Background:

Amphomycin is a natural antibacterial lipopeptide.

Cyclic lipopeptides are a promising class of natural products with antibiotic properties. Cyclic lipopeptides are amphiphilic molecules, composed of a fatty acid tail linked to a short oligopeptide which form a macrocylic ring structure.

In vitro: In previous study, Calf brain endoplasmic reticulum membranes were incubated with varying concentrations of GDP-mannose in the presence and absence of amphomycin, results showed no significant difference in apparent Km for GDP-mannose. However, the Vmax was reduced in the presence of amphomycin as compared with in its absence. Moreover, when mannosylphosphoryldolichol synthase activity was measured in the presence of amphomycin, the shape of the substrate velocity curve changed from a rectangular hyperbola to a sigmoid [1].

In vivo: The PK of lipopeptides, the semi-synthetic amphomycin analogues, were evaluated in mice and rats following single i.v. and oral administration. Following oral administration at 50 mg/kg, plasma concentrations of amphomycin analogues were<0.3-0.9 μg/mL, indicating that oral availability was low. Following i.v. administration (5-10 mg/kg), the majority of lipopeptides demonstrated a long half-life, low clearance and a volume of distribution indicative of extracellular penetration. The long half-life and low clearance indicated that drug serum concentrations remained above the target minimal inhibitory concentration levels for significant periods of time. When combined with the potent efficacy against Gram-positive organisms, the results supported further development of these lipopeptide analogues towards clinical evaluation [2].

Clinical trial: Up to now, amphomycin is still in the preclinical development stage.

参考文献:
[1] D.  K. Banerjee. Amphomycin inhibits mannosylphosphoryldolichol synthesis by forming a complex with dolichylmonophosphate. The Journal of Biological Chemisty 264(4), 2024-2028 (1989).
[2] Pasetka CJ, Erfle DJ, Cameron DR, Clement JJ, Rubinchik E.  Novel antimicrobial lipopeptides with long in vivo half-lives. Int J Antimicrob Agents. 2010 Feb;35(2):182-5.