Structural identification of (1→6)-α-d-glucan, a key responsible for the health benefits of longan, and evaluation of anticancer activity.

Longan is a delicious subtropical fruit with great health-beneficial effects. It has been utilized for disease prevention and health care since ancient age. To explore the chemicals responsible for the health benefits, water-soluble polysaccharides were extracted from longan flesh in this work. A pure polysaccharide (LPS1) was obtained through column purification. Analysis by gas chromatography showed LPS1 was a homopolysaccharide of glucose with glycosidic linkage of →6)-d-Glc-(1→. Nuclear magnetic resonance (NMR) spectra indicated that the configuration of anomeric carbon in glucose residual was α-form. The polysaccharide structure was further confirmed to be (1→6)-α-d-glucan by chemcial shift of C6. The molecular weight of LPS1 was calculated to be 108 kDa, which had 661 glucose residuals. Anticancer assay showed that LPS1 had anticancer activity against the growth of HepG2 cells to a certain extent. However, it did not show any cytotoxicity against MCF-7 breast cancer cells.

[1]  L. R. Ribeiro,et al.  Effects of β-glucan extracted from Agaricus blazei on the expression of ERCC5, CASP9, and CYP1A1 genes and metabolic profile in HepG2 cells , 2013, Human & experimental toxicology.

[2]  Mouming Zhao,et al.  Identification of a novel phenolic compound in litchi (Litchi chinensis Sonn.) pericarp and bioactivity evaluation. , 2013, Food chemistry.

[3]  Yifa Zhou,et al.  Structural characterization and immunostimulatory activity of a novel linear α-(1 → 6)-D-glucan isolated from Panax ginseng C. A. Meyer , 2012, Glycoconjugate Journal.

[4]  V. Vetvicka,et al.  β 1, 3-Glucan in Cancer Treatment , 2012 .

[5]  Feng Chen,et al.  Prooxidant activities of quercetin, p-courmaric acid and their derivatives analysed by quantitative structure–activity relationship , 2012 .

[6]  M. Ashraf,et al.  Extraction and pharmacological properties of bioactive compounds from longan (Dimocarpus longan Lour.) fruit ! A review , 2011 .

[7]  Xiaoyi Wei,et al.  Antioxidant and anticancer activities of high pressure-assisted extract of longan (Dimocarpus longan Lour.) fruit pericarp , 2009 .

[8]  Feng Chen,et al.  Structural characterisation of polysaccharides purified from longan (Dimocarpus longan Lour.) fruit pericarp , 2009 .

[9]  Doman Kim,et al.  Molecular characterization and expression analysis of the glucansucrase DSRWC from Weissella cibaria synthesizing a alpha(1-->6) glucan. , 2009, FEMS microbiology letters.

[10]  Lina Zhang,et al.  Structure and chain conformation of a (1 → 6)-α-d-glucan from the root of Pueraria lobata (Willd.) Ohwi and the antioxidant activity of its sulfated derivative , 2008 .

[11]  Zhi-rong Yang,et al.  Characterisation and immunostimulatory activity of an α-(1→6)-d-glucan from the cultured Armillariella tabescens mycelia. , 2008, Food chemistry.

[12]  Yang Liu,et al.  Immunomodulatory and anticancer activities of flavonoids extracted from litchi (Litchi chinensis Sonn) pericarp. , 2007, International immunopharmacology.

[13]  Yifan Luo,et al.  Isolation and structural characterization of an immunostimulating polysaccharide from fuzi, Aconitum carmichaeli. , 2006, Carbohydrate research.

[14]  T. Khan,et al.  Structural studies of the glucuronic acid oligomers produced by Gluconacetobacter hansenii strain , 2006 .

[15]  P. Tu,et al.  Isolation and characterization of α-(1→6)-glucans from Cistanche deserticola , 2005 .

[16]  Zongdao Chen,et al.  Characterization and immunostimulatory activity of an (1-->6)-a-D-glucan from the root of Ipomoea batatas. , 2005, International immunopharmacology.

[17]  J. Satayavivad,et al.  Identification and quantification of polyphenolic compounds in Longan (Euphoria longana Lam.) fruit. , 2005, Journal of agricultural and food chemistry.

[18]  Philip J. Barlow,et al.  Antioxidant activity and phenolic content of selected fruit seeds , 2004 .

[19]  B. Matsuhiro,et al.  Opuntia spp mucilage's: a functional component with industrial perspectives , 2004 .

[20]  M. Gershwin,et al.  Mushrooms, Tumors, and Immunity: An Update , 2004, Experimental biology and medicine.

[21]  P. Michaud,et al.  Structure of a polysaccharide from a Rhizobium species containing 2-deoxy-beta-D-arabino-hexuronic acid. , 2001, Carbohydrate research.

[22]  C. W. Kim,et al.  Structural characterization of β-d-(1→3, 1→6)-linked glucans using NMR spectroscopy , 2000 .

[23]  M. Mizuno,et al.  Polysaccharides from Agaricus blazei stimulate lymphocyte T-cell subsets in mice. , 1998, Bioscience, biotechnology, and biochemistry.

[24]  W. Kulicke,et al.  Correlation between immunological activity, molar mass, and molecular structure of different (1-->3)-beta-D-glucans. , 1997, Carbohydrate research.

[25]  R. Selvendran,et al.  Avoiding oxidative degradation during sodium hydroxide/methyl iodide-mediated carbohydrate methylation in dimethyl sulfoxide , 1993 .

[26]  S. Hakomori.  A RAPID PERMETHYLATION OF GLYCOLIPID, AND POLYSACCHARIDE CATALYZED BY METHYLSULFINYL CARBANION IN DIMETHYL SULFOXIDE. , 1964, Journal of biochemistry.

[27]  Yifa Zhou,et al.  Purification and in vitro anti-proliferative effect of novel neutral polysaccharides from Lentinus edodes. , 2013, International journal of biological macromolecules.

[28]  James N. BeMiller,et al.  (1→3)-β-d-Glucans as biological response modifiers: a review of structure-functional activity relationships , 1995 .

[29]  F. Smith,et al.  COLORIMETRIC METHOD FOR DETER-MINATION OF SUGAR AND RELATED SUBSTANCE , 1956 .