Exopolysaccharides (EPS) have attracted a great interest due to their potential health-promoting properties and industrial applications. This study aimed to investigate the physicochemical, rheological, and biological properties of an EPS produced by a potential probiotic strain Enterococcus faecalis 84B. The results show that the extracted EPS, designated EPS-84B, had an average molecular weight of 604.8 kDa, particles size diameter of 322.0 nm, and mainly composed of arabinose and glucose with a molar ratio of 1:2. Furthermore, EPS-84B exhibited a shear-thinning behavior and had a high melting point. The rheological properties of EPS-84B were strongly influenced by the type of salt than by the pH value. EPS-84B displayed ideal viscoelastic properties, with both viscous and storage moduli increasing with frequency. The antioxidant activity of EPS-84B at a concentration of 5 mg/mL was 81.1 % against DPPH and 35.2 % against ABTS. At 5 mg/mL, the antitumor activity of EPS-84B against Caco-2 and MCF-7 cell lines was 74.6 and 38.6 %, respectively. In addition, the antidiabetic activity of EPS-84B towards α-amylase and α-glucosidase was 89.6 and 90.0 %, respectively at 100 μg/mL. The inhibition of foodborne pathogens by EPS-84B was up to 32.6 %. Overall, EPS-84B has promising properties that could be utilized in food and pharmaceutical industries.

NMR, cytotoxicity, antimicrobial, FTIR, Antidiabetic, SEM

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
2,4,6	aDGlcp	98.91	70.91	81.51	70.67	72.41	61.45
2,4	aDGlcp	100.63	72.60	74.05	70.40	72.12	66.85
2	bDGlcp	104.70	74.22	76.79	77.96	75.68	61.55
	aDGlcp	99.16	81.70	72.71	70.45	72.54	61.47


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
2,4,6	aDGlcp	4.97	3.70	3.91	3.72	3.75	3.77-3.85
2,4	aDGlcp	5.36	3.60	3.69	3.52	3.90	3.77-3.99
2	bDGlcp	4.67	3.41	3.80	3.64	3.60	3.79-3.94
	aDGlcp	5.54	3.71	3.91	3.50	3.98	3.76-3.86


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
2,4,6	aDGlcp	98.91/4.97	70.91/3.70	81.51/3.91	70.67/3.72	72.41/3.75	61.45/3.77-3.85
2,4	aDGlcp	100.63/5.36	72.60/3.60	74.05/3.69	70.40/3.52	72.12/3.90	66.85/3.77-3.99
2	bDGlcp	104.70/4.67	74.22/3.41	76.79/3.80	77.96/3.64	75.68/3.60	61.55/3.79-3.94
	aDGlcp	99.16/5.54	81.70/3.71	72.71/3.91	70.45/3.50	72.54/3.98	61.47/3.76-3.86

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

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

648.564 g/mol (C₂₄H₄₀R₂O₂₀, R = next and previous repeats, not counted in mol weight)

Marine microorganisms often produce exopolysaccharides with novel structures and diverse biological activities due to their specific marine environment. The novel active exopolysaccharides from marine microorganisms have become an important research area in new drug discovery, and show enormous development prospects. In the present study, a homogeneous exopolysaccharide from the fermented broth of the mangrove endophytic fungus Penicillium janthinellum N29, designated as PJ1-1, was obtained. The results of chemical and spectroscopic analyses showed that PJ1-1 was a novel galactomannan with a molecular weight of about 10.24 kDa. The backbone of PJ1-1 was composed of →2)-α-d-Manp-(1→, →4)-α-d-Manp-(1→, →3)-β-d-Galf-(1→ and →2)-β-d-Galf-(1→ units with partial glycosylation at C-3 of →2)-β-d-Galf-(1→ unit. PJ1-1 had a strong hypoglycemic activity in vitro, evaluated using the assay of α-glucosidase inhibition. The anti-diabetic effect of PJ1-1 in vivo was further investigated using mice with type 2 diabetes mellitus induced by a high-fat diet and streptozotocin. The results indicated that PJ1-1 markedly reduced blood glucose level and improved glucose tolerance. Notably, PJ1-1 increased insulin sensitivity and ameliorated insulin resistance. Moreover, PJ1-1 significantly decreased the levels of serum total cholesterol, triglyceride and low-density lipoprotein cholesterol, enhanced the level of serum high-density lipoprotein cholesterol and alleviated dyslipidemia. These results revealed that PJ1-1 could be a potential source of anti-diabetic agent.

structure, exopolysaccharide, mangrove endophytic fungus, Penicillium, anti-diabetic activity

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
?,4,2	SUG
?,4	aDManp	102.19	79.67	71.64	71.39	68.35	62.48
?	aDManp	99.76	71.56	71.97	74.78	68.47	64.28
	SUG


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
?,4,2	SUG
?,4	aDManp	5.29	4.15	4.01	3.71	3.66	3.76
?	aDManp	5.16	4.10	3.87	3.82	3.72	3.65
	SUG


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
?,4,2	SUG
?,4	aDManp	102.19/5.29	79.67/4.15	71.64/4.01	71.39/3.71	68.35/3.66	62.48/3.76
?	aDManp	99.76/5.16	71.56/4.10	71.97/3.87	74.78/3.82	68.47/3.72	64.28/3.65
	SUG

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

R1 = SUG
[1*]O[C@H]1O[C@H](CO)[C@@H](O[C@H]2O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]2O[1*])[C@H](O)[C@@H]1O

340.281 g/mol (C₁₂H₂₀R₂O₁₁, R = residue superclass(es), not counted in mol weight)

Marine microorganisms often produce exopolysaccharides with novel structures and diverse biological activities due to their specific marine environment. The novel active exopolysaccharides from marine microorganisms have become an important research area in new drug discovery, and show enormous development prospects. In the present study, a homogeneous exopolysaccharide from the fermented broth of the mangrove endophytic fungus Penicillium janthinellum N29, designated as PJ1-1, was obtained. The results of chemical and spectroscopic analyses showed that PJ1-1 was a novel galactomannan with a molecular weight of about 10.24 kDa. The backbone of PJ1-1 was composed of →2)-α-d-Manp-(1→, →4)-α-d-Manp-(1→, →3)-β-d-Galf-(1→ and →2)-β-d-Galf-(1→ units with partial glycosylation at C-3 of →2)-β-d-Galf-(1→ unit. PJ1-1 had a strong hypoglycemic activity in vitro, evaluated using the assay of α-glucosidase inhibition. The anti-diabetic effect of PJ1-1 in vivo was further investigated using mice with type 2 diabetes mellitus induced by a high-fat diet and streptozotocin. The results indicated that PJ1-1 markedly reduced blood glucose level and improved glucose tolerance. Notably, PJ1-1 increased insulin sensitivity and ameliorated insulin resistance. Moreover, PJ1-1 significantly decreased the levels of serum total cholesterol, triglyceride and low-density lipoprotein cholesterol, enhanced the level of serum high-density lipoprotein cholesterol and alleviated dyslipidemia. These results revealed that PJ1-1 could be a potential source of anti-diabetic agent.

structure, exopolysaccharide, mangrove endophytic fungus, Penicillium, anti-diabetic activity

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
?,2,2	SUG
?,2	aDManp	102.19	79.67	71.64	71.39	68.35	62.48
?	aDManp	102.19	79.67	71.64	71.39	68.35	62.48
	SUG


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
?,2,2	SUG
?,2	aDManp	5.29	4.15	4.01	3.71	3.66	3.76
?	aDManp	5.29	4.15	4.01	3.71	3.66	3.76
	SUG


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
?,2,2	SUG
?,2	aDManp	102.19/5.29	79.67/4.15	71.64/4.01	71.39/3.71	68.35/3.66	62.48/3.76
?	aDManp	102.19/5.29	79.67/4.15	71.64/4.01	71.39/3.71	68.35/3.66	62.48/3.76
	SUG

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

R1 = SUG
[1*]O[C@H]1O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]1O[C@H]1O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]1O[1*]

340.281 g/mol (C₁₂H₂₀R₂O₁₁, R = residue superclass(es), not counted in mol weight)

Marine microorganisms often produce exopolysaccharides with novel structures and diverse biological activities due to their specific marine environment. The novel active exopolysaccharides from marine microorganisms have become an important research area in new drug discovery, and show enormous development prospects. In the present study, a homogeneous exopolysaccharide from the fermented broth of the mangrove endophytic fungus Penicillium janthinellum N29, designated as PJ1-1, was obtained. The results of chemical and spectroscopic analyses showed that PJ1-1 was a novel galactomannan with a molecular weight of about 10.24 kDa. The backbone of PJ1-1 was composed of →2)-α-d-Manp-(1→, →4)-α-d-Manp-(1→, →3)-β-d-Galf-(1→ and →2)-β-d-Galf-(1→ units with partial glycosylation at C-3 of →2)-β-d-Galf-(1→ unit. PJ1-1 had a strong hypoglycemic activity in vitro, evaluated using the assay of α-glucosidase inhibition. The anti-diabetic effect of PJ1-1 in vivo was further investigated using mice with type 2 diabetes mellitus induced by a high-fat diet and streptozotocin. The results indicated that PJ1-1 markedly reduced blood glucose level and improved glucose tolerance. Notably, PJ1-1 increased insulin sensitivity and ameliorated insulin resistance. Moreover, PJ1-1 significantly decreased the levels of serum total cholesterol, triglyceride and low-density lipoprotein cholesterol, enhanced the level of serum high-density lipoprotein cholesterol and alleviated dyslipidemia. These results revealed that PJ1-1 could be a potential source of anti-diabetic agent.

structure, exopolysaccharide, mangrove endophytic fungus, Penicillium, anti-diabetic activity

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
?,2,2	SUG
?,2,3	SUG
?,2	bDGalf	108.67	89.53	75.87	81.42	61.98	?
?	bDGalf	106.25	89.53	71.64	83.23	61.98	?
	SUG


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
?,2,2	SUG
?,2,3	SUG
?,2	bDGalf	5.25	4.17	4.10	3.87	3.98	?
?	bDGalf	5.23	4.17	4.03	3.87	3.78	?
	SUG


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
?,2,2	SUG
?,2,3	SUG
?,2	bDGalf	108.67/5.25	89.53/4.17	75.87/4.10	81.42/3.87	61.98/3.98	?/?
?	bDGalf	106.25/5.23	89.53/4.17	71.64/4.03	83.23/3.87	61.98/3.78	?/?
	SUG

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

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

R1 = SUG
[1*]O[C@@H]1O[C@@H]([C@H](O)CO)[C@H](O)[C@H]1O[C@@H]1O[C@@H]([C@H](O)CO)[C@H](O[1*])[C@H]1O[1*]

339.273 g/mol (C₁₂H₁₉R₃O₁₁, R = residue superclass(es), not counted in mol weight)