Lentinan extract from shiitake

[Bruno Pretto]

This is a second request for procedures on extracting Lentinan from shiitake 
using the aqueous extraction method. Also does anyone know the rate of 
degradation of Lentinan in a mushroom, in practical terms if using fresh 
shiitakes, when are they totally useless for extraction.
  Bruno Pretto, Fun Guy Farm (Toronto,Canada).
      Home page http://www.io.org/~bpretto
      NAMA Trustee for Toronto Mycological Society.
      Secretary Oak Forest Mushroom Association (outdoor shiitake growers).