Abstract
A series of novel vasicine-based derivatives were designed and synthesized, and in vitro antifungal activities were evaluated. Most compounds showed synergistic antifungal effects with fluconazole (FLC) against FLC-resistant C. albicans. Compound 3n exhibited the best activity (MIC50 = 1.29 μM, FICI = 0.01) with no obvious cytotoxicity to 16HBE cells. Mechanistic studies revealed that 3n combined with FLC inhibited biofilm formation and efflux pump activity, and synergistically targeted the Ras/cAMP/PKA pathway to block yeast-to-hyphae transition. This dual mechanism provides a new strategy for treating FLC-resistant C. albicans infections.
Keywords: synergistic antifungal, vasicine-based derivatives, FLC-resistant C. albicans , Ras/cAMP/PKA
Candida albicans (C. albicans) commonly colonizes multiple sites in healthy individuals, including the oral cavity, vagina, and intestinal mucosa, coexisting with our bodies and forming a part of the complex microbial ecosystem of the human body. However, once this balance is disrupted due to weakened immunity or antibiotic abuse, C. albicans will rapidly transform into a dangerous pathogen, causing various diseases ranging from superficial mucosal infections to fatal systemic infections. In recent years, the incidence of C. albicans infections has significantly increased, possibly related to the use of antibiotics and immunosuppressants, and the popularization of immunodeficiency viruses and cancer treatments has also played a facilitating role. , In 2022, the World Health Organisation (WHO) released the first list of priority fungal pathogens, classifying C. albicans into the key priority category. C. albicans infections are becoming an increasingly serious public health problem, especially as drug resistance is increasing in treatment drugs, and the impact is particularly severe on those with serious underlying diseases and compromised immune systems.
Currently, the clinical treatment methods for C. albicans infections are mainly divided into three categories, including polyene drugs, azole drugs, and echinocandin drugs, with representative drugs including fluconazole, itraconazole, caspofungin, etc. , However, with the increasing clinical use of antifungal drugs, the resistance of C. albicans also increases, manifested as changes in drug targets, enhanced multidrug efflux pump activity, and induction of cellular stress response pathways. However, the number of clinically effective antifungal drugs is limited, and coupled with the continuously rising resistance rate, this highlights the urgent need for the development of innovative antiresistant fungal drugs.
C. albicans is a typical yeast-filament dual-phase fungus, and its pathogenic process is closely related to the morphological transformation. Following mucosal colonization, the yeast form converts to invasive filaments that facilitate host tissue penetration and damage. Filamentous growth is not only a core virulence determinant but also a key driver of biofilm formation and fluconazole (FLC) resistance. This morphological switch is tightly regulated by the Ras/cAMP/PKA signaling pathway, which triggers the expression of filament-specific genes and promotes the development of resistant phenotypes. , Therefore, targeting this pathway represents a promising strategy for reversing FLC resistance.
The combined therapy refers to the simultaneous or sequential use of two or more drugs with the aim of enhancing efficacy, reducing toxicity, delaying drug resistance, or covering multiple pathological mechanisms. This strategy is widely applied in the treatment of complex diseases, such as gout, diabetes, fungal infections, cancers, and skin diseases. , Fluconazole (FLC) is a first-line antifungal drug, but it only has inhibitory effects on C. albicans. Therefore, during long-term use, C. albicans may develop resistance. The combination strategy used in combination with FLC provides a novel treatment option for the treatment of C. albicans infections.
Except for a few natural active ingredients that can be directly used as drugs, using these lead compounds as templates for structural modification and ultimately developing them into drugs with better efficacy and pharmacokinetic properties is a shortcut in drug research. , The success of drugs such as artemether, camptothecin, paclitaxel, and jatrorrhizine has further confirmed the significance and feasibility of new drug development based on the natural product framework. Adhatoda vasica is a traditional herbal that has been used in folk for over 2,000 years. Vasicine, one of the most important active β-cyanine alkaloids from Adhatoda vasica, exhibits a variety of biological activities, including antitumor, antibacterial, antiviral and central nervous system effects. The clinical drugs bromhexine and ambroxol are both derivatives of vasicine, indicating that it has broad application prospects in the development of drugs (Scheme A).
1. Design and Synthetic Route of Vasicine-Based Derivatives.
In former work, we have performed structural modification of vasicine, and they showed good anti-inflammatory activities as potent antipsoriasis agents. Based on this, we have designed and prepared new vasicine derivatives by recombination of bromhexine and ambroxol structure units in present work (Scheme B), and their antifungal activities have been studied used alone and combined with FLC against C. albicans SC5314 and FLC-resistant SC5314FR.
The new vasicine-based derivatives (3–5) were prepared by a general procedure (Scheme C). First, 2-amino-3,5-dibromobenzaldehyde was treated with 4-(Boc-amino)piperidine to give compound 1 in the presence of NaBH3CN. Subsequently, 1 was hydrolyzed by CF3COOH (TFA) to remove the Boc group to obtain key intermediate 2. Then, 2 was reacted with sulfonyl chloride, aldehyde, or acyl chloride to afford title derivatives (3–5) in 56%–83% yields (Table ), respectively.
1. Structure and Yield of Derivatives 3–5 .
The antifungal activities of compounds 3–5 were determined used alone and combined with FLC by microdilution method against sensitive C. albicans SC5314 and FLC-resistant SC5314FR, and the MIC50 and FICI value was shown in Table . When used alone, most compounds showed no obvious inhibition on both SC5314 and SC5314FR except 4d, 4f, 4g, and 4k. To our delight, when combined with FLC, vasicine-based derivatives exhibited excellent antifungal activities against SC5314 and SC5314FR (MIC50 < 10 μM). It was worth noting that even though vasicine-based derivatives had no inhibitory effect on FLC-resistant C. albicans alone, but could significantly enhance inhibition of FLC on SC5314FR. Especially, 3f, 3h, 3j–3p, 3r, 3w, 4a, 4d, 4e, 4g–4k, and 5a–5d displayed better synergistic antifungal activity against SC5314FR (MIC50 < 5 μM). Among them, 3n showed the best inhibitory effect on SC5314FR combined with FLC (MIC50 = 1.29 μM, FICI = 0.01), which could be used to treat drug-resistant fungal infections.
2. Inhibitory Effect of Compounds 3–5 on C. albicans .
| MIC50 (μM) |
FICI |
|||
|---|---|---|---|---|
| Compound | SC5314 | SC5314FR | SC5314 | SC5314FR |
| FLC | 5.59 | >200 | – | – |
| 3a | >200 | >200 | – | – |
| 3a+FLC | 3.70 | 5.79 | 0.68 | 0.057 |
| 3b | >200 | >200 | – | – |
| 3b+FLC | 1.30 | 7.63 | 0.24 | 0.076 |
| 3c | >200 | >200 | – | – |
| 3c+FLC | 2.52 | 15.45 | 0.46 | 0.15 |
| 3d | >200 | >200 | – | – |
| 3d+FLC | 4.07 | 9.79 | 0.80 | 0.098 |
| 3e | >200 | >200 | – | – |
| 3e+FLC | 3.58 | 5.75 | 0.66 | 0.057 |
| 3f | >200 | >200 | – | – |
| 3f+FLC | 3.46 | 4.07 | 0.63 | 0.041 |
| 3g | >200 | >200 | – | – |
| 3g+FLC | 4.12 | 12.84 | 0.76 | 0.13 |
| 3h | >200 | >200 | – | – |
| 3h+FLC | 3.47 | 3.79 | 0.64 | 0.038 |
| 3i | >200 | >200 | – | – |
| 3i+FLC | 5.83 | 6.19 | 1.07 | 0.062 |
| 3j | >200 | >200 | – | – |
| 3j+FLC | 5.12 | 4.22 | 0.94 | 0.042 |
| 3k | >200 | >200 | – | – |
| 3k+FLC | 2.36 | 3.63 | 0.43 | 0.036 |
| 3l | >200 | >200 | – | – |
| 3l+FLC | 2.03 | 4.17 | 0.37 | 0.042 |
| 3m | >200 | >200 | – | – |
| 3m+FLC | 3.53 | 3.93 | 0.65 | 0.039 |
| 3n | >200 | >200 | – | – |
| 3n+FLC | 2.89 | 1.29 | 0.53 | 0.01 |
| 3o | >200 | >200 | – | – |
| 3o+FLC | 3.62 | 3.93 | 0.66 | 0.039 |
| 3p | >200 | >200 | – | – |
| 3p+FLC | 3.72 | 4.95 | 0.68 | 0.05 |
| 3q | >200 | >200 | – | – |
| 3q+FLC | 3.51 | 8.70 | 0.64 | 0.09 |
| 3r | >200 | >200 | – | – |
| 3r+FLC | 3.65 | 4.34 | 0.67 | 0.13 |
| 3s | >200 | >200 | – | – |
| 3s+FLC | 3.45 | 12.61 | 0.63 | 0.13 |
| 3t | >200 | >200 | – | – |
| 3t+FLC | 3.76 | 15.62 | 0.69 | 0.16 |
| 3u | >200 | >200 | – | – |
| 3u+FLC | 4.84 | 69.62 | 0.89 | 0.70 |
| 3v | >200 | >200 | – | – |
| 3v+FLC | 3.55 | 5.64 | 0.65 | 0.06 |
| 3w | >200 | >200 | – | – |
| 3w+FLC | 3.32 | 4.29 | 0.61 | 0.04 |
| 4a | 69.82 | 73.14 | – | – |
| 4a+FLC | 3.28 | 4.00 | 0.63 | 0.04 |
| 4b | 117.38 | >200 | – | – |
| 4b+FLC | 16.68 | 18.93 | 3.12 | 0.19 |
| 4c | >200 | >200 | – | – |
| 4c+FLC | 2.81 | 9.25 | 0.52 | 0.09 |
| 4d | 3.68 | 13.82 | – | – |
| 4d+FLC | 2.47 | 3.90 | 0.45 | 0.04 |
| 4e | >200 | >200 | – | – |
| 4e+FLC | 2.90 | 3.86 | 0.53 | 0.04 |
| 4f | 17.12 | 93.70 | – | – |
| 4f+FLC | 3.65 | 5.36 | 0.86 | 0.05 |
| 4g | 15.99 | 18.27 | – | – |
| 4g+FLC | 3.07 | 3.68 | 0.74 | 0.04 |
| 4h | 49.22 | 89.80 | – | – |
| 4h+FLC | 3.41 | 3.70 | 0.68 | 0.04 |
| 4i | >200 | >200 | – | – |
| 4i+FLC | 2.69 | 2.88 | 0.49 | 0.03 |
| 4j | >200 | >200 | – | – |
| 4j+FLC | 3.35 | 3.77 | 0.61 | 0.04 |
| 4k | 15.20 | 18.52 | – | – |
| 4k+FLC | 0.68 | 1.44 | 0.17 | 0.01 |
| 5a | >200 | >200 | ||
| 5a+FLC | 0.89 | 3.37 | 0.16 | 0.03 |
| 5b | >200 | >200 | ||
| 5b+FLC | 0.78 | 2.26 | 0.14 | 0.02 |
| 5c | >200 | >200 | ||
| 5c+FLC | 1.22 | 3.01 | 0.22 | 0.03 |
| 5d | >200 | >200 | ||
| 5d+FLC | 0.83 | 2.27 | 0.15 | 0.02 |
Based on in-vitro synergistic antifungal results, the structure–activity relationship (SAR) toward vasicine-based derivatives against FLC-resistant C. albicans strain could be summarized. In this work, there were three types of compounds including sulfonamides 3, amines 4, and amides 5, and there was no obvious difference between them. Among amide compounds (3a–3w), aromatic amides combined with FLC exhibited better synergistic inhibition on SC5314FR than aliphatic amides. In addition, halogen atoms (Cl, F), electron-withdrawing groups (CF3, CN), and electron-donating groups (t-Bu, OCH3) were beneficial for enhancing the activity of compounds. Among amine compounds (4a–4k), when there were X, NO2, or OH on the benzene ring, they showed better biological activity. Finally, we found that all amides (5a–5d) showed good synergistic antifungal activity against SC5314FR whether containing EWG or EDG and halogen, respectively.
On the basis of the above results, 3n was selected for the subsequent mechanism study. To further observe the antifungal effect of the combined treatment, the time-killing curve was measured (Figure ). The results showed that the inhibitory effect of the 3n + FLC group on SC5314FR was better than that of the control group and the FLC group.
1.
Time-kill curves of 3n against SC5314FR (FLC: 6.34 μM, 3n: 6.34 μM; 3n+FLC,-H: 3n 12.68 μM + FLC 6.34 μM; 3n+FLC-M: 3n 6.34 μM + FLC 6.34 μM; 3n+FLC-L: 3n 3.17 μM + FLC 6.34 μM).
The clinical application of drugs needs to take into account both antibacterial activity and the safety of host cells. The cytotoxicity test is the core indicator for evaluating the biocompatibility of candidate drugs, which can clearly identify the potential damage to normal human cells at the effective antibacterial concentration, providing a reference for the safe dosage in subsequent experiments and clinical translation. In this study, the CCK-8 method was used to detect the toxicity of 3n + FLC group on human normal bronchial epithelial cells (16HBE), in order to verify the safety of the combined medication. The cytotoxicity of 3n combined with FLC on 16HBE cells was evaluated using the CCK 8 assay (Figure ). The control group (0 μM) showed 95% cell viability, which was set as the reference. At concentrations of 5–20 μM, cell viability ranged from 99% to 100%. One-way ANOVA with Dunnett’s post hoc test revealed no statistically significant differences between any of these groups and the control (p > 0.05). At 40 μM, viability remained comparable to the control. At 80 μM, cell viability decreased to approximately 78%, which was statistically significant compared with the control (p < 0.05). However, this concentration was substantially higher than the effective antifungal concentration (MIC50 = 1.29 μM for 3n in combination with FLC). Therefore, 3n combined with FLC exhibited low cytotoxicity to normal human bronchial epithelial cells within the therapeutically relevant concentration range.
2.
Cytotoxicity of 3n + FLC on 16HBE. Compared with the control group, (*) P < 0.05 (n = 3). In all combination groups, 3n and FLC were used at a constant 1:1 molar ratio. The concentrations shown on the X-axis indicate the concentration of each compound (e.g., 80 μM means 3n 80 μM + FLC 80 μM).
Biofilm formation is an important virulence factor and drug-resistance mechanism of C. albicans. It forms a dense structure by encapsulation with an extracellular matrix, reducing drug permeability and enhancing the resistance of C. albicans to FLC. After repeated biofilm experiments, it was found that the control group without treatment had a thick and dense biofilm with abundant extracellular matrix; while the 3n group and the FLC group had significantly looser and thinner biofilm structures, with reduced hyphae; the 3n + FLC group had almost completely disintegrated biofilm structure, with only sparse yeast cells and fragments remaining, unable to form a continuous tissue architecture (Figure ).
3.
Effect of 3n+FLC on biofilm formation of SC5314FR (FLC: 6.34 μM, 3n: 6.34 μM; 3n+FLC-H: 3n: 12.68 μM + FLC 6.34 μM; 3n+FLC-M: 3n: 6.34 μM + FLC 6.34 μM, 3n+FLC-L: 3n: 3.17 μM + FLC 6.34 μM).
The formation of hyphae is the key for C. albicans to shift from a symbiotic state to a pathogenic state, enhancing the strain’s ability, promoting biofilm formation and intensifying drug resistance. The results of the hyphae experiment revealed that the control group had hyphae formation ability in both culture media, with hyphae visible at 4 h and a dense network of yeast cells and hyphae at 8 h; the FLC group only slightly inhibited hyphae growth at 4 h, and still formed a complex hyphae structure at 8 h; the 3n group had no significant inhibition on hyphae formation; while the 3n+FLC group had hyphae inhibitory effects in both culture media, with hyphae formation significantly inhibited at 4 h and the hyphae becoming shorter, more short and thin, and less densely distributed at 8 h (Figure ). This indicated that the 3n+FLC group blocked the yeast-hypha transformation of drug-resistant SC5314FR, weakening its pathogenicity and drug resistance.
4.
Effect of 3n+FLC on hyphal growth of FLC-resistant C. albicans SC5314FR. All experimental groups were tested using this strain. Concentrations: FLC 6.34 μM, 3n: 6.34 μM; 3n+FLC-H: 3n: 12.68 μM+FLC 6.34 μM; 3n+FLC-M: 3n: 6.34 μM+FLC 6.34 μM; 3n+FLC-L, 3n: 3.17 μM+FLC 6.34 μM.
Excessive activation of the efflux pump is one of the core mechanisms racellular drugs, preventing FLC from reaching an effective inhibitory concentration. The passive efflux experiment (without glucose, Figure A) showed no significant differences in fluorescence intensity among any of the groups, indicating that 3n did not affect passive diffusion. In the active efflux experiment (with glucose, Figure B), the fluorescence intensity of the control (untreated) and FLC alone groups increased steadily over time, reflecting active drug efflux by SC5314FR. Among the combination groups, the 3n+FLC-M (medium dose) exhibited the most pronounced reduction in fluorescence intensity at each time point compared to the control, followed by the 3n+FLC-H (high dose) and then the 3n+FLC-L (low dose). This order (M > H > L) was consistently observed across three independent experiments, suggesting a nonmonotonic dose–response pattern. However, two-way ANOVA with Bonferroni’s posthoc test revealed that none of the differences between any treatment group and the control reached statistical significance (P > 0.05 at time points). The reproducible trend nevertheless implied that 3n at an appropriate concentration (particularly the medium dose) might partially inhibit active efflux pump function.
5.
Effect of 3n+FLC on the efflux levels of SC5314FR (A: without glucose, B: with glucose. FLC: 6.34 μM, 3n 6.34 μM; 3n+FLC-H: 3n 12.68 μM + FLC 6.34 μM; 3n+FLC-M: 3n 6.34 μM + FLC 6.34 μM; 3n+FLC-L: 3n 3.17 μM + FLC 6.34 μM). Two-way ANOVA with Bonferroni’s posthoc test showed no significant differences between any treatment group and the control at any time point (P > 0.05).
To clarify the molecular basis of the synergistic effect of 3n, we detected the transcriptional levels of genes related to mycelial formation. As shown in Figure , compared with the control group, the expressions of RAS1, CYR1, TPK2, BCR1, ALS2, ALS3, ECE1, and HWP1 were significantly downregulated in the 3n+FLC group. These results indicated that the combined use of the two could inhibit mycelial growth by downregulating the expression of core genes in the Ras/cAMP/PKA pathway, thereby achieving drug-resistance reversal.
6.
Expression of hyphal formation genes. The relative mRNA expression levels of target genes were calculated using the 2–ΔΔCt method and normalized to ACT-1 as the reference gene. All data were repeated three times. (Compared with the control group, the asterisk symbol (*) indicates a statistically significant difference: (*)P < 0.05, (**) P < 0.01, (***) P < 0.001, (****) P < 0.0001.)
In summary, a series of new vasicine-based derivatives have been designed and prepared. The biological tests indicated that when combined with FLC, compounds exhibited good synergistic antifungal activity against FLC-resistant C. albicans with low toxicity on normal 16HBE. Further mechanism study proved that 3n combined with FLC could inhibit the expression of the initiating genes and the transcription of fungal hyphae effect genes targeting the Ras/cAMP/PKA signaling pathway. Therefore, 3n could reverse FLC resistance and provide a new strategy for clinical treatment of FLC-resistant C. albicans infection and was expected to be developed as a new antifungal synergist.
We acknowledge that the present study evaluated the synergistic antifungal activity using only a single FLC-resistant C. albicans strain (SC5314FR), further testing across a broader panel of clinical resistant isolates and other Candida species is currently underway to confirm the broad spectra efficacy of compound 3n. Although the present study demonstrates promising synergistic antifungal activity and mechanistic insights into Ras/cAMP/PKA pathway modulation, deep pharmacokinetic and drug-likeness studies (ADME, solubility, and stability) are also underway in our laboratory to fully support the therapeutic potential of 3n.
Supplementary Material
Acknowledgments
This work was supported by the National Natural Science Foundation of China (82360842), Yunnan Science and Technology Talent and Platform Program (202105AG070012), Yunnan Fundamental Research Projects(202301AT070252), Open Fund for Yunnan Key Laboratory of Dai and Yi Medicines (2025SS2508), and “Xing Dian Ying Cai” Support Project for Young Talents of Yunnan Province (to Huan Chen).
Glossary
Abbreviations
- 16HBE
Human bronchial epithelial cell line
- ACT1
Actin reference gene
- ALS2
Agglutinin-like sequence protein 2 gene
- ALS3
Agglutinin-like sequence protein 3 gene
- BCR1
Biofilm and hypha regulator 1 gene
- CYR1
Adenylate cyclase gene
- ECE1
Extent of cell elongation protein 1 gene
- HWP1
Hyphal wall protein 1 gene
- RAS1
Ras protein gene 1
- TPK2
Protein kinase A catalytic subunit gene
- cAMP
Cyclic adenosine monophosphate
- CCK-8
Cell Counting Kit-8
- ATP
Adenosine triphosphate
- FICI
Fractional inhibitory concentration index
- FLC
Fluconazole
- MIC50
Minimum inhibitory concentration (50% inhibition)
- PKA
Protein kinase A
- qRT-PCR
Quantitative real-time polymerase chain reaction
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsmedchemlett.6c00192
Experimental details, NMR data and spectra (PDF)
∇.
Authors Di Zhao and Wengang Wang contributed equally to this work. The manuscript was organized and written through contributions of all authors.
Safety statement: No unexpected or unusually high safety hazards were encountered.
The authors declare no competing financial interest.
References
- Katsipoulaki M., Stappers M. H. T., Malavia-Jones D., Brunke S., Hube B., Gow N. A. R.. Candida albicans and Candida glabrata: global priority pathogens. Microbiol. Mol. Biol. Rev. 2024;88(2):e0002123. doi: 10.1128/mmbr.00021-23. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schille T. B., Sprague J. L., Naglik J. R., Brunke S., Hube B.. Commensalism and pathogenesis of Candida albicans at the mucosal interface. Nat. Rev. Microbiol. 2025;23(8):525–540. doi: 10.1038/s41579-025-01174-x. [DOI] [PubMed] [Google Scholar]
- Li R., Yang X., Dan W., Dai J.. Natural product-derived antifungals against Candida albicans: Chemical diversity and mechanisms of action. Bioorg. Med. Chem. 2026;132:118435. doi: 10.1016/j.bmc.2025.118435. [DOI] [PubMed] [Google Scholar]
- Sahoo B., Goyal R., Dutta S., Joshi P., Sanyal K.. Candida albicans: Insights into the Biology and Experimental Innovations of a Commonly Isolated Human Fungal Pathogen. ACS Infect Dis. 2025;11(7):1780–1815. doi: 10.1021/acsinfecdis.5c00079. [DOI] [PubMed] [Google Scholar]
- World Health Organisation (WHO) . WHO fungal priority pathogens list to guide research, development and public health action; 2022.
- Lee Y., Puumala E., Robbins N., Cowen L. E.. Antifungal drug resistance: Molecular mechanisms in Candida albicans and beyond. Chem. Rev. 2021;121(6):3390–3411. doi: 10.1021/acs.chemrev.0c00199. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lu X., Zhou J., Ming Y., Wang Y., He R., Li Y., Feng L., Zeng B., Du Y., Wang C.. Next-generation antifungal drugs: Mechanisms, efficacy, and clinical prospects. Acta Pharm. Sin B. 2025;15(8):3852–3887. doi: 10.1016/j.apsb.2025.06.013. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Howard K. C., Dennis E. K., Watt D. S., Garneau-Tsodikova S.. A comprehensive overview of the medicinal chemistry of antifungal drugs: perspectives and promise. Chem. Soc. Rev. 2020;49(8):2426–2480. doi: 10.1039/C9CS00556K. [DOI] [PubMed] [Google Scholar]
- Bergmann F., Prager M., Pracher L., Jorda A., Haselwanter P., Zeitlinger M.. Tissue pharmacokinetics of antifungal drugs: a review. Int. J. Antimicrob Agents. 2026;67(5):107743. doi: 10.1016/j.ijantimicag.2026.107743. [DOI] [PubMed] [Google Scholar]
- Jampilek J.. Novel avenues for identification of new antifungal drugs and current challenges. Expert Opin. Drug Discovery. 2022;17(9):949–968. doi: 10.1080/17460441.2022.2097659. [DOI] [PubMed] [Google Scholar]
- Meyer V., Cairns T., Barthel L., King R., Kunz P., Schmideder S., Müller H., Briesen H., Dinius A., Krull R.. Understanding and controlling filamentous growth of fungal cell factories: novel tools and opportunities for targeted morphology engineering. Fungal Biol. Biotechnol. 2021;8(1):8. doi: 10.1186/s40694-021-00115-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Du H., Ennis C. L., Hernday A. D., Nobile C. J., Huang G.. N-Acetylglucosamine (GlcNAc) Sensing, Utilization, and Functions in Candida albicans. J. Fungi (Basel) 2020;6(3):129. doi: 10.3390/jof6030129. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zu W. B., Wang Z. J., Tang D. M., Lu Q. Y., Zhu Y. Y., Zhou Z. S., Wei M. Z., Luo X. D.. Prosapogenin CP4 and ursolic acid from Eriocapitella rivularis inhibit fluconazole-resistant Candida albicans synergistically by regulating Ras/cAMP/PKA pathway. Phytomedicine. 2026;155:158142. doi: 10.1016/j.phymed.2026.158142. [DOI] [PubMed] [Google Scholar]
- Wang H., Wang B., Zhang J., Tong H., Ares I., Martínez M., Lopez-Torres B., Martínez-Larrañaga M. R., Pan Y., Zhang J., Anadón A., Wang X., Martínez M. A.. Concurrent management of gout and type 2 diabetes mellitus: combined therapy insights. Diabetes Res. Clin. Pract. 2026;234:113169. doi: 10.1016/j.diabres.2026.113169. [DOI] [PubMed] [Google Scholar]
- Bartalucci C., Sepulcri C., Portunato F., Briano F., Dentone C., Bassetti M.. Advances and updates in antibiotic combination therapy. Expert Rev. Anti Infect. Ther. 2025;23(12):1143–1162. doi: 10.1080/14787210.2025.2595462. [DOI] [PubMed] [Google Scholar]
- Tan J., Jiang S., Tan L., Shi H., Yang L., Sun Y., Wang X.. Antifungal activity of Minocycline and Azoles against fluconazole-resistant Candida species. Front. Microbiol. 2021;12:649026. doi: 10.3389/fmicb.2021.649026. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Newman D. J.. Natural products and drug discovery. Natl. Sci. Rev. 2022;9(11):nwac206. doi: 10.1093/nsr/nwac206. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chopra B., Dhingra A. K.. Natural products: A lead for drug discovery and development. Phytother. Res. 2021;35(9):4660–4702. doi: 10.1002/ptr.7099. [DOI] [PubMed] [Google Scholar]
- Fatima M., Zafar I., Ain Q. U., Anwar M. M., Yousaf W., Rather M. A., Nainu F., Sharma R.. Multifunctional analysis and antimicrobial activity of Adhatoda vasica: a traditional medicinal plant. Drug Metab. Pers. Ther. 2024;38(4):359–366. doi: 10.1515/dmpt-2023-0012. [DOI] [PubMed] [Google Scholar]
- Grange J. M., Snell N. J.. Activity of bromhexine and ambroxol, semi-synthetic derivatives of vasicine from the Indian shrub Adhatoda vasica, against Mycobacterium tuberculosis in vitro. J. Ethnopharmacol. 1996;50:49–53. doi: 10.1016/0378-8741(95)01331-8. [DOI] [PubMed] [Google Scholar]
- Mo Q. Y., Wang W. G., Li X. H., Shen Y. H., Sun Y., Mao Z. W., Wan C. P.. Vasicine derivatives as potent MAPK inhibitors for psoriasis treatment. Mol. Divers. 2026;30(3):4541–4554. doi: 10.1007/s11030-025-11399-w. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.