A new anti-MRSA antibiotic complex, WAP-8294A II. Structure characterization of minor components by ESI LCMS and MS/MS

Abstract

The anti-MRSA antibiotic, WAP-8294A, was isolated from the fermentation broth of Lysobacter sp. The major component,and 2 mol of L-Ser, D-Orn and D-3-hydroxy-7-Me-octanoic acid. The structure of the WAP-8294A2 was mainly determined as a cyclic depsipeptide by 2D NMR experiments. However, it was difficult to use the NMR experiment to determine the minor components, A1, A4 and Ax13, isolated in small amounts. In the present study, ESI MS/MS was applied to the structure elucidation of these minor components. The structures of these minor components were determined on the basis of the fragmentation pattern of the product ions of WAP-8294A2 in the ESI MS/MS. As a result, it was confirmed that A1 and A4 had the same amino acid sequence as A2, while A1 and A4 had the 3-OH-octanoic acid and 3-OH-8-Me-nonanoic acid, respectively, in the place of the 3-OH-7-Meoctanoic acid in A2. In the structure of Ax13, it was found that Gly of A2 was changed to b-Ala of Ax13.

Identification and Characterization of the Anti-Methicillin-Resistant Staphylococcus aureus WAP-8294A2 Biosynthetic Gene Cluster from Lysobacter enzymogenes OH11

“…The results suggested that the WAP-8492A biosynthetic pathway likely recruits an ACL from other pathways. This type of in trans ACL generally exhibits a broad specificity and is functionally redundant (2), which is consistent with the fact that all WAP-8492A compounds have the same amino acid composition but vary in the length of the fatty acid side chain (16,(22)(23)(24).…”

“…13 C NMR data are summarized in Table 1 ( 1 H and 13 C NMR spectra and selected HSQC correlations are provided in the supplemental material). A comparison of these data to those in the literature readily revealed that this compound is WAP-8294A2, a cyclic lipodepsipeptide originally isolated from L. staphylocidin (16,(22)(23)(24). WAP-8294A2 consists of 12 amino acid residues and a fatty acid side chain (3-hydroxy-7-methyloctanoic acid) (Fig.…”

“…Since the disruption of the WASP1 gene also led to the disappearance of at least one other compound with similar retention time as WAP-8294A2, it is likely that this gene cluster is also responsible for other members in the WAP-8294A family that differ only in the acyl side chain length ( Fig. 1) (16,(22)(23)(24). Predicted substrate specificity of NRPS adenylation domains.…”

“…Dihydromaltophilin exhibits potent inhibitory activities against a wide range of fungi and shows a novel mode of action, as it disrupts the biosynthesis of sphingolipids (30). WAP8294As are cyclic depsipeptides originally isolated from Lysobacter staphylocidin (16,(22)(23)(24). They are potent anti-MRSA compounds (50% effetive dose [ED 50 ]14 times more active than vancomycin) and, among them, WAP-8294A2 is in phase I/II clinical studies by aRigen Pharmaceuticals (1).…”

ESI LC-MS and MS/MS Characterization of Antifungal Cyclic Lipopeptides Produced by <b><i>Bacillus subtilis </i></b>XF-1

“…Liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) has become the main method for analyzing proteins and peptides [Kato et al, 2011]. It is also used to analyze CLPs, such as fengycin [Bie et al, 2009;De Faria et al, 2011;Wang et al, 2004], surfactin [Cho et al, 2003a;Lee et al, 2007;Pecci et al, 2010;Wang et al, 2010] and iturin [Caldeira et al, 2011;Cho et al, 2003b].…”