title: Structure of insect chitin isolated from beetle larva cuticle and silkworm (Bombyx mori) pupa exuvia.
abstract: Chitin samples in a alpha-form structure were isolated from beetle larva cuticle and silkworm (Bombyx mori) pupa exuvia by treatment with 1 N HCl and 1 N NaOH. Chitosan was prepared by treating them in 40% NaOH containing NaBH(4). Chitin and chitosan were analyzed by X-ray, [13C]CP/MAS NMR, [13C]FT-NMR, and scanning electron microscopy (SEM) methods. Insect chitin degraded more readily than shrimp chitin when treated with 6 N HCl and the enzyme-chitinase. After treatment with 2 N HCl at 100 degrees C, the insect chitin crystallinity increased. N-deacetylation of insect chitin was easier than that of crustaceous chitin, and about 94% of the N-acetyl groups were removed in one treatment with 40% NaOH for 4 h at 110 degrees C. After treatment with 2 N HCl, 55% of the N-acetyl groups of silkworm chitin were removed under the same conditions. Beetle chitin showed a higher affinity for chitinase than shrimp chitin.
authors.affiliation: National Institute of Sericultural and Entomological Science, Tsukuba, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Zhang
authors.forename: A
authors.initials: A
authors.lastname: Haga
authors.forename: H
authors.initials: H
authors.lastname: Sekiguchi
authors.forename: S
authors.initials: S
authors.lastname: Hirano
mesh_terms: D000818:Animals; D012831:Bombyx / Q000737:chemistry; D002236:Carbohydrate Conformation; D002247:Carbon Isotopes; D002686:Chitin / Q000031:analogs & derivatives / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D048271:Chitosan; D001517:Coleoptera / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006868:Hydrolysis; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D011679:Pupa; D014961:X-Ray Diffraction
chemical_list: D002247:Carbon Isotopes; D002686:Chitin; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D048271:Chitosan