Synthesis of Linear Geranylphenols and Their Effect on Mycelial Growth of Plant Pathogen Botrytis cinerea
作者:Luis Espinoza、Lautaro Taborga、Katy Díaz、Andrés Olea、Hugo Peña-Cortés
DOI:10.3390/molecules19021512
日期:——
Natural geranyl compounds are known to exhibit important biological activities. In this work a series of geranylphenols were synthesized to evaluate their effect on the mycelial growth of Botrytis cinerea. Geranyl derivatives were synthesized by direct geranylation reactions between the corresponding phenol derivatives and geraniol, using BF3.OEt2 as catalyst and AgNO3 as secondary catalyst. Previously reported molecules [geranylhydroquinone (2), geranylhydroquinone diacetate (6) and geranylphloroglucinol (9)], and new substances [(E)-4-(3,7-dimethylocta-2,6-dienyl)benzene-1,2,3-triol (geranyl-pyrogallol, 7), (E)-4-(3,7-dimethylocta-2,6-dienyl)benzene-1,2,3-triyl triacetate (8), (E)-2-(3,7-dimethylocta-2,6-dienyl)benzene-1,3,5-triyl triacetate geranylphloroglucinol triacetate (10), 2,4-bis((E)-3,7-dimethylocta-2,6-dienyl)benzene-1,3,5-triyl triacetate (11), 2,6-bis((E)-3,7-dimethylocta-2,6-dienyl)-3,5-dihydroxyphenyl acetate (12)], were obtained. All compounds were characterized by IR, HRMS and NMR spectroscopic data. The inhibitory effect of the synthesized compounds on the mycelial growth of Botrytis cinerea was tested in vitro. Excepting compound 11, all substances constrained the mycelial growth of Botrytis cinerea. The antifungal activity depends on the chemical structure of geranylphenol derivatives. Compounds 2 and 9 were the more effective substances showing inhibition degrees higher than those obtained with the commercial fungicide Captan, even at lower concentrations. Monosubstitution on the aromatic nucleus by a geranyl chain seems to be more effective for the inhibition of mycelial growth than a double substitution. These results suggest that the new derivatives of geranylphenols have the ability to block the mycelial development of the plant pathogen B. cinerea and that this capacity depends strongly on the structural features and lipophilicity of the compounds.
已知天然香叶基化合物表现出重要的生物活性。在这项工作中,合成了一系列香叶基酚,以评估它们对灰葡萄孢菌丝生长的影响。以BF3.OEt2为催化剂,AgNO3为辅助催化剂,通过相应苯酚衍生物与香叶醇直接香叶基化反应合成了香叶基衍生物。先前报道的分子[香叶基氢醌(2)、香叶基氢醌二乙酸酯(6)和香叶基间苯三酚(9)],以及新物质[(E)-4-(3,7-二甲基辛基-2,6-二烯基)苯-1,2、 3-三醇(香叶基-连苯三酚,7),(E)-4-(3,7-二甲基辛基-2,6-二烯基)苯-1,2,3-三乙酸三酯(8),(E)-2- (3,7-二甲基辛基-2,6-二烯基)苯-1,3,5-三乙酸基香叶基间苯三酚三乙酸酯 (10), 2,4-双((E)-3,7-二甲基辛基-2,6-二烯基)苯-1,3,5-三乙酸酯(11)、2,6-双((E)-3,7-二甲基辛基-2,6-二烯基)-3,5-二羟基苯乙酸酯(12)],获得。所有化合物均通过 IR、HRMS 和 NMR 光谱数据进行表征。体外测试了合成的化合物对灰葡萄孢菌丝生长的抑制作用。除化合物11外,所有物质均抑制灰霉病菌的菌丝生长。抗真菌活性取决于香叶基酚衍生物的化学结构。化合物 2 和 9 是更有效的物质,即使在较低浓度下,其抑制程度也高于市售杀菌剂克菌丹 (Captan)。香叶基链对芳香核的单取代似乎比双取代更有效地抑制菌丝体生长。这些结果表明,香叶基酚的新衍生物能够阻止植物病原体灰霉病菌的菌丝体发育,并且这种能力在很大程度上取决于化合物的结构特征和亲脂性。