title: Extraction and Identification of the Pigment in the Adductor Muscle Scar of Pacific Oyster Crassostrea gigas.
abstract: In this study, UV (ultraviolet) and IR (infrared radiation) spectral analysis were integrated to identify the pigment in the adductor muscle scar of the Pacific oyster Crassostrea gigas. The pigment was extracted from the adductor muscle scars of cleaned oyster shells that were pulverized, hydrolyzed in hot hydrochloric acid, purified with diethyl ether, and dissolved in 0.01 mL/L NaOH. The maximum absorption of the pigment in the UV absorption spectrum within the range of 190-500 nm was observed between 210-220 nm. The UV absorbance decreased with increasing wavelength which was consistent with the UV spectral absorption characteristics of melanin. In addition, Fourier transform infrared spectroscopy scanning revealed characteristic absorption peaks that emerged near 3440 cm-1 and 1630 cm-1, which was consistent with infrared scanning features of eumelanin (a type of melanin). This study has demonstrated for the first time that the pigment in the adductor muscle scar of the Pacific oyster is melanin, hinting that the adductor muscle could be another organ pigmenting the mollusc shell with melanin other than mantle.
authors.affiliation: School of Agriculture, Ludong University, Yantai, Shandong, China.
authors.forename: Shixin
authors.initials: S
authors.lastname: Hao
authors.affiliation: School of Life Sciences, Ludong University, Yantai, Shandong, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Hou
authors.affiliation: School of Agriculture, Ludong University, Yantai, Shandong, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wei
authors.affiliation: School of Agriculture, Ludong University, Yantai, Shandong, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Agriculture, Ludong University, Yantai, Shandong, China.
authors.forename: Zhonghu
authors.initials: Z
authors.lastname: Li
authors.affiliation: School of Agriculture, Ludong University, Yantai, Shandong, China.
authors.forename: Xiaotong
authors.initials: X
authors.lastname: Wang
mesh_terms: D000818:Animals; D049896:Crassostrea / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D010860:Pigments, Biological / Q000378:metabolism*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D010860:Pigments, Biological