title: Quantification of the antifungal lipopeptide iturin A by high performance liquid chromatography coupled with aqueous two-phase extraction.
abstract: Iturin A, a powerful antifungal surfactant, is a kind of bacterial lipopeptide produced by Bacillus strains. This study addresses the use of an aqueous two-phase system (ATPS) using ethanol/ammonium sulfate to extract iturin A from Bacillus amyloliquefaciens NJN-6 fermentation broth and the quantification of iturin A by HPLC. Baseline separation of iturin A homologues was performed using an RP-C(18) column with a mixture of water and acetonitrile. The results showed that the correlation coefficient between integral area and concentration was 0.9961 within the range of 20-140 mg/l. The RSD of the retention time and the peak area were 1.29% and 1.45%, respectively. The effects of some operating parameters in ATPS, e.g., pH, temperature and centrifugation time, were also studied. This method can be successfully used for the rapid quantification of iturin A.
authors.affiliation: Jiangsu Key Lab for Organic Solid Waste Utilization, Nanjing Agricultural University, 210095 Nanjing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yuan
authors.forename: Waseem
authors.initials: W
authors.lastname: Raza
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Huang
authors.forename: Qirong
authors.initials: Q
authors.lastname: Shen
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D000935:Antifungal Agents / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D001407:Bacillus / Q000737:chemistry; D001426:Bacterial Proteins / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D005591:Chemical Fractionation / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D016014:Linear Models; D055666:Lipopeptides / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D010456:Peptides, Cyclic / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D015203:Reproducibility of Results; D012988:Soil Microbiology; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D000935:Antifungal Agents; D001426:Bacterial Proteins; D055666:Lipopeptides; D010456:Peptides, Cyclic; D014867:Water; C013579:iturin A; C032159:acetonitrile