Rosei M A, Mosca L
Dipartimento di Scienze Biochimiche, Università La Sapienza, Roma, Italia.
Biochem Mol Biol Int. 1995 May;35(6):1253-9.
Tetrahydropapaveroline (THP) oxidation was studied in various experimental conditions by absorbance spectroscopy. THP was found to be easily oxidized by mushroom tyrosinase, giving rise to the formation of a chromophore (THP-chrome) with absorption maxima at 308 and 470 nm. The oxidation further proceeds leading to the formation of a melanin-like pigment. The use of periodate as oxidant at pH 7.4 allows the visualization of the THP-chrome, as well. Other tetrahydroisoquinolines bearing a catechol moiety, such as salsolinol, laudanosoline and apomorphine, have been found to be easily oxidized in the same conditions, giving rise to pigmented derivatives. The products of THP oxidation are able to copolymerize with dopa or opioid peptides in the presence of tyrosinase, generating mixed-type melanins.
通过吸光光谱法在各种实验条件下研究了四氢罂粟碱（THP）的氧化。发现THP很容易被蘑菇酪氨酸酶氧化，生成一种发色团（THP-铬），其在308和470nm处有最大吸收峰。氧化进一步进行导致形成类似黑色素的色素。在pH 7.4下使用高碘酸盐作为氧化剂也能使THP-铬可视化。已发现其他带有儿茶酚部分的四氢异喹啉，如salsolinol、劳丹索林和阿扑吗啡，在相同条件下很容易被氧化，生成有色衍生物。THP氧化产物能够在酪氨酸酶存在下与多巴或阿片肽共聚，生成混合型黑色素。
