Identification of pyrroloindoline-containing cyclic hexapeptides in the metabolites of Streptomyces alboflavus 313 by HPLC-DAD-ESI-MS/MS.
To investigate the chemical biodiversity of biologically active cyclic hexapeptides in the metabolites from microorganisms, the fermentation broth of Streptomyces alboflavus 313 was analyzed using HPLC, equipped with a diode array detector (DAD), coupled with ESI tandem MS (HPLC-DAD-ESI-MS/MS). In the mass spectra of cyclic hexapeptides, predominant ions [M+H](+), as well as [M-18+H](+), [M-28+H](+) and [M+Na](+), were observed and used to determine the molecular masses, while fragmentation reactions of [M+H](+) were recorded to provide information on the contents of amino acids and their linkage sequence. Based on the fragmentation patterns and comparison with standards, 15 pyrroloindoline-containing natural cyclic hexapeptides, cp01-15, were identified from the microorganism and six of these are reported for the first time.
College of Plant Protection, Northwest A and F University, Yangling, People's Republic of China. jizhiqin@nwsuaf.edu.cn
Zhiqin
Z
Ji
Nan
N
Xu
Qiao
Q
Gang
Shaopeng
S
Wei
D000596:Amino Acids / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media / Q000737:chemistry*; D015394:Molecular Structure; D008970:Molecular Weight; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000302:isolation & purification*; D021241:Spectrometry, Mass, Electrospray Ionization; D013302:Streptomyces / Q000254:growth & development* / Q000378:metabolism*; D053719:Tandem Mass Spectrometry
D000596:Amino Acids; D003470:Culture Media; D010456:Peptides, Cyclic