靶向细菌细胞壁新型食品保鲜剂的虚拟筛选

Virtual Screening of New Food Preservatives for Targeting to Bacterial Cell Walls

食品保鲜剂种类繁多,然而很多保鲜剂仅对革兰氏阳性菌有效,对革兰氏阴性菌的抑菌效果较差。为了开发对革兰氏阴性菌和阳性菌均具有较好抗菌活性的新型食品保鲜剂,以铜绿假单胞菌的粘肽合成酶PBP3和大肠杆菌的粘肽合成酶PBP1b,PBP4和PBP5为靶点,通过分子对接软件DOCK6.5,对含有580万个小分子化合物的ZINC数据库进行大规模虚拟筛选,从中选出一种打分较高且结构新颖的先导化合物进行有机合成。以山梨酸钾为阳性对照,测定先导化合物对冷鲜肉的保鲜效果,结果表明,先导化合物处理组除了色差略逊于山梨酸钾组外,其pH值、菌落总数、挥发性盐基氮、汁液流失率等指标均优于后者。同时,二者的保鲜效果均显著优于空白对照组。研究结果证明了先导化合物对冷鲜肉具有更优异的保鲜效果,有望进一步将其开发为新型食品保鲜剂。

There are kinds of food preservatives applied in the food industry,however,most of them only aim at gram-positive bacteria and have no effects on gram-negative bacteria.In order to develop new food preservatives with good antibacterial activity,molecular docking was carried out using UCSF DOCK6.5.The penicillin-binding protein 3(PBP3)of Pseudomonas aeruginosa and PBP1b,PBP4 and PBP5 of Escherichia coli were chosen as the targets.ZINC database,containing 5800000 drug-like small molecules,was used for the virtual screening.After analysis,one of the hits was selected as lead compound and subjected to organic synthesis and food preservation.Compared with potassium sorbate,the lead compound was more effective on the control of pH value,total number of bacterial colonies,drop loss and TVB-N of chilled pork except color protection.But both of them had better results than control group.The research results proved that the lead compound had a better preservation effect on chilled pork,and it was expected to further develop it into a new food preservative.