Meleagrin (Synonyms: 6-O-Methyloxaline)

MIC: 32-64 μg/ml for S. aureus, E. coli, and S. pneumoniae

Meleagrin is an antibiotic.

Meleagrin is an antibiotic derived from a deep ocean, penicillin-producing P. chrysogenum.

In vitro: It was found that consistent with their selective inhibition of Staphylococcus aureus FabI, meleagrin and its more active derivatives could directly bind to S. aureus FabI that was measured in a fluorescence quenching assay, inhibit intracellular fatty acid biosynthesis and growth of S. aureus, and increase the minimum inhibitory concentration (MIC) for fabI-overexpressing S. aureus. The compounds that were not effective against the FabK isoform, however, were able to inhibit the growth of Streptococcus pneumoniae containing only the FabK isoform. In addition, no resistant mutant to these compounds was obtained. Notely, fabK-overexpressing Escherichia coli was found to be not resistant to these compounds, but was resistant to triclosan [1]. Another study found that meleagrin was able to inhibit the growth of the human breast cancer cell lines, while similar treatment doses had no effect on the growth and viability of the non-tumorigenic human mammary epithelial cells MCF10A. Meleagrin also displayed good ATP competitive c-Met inhibitory activity in Z-Lyte assay [2].

In vivo: Up to now, there is no animal in vivo data reported.

Clinical trial: So far, no clinical study has been conducted.

References:
[1] Zheng, C. J.,Sohn, M.J.,Lee, S., et al. Meleagrin, a new FabI inhibitor from Penicillium chryosogenum with at least one additional mode of action. PLoS One 8(11), (2013).
[2] Mady MS et al.  The indole alkaloid meleagrin, from the olive tree endophytic fungus Penicillium chrysogenum, as a novel lead for the control of c-Met-dependent breast cancer proliferation, migration and invasion. Bioorg Med Chem. 2016 Jan 15;24(2):113-22.