title: Chitin-based scaffolds are an integral part of the skeleton of the marine demosponge Ianthella basta.
abstract: The skeletons of demosponges, such as Ianthella basta, are known to be a composite material containing organic constituents. Here, we show that a filigree chitin-based scaffold is an integral component of the I. basta skeleton. These chitin-based scaffolds can be isolated from the sponge skeletons using an isolation and purification technique based on treatment with alkaline solutions. Solid-state (13)C NMR, Raman, and FT-IR spectroscopies, as well as chitinase digestion, reveal that the isolated material indeed consists of chitin. The morphology of the scaffolds has been determined by light and electron microscopy. It consists of cross-linked chitin fibers approximately 40-100 nm in diameter forming a micro-structured network. The overall shape of this network closely resembles the shape of the integer sponge skeleton. Solid-state (13)C NMR spectroscopy was used to characterize the sponge skeleton on a molecular level. The (13)C NMR signals of the chitin-based scaffolds are relatively broad, indicating a high amount of disordered chitin, possibly in the form of surface-exposed molecules. X-ray diffraction confirms that the scaffolds isolated from I. basta consist of partially disordered and loosely packed chitin with large surfaces. The spectroscopic signature of these chitin-based scaffolds is closer to that of alpha-chitin than beta-chitin.
authors: TU Dresden, Fachrichtung Chemie und Lebensmittelchemie, Bioanalytische Chemie, Postfach, Dresden, Germany. eike.brunner@tu-dresden.de
authors: E
authors: E
authors: Brunner
authors: H
authors: H
authors: Ehrlich
authors: P
authors: P
authors: Schupp
authors: R
authors: R
authors: Hedrich
authors: S
authors: S
authors: Hunoldt
authors: M
authors: M
authors: Kammer
authors: S
authors: S
authors: Machill
authors: S
authors: S
authors: Paasch
authors: V V
authors: VV
authors: Bazhenov
authors: D V
authors: DV
authors: Kurek
authors: T
authors: T
authors: Arnold
authors: S
authors: S
authors: Brockmann
authors: M
authors: M
authors: Ruhnow
authors: R
authors: R
authors: Born
mesh_terms: D000818:Animals; D002686:Chitin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D011161:Porifera / Q000033:anatomy & histology* / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014961:X-Ray Diffraction
chemical_list: D002686:Chitin