Zeise L, Chedekel M R
Department of Chemistry, California State University, Chico 95929.
Pigment Cell Res. 1992 Nov;5(5 Pt 1):230-9. doi: 10.1111/j.1600-0749.1992.tb00542.x.
Melanin isolated from the ink sac of Sepia officinalis (Sepia melanin) has been proposed as a standard for natural eumelanin, and a standard mild isolation and purification protocol for Sepia melanin has been developed (Zeise, doctoral dissertation, Johns Hopkins University, 1991). The goal of the present work, developed using Sepia melanin, was to quantify the bioavailable carboxylic acid groups present in melanin particles. Bioavailability is governed by the accessibility of carboxy groups to the surrounding biological milieu, and is expressed as microequivalents of carboxy group per gram of melanin. The present work was carried out using an heterogeneous slurry of melanin in a nonaqueous system. A standard acidic titrant, and an automatic titrator operating in an equilibrium titration mode were used to characterize and quantify the carboxy group content of Sepia melanins and several other commonly used melanins purified by a standard method (Zeise et al., Pigment Cell Res. [Suppl] 2:48-53, 1992).
从乌贼墨囊中分离出的黑色素（乌贼黑色素）已被提议作为天然真黑素的标准，并且已经开发出一种标准的温和乌贼黑色素分离和纯化方案（蔡斯，博士论文，约翰霍普金斯大学，1991年）。本研究使用乌贼黑色素，目的是量化黑色素颗粒中存在的生物可利用羧酸基团。生物利用度取决于羧基对周围生物环境的可及性，并以每克黑色素中羧基的微当量表示。本研究是在非水体系中使用黑色素的非均相浆料进行的。使用标准酸性滴定剂和以平衡滴定模式运行的自动滴定仪来表征和量化乌贼黑色素以及通过标准方法纯化的其他几种常用黑色素的羧基含量（蔡斯等人，《色素细胞研究》[增刊]2：48 - 53，1992年）。
