Design, Synthesis, Bioactive Evaluation, and Molecular Dynamics Simulation of Novel 4H-Pyrano[3,2-c]pyridine Analogues as Potential Sterol 14α-Demethylase (CYP51) Inhibitors.

To discover potential sterol 14α-demethylase (CYP51) inhibitors, thirty-four unreported 4H-pyrano[3,2-c]pyridine derivatives were designed and synthesized. The assay results indicated that most compounds displayed significant fungicidal activity against Sclerotinia sclerotiorum, Colletotrichum lagenarium, Botrytis cinerea, Penicillium digitatum, and Fusarium oxysporum at 16 µg/mL. The half maximal effective concentration (EC50) values of compounds 7a, 7b, and 7f against B. cinerea were 0.326, 0.530, and 0.610, respectively. Namely, they had better antifungal activity than epoxiconazole (EC50 = 0.670 µg/mL). Meanwhile, their half maximal inhibitory concentration (IC50) values against CYP51 were 0.377, 0.611, and 0.748 µg/mL, respectively, representing that they also possessed better inhibitory activities than epoxiconazole (IC50 = 0.802 µg/mL). The fluorescent quenching tests of proteins showed that 7a and 7b had similar quenching patterns to epoxiconazole. The molecular dynamics simulations indicated that the binding free energy of 7a and epoxiconazole to CYP51 was -35.4 and -27.6 kcal/mol, respectively.

Construction and Activity Evaluation of Novel Bifunctional Inhibitors and a COF Carrier Based on a Fungal Infection Microenvironment.

Faced with increasingly serious fungal infections and drug resistance issues, three different series of novel dual-target (programmed death ligand 1/14 α-demethylase) compounds were constructed through the fragment combination pathway in the study. Their chemical structures were synthesized, characterized, and evaluated. Among them, preferred compounds 10c-1, 17b-1, and 18b-2 could efficiently exert their antifungal and antidrug-resistant fungal ability through blocking ergosterol biosynthesis, inducing the upregulation of reactive oxygen species level, and triggering apoptosis. Especially, compound 18b-2 exhibited the synergistic function of fungal inhibition and immune activation. Moreover, the covalent organic framework carrier was also generated based on the acidic microenvironment of fungal infection to improve the bioavailability and targeting of preferred compounds; this finally accelerated the body's recovery rate.

Novel Pyrido[4,3-d]pyrimidine Derivatives as Potential Sterol 14α-Demethylase Inhibitors: Design, Synthesis, Inhibitory Activity, and Molecular Modeling.

Thirty-four new pyrido[4,3-d]pyrimidine analogs were designed, synthesized, and characterized. The crystal structures for compounds 2c and 4f were measured by means of X-ray diffraction of single crystals. The bioassay results showed that most target compounds exhibited good fungicidal activities against Pyricularia oryzae, Rhizoctonia cerealis, Sclerotinia sclerotiorum, Botrytis cinerea, and Penicillium italicum at 16 µg/mL. Compounds 2l, 2m, 4f, and 4g possessed better fungicidal activities than the commercial fungicide epoxiconazole against B. cinerea. Their half maximal effective concentration (EC50) values were 0.191, 0.487, 0.369, 0.586, and 0.670 µg/mL, respectively. Furthermore, the inhibitory activities of the bioactive compounds were determined against sterol 14α-demethylase (CYP51). The results displayed that they had prominent activities. Compounds 2l, 2m, 4f, and 4g also showed better inhibitory activities than epoxiconazole against CYP51. Their half maximal inhibitory concentration (IC50) values were 0.219, 0.602, 0.422, 0.726, and 0.802 µg/mL, respectively. The results of molecular dynamics (MD) simulations exhibited that compounds 2l and 4f possessed a stronger affinity to CYP51 than epoxiconazole.

Identification of Potent and Selective Inhibitors of Acanthamoeba: Structural Insights into Sterol 14α-Demethylase as a Key Drug Target.

Acanthamoeba are free-living pathogenic protozoa that cause blinding keratitis, disseminated infection, and granulomatous amebic encephalitis, which is generally fatal. The development of efficient and safe drugs is a critical unmet need. Acanthamoeba sterol 14α-demethylase (CYP51) is an essential enzyme of the sterol biosynthetic pathway. Repurposing antifungal azoles for amoebic infections has been reported, but their inhibitory effects on Acanthamoeba CYP51 enzymatic activity have not been studied. Here, we report catalytic properties, inhibition, and structural characterization of CYP51 from Acanthamoeba castellanii. The enzyme displays a 100-fold substrate preference for obtusifoliol over lanosterol, supporting the plant-like cycloartenol-based pathway in the pathogen. The strongest inhibition was observed with voriconazole (1 h IC50 0.45 µM), VT1598 (0.25 µM), and VT1161 (0.20 µM). The crystal structures of A. castellanii CYP51 with bound VT1161 (2.24 Å) and without an inhibitor (1.95 Å), presented here, can be used in the development of azole-based scaffolds to achieve optimal amoebicidal effectiveness.

Antifungal and Antiparasitic Activities of Metallocene-Containing Fluconazole Derivatives.

The search for new anti-infectives based on metal complexes is gaining momentum. Among the different options taken by researchers, the one involving the use of organometallic complexes is probably the most successful one with a compound, namely, ferroquine, already in clinical trials against malaria. In this study, we describe the preparation and in-depth characterization of 10 new (organometallic) derivatives of the approved antifungal drug fluconazole. Our rationale is that the sterol 14α-demethylase is an enzyme part of the ergosterol biosynthesis route in Trypanosoma and is similar to the one in pathogenic fungi. To demonstrate our postulate, docking experiments to assess the binding of our compounds with the enzyme were also performed. Our compounds were then tested on a range of fungal strains and parasitic organisms, including the protozoan parasite Trypanosoma cruzi (T. cruzi) responsible for Chagas disease, an endemic disease in Latin America that ranks among some of the most prevalent parasitic diseases worldwide. Of high interest, the two most potent compounds of the study on T. cruzi that contain a ferrocene or cobaltocenium were found to be harmless for an invertebrate animal model, namely, Caenorhabditis elegans (C. elegans), without affecting motility, viability, or development.

Design, Synthesis, and Biological Evaluation of Dual-Target COX-2/CYP51 Inhibitors for the Treatment of Fungal Infectious Diseases.

The design of novel dual-target (COX-2/CYP51) inhibitors was proposed in the study, and three series of compounds were constructed though the pathway of skeleton screening and combination; their molecular structures were synthesized and evaluated. Most of the compounds exhibited significant antifungal ability. Among them, potential compounds (10a-2, 16b-3) with excellent antifungal and anti-drug-resistant fungal ability (MIC50, 0.125-2.0 µg/mL) were selected for the subsequent mechanistic study. On the one hand, these compounds could block the ergosterol biosynthesis pathway by inhibiting CYP51 and influence the internal physiological function of fungal cells, which included the increase of the ROS level, the anomaly of ΔΨm, and the emergence of an apoptotic state. On the other hand, these compounds also effectively showed COX-2 inhibition ability, eliminated the inflammatory reaction of the infected region, and activated the body's immune function. In summary, this study not only provided a novel antifungal drug design pathway but also discovered excellent target compounds.

In silico Prediction and Pharmacokinetic Studies on Glucosinolates as a Potential Drug and Key Inhibitor Molecule for Lanosterol-14α- demethylase: A Fungal Membrane Biosynthesis Enzyme.

BACKGROUND: Glucosinolates (ß-thioglucoside-N-hydroxysulfates) are a water-soluble organic anion with sulfur- and nitrogen-containing glycosides which are found in abundance in Cruciferous plants. Ergosterol (ERG13) lanosterol-14α-demethylase protein has been targeted for inhibition studies as a key regulator enzyme of fungal membrane biosynthesis. OBJECTIVES: To understand the molecular mechanism of inhibition of Ergosterol (ERG13) lanosterol- 14α-demethylase by various phytochemicals from brassicales, i.e., glucosinolates and their potential role as putative drug molecules. METHODS: In this study, in silico analyses were performed to predict the molecular basis of various glucosinolates as a potential inhibitor of lanosterol-14α-demethylase protein, which is a key regulator of fungal membrane biosynthesis and its pharmacodynamics and toxicity profile. 3d structures of various glucosinolates were retrieved from PubChem, and the target protein, lanosterol-14α-demethylase (Pdb ID- 4lxj), was retrieved from the RCSB protein data bank. Molecular docking and interactions were carried out using the PyRx software using the AutoDOCK toolbar with default parameters. Dru- LiTo, ORISIS web servers were used to predict various drug likeliness predictions and Lipinski's Rule of 5, whereas admetSAR was used for prediction of toxicity, and PASS Program was used to study the antifungal and antimicrobial properties of these compounds. RESULTS: This study shows that among the different compounds screened, gluconasturtiin, Glucotropaeolin, and Indolylmethyl-Glucosinolate showed the highest binding energies of -8.7 kcal/mol, -8.5 kcal/mol, and -8.3 kcal/mol with the lanosterol-14α-demethylase, respectively. Further all the compounds follow the Lipinski's rule as well as they are found to be non-carcinogenic and non-cytotoxic in nature. These compounds also show antifungal properties. CONCLUSION: This study thus reveals that various glucosinolates interact with the ERG13 enzyme at various amino acid positions, which behaves as a catalytic site, thus indicates the probable mechanism of inactivation, and subsequently, these can be used as potential drug molecules. In vitro studies can be taken to further examine the utility of these compounds as antifungal agents.

Mulberrin inhibits Botrytis cinerea for strawberry storage by interfering with the bioactivity of 14α-demethylase (CYP51).

Currently, chemical agents hold great promise in preventing and combating Botrytis cinerea. However, the antifungal mechanism of some agents for B. cinerea remains rather vague, imposing restrictions on the research and development of novel antifungal inhibitors. In this work, we discovered that mulberrin (MBN), a natural compound from the root bark of Ramulus Mori, with an IC50 of 1.38 µM together, demonstrated marked anti-14α-demethylase (CYP51) activity through high throughput virtual screening and in vitro bioactivity assay. The computational biology results demonstrated that MBN and its derivatives were bound to the catalytic activity region of CYP51, but only MBN could form a strong π-cation interaction with the Fe ion of heme in CYP51 via the 2-methylpent-2-ene moiety at atom C9. MBN had a stronger binding free energy than the other three compounds with CYP51, implying that the 2-methylpent-2-ene moiety at atom C9 is a critical pharmacophore for CYP51 inhibitors. Subsequently, through an antifungal test, MBN demonstrated excellent anti-B. cinerea activity by inhibiting CYP51 activity. The EC50 values of MBN toward hyphal growth and spore germination in B. cinerea were 17.27 and 9.56 µg mL-1, respectively. The bioactivity loss of CYP51 by direct interaction with MBN induced the increase of cell membrane permeability, membrane destruction, and cell death. Meanwhile, in the B. cinerea infection model, MBN significantly prolonged the preservation of strawberries by preventing B. cinerea from infecting strawberries and could be used as a potential natural preserving agent for storing fruits.

Construction and activity evaluation of novel benzodioxane derivatives as dual-target antifungal inhibitors.

Ergosterol exert the important function in maintaining the fluidity and osmotic pressure of fungal cells, and its key biosynthesis enzymes (Squalene epoxidase, SE; 14 α-demethylase, CYP51) displayed the obvious synergistic effects. Therefore, we expected to discover the novel antifungal compounds with dual-target (SE/CYP51) inhibitory activity. In the progress, we screened the different kinds of potent fragments based on the dual-target (CYP51, SE) features, and the method of fragment-based drug discovery (FBDD) was used to guide the construction of three different series of benzodioxane compounds. Subsequently, their chemical structures were synthesized and evaluated. These compounds displayed the obvious biological activity against the pathogenic fungal strains. Notably, target compounds 10a-2 and 22a-2 possessed the excellent broad-spectrum anti-fungal activity (MIC50, 0.125-2.0 µg/mL) and the activity against drug-resistant strains (MIC50, 0.5-2.0 µg/mL). Preliminary mechanism studies have confirmed that these compounds effectively inhibited the dual-target (SE/CYP51) activity, they could cause fungal rupture and death by blocking the bio-synthetic pathway of ergosterol. Further experiments discovered that compounds 10a-2 and 22a-2 also maintained a certain of anti-fungal effect in vivo. In summary, this study not only provided the new dual-target drug design strategy and method, but also discover the potential antifungal compounds.

Lanosterol 14α-demethylase (CYP51)/histone deacetylase (HDAC) dual inhibitors for treatment of Candida tropicalis and Cryptococcus neoformans infections.

Invasive fungal infections remain a challenge due to lack of effective antifungal agents and serious drug resistance. Discovery of antifungal agents with novel antifungal mechanism is important and urgent. Previously, we designed the first CYP51/HDAC dual inhibitors with potent activity against resistant Candida albicans infections. To better understand the antifungal spectrum and synergistic mechanism, herein new CYP51/HDAC dual inhibitors were designed which showed potent in vitro and in vivo antifungal activity against C. neoformans and C. tropicalis infections. Antifungal mechanism studies revealed that the CYP51/HDAC dual inhibitors acted by inhibiting various virulence factors of C. tropicalis and C. neoformans and down-regulating resistance-associated genes. This study highlights the potential of CYP51/HDAC dual inhibitors as a promising strategy for the discovery of novel broad-spectrum antifungal agents.

Lead optimization generates selenium-containing miconazole CYP51 inhibitors with improved pharmacological profile for the treatment of fungal infections.

A series of selenium-containing miconazole derivatives were identified as potent antifungal drugs in our previous study. Representative compound A03 (MIC = 0.01 µg/mL against C.alb. 5314) proved efficacious in inhibiting the growth of fungal pathogens. However, further study showed lead compound A03 exhibited potential hemolysis, significant cytotoxic effect and unfavorable metabolic stability and was therefore modified to overcome these drawbacks. In this article, the further optimization of selenium-containing miconazole derivatives resulted in the discovery of similarly potent compound B17 (MIC = 0.02 µg/mL against C.alb. 5314), exhibiting a superior pharmacological profile with decreased rate of metabolism, cytotoxic effect and hemolysis. Furthermore, compound B17 showed fungicidal activity against Candida albicans and significant effects on the treatment of resistant Candida albicans infections. Meanwhile, compound B17 not only could reduce the ergosterol biosynthesis pathway by inhibiting CYP51, but also inhibited biofilm formation. More importantly, compound B17 also shows promising in vivo efficacy after intraperitoneal injection and the PK study of compound B17 was evaluated. In addition, molecular docking studies provide a model for the interaction between the compound B17 and the CYP51 protein. Overall, we believe that these selenium-containing miconazole compounds can be further developed for the potential treatment of fungal infections.

Sterol 14α-Demethylase from Trypanosomatidae Parasites as a Promising Target for Designing New Antiparasitic Agents.

Trypanosomatidae family belongs to the Kinetoplastida order, which consists of obligatory parasites that affect plants and all classes of vertebrates, especially humans and insects. Among the heteroxenic parasites, Leishmania spp., Trypanosoma cruzi, and T. brucei are protozoa of most significant interest for medicinal chemistry, being etiological agents of Leishmaniasis, Chagas, and Sleep Sickness diseases, respectively. Currently, inefficient pharmacotherapy, especially in chronic phases and low selectivity towards parasite/host cells, justifies the need to discover new drugs to treat them effectively. Among other targets, the sterol 14α-demethylase (CYP51), an enzyme responsible for ergosterol's biosynthesis in Trypanosomatidae parasites, has received more attention in the development of new bioactive compounds. In this context, antifungal ravuconazole proved to be the most promising drug among this class against T. cruzi, being used in combined therapy with Bnz in clinic trials. Non-antifungal inhibitors, such as VFV and VNF, have shown promising results against T. cruzi and T.brucei, respectively, being tested in Bnz-combined therapies. Among the experimental studies involving azoles, compound (15) was found to be the most promising derivative, displaying an IC50 value of 0.002 µM against amastigotes from T. cruzi, in addition to being non-toxic and highly selective towards TcCYP51 (< 25 nM). Interestingly, imidazole analog (16) was active against infectious forms of these three parasites, demonstrating Ki values of 0.17, 0.02, and 0.36 nM for CYP51 from T. cruzi, T. brucei, and L. infantum. Finally, this review will address promising inhibitors targeting sterol 14α-demethylase (CYP51) from Trypanosomatidae parasites, highlighting SAR studies, interactions with this target, and recent contributions and advances in the field, as well.

A binding mode hypothesis for prothioconazole binding to CYP51 derived from first principles quantum chemistry.

In order to assess safety and efficacy of small molecule drugs as well as agrochemicals, it is key to understanding the nature of protein-ligand interaction on an atomistic level. Prothioconazole (PTZ), although commonly considered to be an azole-like inhibitor of sterol 14-α demethylase (CYP51), differs from classical azoles with respect to how it binds its target. The available evidence is only indirect, as crystallographic elucidation of CYP51 complexed with PTZ have not yet been successful. We derive a binding mode hypothesis for PTZ binding its target, compare to DPZ, a triazole-type metabolite of PTZ, and set our findings into context of its biochemistry and spectroscopy. Quantum Theory of Atoms in Molecules (QTAIM) analysis of computed DFT electron densities is used to qualitatively understand the topology of binding, revealing significant differences of how R- and S-enantiomers are binding and, in particular, how the thiozolinthione head of PTZ binds to heme compared to DPZ's triazole head. The difference of binding enthalpy is calculated at coupled cluster (DLPNO-CCSD(T)) level of theory, and we find that DPZ binds stronger to CYP51 than PTZ by more than ΔH ~ 11 kcal/mol.

CDATA[Recent Advances in the Development of 1,2,3-Triazole-containing Derivatives as Potential Antifungal Agents and Inhibitors of Lanoster ol 14α-Demethylase.

1,2,3-Triazole, a five-membered heterocyclic nucleus, is widely recognized as a key chromophore of great value in medicinal chemistry for delivering compounds possessing innumerable biological activities, including antimicrobial, antitubercular, antidiabetic, antiviral, antitumor, antioxidants, and anti-inflammatory activities. Mainly, in the past years, diverse conjugates carrying this biologically valuable core have been reported due to their attractive fungicidal potential and potent effects on various infective targets. Hence, hybridization of 1,2,3-triazole with other antimicrobial pharmacophores appears to be a judicious strategy to develop new effective anti-fungal candidates to combat the emergence of drug-sensitive and drug-resistant infectious diseases. Thus, the current review highlights the recent advances of this promising category of 1,2,3-triazole-containing hybrids incorporating diverse varieties of bioactive heterocycles such as conozole, coumarin, imidazole, benzimidazole, pyrazole, indole, oxindole, chromene, pyrane, quinazoline, chalcone, isoflavone, carbohydrates, and amides. It underlies their inhibition behavior against a wide array of infectious fungal species during 2015-2020.

Antimicrobial Screening, in Silico Studies and QSAR of Chalcone-based 1,4-disubstituted 1,2,3-triazole Hybrids.

The in vitro antimicrobial properties of some chalcones (1A-1C: ) and chalcone tethred 1,4-disubstituted 1,2,3-triazoles (2A-2U: ) towards different microbial strains viz. Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger and Candida albicans are reported. Compounds 2G: and 2U: exhibited better potency than the standard Fluconazole with MIC values of 0.0063 µmol/mL and 0.0068 µmol/mL, respectively. Furthermore, molecular docking was performed to investigate the binding modes of two potent compounds 2Q: and 2G: with E. coli topoisomerase II DNA gyrase B and C. albicans lanosterol 14α-demethylase, respectively. Based on these results, a statistically significant quantitative structure activity relationship (QSAR) model was successfully summarized for antibacterial activity against B. subtilis.

Targeted potent antimicrobial benzochromene-based analogues: Synthesis, computational studies, and inhibitory effect against 14α-Demethylase and DNA Gyrase.

7H-Benzo[7,8]chromeno[2,3-d]pyrimidin-9(8H)-amine (6a,b) have been synthesized via hydrazinolysis of the imidates (5a,b). Polysubstituted chromenotriazolopyrimidine (7a-j), (12a,b) and Schiff base (8a,b) derivatives have also been prepared. The new heterocyclic derivatives were affirmed by spectral data. The target compounds have been screened for antibacterial and antifungal activity. Compounds 6a,b and 7a-c, g,h displayed the most favorable antimicrobial activities in resemblance to the reference antimicrobial agents by IZ range over 24 mm. In addition, MIC, MBC and MFC were also tested and screen for most active compound 6a by 6.25 µg/mL showing bactericidal effect. SAR study revealed that the antimicrobial vitality of the target compounds was safely influenced by the lipophilicity substituents and the calculated log P value. The potent compounds were subjected into in vitro enzyme screening (14α-Demethylase and DNA Gyrase) against both interesting targets and showed good inhibitory profile. Molecular modeling analyses were introduced and discussed focusing on the docking of active compounds into two essential targets, and their ADMET properties were studied.

Design, synthesis and bioactivity evaluation of novel arylalkene-amide derivatives as dual-target antifungal inhibitors.

Ergosterol as the core component of fungal cell membrane plays a key role in maintaining cell morphology and permeability. The squalenee epoxidase (SE) and 14-demethylase (CYP51) are the important rate-limiting enzymes for ergosterol synthesis. In the study, these active fragments, which is derived from the structural groups of the common antifungal agents, were docked into the active sites of dual targets (SE, CYP51), respectively. Some of active fragments with the matching MCSS_Score values were selected and connected to construct three different series of novel arylalkene-amide derivatives as dual-target (SE, CYP51) antifungal inhibitors. Subsequently, these compounds were further synthesized, and their bioactivity was evaluated. Most of compounds showed a certain degree of antifungal activity in vitro. It was worth noting that the target compounds 17a and 25a with excellent antifungal activity (0.125-4 µg/mL) can inhibit the fluconazole-resistant Candida Strain 17#, CaR, 632, and 901 in the range of MIC values (4-8 µg/mL). Furthermore, their molecular mechanism, structural stability and low toxicity were further confirmed. The molecular docking and ADMET properties were predicted to guide the subsequent optimization of target compounds.

Oxidation of Isodrimeninol with PCC Yields Drimane Derivatives with Activity against Candida Yeast by Inhibition of Lanosterol 14-Alpha Demethylase.

Candida species cause an opportunistic yeast infection called Candidiasis, which is responsible for more than 50,000 deaths every year around the world. Effective treatments against candidiasis caused by non-albicans Candida species such as C. glabrata, C. parapsilosis, C. aureus, and C.krusei are limited due to severe resistance to conventional antifungal drugs. Natural drimane sesquiterpenoids have shown promising antifungal properties against Candida yeast and have emerged as valuable candidates for developing new candidiasis therapies. In this work, we isolated isodrimeninol (C1) from barks of Drimys winteri and used it as starting material for the hemi-synthesis of four sesquiterpenoids by oxidation with pyridinium chlorochromate (PCC). The structure of the products (C2, C3, C4, and C5) was elucidated by 1D and 2D NMR spectroscopy resulting in C4 being a novel compound. Antifungal activity assays against C. albicans, C. glabrata, and C. krusei revealed that C4 exhibited an increased activity (IC50 of 75 µg/mL) compared to C1 (IC50 of 125 µg/mL) in all yeast strains. The antifungal activity of C1 and C4 was rationalized in terms of their capability to inhibit lanosterol 14-alpha demethylase using molecular docking, molecular dynamics simulations, and MM/GBSA binding free energy calculations. In silico analysis revealed that C1 and C4 bind to the outermost region of the catalytic site of 14-alpha demethylase and block the entrance of lanosterol (LAN) to the catalytic pocket. Binding free energy estimates suggested that C4 forms a more stable complex with the enzyme than C1, in agreement with the experimental evidence. Based on this new approach it is possible to design new drimane-type sesquiterpenoids for the control of Candida species as inhibitors of 14-alpha demethylase.

Current and Future Prospective of a Versatile Moiety: Imidazole.

Imidazole containing compounds have been a very much explored field since ancient times. Subsequently, it constitutes a significant moiety for the new drug development. A variety of compounds having imidazole moiety have been synthesized, evaluated and marketed for the treatment of various diseases such as antifungal, antiepileptic, ACE inhibitors and so on, as shown in the figure. The search for imidazole containing compounds with more selective biological potency with low side effects continues to be an active area of research in medicinal chemistry. This review is in an effort to highlight the marketed drugs with imidazole ring. The article also demonstrates the future prospective of marketed imidazoles as antifungal with potential activity targeting 14α-demethylase enzyme.

Small-Molecule Inhibitors Targeting Sterol 14α-Demethylase (CYP51): Synthesis, Molecular Modelling and Evaluation Against Candida albicans.

Fungal infections are a global issue affecting over 150 million people worldwide annually, with 750 000 of these caused by invasive Candida infections. Azole drugs are the frontline treatment against fungal infections; however, resistance to current azole antifungals in C. albicans poses a threat to public health. Two series of novel azole derivatives, short and extended derivatives, have been designed, synthesised and investigated for CYP51 inhibitory activity, binding affinity and minimum inhibitory concentration (MIC) against C. albicans strains. The short derivatives were more potent against the C. albicans strains (e. g., MIC 2-(4-chlorophenyl)-N-(2,4-dichlorobenzyl)-3-(1H-imidazol-1-yl)propanamide (5 f) <0.03 µg/mL, N-(4-((4-chlorophenyl)sulfonamido)benzyl)-2-phenyl-3-(1H-1,2,4-triazol-1-yl)propanamide (12 c), 1 µg/mL, fluconazole 0.125 µg/mL) but both displayed comparable enzyme binding and inhibition (5 f Kd 62±17 nM, IC50 0.46 µM; 12 c Kd 43±18 nM, IC50 0.33 µM, fluconazole Kd 41±13 nM, IC50 0.31 µM, posaconazole Kd 43±11 nM, IC50 0.2 µM). The short series had poor selectivity for CaCYP51 over the human homologue, whereas the selectivity of the extended series, for example, compound 12 c, was higher (21.5-fold) than posaconazole (4.7-fold) based on Kd values, although posaconazole was more selective (615-fold) than 12 c (461-fold) based on IC50 values. Based on inhibitory activity and selectivity profile, the extended series are the better of the two series for further development.