Department of Chemistry, Universidade Federal de Viçosa, Av. P. H. Rolfs S/N, 36.570.000 Viçosa, Minas Gerais, Brazil.
J Agric Food Chem. 2013 Jun 12;61(23):5540-9. doi: 10.1021/jf400698j. Epub 2013 May 29.
A series of isobenzofuran-1(3H)-ones (phthalides), analogues of the naturally occurring phytotoxin cryphonectric acid, were designed, synthesized, and fully characterized by NMR, IR, and MS analyses. Their synthesis was achieved via condensation, aromatization, and acetylation reactions. The measurement of the electron transport chain in spinach chloroplasts showed that several derivatives are capable of interfering with the photosynthetic apparatus. Few of them were found to inhibit the basal rate, but a significant inhibition was brought about only at concentrations exceeding 50 μM. Some other analogues acted as uncouplers or energy transfer inhibitors, with a remarkably higher effectiveness. Isobenzofuranone addition to the culture medium inhibited the growth of the cyanobacterium Synechococcus elongatus , with patterns consistent with the effects measured in vitro upon isolated chloroplasts. The most active derivatives, being able to completely suppress algal growth at 20 μM, may represent structures to be exploited for the design of new active ingredients for weed control.
一系列异苯并呋喃-1(3H)-酮（苯酞）是天然植物毒素 Cryphonectric acid 的类似物，通过缩合、芳构化和乙酰化反应进行设计、合成并通过 NMR、IR 和 MS 分析进行了充分的表征。测定菠菜叶绿体中的电子传递链表明，几种衍生物能够干扰光合作用装置。发现其中一些能够抑制基础速率，但只有在浓度超过 50 μM 时才会产生显著抑制。其他一些类似物充当解偶联剂或能量转移抑制剂，效果明显更高。苯酞酮添加到培养基中抑制了蓝藻 Synechococcus elongatus 的生长，其模式与在体外测定的对分离叶绿体的影响一致。最有效的衍生物能够在 20 μM 时完全抑制藻类生长，它们可能代表着可用于设计新型杂草控制活性成分的结构。
