An integrated approach to the structure of Sepia melanin. Evidence for a high proportion of degraded 5,6-dihydroxyindole-2-carboxylic acid units in the pigment backbone

被引：101

作者：

Pezzella, A

dIschia, M

Napolitano, A

Palumbo, A

Prota, G

机构：

[1] UNIV NAPLES FEDERICO II, DEPT ORGAN & BIOL CHEM, I-80134 NAPLES, ITALY

[2] Staz Zool Anton Dohrn, I-80121 NAPLES, ITALY

来源：

TETRAHEDRON | 1997年 / 53卷 / 24期

关键词：

D O I：

10.1016/S0040-4020(97)00494-8

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The relative proportion of 5,6-dihydroxyindole (DHI) versus 5,6-dihydroxyindole-2-carboxylic acid (DHICA) units in Sepia melanin and their degree of structural integrity were assessed by an integrated approach involving quantitative determination of pyrrole-2,3-dicarboxylic acid (PDCA) and pyrrole-2,3,5-tricarboxylic acid (PTCA), specific degradation products of DHI- and DHICA-derived units; carboxyl content; rate of ferricyanide consumption; and absorption spectrum. Analyses of both intact and surfactant-solubilised pigment samples, in comparison with synthetic DHI and DHICA melanins, revealed that Sepia melanin consists of a mixture of oligomeric structures incorporating over 75% of DHICA-derived units and only 20% of DHI-derived units, occurring for the most part in an irreversibly degraded form, possibly as pyrrolecarboxylic acids. (C) 1997 Elsevier Science Ltd.

引用

页码：8281 / 8286

页数：6

共 29 条

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