The MICs of all the synthesized cyclic peptides against fungal strains (A. fumigatus, C. albicans, and C. krusii) was determined using the microscale broth dilution method, as outlined by the M27-A3 documents of the Clinical and Laboratory Standard Institute (CLSI). Briefly, planktonic cells cultured in Sabouraud dextrose Broth (SDB) were harvested at midlogarithmic phase, washed with 10 mM phosphate-buffered saline (PBS, pH 7.4), and resuspended at a density of 0.5~2.5 × 10 3 CFU/mL in RPMI 1640 medium (Gibco, BRL Invitrogen, US). A 100 μL portion of the fungal suspension and 100 μL of each peptide (with final concentrations ranging from 0.7-100 μg/mL) and standard antibiotics (Amphotericin B and Fluconazole) were added to a 96-well plate for susceptibility testing. The plates were incubated at 35 °C for 48 h (Candida strains) and 72 h (Aspergillus strain). The OD at 630 nm for each well was measured using a microplate reader. The lowest concentration corresponding Where, A represents the absorbance of the peptide sample at 567 nm, A0 and At represent zero percent and 100% hemolysis determined in PBS and 1% Triton X-100, respectively.