Echinococcins are a class of antifungal drugs. These drugs inhibit glucan synthase, which is responsible for synthesis β1-3 linked glucans. Meanwhile, echinococcin inhibits 1,3 through noncompetitive inhibition- β Glucan synthase to inhibit fungal cell wall β- Synthesis of dextran. β- (1,3)-D-glucan synthase is an important component of fungal cell walls that do not exist in mammals. Nonetheless, organisms cannot synthesize β-(1,3)-D-glucan causes osmotic instability and cell death. Echinococcin is a group of semi synthetic cyclic lipopeptides with N-linked acyl lipid side chains. Besides, it plays a role in anchoring the hexapeptide nucleus to the fungal cell membrane. Moreover, drugs are synthesized by interacting with target enzyme complexes involved in the cell wall.

Furthermore, echinolectin exhibits good fungicidal activity against Candida albicans, Candida nearly smooth, and Candida Gilleymont. Importantly, it also showed good activity against amphotericin B and fluconazole resistant Candida glabrata. Resistance to echinocandin is conferred by mutations in the FKS gene, which encodes β- The catalytic subunit of the glucan synthase complex. Mutations in FKS1 and/or FKS2 can alter the kinetic properties of glucan synthase. Therefore, it reduces the relative adaptability of mutant strains and reduces their pathogenicity. Echinococcins can also alter the structure of cell walls, exposing buried glucans, and inducing a variety of important host immune responses. Now, we will introduce a broad-spectrum and long-lasting echinocandin, Rezafungin.

Rezafungin is an Echinocandin for Candidemia and Invasive Candidiasis.

First of all, Rezafungin (Biafungin) is a next-generation, broad-spectrum, and long-lasting echinocandin. Particularly, Rezafungin shows potent antifungal activity against Candida spp., Aspergillus spp., and Pneumocystis spp.

In the second place, Rezafungin shows potent in vivo efficacy as prophylaxis against Pneumocystis in an in vivo mouse infection model. Obviously, Rezafungin significantly reduced nuclei and asci burdens. Interestingly, Rezafungin is a cyclic hexapeptide. Rezafungin is a promising new candidate in the antifungal arsenal

All in all, Rezafungin (Biafungin) is a next-generation, broad-spectrum, and long-lasting echinocandin for candidemia and invasive candidiasis.

References:

Sofjan AK, et al. J Glob Antimicrob Resist. 2018 Sep;14:58-64.