Heisey R M, Putnam A R
J Nat Prod. 1986 Sep-Oct;49(5):859-65. doi: 10.1021/np50047a016.
Geldanamycin (2) and nigericin (1) (primarily the Na+ salt) are responsible for the phytotoxicity of a Streptomyces hygroscopicus strain found to be highly active in our screens for producers of herbicidal antibiotics. After extraction from the cells, the compounds were purified with column and thin layer layer chromatography on silica gel, bioassayed for inhibition of garden cress (Lepidium sativum L.) radicle elongation, and identified with ms, ir, nmr, and co-chromatography with authentic standards. Both caused 50% reduction in garden cress radicle growth at concentrations of 1-2 ppm and nearly complete inhibitions at 3-4 ppm. Symptoms of toxicity differed markedly for the two compounds. Geldanamycin at high concentrations caused radicles to turn brown and disintegrate, whereas, nigericin did not cause visible necrosis. Geldanamycin is structurally similar to the herbimycins, which are also produced by S. hygroscopicus and have been reported to have herbicidal activity. The phytotoxicity of geldanamycin and nigericin has stimulated investigation of their potential for use as natural product herbicides.
格尔德霉素（2）和尼日利亚菌素（1）（主要是钠盐）是一种吸水链霉菌菌株产生植物毒性的原因，该菌株在我们针对除草抗生素生产者的筛选中被发现具有高活性。从细胞中提取后，这些化合物通过硅胶柱色谱和薄层色谱进行纯化，通过生物测定法检测对水芹（独行菜）胚根伸长的抑制作用，并通过质谱、红外光谱、核磁共振以及与标准品共色谱法进行鉴定。两种化合物在浓度为1 - 2 ppm时均使水芹胚根生长减少50%，在3 - 4 ppm时几乎完全抑制。两种化合物的毒性症状明显不同。高浓度的格尔德霉素会使胚根变成褐色并解体，而尼日利亚菌素不会导致可见的坏死。格尔德霉素在结构上与除草霉素相似，除草霉素也是由吸水链霉菌产生的，并且据报道具有除草活性。格尔德霉素和尼日利亚菌素的植物毒性激发了对它们作为天然产物除草剂潜力的研究。
