Antimicrobial potentials of active component isolated from Citrullus colocynthis fruits and structure-activity relationships of its analogues against foodborne bacteria.
BACKGROUND
Synthetic preservatives have been consistently used to maintain the quality of food products. However, the degree of danger to human health cannot be ignored. In this study, the antimicrobial activities of Citrullus colocynthis fruits and 4-methylquinoline analogues were investigated to develop natural preservatives against foodborne bacteria.


RESULTS
Antimicrobial activities of the methanol extract and five fractions derived from C. colocynthis fruits were evaluated against five foodborne bacteria. The chloroform fraction possessed strong activities against five foodborne bacteria. 4-Methylquinoline was isolated by chromatographic analyses. To establish the structure-activity relationships, the antimicrobial activities of 4-methylquinoline analogues (2-hydroxyquinoline, 4-hydroxyquinoline, 6-hydroxyquinoline, 2-methylquinoline, 6-methyquinoline, 8-methylquinoline and 2-methyl-8-hydroxyquinoline) were tested against food-borne bacteria. When employing the agar diffusion method, 2-methyl-8-hydroxyquinoline was found to have potent activities against the five foodborne bacteria. In terms of minimum bactericidal concentration or minimum inhibitory concentration, 2-methyl-8-hydroxyquinoline had significantly higher antimicrobial activity against the five foodborne bacteria.


CONCLUSIONS
Citrullus colocynthis fruits and 4-methylquinoline analogues could be useful for the development of eco-friendly food supplemental agents and pharmaceuticals.
Department of Bioenvironmental Chemistry and Institute of Agricultural Science and Technology, Chonbuk National University, Jeonju, 561-756, South Korea.
Min-Gi
MG
Kim
Sung-Eun
SE
Lee
Ji-Yeon
JY
Yang
Hoi-Seon
HS
Lee
D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D065986:Citrullus colocynthis / Q000737:chemistry*; D005517:Foodborne Diseases / Q000382:microbiology; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011804:Quinolines / Q000302:isolation & purification / Q000494:pharmacology*; D013329:Structure-Activity Relationship
D000900:Anti-Bacterial Agents; D010936:Plant Extracts; D011804:Quinolines; C057608:4-methylquinoline
4-methylquinoline analogues; Citrullus colocynthis fruits; antimicrobial activity; foodborne bacteria