Sacchachitin, a novel chitin-polysaccharide conjugate macromolecule present in Ganoderma lucidum: purification, composition, and properties

Pharm Biol. 2013 Jan;51(1):84-95. doi: 10.3109/13880209.2012.711840. Epub 2012 Oct 8.

Abstract

Context: The extraction method and the crude wound healing effects of sacchachitin from Ganoderma tsugae Murr. (Ganodermataceae) has been cited. However, its purity is still largely limited.

Objective: An improvement of the fractionation protocol to purify the sacchachitin from Ganoderma lucidum L. (Ganodermataceae) (SGL) is needed.

Methods: Fruiting bodies were extracted with double distilled water and subsequently the residue treated with 95% ethanol and then 40% ethanol. After being filtered, the pH of the supernatant was adjusted to 4.0 with 1 N HCl and lyophilized. The supernatant was added (3:1 v/v) ethanol, the precipitate was collected, 2% NaOH was added and refluxed. The supernatant was collected with pH adjusted to 4.0, then treated with 10% potassium hydroxide (KOH) with repeating acid precipitation and (3:1) ethanol precipitation twice more to obtain the sacchachitin.

Results: SGL had a hexosamine content 16.3% (w/w), firmly linked to a talomannan. Its Fourier Transform Infrared Spectroscopy (FTIR) spectrum revealed specific absorption (in cm(-1)) ν(O-H) 3455.5 b,s, amide ν(C=O) 1678.5, and amide I° δ(N-H) 1550.4. The percentage deacetylation degree was 37.6 and 39.4% for SGL and MSC, respectively. As contrast, MSC contained only 6.6% of hexosamine with a low protein/carbohydrate ratio 0.35 comparing to 0.82 for SGL. SGL was only moderately strong antioxidant regarding the anti-DPPH, antihydroxyl free radical, and antisuperoxide anion capabilities, exhibiting an IC(33) values of 10 mg/mL (the highest scavenging capability never exceeding 33%), 0.9 mg/mL, and 4.8 mg/mL, respectively.

Conclusion: We have successfully isolated the pure sacchachitin from the fruiting bodies of G. lucidum that exhibits potent antioxidative activity and may be useful in fabrication of the artificial skin composite substitute.

MeSH terms

  • Antioxidants / chemistry
  • Antioxidants / isolation & purification
  • Antioxidants / pharmacology*
  • Chitin / chemistry
  • Chitin / isolation & purification
  • Chitin / pharmacology*
  • Free Radical Scavengers / chemistry
  • Free Radical Scavengers / isolation & purification
  • Fruiting Bodies, Fungal
  • Hydroxyl Radical / metabolism
  • Polysaccharides / chemistry
  • Polysaccharides / isolation & purification
  • Polysaccharides / pharmacology*
  • Reishi / chemistry*
  • Spectroscopy, Fourier Transform Infrared
  • Superoxides / metabolism

Substances

  • Antioxidants
  • Free Radical Scavengers
  • Polysaccharides
  • Superoxides
  • Chitin
  • Hydroxyl Radical