Edible mushrooms have potential in anti-diabetic phytotherapy. They are rich in natural compounds such as polysaccharides, which have been known to have antihyperlipidemic effects since ancient times. A polysaccharide fraction of PP80 and a contained low molecular-weight (Mw), water-soluble polysaccharide (PPW-1, Mw: 3.2 kDa) were isolated from the fruiting body of Phellinus pini. Both PP80 and PPW-1 possess α-glucosidase inhibition and glucose consumption amelioration in an insulin-resistant HepG2 cell model. The α-glucosidase inhibitory activity of PPW-1 (IC50 = 2.2 ± 0.1 mg mL-1) is significantly (P < 0.01) higher than those of PP80 (IC50 = 13.1 ± 0.5 mg mL-1) and acarbose (IC50 = 4.3 ± 0.2 mg mL-1), behaving in a non-competitive inhibition manner. The structural characterization results indicated that PPW-1 is a homogeneous heteropolysaccharide composed of d-glucose, d-mannose, d-galactose and l-rhamnose. The major backbone of PPW-1 is primarily comprised of 1,6-linked glucopyranose, every third residue of which is branched at the O-3 position by a side chain consisting of 1,3-linked and terminal glucopyranose. In addition, small amounts of 1,2-linked-α-d-Manp, 1,6-linked-3-O-Me-α-d-Galp and rhamnose exist in PPW-1. In summary, PPW-1 is a novel heteropolysaccharide with potent in vitro hypoglycemic activity, and it may be a potential dietary component for improving glucose homeostasis.

structure, polysaccharides, purification, fungi, bioactivities, Phellinus pini

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
6,6	bDGlcp
6	bDGlcp	103.24	73.40	75.85	69.89	75.16	69.09
3,3	bDGlcp	103.00	73.40	75.85	69.52	76.23	60.96
3	bDGlcp	103.00	72.89	85.07	68.45	76.23	60.96
	bDGlcp	103.00	72.36	85.13	68.45	75.16	69.09


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
6,6	bDGlcp
6	bDGlcp	4.55	3.37	3.53	3.49	3.67	3.92-4.24
3,3	bDGlcp	4.75	3.43	3.55	3.52	3.57	3.79-3.95
3	bDGlcp	4.82	3.61	3.81	3.59	3.57	3.79-3.95
	bDGlcp	4.58	3.58	3.78	3.56	3.66	3.92-4.24


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
6,6	bDGlcp
6	bDGlcp	103.24/4.55	73.40/3.37	75.85/3.53	69.89/3.49	75.16/3.67	69.09/3.92-4.24
3,3	bDGlcp	103.00/4.75	73.40/3.43	75.85/3.55	69.52/3.52	76.23/3.57	60.96/3.79-3.95
3	bDGlcp	103.00/4.82	72.89/3.61	85.07/3.81	68.45/3.59	76.23/3.57	60.96/3.79-3.95
	bDGlcp	103.00/4.58	72.36/3.58	85.13/3.78	68.45/3.56	75.16/3.66	69.09/3.92-4.24

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

810.705 g/mol (C₃₀H₅₀R₂O₂₅, R = next and previous repeats, not counted in mol weight)