Saadouli Ilhem, Zendah El Euch Imène, Trabelsi Emna, Mosbah Amor, Redissi Alaeddine, Ferjani Raoudha, Fhoula Imene, Cherif Ameur, Sabatier Jean-Marc, Sewald Norbert, Ouzari Hadda-Imene
LR03ES03, Laboratoire de Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, Université Tunis Manar, Tunis 2092, Tunisia.
Organic and Bioorganic Chemistry, Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
Antibiotics (Basel). 2020 May 21;9(5):270. doi: 10.3390/antibiotics9050270.
Streptomyces is the most frequently described genus of Actinomycetes, a producer of biologically active secondary metabolites. Indeed, the Streptomyces species produces about 70% of antibiotics and 60% of antifungal molecules used in agriculture. Our study was carried out with the goal of isolating and identifying antimicrobial secondary metabolites from V16R3Y1 isolated from the date palm rhizosphere (southern Tunisia). This strain presented a broad range of antifungal activity against , , , , , , and and antibacterial activity against human pathogenic bacteria, including , , , , and . The purification procedure entailed ethyl acetate extract, silica gel column, and thin layer chromatography. Based on 1H NMR metabolomic procedure application, also supported by the GC-MS analysis, cyclic dipeptide (l-Leucyl-l-Proline) was identified as the major compound in the bioactive fraction. In order to confirm the identity of the active compound and to have a large quantity thereof, a chemical synthesis of the cyclic dipeptide was performed. The synthetic compound was obtained with a very good yield (50%) and presented almost the same effect compared to the extracted fraction. This study indicates for the first time that V16R3Y1 exhibits a broad spectrum of antimicrobial activities, produced cyclic dipeptide (l-Leucyl-l-Proline) and might have potential use as a natural agent for pharmaceutical and agri-food applications.
链霉菌是放线菌中最常被描述的属，是生物活性次级代谢产物的生产者。实际上，链霉菌物种产生了约70%的抗生素和60%用于农业的抗真菌分子。我们的研究旨在从突尼斯南部枣椰树 rhizosphere 分离的V16R3Y1中分离和鉴定抗菌次级代谢产物。该菌株对 、 、 、 、 、 和 表现出广泛的抗真菌活性，对包括 、 、 、 、 和 在内的人类病原菌具有抗菌活性。纯化过程包括乙酸乙酯萃取、硅胶柱和薄层色谱。基于1H NMR代谢组学方法的应用，并得到GC-MS分析的支持，环二肽（l-亮氨酰-l-脯氨酸）被鉴定为生物活性部分的主要化合物。为了确认活性化合物的身份并大量获得该化合物，进行了环二肽的化学合成。合成化合物的产率非常高（50%），与提取部分相比几乎具有相同的效果。这项研究首次表明V16R3Y1具有广谱抗菌活性，产生环二肽（l-亮氨酰-l-脯氨酸），可能有作为药物和农业食品应用的天然剂的潜在用途。
