Campana Raffaella, Favi Gianfranco, Baffone Wally, Lucarini Simone
Department of Biomolecular Science, Division of Toxicological, Hygiene and Environmental Science, Via S. Chiara 27, University of Urbino Carlo Bo, 61029 Urbino, Italy.
Department of Biomolecular Science, Section of Organic Chemistry and Organic Natural Compounds, University of Urbino Carlo Bo, Via I Maggetti 24, 61029 Urbino, Italy.
Microorganisms. 2019 Jan 23;7(2):28. doi: 10.3390/microorganisms7020028.
The antimicrobial activity of the marine bisindole alkaloid 2,2-bis(6-bromo-3-indolyl) ethylamine () and related synthetic analogues (compounds ⁻) against target microorganisms was investigated by Minimum Inhibitory Concentration (MIC) determination. Compound showed the greatest antimicrobial activity with the lowest MIC (8 mg/L) against , , and , while the derivatives exhibited higher MICs values (from 16 to 128 mg/L). Compounds , , , and , the most active ones, were then tested against , , , and during biofilms formation as well as on 24 h developed biofilms. The natural alkaloid inhibited the biofilm formation of all the tested microorganisms up to 82.2% and disaggregated biofilms of , , , and after 30 min of contact, as assessed by viable plate count and crystal violet (CV) staining (optical density at 570 nm). Synthetic derivatives , , and displayed anti-biofilm activity toward individual bacterial populations. This study highlights the potential of marine bisindole alkaloid as anti-biofilm agent and shows, through a preliminary structure activity relationship (SAR), the importance of halogens and ethylamine side chain for the antimicrobial and antibiofilm activities of this bisindole series.
通过最低抑菌浓度（MIC）测定，研究了海洋双吲哚生物碱2,2-双（6-溴-3-吲哚基）乙胺（）及相关合成类似物（化合物⁻）对目标微生物的抗菌活性。化合物对、和显示出最大的抗菌活性，最低MIC为8 mg/L，而其衍生物的MIC值较高（16至128 mg/L）。然后对活性最高的化合物、、、和在生物膜形成过程中以及在形成24小时的生物膜上针对、、、和进行了测试。天然生物碱对所有测试微生物的生物膜形成抑制率高达82.2%，并在接触30分钟后使、、、和的生物膜解体，这通过活菌平板计数和结晶紫（CV）染色（570 nm处的光密度）进行评估。合成衍生物、和对单个细菌群体表现出抗生物膜活性。本研究突出了海洋双吲哚生物碱作为抗生物膜剂的潜力，并通过初步的构效关系（SAR）表明了卤素和乙胺侧链对该双吲哚系列抗菌和抗生物膜活性的重要性。
