Biological xylans

Xylan sulphates, known also as pentosan polysulphates (PPS), are permanently studied with regard to their biological activities [3,419-422]. Usually, sulphuric acid, sulphur trioxide, or chlorsulphonic acid are employed as sul-phating agents alone or in combination with alcohols, amines or chlorinated hydrocarbons as reaction media [423]. 

The close association of histamine and heparin release in anaphylactic shock and in peptone shock suggests that complexes of histamine and heparin are held in biological systems. Histamine binds heparin in vitro, as shown by displacement tests, by dialysis, and by paper chromatography . Dextran sulphate, polymannuronic acid sulphate, polysulphated xylan and the iV-succinyl derivative of de-W-sulphated heparin give compounds with... 

Yet, each biological property that is studied turns out to be surprisingly simple. Whether it is the attachment of the gecko s feet to vertical surfaces or the height to which water rises in the xylan tubes of the giant Sequoia, that which was once not understood and so thought to be very complex turns out to be based on very simple principles. And because the principles are simple, the effects are robust. 

The biodegradation of various carboxylic group containing polymers was studied by Matsumura et al. 18-20). The aim of this work was to develop compounds which are biologically degradable detergents. Thus, xylan from oat... 

Table 3. Biological assays for organostannane containing products derived from xylan.

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