Probiotic lactobacilli have been implicated in the production of many low molecular weight bioactive molecules with tremendous potential to kill multidrug resistant human pathogens. The aim of the present study is to purify, characterise and evaluate a novel compound produced by a probiotic Lactobacillus plantarum LJR13 strain. The compound was purified employing silica gel column chromatography followed by RP-HPLC technique. The compound was identified as tert-butyl-4-(4-oxo-(2-((2-oxo-1- (p-tolyl) -2- (p-tolyloxy) ethyl) carbamoyl) pyrrolidin-1-yl) butanoyl) piperazine-carboxylate (BPBP) through various spectral techniques. Exhaustive literature search has revealed that the compound BPBP has not been reported from Lactobacillus species so far and ours is the first report describing its spectrum of activities against multidrug resistant human pathogens together with the morphological and physiological manifestations it brings about in the normal as well as human colon carcinoma cells. The MIC of BPBP for Listeria monocytogenes and Staphylococcus aureus was 15.62 μg/mL and 62.50 μg/mL respectively; however, for Acinetobacter baumannii the MIC was determined to be 31.25 μg/mL. Scanning electron microscopic studies of BPBP treated L. monocytogenes, S. aureus, and A. baumannii revealed the presence of blebs on the cell wall which represents the compromise in the cell wall integrity. While BPBP showed no significant cytotoxicity on mouse embryonic fibroblast cells, (NIH-3T3), marked discernible cytotoxic effect was observed on colorectal carcinoma cells, HCT-116, suggesting potential anti-cancer activity. Molecular docking studies displayed the interaction of BPBP with appropriate drug resistance associated proteins such as Penicillin binding proteins in gram positive L. monocytogenes and S. aureus and beta-lactamase in gram negative A. baumannii.

益生菌乳酸菌与许多低分子量生物活性分子的生产有关，这些分子具有杀死多药耐药人类病原体的巨大潜力。本研究的目的是纯化，表征和评估由益生菌植物乳杆菌LJR13菌株产生的新型化合物。使用硅胶柱色谱，然后用RP-HPLC技术纯化该化合物。将该化合物鉴定为叔丁基-4-（4-氧代-（2-（（2-氧代-1-（对甲苯基）-2-（对甲苯氧基）乙基）氨基甲酰基）吡咯烷-1-基）各种光谱技术来合成哌嗪-羧酸盐（BP）。详尽的文献搜索表明，尚未从乳杆菌中报道过该化合物BPBP。迄今为止，这是我们的第一个报道，它描述了其抗多药耐药性人类病原体的活性谱，以及它在正常和人类结肠癌细胞中引起的形态学和生理学表现。单核细胞增生李斯特菌和金黄色葡萄球菌的BPBP MIC分别为15.62μg / mL和62.50μg/ mL。但是，鲍曼不动杆菌的MIC被确定为31.25μg/ mL。BPBP处理的单核细胞增生李斯特菌，金黄色葡萄球菌和鲍曼不动杆菌的扫描电子显微镜研究揭示了在细胞壁上存在气泡，这代表了细胞壁完整性的损害。尽管BPBP对小鼠胚胎成纤维细胞（NIH-3T3）没有显示出明显的细胞毒性，但对结直肠癌细胞HCT-116却观察到了明显的细胞毒性作用，表明其潜在的抗癌活性。分子对接研究显示BPBP与合适的抗药性相关蛋白（如革兰氏阳性单核细胞增生李斯特菌中的青霉素结合蛋白和金黄色葡萄球菌和革兰氏阴性鲍曼不动杆菌中的β-内酰胺酶）相互作用。