A low molecular-weight polysaccharide named BIWP2 was purified from the fruit bodies of Bulgaria Inquinans (Fries) via hot-water extraction, followed by freeze-thawing and gel filtration chromatography on Sephadex G-75. Monosaccharide composition analysis revealed that BIWP2 contained exclusively glucose. High performance size exclusion chromatography (HPSEC) showed that it was a homogeneous polysaccharide fraction. Its molecular weight was estimated to be 2.6 KD and the polydispersity index (Mw/Mn) was calculated to be 1.4. Periodate oxidation, methylation, and NMR analyses indicated that BIWP2 was a linear β-(1→6)-d-glucan without side chains. This is the first time to report a linear β-(1→6)-d-glucan with low molecular weight in non-lichenized ascomycete.

polysaccharide, methylation, β-(1-6)-d-glucan, Bulgaria inquinans (Fries)

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
	bDGlcp	104.66	74.71	76.57	71.14	77.25	70.48


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
	bDGlcp	4.42	3.22	3.40	3.35	3.53	3.75-4.12


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
	bDGlcp	104.66/4.42	74.71/3.22	76.57/3.40	71.14/3.35	77.25/3.53	70.48/3.75-4.12

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

[*]OC[C@H]1O[C@@H]([*])[C@H](O)[C@@H](O)[C@@H]1O

162.141 g/mol (C₆H₁₀R₂O₅, R = next and previous repeats, not counted in mol weight)