Urbach D, Suchanka M, Urbach W
Z Naturforsch C Biosci. 1976 Nov-Dec;31(11-12):653-5.
The carotenoid biosynthesis of the green alga Ankistrodesmus braunii is blocked if these cells are cultured in presence of sublethal doses of pyridazinone herbicides (San 9789, San 6706, BASF 44521) or of the herbicide difunone (EMD-IT 5914). The amount of colored carotenoids normally found in these algae is reduced drastically and the precursors phytoene and phytofluene are accumulated. Furthermore a decrease in the chlorophyll level occurs in the treated cells, but there is a stronger loss of chlorophyll a, resulting in a lowering of the chlorophyll a/b ratio with time. Concerning the activity of substituted pyridazinones leading to inhibition of carotenoid biosynthesis this effect can be related to the chemical structure of these compounds: a trifluormethyl substitution of the phenyl ring and a mono- or dimethyl substitution of the amine (San 9789, San 6706) or a methoxy group instead of the substituted amine (BASF 44521) are required both for this effect. Other pyridazinone derivatives with either a trifluoromethyl substitition of the phenyl ring (San 9774) or a dimethyl subsittution of the amine (San 9785) or a methoxy group (BASF 13761) are without any effect on the pigment pattern of these algae.
如果绿藻布朗葡萄藻（Ankistrodesmus braunii）的细胞在亚致死剂量的哒嗪酮类除草剂（San 9789、San 6706、巴斯夫44521）或除草剂敌草隆（EMD - IT 5914）存在的情况下培养，其类胡萝卜素生物合成会受到阻碍。这些藻类中通常发现的有色类胡萝卜素的量会急剧减少，并且前体八氢番茄红素和六氢番茄红素会积累。此外，处理过的细胞中叶绿素水平会下降，但叶绿素a的损失更为严重，导致叶绿素a/b比值随时间降低。关于导致类胡萝卜素生物合成受到抑制的取代哒嗪酮的活性，这种效应可能与这些化合物的化学结构有关：要产生这种效应，苯环需要有三氟甲基取代，胺需要有单甲基或二甲基取代（San 9789、San 6706），或者用甲氧基取代取代胺（巴斯夫44521）。其他具有苯环三氟甲基取代（San 9774）、胺二甲基取代（San 9785）或甲氧基（巴斯夫13761）的哒嗪酮衍生物对这些藻类的色素模式没有任何影响。
