Structure and antioxidative property of a polysaccharide from an ammonium oxalate extract of Phellinus linteus.

In this paper, the novel polysaccharide PL-A11 was purified from an ammonium oxalate extract of Phellinus linteus mycelia. Its physicochemical properties, structural characteristics, and antioxidant activities were investigated. Results showed that PL-A11 had a weight-average molecular weight (Mw) of 13.8kDa and was mainly composed of arabinose, xylose, mannose, and glucose in a molar ratio of 1.1:1.3:1.0:6.6. The backbone of PL-A11 was composed of (1→4)-α-d-glucopyranosyl, (1→2)-α-d-xylopyranosyl, and (1→3)-α-d-arabinofuranosyl residues, whereas the (1→6)-α-d-mannopyranosyl residues formed branches at the O-2 position with 1-linked-α-d-glucopyranosyl terminal residues. From the antioxidative activity tests in vivo, the administration of PL-A11 obviously enhanced the activity of antioxidant enzymes and significantly reduced the level of malondiadehyde (MDA) in the serum and liver of d-galactose-treated aging mice in a dose-dependent manner, as well as effectively stimulated the immune system of aging mice. These findings implied that PL-A11 could be developed as a potential antioxidant for applications in the functional food, pharmaceutical, cosmetic or nutraceutical industries.

Structural features and antitumor activity of a novel polysaccharide from alkaline extract of Phellinus linteus mycelia.

A novel high molecular weight polysaccharide (PL-N1) was isolated from alkaline extract of the cultured Phellinus linteus mycelia. The weight average molecular weight (Mw) of PL-N1 was estimated at 343,000kDa. PL-N1 comprised arabinose, xylose, glucose, and galactose in the molar ratio of 4.0:6.7:1.3:1.0. The chemical structure of PL-N1 was investigated by FTIR and NMR spectroscopies and methylation analysis. The results showed that the backbone of PL-N1 comprised (1→4)-linked ß-D-xylopyranosyl residues, (1→2)-linked α-D-xylopyranosyl residues, (1→4)-linked α-D-glucopyranosyl residues, (1→5)-linked ß-D-arabinofuranosyl residues, (1→4)-linked ß-D-xylopyranosyl residues which branched at O-2, and (1→4)-linked ß-D-galactopyranosyl residues which branched at O-6. The branches consisted of (1→)-linked α-D-arabinofuranosyl residues. Antitumor activity assay in vitro showed that PL-N1 could inhibit the growth of HepG2 cells to a certain extent in a dose-dependent manner. Thus, PL-N1 may be developed as a potential, natural antitumor agent and functional food.

Thermal stability of ginkgolic acids from Ginkgo biloba and the effects of ginkgol C17:1 on the apoptosis and migration of SMMC7721 cells.

Ginkgolic acids are alkylsalicylic acid derivatives with a thermolabile carboxylic group from Ginkgo biloba L., and they exhibit anticancer activity. Their anticancer effects are closely associated with their thermal stability. In this study, the thermal decomposition of ginkgolic acids was analyzed at temperatures of 30, 50, 70 and 250°C. The results clearly showed that an obvious slow decarboxylation of the ginkgolic acids was detected at 70°C. When the temperature increased to 250°C, the decarboxylation reaction was rapidly completed. The ginkgolic acids were decarboxylated to yield ginkgols. The ginkgols C13:0, C15:1 and C17:1 were separated and definitively identified by IR, NMR and GC-MS. The cytotoxic effects of ginkgols C13:0, C15:1 and C17:1 were tested and compared with those of the corresponding ginkgolic acids. An MTT assay showed that ginkgol C17:1 (48-h IC50=8.5 µg·ml(-1)) has the strongest inhibition on SMMC-7721 cells in a dose- and time-dependent manner. The anticancer action may occur via the induction of apoptosis by the activation of caspases-3, the upregulation of Bax expression, and the inhibition migration of SMMC7721 cells. The results indicated that ginkgol C17:1 might be useful for the further development of a hepatocellular carcinoma preventive agent.

Antioxidant and immunity activity of water extract and crude polysaccharide from Ficus carica L. fruit.

The antioxidative activities of water extract (WE) and crude hot-water soluble polysaccharide (PS) from Ficus carica L. fruit were investigated using various assays in vitro, including scavenging abilities on DPPH, superoxide and hydroxyl radicals and reducing power. The immunity activities of PS were evaluated using the carbon clearance test and serum hemolysin analysis in mice. In addition, total phenolics and flavonoids contents were also determined. Both WE and PS have notable scavenging activities on DPPH with the EC(50) values of 0.72 and 0.61 mg/ml, respectively. The PS showed higher scavenging activity than WE on superoxide radical (EC(50), 0.95 mg/ml) and hydroxyl anion radical (scavenging rate 43.4% at concentration of 4 mg/ml). The PS (500 mg/kg) also has a significant increase in the clearance rate of carbon particles and serum hemolysin level of normal mice. The results indicate that both WE and PS might be applicable in healthy medicine and food industry.

[Separation and regeneration of protoplast from Phellinus igniarius].

OBJECTIVE: To study the conditions on separation and regeneration of protoplast from Phellinus igniarius. METHOD: The effects of enzymolysis conditions of P. igniarius mycelia on yield of protoplast and culturing conditons on regeneration ratio of protoplast were investigated. RESULT: When the 8 days-old mycelia was hydrolysed by 1.5% of lywallzyme adding to driselase of 0. 5% and at 30 degrees C for 3 h and enzymolysis was stablized by sucrose as a stablisher of osmotic pressure, higher yield of P. igniarius protoplast was obtained. If 10 days-old mycelia was used as raw material of enzymolysis and manntol was selected as stablisher of osmotic pressure of enzymolysis, higher regeneration ratio of P. igniarius protoplast also would be obtained in following regeneration step at same time keeping higher yield. For the regeneration processing, it was beneficial for the regeneration of P. igniarius protoplast that PDA plusing mulberry ramulus was used as the culture medium of regeneration and manntol was selected as the osmotic pressure establisher of regeneration culture medium. CONCLUSION: The method and conditions to keep both higher yield and regeneration ratio of P. igniarius protoplast were obtained.

[Study on anti-cancer components of Fig residues with supper critical fluid CO2 extracting technique].

OBJECTIVE: To optimize Supper Critical CO2 extracting technical (SFE-CO2) methods for extraction of anti-cancer active components of Fig Residues and to investigate the anti-cancer effect of the extract in vitro and in vivo. METHOD: The anti-cancer activity of extracted compound was measured on U937,95D and AGS cancer cells in vitro by MTT method. The anti-cancer effect of the extraction of Fig Residues was studied on mice transplant liver cancer in vivo. RESULT: The SFE-CO2 condition for extraction of the anti-cancer components of Fig Residues was optimized as follows: granularity was 100, the extraction pressure was 30 MPa, the extraction temperature was 45 degrees C, the extraction time was 6 h and the CO2 flux was 12 L x h(-1); The IC50 of anti-cancer active components of Fig Residues on U937, 95D and AGS cells were 70.125 microg x mL(-1), 127.957 microg x mL(-1), 116.000 microg x mL(-1); The anti-cancer active components of Fig Residues inhibited 49.3% of the transplanted liver cancer in the mice. CONCLUSION: The method for extracting the anticancer active components of Fig Residues is stable and reasonable, and the extract from Fig Residues is of the anticancer effect.