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    Isolation and identification of chitin from heavy mineralized skeleton of Suberea clavata (Verongida: Demospongiae: Porifera) marine demosponge
    (Elsevier, 2017) Ehrlich, Hermann; Bazhenov, Vasilii V.; Debitus, Cecile; de Voogd, Nicole; Galli, Roberta; Tsurkan, Mikhail V.; Wysokowski, Marcin; Meissner, Heike; Bulut, Esra; Kaya, Murat; Jesionowski, Teofil
    Since the discovery of chitin in skeletal structures of sponges (Porifera) in 2007, studies on search of novel species which possess this structural aminopolysaccharide continue up today. The most potential source of chitin is suggested to be localized in the four families of sponges related to the order Verongida (Demospongiae) which nevertheless require further clarification. Here, we report for the first time the isolation and identification of alpha-chitin from the Suberea clavata demosponge (Aplysinidae: Verongida). Raman spectroscopy, Calcofluor White staining, chitinase test and ESI-MS techniques were used to identify chitin. We suggest that the presence of chitin within fibrous skeletons of diverse species of Verongida order, and, especially in all species of the Aplysinidae family, may be useful for the identification of novel, previously unidentified marine demosponges. (C) 2017 Elsevier B.V. All rights reserved.
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    On chemistry of ?-chitin
    (ELSEVIER SCI, 2017) Kaya, Murat; Mujtaba, Muhammad; Ehrlich, Hermann; Salaberria, Asier; Baran, Talat; Amemiya, Chris T.; Galli, Roberta; Akyüz, Lalehan
    The biological material, chitin, is present in nature in three allomorphic forms: alpha, beta and gamma. Whereas most studies have dealt with alpha- and beta-chitin, only few investigations have focused on gamma-chitin, whose structural and physicochemical properties have not been well delineated. In this study, chitin obtained for the first time from the cocoon of the moth (Orgyia dubia) was subjected to extensive physicochemical analyses and examined, in parallel, with alpha-chitin from exoskeleton of a freshwater crab and 5-chitin from cuttlebone of the common cuttlefish. Our results, which are supported by13C CP-MAS NMR, XRD, FT-IR, Raman spectroscopy, TGA, DSC, SEM, AFM, chitinase digestive test and elemental analysis, verify the authenticity of beta-chitin. Further, quantum chemical calculations were conducted on all three allomorphic forms, and, together with our physicochemical analyses, demonstrate that gamma-chitin is distinct, yet closer in structure to alpha-chitin than beta-chitin.