Phytochemistry, antioxidant potential and antifungal of Byrsonima crassifolia on soil phytopathogen control

Abstract The use of chemical defensives to control fungal diseases has by consequence to impact negatively over the environment and human health, this way, the use of plant extracts with antifungal properties along with proper cultural management makes viable an alternative plant production control, specially for familiar and organic cultures. The objective of this study was to perform phytochemical and antioxidant analysis of Byrsonima crassifolia (canjiqueira) barks and evaluate its antifungal potential over Fusarium solani and Sclerotinia sclerotiorum mycelial growth. The ethanol extract from plants collected in Pantanal, Mato Grosso do Sul, Brazil was submitted to phytochemical prospection, total phenol and flavonoids quantification and antioxidant activiy determination (DPPH). To evaluate antifungal activity concentrations of 800, 1200, 1600, 2000 and 2400 µg 100 mL-1 of ethanol extract were used. Which concentration was separately incorporated in agar (PDA) and shed in Petri dishes, followed by the fungi mycelial disc where the colonies diameter was measured daily. Negatives control with agar without extract and agar with an ethanol solution were used. The B. crassifolia ethanol extract presented inhibitory activity over the fungi studied where concentrations of 800 and 1600 µg 100 mL-1, inhibited 38% of the mycelial growth of F. solani; to S. sclerotiorum the best concentration was 2400 µg 100 mL1, reducing 37.5%. The antifungal bark extract potential of this specie is attributed to phenolic compounds and to triterpenes derivatives.

摘要：使用化学防护剂防治真菌病害会对环境与人体健康造成负面影响，因此，结合具备抗真菌特性的植物提取物与科学的栽培管理措施，可成为一种可行的植物生产病害防控替代方案，尤其适用于家庭式栽培与有机栽培体系。本研究旨在对金英木（*Byrsonima crassifolia*，俗称canjiqueira）树皮开展植物化学初筛、总酚与总黄酮含量定量分析，以及采用DPPH法进行抗氧化活性测定，并评估其对茄病镰刀菌（*Fusarium solani*）及核盘菌（*Sclerotinia sclerotiorum*）菌丝生长的抗真菌潜力。本研究使用采集自巴西马托格罗索州潘塔纳尔湿地的植株乙醇提取物完成了上述检测。为评估抗真菌活性，本研究设置了800、1200、1600、2000及2400 µg·100mL⁻¹共5个浓度梯度的乙醇提取物溶液，将各浓度分别掺入马铃薯葡萄糖琼脂（Potato Dextrose Agar，PDA）培养基后倾倒至培养皿中，随后接种真菌菌丝块，每日测量菌落直径。实验设置两组阴性对照：不含提取物的琼脂培养基，以及仅含乙醇溶液的琼脂培养基。结果显示，金英木乙醇提取物对供试真菌均表现出抑制活性：当浓度为800和1600 µg·100mL⁻¹时，对茄病镰刀菌的菌丝生长抑制率可达38%；对核盘菌而言，最佳抑制浓度为2400 µg·100mL⁻¹，抑制率达37.5%。该物种树皮提取物的抗真菌活性潜力，可归因于其含有的酚类物质与三萜类衍生物。