This review describes the most common methods for recovery of chitin from marine organisms. In depth, both enzymatic and chemical treatments for the step of deproteinization are compared, as well as different conditions for demineralization. The conditions of chitosan preparation are also discussed, since they significantly impact the synthesis of chitosan with varying degree of acetylation (DA) and molecular weight (MW). In addition, the main characterization techniques applied for chitin and chitosan are recalled, pointing out the role of their solubility in relation with the chemical structure (mainly the acetyl group distribution along the backbone). Biological activities are also presented, such as: antibacterial, antifungal, antitumor and antioxidant. Interestingly, the relationship between chemical structure and biological activity is demonstrated for chitosan molecules with different DA and MW and homogeneous distribution of acetyl groups for the first time. In the end, several selected pharmaceutical and biomedical applications are presented, in which chitin and chitosan are recognized as new biomaterials taking advantage of their biocompatibility and biodegradability.

/pdf/chitin-and-chitosan-preparation-from-marine-sources-395brtgt7i.pdf

Chitin and Chitosan Preparation from Marine Sources. Structure, Properties and Applications

http://biomimetic.pbworks.com/f/Design+and+mechanical+properties+ofVincent.pdf

Design and mechanical properties of insect cuticle

Biology of the Arthropod Cuticle

Detection of chitinase activity after polyacrylamide gel electrophoresis

Publisher Summary The genetics of Drosophila provides a number of different approaches toward initiating the investigation of the areas of biogenic-amine metabolism that have previously not been studied or are completely novel to any organism. Biogenic amines are particularly important compounds in insects, for they not only serve as neurotransmitters and modulaters of adenylate cyclase activity in their neurophysiology but also are essential for cross-linking proteins and chitin during sclerotization in the insect cuticle throughout development and especially at times of eclosion (hatching) and molting. A thorough understanding of the regulation of the synthesis, inactivation, and degradation of biogenic amines in the nervous system is mandatory for the elucidation of their roles in the neurophysiology and behavior of any organism. The availability of mutations that interrupt biogenic-amine metabolism in an experimentally suitable organism such as Drosophila should provide powerful analytical tools for neurochemists, neurophysiologists, and behavioral biologists. To facilitate and stimulate research on biogenic amines and sclerotization, this chapter discusses some known facts about the genetics and biochemistry of biogenic amines and sclerotization in Drosophila .

Mary Goldberg

Papers

New substrates for use with chitinases.

Studies on the hardening and darkening of insect cuticles

Proteins of the larval cuticle of Agrianome spinicollis (Coleoptera)

The o-diphenoloxidases of fly larvae

Light-scattering and infrared-spectrophotometric studies of chitin and chitin derivatives