70.7/3.42	73.2/3.73	61.6/3.85
6,6,3	aDGlcp	100.9/5.32	72.9/3.59	74.4/3.73	70.6/3.56	71.6/4.20	66.5/3.68
6,6,6	aDGlcp	99.1/4.96	72.9/3.55	74.4/3.72	70.7/3.42	73.2/3.73	61.6/3.85
6,6	aDGlcp	99.0/4.99	71.4/3.68	82.3/3.82	71.3/3.77	71.2/3.93	66.7/?
6	aDGlcp	99.3/4.99	72.8/3.59	74.8/3.73	?/3.54	?/?	66.7/?
	aDGlcp	97.5/5.24	75.4/3.54	77.3/3.71	70.8/3.52	75.6/4.02	66.9/3.71

The spectrum also has 2 signals at unknown positions (not plotted).

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

OC[C@H]1O[C@H](OC[C@H]2O[C@H](O[C@@H]3[C@@H](O)[C@@H](OC[C@H]4O[C@H](OC[C@H]5O[C@H](O)[C@H](O)[C@@H](O)[C@@H]5O)[C@H](O)[C@@H](O)[C@@H]4O)O[C@H](CO[C@H]4O[C@H](CO)[C@@H](O)[C@H](O)[C@H]4O)[C@H]3O)[C@H](O)[C@@H](O)[C@@H]2O)[C@H](O)[C@@H](O)[C@@H]1O

990.861 g/mol (C₃₆H₆₂O₃₁)