Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126 Napoli, Italy.
BBCA onlus, Via A. Signorelli 105, 00123 Rome, Italy.
Molecules. 2019 Jul 31;24(15):2793. doi: 10.3390/molecules24152793.
Radicinin (), is a fungal dihydropyranopyran-4,5-dione isolated together with some analogues, namely 3--radicinin, radicinol, 3--radicinol, and cochliotoxin (-), from the culture filtrates of the fungus , a foliar pathogen of buffelgrass (), an invasive weed in North America. Among the different metabolites showed target-specific activity against the host plant and no toxicity on zebrafish embryos, promoting its potential use to develop a natural bioherbicide formulation to manage buffelgrass. These data and the peculiar structural feature of suggested to carry out a structure-activity relationship study, preparing some key hemisynthetic derivatives and to test their phytotoxicity. In particular, -bromobenzoyl, 5-azidopentanoyl, stearoyl, mesyl and acetyl esters of radicinin were semisynthesized as well as the monoacetyl ester of 3--radicinin, the diacetyl esters of radicinol and its 3 epimer, and two hexa-hydro derivatives of radicinin. The spectroscopic characterization and the activity by leaf puncture bioassay against buffelgrass of all the derivatives is reported. Most of the compounds showed phytotoxicity but none of them had comparable or higher activity than radicinin. Thus, the presence of an α,β unsaturated carbonyl group at C-4, as well as, the presence of a free secondary hydroxyl group at C-3 and the stereochemistry of the same carbon proved to be the essential feature for activity.
瑞迪辛宁（），是一种真菌二氢吡喃并吡喃-4,5-二酮，与一些类似物一起从真菌的培养滤液中分离出来，这种真菌是北美一种入侵性杂草布法罗草（）的叶病原体。在不同的代谢产物中，表现出对宿主植物的靶向特异性活性，对斑马鱼胚胎没有毒性，这促进了其在开发天然生物除草剂配方以管理布法罗草方面的潜在用途。这些数据和的特殊结构特征表明需要进行结构-活性关系研究，制备一些关键的半合成衍生物，并测试它们的植物毒性。特别是，瑞迪辛宁的 -溴苯甲酰基、5-叠氮戊酰基、硬脂酰基、甲磺酰基和乙酰酯以及 3--瑞迪辛宁的单乙酰酯、瑞迪辛醇及其 3 差向异构体的二乙酰酯，以及瑞迪辛宁的两个全氢衍生物被半合成。报告了所有衍生物的光谱特征和通过叶穿刺生物测定对布法罗草的活性。大多数化合物表现出植物毒性，但没有一种化合物的活性与瑞迪辛宁相当或更高。因此，C-4 上存在α,β不饱和羰基以及 C-3 上存在游离的仲羟基以及同一碳原子的立体化学被证明是活性的必要特征。
