Abstract

The phytotoxic potential of the leaves and twigs of Schumannianthus dichotomus, discarded in the mat-making industry against four test plants (lettuce (Lactuca sativa L.), rapeseed (Brassica napus L.), foxtail fescue (Vulpia myuros (L.) C.C. Gmel.) and timothy (Phleum pratense L.)) was investigated and found strong phytotoxic activity. An assay-guided fractionation of S. dichotomus extarcts against cress (Lepidium sativum L.) through a series of column chromatography steps yielded two compounds, 8-(5-oxo-2,5-dihydrofuran-2-yl) octanoic acid (ODFO) and (E)-6-hydroxy-2,6-dimethylocta-2,7-dienoic acid (8-carboxylinalool). ODFO and 8-carboxylinalool showed strong phytotoxic activity against cress and timothy. The concentrations required for 50% growth inhibition (I₅₀ value) of the seedlings of cress and timothy were 111.94–128.01 and 36.30–91.75 µM, respectively, for ODFO, but the values were much higher at 315.98–379.13 and 107.92–148.41 µM, respectively, for 8-carboxylinalool, indicating the stronger phytotoxic activity of ODFO. This study is the first to isolate ODFO and 8-carboxylinalool from S. dichotomus and their phytotoxic potential while ODFO is firstly encountered from any natural source. The growth inhibitory activity of the identified compounds may explain their role in the phytotoxic activity of S. dichotomus, which suggests the possible use of its leaves and twigs or its active constituents as natural bioherbicides.

摘要

Schumannianthus dichotomus的叶子和细枝的植物毒性潜力，在制垫工业中被丢弃，对四种试验植物（莴苣（Lactuca sativa L.），油菜籽（甘蓝），狐尾羊茅（Vulpia myuros（L.）CC）进行了研究（Gmel。）和蒂莫西（Phleum pratense L.）），发现它们具有很强的植物毒性活性。通过一系列柱色谱步骤对水芹（Lepidium sativum L.）的分枝链霉链球菌提取物进行测定指导的分馏，得到两种化合物，即8-（5-氧代-2,5-二氢呋喃-2-基）辛酸（ODFO） ）和（E）-6-羟基-2,6-二甲基辛基-2,7-二烯酸（8-羧基芳樟醇）。ODFO和8-羧基芳樟醇对水芹和蒂莫西具有很强的植物毒活性。水芹和提摩太苗的50％生长抑制所需的浓度（I ₅₀值）对于ODFO分别为111.94–128.01和36.30–91.75 µM，但该值要高得多，为315.98–379.13和107.92–148.41 µM分别针对8-羧基芳樟醇，表明ODFO具有更强的植物毒性。这项研究是第一次分离ODFO并从8 carboxylinalool S. dichotomus和他们的毒性潜力，同时ODFO首先从任何天然来源中遇到。鉴定出的化合物的生长抑制活性可能解释了它们在植物毒性中的作用。S. dichotomus，表明可能使用其叶子和嫩枝或其活性成分作为天然生物除草剂。