1. Our experimentation was conducted before the commercialization of Chiral HPLC during years 1978-9. A ninhydrin test of a tertiary amine would be negative, as would a test of a non-nitrogenous substance; while tests of secondary and primary amines are positive. A preliminary communication of this work is published: see ref. 12. In that work and this, we used a commercial mixture of polymyxin B 1 and B 2 . For simplicity;2009 Schering-Plough purchased Merck, Sharp & Dome and in a reverse merger changed its name to Merck & Co. in Canada and USA
2. Outer Membrane Interaction Kinetics of New Polymyxin B Analogs in Gram-Negative Bacilli;J Wang;Study of the structure-activity relationship of polymyxin analogues,2016
3. Selective permeabilization of gram-negative bacterial membranes using multivalent peptide constructs for antibiotic sensitization;A L Cui;ACS Infectious Diseases,1393
4. Specific fragmentation of human erythrocyte spectrin by chemical cleavage at cysteine residues;Y Eshdat;Biochimica et Biophysica Acta (BBA)-Protein Structure,1979