A carboxylate chitooligomer (C-COS) containing carboxyl groups attached to chitooligomer (COS) molecules has been prepared by laccase/2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) system, which is a green-chemistry method. Several experiments were designed to evaluate inhibition effects on melanin and mechanisms of C-COS. The results indicated that C-COS exhibited more distinct anti-melanogenic effects compared to COS. C-COS inhibits melanin production with tyrosine (Tyr) and DOPA as the substrate of melanin formation, and the inhibition rates are, respectively, 89.07% and 84.45%, which reach 1.4 to 2 times those of COS. UV-visible spectroscopy was used to elucidate the interaction mechanism between C-COS and tyrosinase (TYR). It is C-COS chelating with metal Cu ions in tyrosinase (TYR) that decreases the enzyme activity. Half-maximal inhibitory concentrations (IC₅₀) of C-COS were calculated as 13.49 and 4.07 mg/mL for monophenolase (cresolase) and diphenolase (catecholase), respectively.

通过漆酶/ 2,2,6,6-四甲基哌啶-1-氧基（TEMPO）系统已经制备了含有连接至壳聚糖（COS）分子的羧基的羧酸基壳聚糖（C-COS），这是一种绿色化学方法。设计了几个实验来评估对黑色素的抑制作用和C-COS的机理。结果表明，与COS相比，C-COS具有更明显的抗黑色素生成作用，C-COS以酪氨酸（Tyr）和DOPA为黑色素形成底物抑制黑色素生成，抑制率分别为89.07％和84.45。 ％，达到COS的1.4到2倍，使用紫外可见光谱阐明C-COS与酪氨酸酶（TYR）之间的相互作用机理。酪氨酸酶（TYR）中的金属铜离子与C-COS螯合会降低酶的活性。单酚酶（甲酚酶）和双酚酶（儿茶酚酶）的C-COS的₅₀分别计算为13.49和4.07 mg / mL。