ABSTRACT
Vanillic acid (VA) - a naturally occurring phenolic compound in plants - is not only used as a flavoring agent but also a prominent metabolite post tea consumption. VA and its associated compounds are believed to play a significant role in preventing diseases, underscoring the need for a systematic investigation. Herein, we report a 4-step synthesis employing the classical organic reactions, such as Willamson's alkylation, Fischer-Spier reaction, and Steglich esterification, complemented with a protection-deprotection strategy to prepare 46 VA derivatives across the five series (1a-1i, 2a-2i, 3, 3a-3i, 4a-4i, 5a-5i) in high yields. The synthesized compounds were investigated for their antifungal, anti-inflammatory, and toxic effects. Notably, compound 1a demonstrated remarkable ROS inhibition with an IC50 value of 5.1 ± 0.7 µg/mL, which is more than twice as effective as the standard ibuprofen drug. A subset of the synthesized derivatives (2b, 2c, 2e, 3b-3d, 4a-4c, 5a, and 5e) manifested their antifungal effect against drug-resistant Candida strains. Compound 5g, in particular, revealed synergism with the established antifungal drugs amphotericin B (AMB) and fluconazole (FLZ), doubling FLZ's potency against azole resistant Candida albican ATCC 36082. Furthermore, 5g improved the potency of these antifungals against FLZ-sensitive strains, including C. glabrata ATCC 2001 and C. parapsilosis ATCC 22019, as well as various multidrug-resistant (MDR) Candida strains, namely C. albicans ATCC 14053, C. albicans CL1, and C. krusei SH2L OM341600. Additionally, pharmacodynamics of compound 5g was examined using time-kill assay, and a benign safety profile was observed with no hemolytic activity in whole blood, and no cytotoxicity towards the normal BJ human cell line. The synergistic potential of 5g was further investigated through both experimental methods and docking simulations.These findings highlight the therapeutic potential of VA derivatives, particularly in addressing inflammation and circumventing FLZ resistance in Candida albicans.
Subject(s)
Antifungal Agents , Mycoses , Humans , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Vanillic Acid/pharmacology , Vanillic Acid/therapeutic use , Azoles/pharmacology , Microbial Sensitivity Tests , Mycoses/drug therapy , Fluconazole/pharmacology , Candida , Candida albicans , Candida glabrata , Inflammation/drug therapyABSTRACT
Most of the drugs are hydrophobic and have low water solubility, therefore posing issues in their absorption and bioavailability. Nonionic surfactants improve the solubility of hydrophobic drugs by entrapping them in their lipid bilayers. Two nonionic surfactants NODNH-16 and NODNH-18 are synthesized and characterized using different techniques i.e. EI-MS, 1H NMR, and FTIR. These newly synthesized surfactants were screened for blood hemolysis assay and cell toxicity studies using the NIH/3T3 cell line to assess their biocompatibility. Then amphotericin B was loaded into niosomal vesicles, and the drug entrapment efficiency of these surfactants was measured using UV-visible spectroscopy. The morphology of drug-loaded niosomes of synthesized surfactants was investigated using AFM, and their size, polydispersity, and zeta potential were measured with the Zetasizer instrument. Finally, a simulation study was performed to determine the pattern of self-assembly of the synthesized amphiphiles. Both synthesized nonionic surfactants showed good entrapment efficiency of 60.65 ± 2.12% and 68.45 ± 2.12%, respectively. It was also confirmed that both these synthesized nonionic surfactants were safe and biocompatible and showed less blood hemolysis (i.e. 21.13 ± 2.11% and 23.32 ± 2.45%) and higher 3T3 cells' viability at 150 µg/mL concentration as compared to Tween®-80. The antifungal potential of amphotericin B-loaded niosomes has been evaluated against unicellular multi-fungal species, which showed a promising potential for fungicidal activity. These results are substantiated by constructing a safe vehicle system for drug delivery.