| Author | Khan, Munawwar Ali |
| Call Number | AIT Thesis no. BP-98-13 |
| Subject(s) | Chitin
|
| Note | A thesis submitted in pa11ial fulfillment of the requirements for the degree of Master of
Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | The crystallinity of natural chitin makes it difficult to dissolve the compound in water and in
various common organic solvents and to modify it chemically or biochemically into various
useful forms. A nondegrading aprotic solvent Lithium chloride - N, N-dimethylacetamide
(LiCl-DMAc) system was used to solublize chitin. Chitin from different sources like
cuttlefish, crab and squid gave a clear transparent solution up to 1 % concentration range while
slu·imp chitin can be solubilized to a concentration of maximum 5 %.
Chitin solubilized in LiCl-DMAc solvent was modified by succinic anhydride and
triethylamine to give a purple color gel. This succinylated chitin/triethylamine complex was
found to be soluble in water in the pH range 3-12. The chitin solution in LiCl-DMAc system
has been used to prepare chitin gel and chitin films. The chitin gel on further reaction with
monochloroacetic acid in 2-propanol gave a gel of carboxymethylated chitin.
The shrimp chitin has been also modified by butyric anhydride in presence of 65 % perchloric
acid to give butyryl chitin which was found to soluble in various solvents like N, N -
dimethylformamide, acetone and methanol. Butyryl chitin film was casted from their 5 %
solution in acetone. The alkaline treatment converted butyryl chitin film back into chitin film,
which was proved by the appearance of pertinent absorbances in the infra red spectrum.
The solubility of chitin from different sources has been also examined in other acidic solvents
like 99 % formic acid and 85 % phosphoric acid. The 85 % phosphoric acid gave a very clear
solution of slu·imp chitin within very short time. Chitin was recovered back from their solution
in 99 % formic acid and 85 % phosphoric acid by diluting with water.
The various forms of modified chitin like glycol chitin, water soluble succinylated chitin,
butyryl chitin, regenerated chitin in acidic solvents, chitin film, gel in LiCl-DMAc were tested
as substrate for the enzyme chitin deacetylase (CDA). The regenerated chitin from its solution
in 99 % formic acid is about three times more suitable as substrate for the CDA as compared
with natural chitin. |
| Year | 1998 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Bioprocess Technology (BP) |
| Chairperson(s) | Stevens, Willem F.; |
| Examination Committee(s) | Suwalee Chandrkrachang ;Rakshit, Sudip Kumar ;Montet, Didier ;Pakorn Nuchnoi ; |
| Scholarship Donor(s) | H. M. King's Scholarship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1998 |