The rapid increase in the emergence of multidrug resistance and the declining discovery rate of novel antibiotics are growing threats to public health. A brief summary of our recent 7-year research work is presented here. Our group has been carrying out a comprehensive and systemic work with the discovery, research and development of natural or synthetic xanthone-based peptidomimetics as antibiotics for the treatment of bacterial and fungal infections. [1-4] As a typical example, this study is the first report of the design of a new series of symmetric xanthone derivatives that mimic antimicrobial peptides (AMPs) using a total synthesis approach. This novel design is advantageous because of its low cost, synthetic simplicity, large scale of production and versatility, and easy tuning of amphiphilicity by controlling the incorporated cationic and hydrophobic moieties. Two water-soluble optimized compounds, 6 and 18, showed potent activities against Gram-positive bacteria, including MRSA and VRE (MICs = 0.78-6.25 µg/mL), with a rapid bactericidal effect, low toxicity in vitro and in vivo, and no emergence of drug resistance. Both compounds demonstrated enhanced membrane selectivity that was higher than those of most membrane-active antimicrobials in clinical trials or previous reports. The compounds appear to kill bacteria by disrupting their membranes. Significantly, 6 was also effective in vivo using a mouse model of corneal infection against both Staphylococcus aureus and MRSA Staphylococcus aureus-infected mouse model. [5] These results provide compelling evidence that these compounds have therapeutic potential as novel antimicrobials for topical and systemic application in the treatment of multidrug-resistant pathogens infections.