Abstract: Provided herein is an antibacterial compound of the following formula: or a pharmaceutically acceptable salt thereof. The antibacterial compound has antibacterial properties against a diverse range of gram negative bacteria and reduced toxicity compared to polymyxins such as polymyxin B. Also provided are antibacterial pharmaceutical compositions containing the antibacterial compound, as well as methods for preparing the antibacterial compound.

Abstract: Provided herein are novel compounds and novel protected compounds that can be derived from polymyxin, including, e.g., polymyxin A. The novel compounds have antibacterial properties against a diverse range of Gram negative bacteria and reduced toxicity compared to polymyxins such as polymyxin A. Also provided are antibacterial pharmaceutical compositions containing the novel compounds and novel protected compounds, as well as methods for preparing the antibacterial compounds and protected compounds.

Abstract: Disclosed herein are novel peptides and protected peptides. These compounds can be derived from naturally occurring peptides, such as those selected from colistin, circulin A, polymyxin A, polymyxin B, polymyxin D, octapeptin B, octapeptin C, and [Ile7]polymyxin B1. Also disclosed are pharmaceutical compositions containing the new peptides, as well as methods for preparing the novel peptides and protected peptides.

Abstract: Provided herein are novel compounds and novel protected compounds that can be derived from polymyxin, including, e.g., polymyxin A. The novel compounds have antibacterial properties against a diverse range of Gram negative bacteria and reduced toxicity compared to polymyxins such as polymyxin A. Also provided are antibacterial pharmaceutical compositions containing the novel compounds and novel protected compounds, as well as methods for preparing the antibacterial compounds and protected compounds.

Abstract: Provided herein are novel compounds and novel protected compounds that can be derived from polymyxin, including, e.g., polymyxin B1 and [Ile7] polymyxin B1. The novel compounds have antibacterial properties against a diverse range of gram negative bacteria and reduced toxicity compared to polymyxins such as polymyxin B. Also provided are antibacterial pharmaceutical compositions containing the novel compounds and novel protected compounds, as well as methods for preparing the antibacterial compounds and protected compounds.

Abstract: Provided herein are novel compounds and novel protected compounds that can be derived from polymyxin, including, e.g., polymyxin A. The novel compounds have antibacterial properties against a diverse range of Gram negative bacteria and reduced toxicity compared to polymyxins such as polymyxin A. Also provided are antibacterial pharmaceutical compositions containing the novel compounds and novel protected compounds, as well as methods for preparing the antibacterial compounds and protected compounds.

Abstract: Provided herein is an antibacterial compound of the following formula: or a pharmaceutically acceptable salt thereof. The antibacterial compound has antibacterial properties against a diverse range of gram negative bacteria and reduced toxicity compared to polymyxins such as polymyxin B. Also provided are antibacterial pharmaceutical compositions containing the antibacterial compound, as well as methods for preparing the antibacterial compound.

Abstract: Novel protected cyclopeptide intermediates are prepared from polymyxin B are used to synthesize new peptide antibiotics. Intermediates are readily derivatized and deprotected to provide new families of antibiotics, which have potent anti-bacterial activity against gram-negative bacteria; but also are useful and potent against gram-positive bacteria.

Abstract: Novel cyclodepsipeptide intermediates have been prepared from the A21978 complex and used to synthesize new lipodepsipeptide antibiotics. The three intermediates can be readily derivatized to give new families of antibiotics that have potent antibacterial activity against gram positive bacteria.

Abstract: This method is for preparing salts of amphotericin B methyl ester and other polyene macrolide esters. The steps of the process involve methylation by use of cesium carbonate for converting to methyl ester and significantly reducing side products, which are over methylation products. The free base-Schiff base mixture is converted to amphotericin B methyl ester hydrochloride or some other salt form, by using tetrahydrofuran-water to dissolve the mixture for acid treatment to obtain the salt. The aldehyde liberated during salt formation is removed by centrifuging, as to any precipitated aldehyde, and the aldehyde remaining in solution is removed by eluting the solution through a reverse phase adsorbent to obtain amphotericin B methyl ester hydrochloride as a yellow powder.