Octanoyl chitosan

Anacardoylated chitosan exhibited sustained release of insulin in the intestinal environment, and the released insulin was stable and retained its conformation/ Oleoyl chitosan exhibited less swelling than octanoyl chitosan at acidic pH and was capable of maintaining the biological activity... 

R = —(CH2)4CH3—Caproyl chitosan R = —(CH2)6CH3—Octanoyl chitosan R = —(CH2)i2t H3—Myristoyl chitosan R=—(CH2)i4CH3—Palmitoyl chitosan FIGURE 13.2 Chitosan derivatization with fatty acyl chlorides. 

A series of biofibers based on chitin and chitosan has been prepared by wet spinning and post modification of chitosan fibers as recently reviewed by Hirano [145]. These biofibers based on chitin, chitosan, chitin-cellulose, chitosan-cellulose-silk fibroin, chitosan-tropocollagen, and chitin-cellulo-silk fibroin have been proposed for applications including antithrombogenic, antimicrobial, hemostatic, and wound healing [145]. N-hexanoyl, and N-octanoyl chitosan are antithrombogenic and emocompatible. 

In Table 2, the amounts of the freezable and nonfreezable water are given. For the chitosan gel itself, the higher the amino content, the lower the amounts of the freezable water. The introduction of an octanoyl group (D.S. = 0.3-0.4) leads to the increase of the freezable water. Further increase of the degree of substitution over 0.6 gives a decrease and finally reaches zero at D.S. = 1.0. On the other hand, in the case of dodecanoyl chitosan, the amounts of freezable water decrease linearly with increasing D.S. In the introduction of a benzoyl group, the amounts of the freezable water increases at D.S. = 0.3 and then decreases to the... 

The fact that K2 and S are quite small for chitosan is explained by a compact structure due to the high crystallinity of approximately 40% (density ca. 1.4). 3 jt is worthwhile to note the difference of the effects of benzoyl and octanoyl groups on the sorptivity of dyes. In comparing the values of Ki for Cb-0.5 and Cs-0.6, it is concluded that benzoyl groups cannot interact as firmly as the octanoyl group due to the bulky structure of the phenyl ring. Thus the Ki value of [4] is found to be seven times larger for Cb-0.5 than Cb-0.6. 

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