Structural characterization and bioactivity evaluation of an acidic proteoglycan extract from Ganoderma lucidum fruiting bodies for PTP1B inhibition and anti‐diabetes

Abstract

A water-soluble PTP1B inhibitor, named FYGL-a, was fractionated for structure investigation and bioactivity evaluation. FYGL-a is an ingredient of a reported antihyperglycemia extract from Ganoderma Lucidum fruiting bodies. Composition analysis indicated that FYGL-a was a 100.2 kDa acidic proteoglycan, consisting of 85 ± 2% heteropolysaccharide chain with rhamnose, galactose, glucose, and glucuronic acid residues in a mole ratio of 1.0:3.7:3.9:2.0, and the 15 ± 2% protein moiety of FYGL-a was covalently bonded to the polysaccharide chain in O-linkage type via threonine residues. The complete sequence of FYGL-a was characterized systematically by periodate oxidation, Smith degradation, methylation analysis, (1)H & (13)C 1D NMR, and 2D NMR (HSQC, HMBC, NOESY, COSY, & TOCSY). The chemical structure of FYGL-a was determined as following, which may play special role in the competitive inhibition of PTP1B and antihyperglycemia potency.

Anti-Diabetic Effect of Portulaca oleracea L. Polysaccharideandits Mechanism in Diabetic Rats

“…Considering that PTP1B directly dephosphorylates insulin receptors and the receptor substrate, thereby negatively regulating the insulin signaling pathway, it may also have a direct effect on its downstream pathways by affecting the activity or expression of insulin signal transduction molecules to inhibit insulin signal transduction, leading to insulin resistance [36,37]. We expected CPOP to be useful in the treatment of type II diabetes [38]. The active ingredient having PTP1B inhibition activity has been extracted from a variety of natural herbs and plants [39].…”

Anti-diabetic effects of Ganoderma lucidum

“…The glycan structure of FYGL was analyzed by periodate oxidation, Smith degradation, methylation analysis, 1 H & 13 C 1D NMR and 2D NMR respectively. FYGL is a homogeneous and acidic proteoglycan (85 ± 2% polysaccharides and 15 ± 2% proteins) that contains O-linkage type polysaccharides (repeat unit: 1,6-linked glucose, 1,2,4-linked galactose, 1,2-linked rhamnose and 1-linked glucose as terminal), and its molecular weight is 100.2 kDa (Pan et al, 2014). Because FYGL is sensitive to glycosidase, the researchers hypothesized that FYGL glycan is removed in the stomach or small intestine, with the glycan-dissociated protein motifs enter into circulation to interact with PTP1B.…”

“…Over 140 triterpenoids have been isolated from Ganoderma, and fifteen triterpenoids have been identified in G. lucidum . Recently, many investigations have sought to analyze relationships between the structure and biological function of these triterpenoids (Fatmawati et al, 2011b;Li et al, 2013;Liu et al, 2006a,b;Shiao, 2003) and glycans (Pan et al, 2014).…”

Chemical properties and anti‐fatigue effect of polysaccharide from Pholiota nameko

“…Fungal polysaccharides that are known as the “biological response regulator” in the world have many functions, such as controlling cell division, regulating cell growth and senescence. It was reported that polysaccharides from hericium mushroom, ganoderma lucidum, and lentinula contained obvious anti‐fatigue effects (Pan et al., 2014; Yang & Zhang, 2009). Therefore, the study of fungal polysaccharides received worldwide attention.…”