Plant pathogenic bacteria cause huge yield losses in crops globally. Therefore, finding effective bactericides to these pathogens is an immediate challenge. In this study, we sought compounds that specifically inhibit the growth of Ralstonia solanacearum. As a result, we identified one promising compound, 1-(4-bromophenyl)-6-methoxy-2,3,4,9-tetrahydro-1H-β-carboline, which inhibited the growth of R. solanacearum (Rs1002) from a pilot library of 376 chemicals provided from RIKEN. We further obtained its structural analogues and assessed their ability to inhibit Rs1002 growth. Then we identified five compounds, named ralhibitins A to E, that specifically inhibit growth of Rs1002 at >5 μg/ml final concentration. The most effective compounds, ralhibitins A, C, and E completely inhibited the growth of Rs1002 at 1.25 μg/ml. In addition, ralhibitins A to E inhibited growth of Xanthomonas oryzae pv. oryzae but not the other bacteria tested at a final concentration of 10 μg/ml. Whereas, ralhibitin E, besides inhibiting R. solanacearum and X. oryzae pv. oryzae, completely inhibited the growth of X. campestris pv. campestris and the Gram-positive bacterium Clavibacter michiganensis subsp. michiganensis at 10 μg/ml. Growth inhibition by these compounds was stable at pH 6–9 and after autoclaving. Because Rs1002 grew in the culture medium in which ralhibitins were incubated with the ralhibitin-insensitive bacteria, the unaffected bacteria may be able to inactivate the inhibitory effect of ralhibitins. These results suggest that ralhibitins might be potential lead compounds for the specific control of phytopathogenic bacteria.

植物病原细菌在全球范围内导致农作物的巨大产量损失。因此，寻找对这些病原体有效的杀菌剂是当下的挑战。在这项研究中，我们寻求了能特异性抑制青枯雷尔氏菌生长的化合物。结果，我们确定了一种有前途的化合物，1-（4-溴苯基）-6-甲氧基-2,3,4,9-四氢-1H-β-咔啉，可抑制青枯菌的生长（Rs 1002）来自RIKEN提供的376种化学品的试验库。我们进一步获得了其结构类似物，并评估了其抑制Rs 1002生长的能力。然后，我们鉴定了五种化合物，分别命名为雷洛汀A至E，可特异性抑制Rs的生长最终浓度> 5μg/ ml时为1002。最有效的化合物雷洛汀A，C和E以1.25μg/ ml的浓度完全抑制Rs 1002的生长。另外，雷比抑制素A至E抑制米黄单胞菌（Xanthomonas oryzae pv）的生长。米粉，但未测试其他细菌，最终浓度为10μg/ ml。而雷比抑制素E，除了抑制茄青枯病菌（R. solanacearum）和米曲霉（X. oryzae pv）。米完全抑制了X. campestris pv的生长。喜树和革兰氏阳性细菌密歇根州亚种。密歇根州浓度为10μg/ ml。这些化合物的生长抑制作用在pH 6-9和高压灭菌后稳定。由于Rs 1002在将雷洛比汀不敏感的细菌孵育的培养基中生长，因此未受影响的细菌可能能够灭活雷洛比汀的抑制作用。这些结果表明，雷洛抑素可能是潜在的导致植物病原菌特异性控制的先导化合物。