A series of novel coumarin-amino acid conjugates was synthesized and structural characterization was done by various spectroscopic methods. All the conjugates were screened for their antifungal activity against five fungal strains namely T. rubrum, A. niger, A. fumigatus, A. flavus and C. albicans by twofold serial microdilution method. Some of them showed significant activity with MIC values in the range of 6.25-25 μg/ mL. Notably, compound 5 e showed potential antifungal effect against three tested strains with MIC's in the range of 6.25-12.5 μg/mL. The molecular docking studies showed that some conjugates possessed good binding affinity with the modelled receptor of integrin-like protein of Cryptococcus neoformans var. grubii. Compounds 5 d and 5 e also exhibited good binding efficiency with the Candida spp. cell wall associated proteins in in vitro binding assay. Additionally, in silico physicochemical parameters such as lipophilicity and pharmacokinetic properties such as absorption, distribution, metabolism, and excretion (ADME) of the synthesized compounds were also evaluated.

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM Objective: Vaginal candidiasis is a frequent infection afflicting the female population. Candida co-infections are reported in escalating frequency and can be associated with severe health hazards or even death. People with severe COVID-19, malignancies, AIDS, and organ transplants are particularly vulnerable to invasive vaginal candidiasis. Due to the high frequency of infections associated with recurrence, vaginal candidiasis poses a significant medical problem worldwide. Treatments of vaginal candidiasis are limited due to drug resistance, side effects, and toxicity. CIN is a natural compound and its antifungal activity is widely reported. The introduction of cinnamaldehyde (CIN) as the anti-Candidal agent will revolutionize the treatment of vaginal candidiasis. In this study, we investigated the anti-Candida activity of CIN against vaginal candidiasis in Swiss albino mice (C3HHC-Strain). Methods Vaginal candidiasis in mice (Swiss albino) was induced under conditions of pseudo-estrus. Persistent vaginal infection was found in estrogenized mice after vaginal challenge with C. albicans. The mice were treated orally after confirmation of infection in mice. The efficacy of CIN treatment was investigated phenotypically by colony-forming unit (CFU) counts in the vaginal smear, fungal load determination in the blood, the ovarian and vaginal tissues and periodic acid-Schiff (PAS) staining of histopathological sections of the vaginal tissues. The hematological parameters of the experimental mice were also evaluated. Results The pseudohyphae and spores of C. albicans were present in the vaginal smear of experimentally infected mice. After treatment, no C. albicans colonies were found in the vaginal lavage of infected mice. The fungal burden was significantly higher in the vagina and the ovaries of infected mice. However, a dose of 262.5 mg/kg BW of CIN reduced the number of CFU in the vagina and ovaries in treated mice. The histopathology revealed the absence of C. albicans in the vaginal tissue of the treated mice. Nonetheless, the vaginal sections of infected mice exhibited pathological changes. The hematological parameters such as RBC count, WBC count, and percentage of hemoglobin showed significant differences in the treatment groups compared to the infected group. Conclusion Cinnamaldehyde showed good in vivo antifungal potential against vaginal candidiasis. However, evaluation of its pharmacodynamic and pharmacokinetic parameters and complete elucidation of its mode of action are desirous.

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM Objectives Combinatorial and retroviral therapies have been found effective in the treatment of cryptococcosis, but safer and more potent antifungal therapeutics are the need of the hour. In this regard, the natural antifungal peptides (AFPs), the essential components of the innate immune system have drawn the attention of researchers and drug developers. AFPs are 12-50 amino-acids-long host defense peptides of cationic nature. Although AFPs have certain limitations like low stability, susceptibility to proteolysis, loss of activity in the presence of metal ions and salts, short half-lives, and peptide aggregation in oral formulation, but these can be addressed by designing and synthesizing the peptidomimetics. Methodology: The whole blood of the rat was collected by cardiac puncture. The blood was mixed with 0.83% aqueous ammonium chloride. The neutrophils were separated from lysed WBCs by centrifugation. The purification of the peptide was carried out by SDS-PAGE, size exclusion, cation exchange chromatography, and HRLCMS. The MSA of the characterized peptide was performed using a T-coffee program. The in vitro antifungal activity of crude was tested against C. n. grubii (ATCC 6352) using flow cytometry. The structure of peptides was altered through ChemDraw by replacing the elements with their bioisosteres to form mimetics. The peptide and its mimetics were docked upon the target of C. n. grubii, i.e., O-acetyl transferase (modeled through Phyre2 web server) using PatchDock, and FireDock web servers. Results The peptide isolated from rat PMNs had a molecular weight of 3 kDa. It has lysine and arginine which are the characteristic residues of an antifungal peptide. The eluted peptide has the highest (83%) similarity with α defensins 5 (accession no NP_001013071 XP_214 386). The mild antifungal activity of peptide was evident against C. n. grubii. The structure of O-acetyl transferase was modeled with 100% confidence and 92% query coverage (Table 1). The mimetic 1 (M1) showed the best interaction with O-acetyl transferase with −54.47 Kcal/mol binding energy and 4 hydrogen bonds (Table 2). Conclusion The designed M1 of α defensins 5 like peptide could be a promising lead in antifungal drug development. As mimetic 1 was designed using an in-silico approach, its synthesis and wet lab validation are desirable.

No abstract