The chitin system in the tubes of deep sea hydrothermal vent worms

Preparation of Bionanomaterials and their Polymer Nanocomposites from Waste and Biomass

“…In contrast, the structure of anhydrous b-chitin appears to be well established. However, the crystal structure of the b-chitin hydrate remains to be refined, as some uncertainty exists, even as to its unit cell parameters [51,52] A number of studies have been reported in the literature about the infrared spectra of chitin [53][54][55][56][57][58] C=O stretching region of the amide moiety, between 1600 and 1500 cm -1 , the amide I band is split at 1656 and 1621 cm -1 , the amide II band is in at 1556 cm -1 . The band at 1656 cm -1 , which occurs at similar wavelengths in polyamides and proteins, is commonly assigned to stretching of the C=O group hydrogen bonded to N-H of the neighboring intra-sheet chain.…”

Exhaustive crystal structure search and crystal modeling of β-chitin

“…The direction of a chain is said to be parallel up in the unit cell when the z-coordinate of O5 is greater than that of C5, and it is parallel down in the other case. Similar to cellulose, native ␤-chitin crystals have been found as highly crystalline microfibrils, whereby all the chitin chains should be aligned in the same direction [5,6]. Using highly crystalline microfibrils isolated from tubes of the vestimentiferan * Corresponding author.…”

Is Chitosan a New Panacea? Areas of Application

“…-Chitin is by far the most abundant; it occurs in fungal and yeast cell walls, krill, lobster and crab tendons and shells, shrimp shells, and insect cuticle. The rarer -chitin is composed of parallel strands of polysaccharides, is found in association with proteins in squid pens [9,10] and in the tubes synthesized by pogonophoran and vestimetiferan worms [11,12]. It also occurs in aphrodite chaetae [13] as well as in the lorica, built by some seaweeds or protozoa [14,15,16].…”