Motuporamine derivatives as antimicrobial agents and antibiotic enhancers against resistant gram-negative bacteria

A composition comprising a combination of an effective amount of one or more compounds selected from the group consisting of 4a, 4b, 5a, 5b, 6a, 6b, 9a, 9b, 10, 11a, 11b, 11c, 12a, 16a, 16b, 16c, and 50, or a pharmaceutically acceptable salt thereof;

• and an effective amount of an antibiotic, wherein the combination of the one or more compounds with the antibiotic enhance activity of the antibiotic, wherein the antibiotic comprises amoxicillin, doxycycline, erythromycin, chloramphenicol, cephalexin, ciprofloxacin, clindamycin, methicillin, metronidazole, penicillin, rifampicin, azithromycin, sulfamethoxazole/trimethoprim, amoxicillin/clavulanate, levofloxacin, or vancomycin, and wherein 4a, 4b, 5a, 5b, 6a, 6b, 11a, 11b, 11c, 12a, 16a, 16b, 16c, and 50 are defined by the following formula:
• wherein:
• 4a:
• X=N, Y=CH2, a=2, b=3, R1=R2=H;
• 4b:
• X=N, Y=CH2, a=3, b=4, R1=R2=H;
• 5a:
• X=CH, Y=N;
• a=3, b=3, R1=R2=H;
• 5b:
• X=CH, Y=N, a=4, b=4, R1=R2=H;
• 6a:
• X=CH, Y=CH2, a=0, b=3, R1=(CH2)3NH2, R2=H;
• 6b:
• X=CH, Y=CH2, a=0, b=4, R1=(CH2)3NH2, R2=H;
• 11a:
• X=CH, Y=CH2, a=0, b=2, R1=(CH2)2NH2, R2=H;
• 11b:
• X=CH, Y=CH2, a=0, b=2, R1=R2=H;
• 11c:
• X=CH, Y=CH2, a=0, b=2, R1=(CH2)2NH(CH2)2NH2, R2=H;
• wherein 9a and 9b have the following formula:
• wherein for 9a:
• x=3 and for 9b:
• x=4;
• wherein 10 has the following formula:
• wherein x=3;
• wherein 16a, 16b and 16c have the following formula, wherein z=2-16:
• and
• wherein 50 has the following formula: