|
|Section2= |Section6= |Section7= }} Malachite green is an organic compound that is used as a dyestuff and has emerged as a controversial antimicrobial used in aquaculture. Malachite green is traditionally used as a dye for materials such as silk, leather, and paper. Although called malachite green, This dye is not prepared from the mineral malachite - the name just comes from the similarity of color. ==Structures and properties== Malachite green is classified in the dyestuff industry as a triarylmethane dye and also using in pigment industry. Formally, malachite green refers to the chloride salt ()Cl, although the term malachite green is used loosely and often just refers to the colored cation. The oxalate salt is also marketed. The anions have no effect on the color. The intense green color of the cation results from a strong absorption band at 621 nm (extinction coefficient of 105 M−1cm−1). Malachite green is prepared by the condensation of benzaldehyde and dimethylaniline to give leuco malachite green (LMG): :C6H5CHO + 2 C6H5N(CH3)2 → C6H5CH(C6H4N(CH3)2)2 + H2O Second, this colorless leuco compound, a relative of triphenylmethane, is oxidized to the cation that is MG: :C6H5CH(C6H4N(CH3)2)2 + HCl + 1/2 O2 → ()Cl + H2O A typical oxidizing agent is manganese dioxide. Hydrolysis of MG gives an alcohol:〔Adina Raducan, Alexandra Olteanu, Mihaela Puiu, Dumitru Oancea "Influence of surfactants on the fading of malachite green" ''Central European Journal of Chemistry'', 2008, Volume 6, pp. 1895–1066 (Print) 1644–3624 (Online). 〕 :()Cl + H2O → C6H5C(OH)(C6H4N(CH3)2)2 + HCl This alcohol is important because it, not MG, traverses cell membranes. Once inside the cell, it is metabolized into LMG. Only the cation MG is deeply colored, whereas the leuco and alcohol derivatives are not. This difference arises because only the cationic form has extended pi-delocalization, which allows the molecule to absorb visible light. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「malachite green」の詳細全文を読む スポンサード リンク
|