Rapid microwave assisted synthesis and antimicrobial bioevaluation of novel steroidal chalcones

Selective synthesis of A-ring Е-arylidene derivatives from β-sitosterol and their activity

A series of 24-ethylcholest-4-ene-3,6-dione 2E-arylidene-derivatives has been synthesized by a Claisen-Schmidt reaction from a natural phytosterol β-sitosterol with yields of 80-85%. The structure of the obtained compounds was confirmed by NMR spectroscopy, including two-dimensional correlation experiments. The synthesized compounds were evaluated for their in vitro cytotoxicity and α-glucosidase inhibitory activity. It was established that compound 3 with pyridin-3-ylmethylene moiety exhibited a selective cytotoxic effect against the U251 cancer cell line with 99.31% inhibition of cancer cell growth. Compounds with pyridin-4-ylmethylene 4 and furan-2-ylmethylene-5 fragments were the most active inhibitors of α-glucosidase with IC50 64.00 and 38.95 µM, being 3- and 5-times more active than acarbose. Binding mode to α-glucosidase and ADMET characteristics for the lead molecule 5 were proposed computationally. To sum up, an efficient approach to the derivatives with promising antidiabetic activity based on available natural product β-sitosterol is suggested.

Synthesis, antifungal evaluation, and molecular docking studies of steroidal thiazolopyrimidines

A series of steroidal thiazolopyrimidine derivatives were developed and evaluated for their antifungal properties against Candida species using steroid as the basic skeletonand a thiazolopyrimidine heterocycle as a pharmacophore in the D-ring. Dehydroepiandrosterone, aromatic aldehydes, and 2-aminothiazole were used in a one-pot multicomponent reaction with silica sulphuric acid to generate the target molecules. Additionally, molecular docking studies were conducted to determine how synthesized steroidal derivatives interacted with the amino acid residues of CYP51 ofCandida albicans.

Design, synthesis, characterization and anticancer activity evaluation of deoxycholic acid-chalcone conjugates

A series of deoxycholic acid-chalcone amides were synthesised and tested against the human lung cancer cell line, A549 and the cervical cancer cell line, SiHa. Among the synthesised deoxycholic acid-chalcone conjugates, some conjugates showed encouraging results as anticancer agents with good in vitro activity. More precisely, deoxycholic acid-chalcone conjugates 4b (IC50: 0.51 μM) and 4e (IC50: 0.84 μM) having 2‑nitrophenyl and 3,4,5‑trimethoxyphenyl groups exhibited a good activity against human cancer cell-line SiHa and while 4d (IC50: 0.25 μM) and 4b (IC50: 1.71 μM) showed better activity against A549 lung cancer cell line with respect to deoxycholic acid and chalcones. The anticancer activity of the bile acid conjugated chalcones was more than the activity of chalcone and deoxycholic acid alone. The results indicate that a bile acid conjugate strategy may be beneficial in improving the biological activity of chalcone derivatives. The enhanced activity of certain compounds may be due to their increased bioavailability.

Synthesis, Crystal Structure, and Insecticidal Activity of Steroidal N-Piperidone

A series of steroidal piperidone derivatives were synthesized, and their agricultural activities were evaluated against Myzus persicae, Aphis citricola, Brevicoryne brassicae Linn., and Bemisia tabaci (Gennadius). Most of the tested compounds exhibited potent insecticidal activity against these four pests. Compound I-9 displayed the highest activity against M. persicae, A. citricola, and Brevicoryne brassicae, with LC₅₀ values of 11.3, 10.4, and 8.68 μg/mL, respectively. The mode of action test indicated that these derivatives had superior contact and systemic insecticidal activity against M. persicae. In addition, we initially explored whether the foregut and midgut might be the action sites of the target derivatives against M. persicae. Furthermore, a field trial showed that the control of compound I-9 was similar to that of acetamiprid against M. persicae, at a dose of 50 μg/mL; the control rates were 97.8 and 99.2% after 14 and 21 days, respectively. The structure-activity relationship of these analogues provided some important insights for the discovery and development of new insecticides to solve the current pesticide resistance crisis.

Synthesis and anti-inflammatory activity of novel steroidal chalcones with 3β-pregnenolone ester derivatives in RAW 264.7 cells in vitro

To identify new potential anti-inflammatory agents, we herein report the synthesis of novel steroidal chalcones with 3β-pregnenolone esters of cinnamic acid derivatives using pregnenolone as the starting material. The structures of the newly synthesised compounds were confirmed by ¹H NMR, ¹³C NMR, HRMS and infrared imaging. All the derivatives were examined to determine their in vitro anti-inflammatory profiles against LPS-induced inflammation in RAW 264.7 cells; the derivates were evaluated by the quantification of the pro-inflammatory mediator nitric oxide (NO) in the cell culture supernatant based on the Griess reaction, which measures nitrite levels, followed by an in vitro cytotoxicity study. Among these novel derivatives, compound 11e [3β-3-phenyl acrylate-pregn-5-en-17β-yl-3' -(p-fluoro)-phenylprop-2'-en-1'-one] was identified as the most potent anti-inflammatory agent, which showed significant anti-inflammatory activity by inhibiting the LPS-induced pro-inflammatory mediator NO in a dose-dependent manner without any cytotoxicity. Moreover, compound 11e markedly inhibited the expression of pro-inflammatory cytokines, including inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), and cyclooxygenase-2 (COX-2), in LPS-induced RAW 264.7 cells. Further studies confirmed that compound 11e significantly suppressed the transcriptional activity of NF-κB in activated RAW 264.7 cells. Molecular docking study revealed the strong binding affinity of compound 11e to the active site of the pro-inflammatory proteins, which confirmed that compound 11e acted as an anti-inflammatory mediator. These results indicated that steroidal chalcones with 3β-pregnenolone esters of cinnamic acid derivatives might be considered for further research in the design of anti-inflammatory drugs, and compound 11e might be a promising therapeutic anti-inflammatory drug candidate.

Highlights on Steroidal Arylidene Derivatives as a Source of Pharmacologically Active Compounds: A Review

Steroids constitute a unique class of chemical compounds, playing an important role in physiopathological processes, and have high pharmacological interest. Additionally, steroids have been associated with a relatively low toxicity and high bioavailability. Nowadays, multiple steroidal derivatives are clinically available for the treatment of numerous diseases. Moreover, different structural modifications on their skeleton have been explored, aiming to develop compounds with new and improved pharmacological properties. Thus, steroidal arylidene derivatives emerged as a relevant example of these modifications. This family of compounds has been mainly described as 17β-hydroxysteroid dehydrogenase type 1 and aromatase inhibitors, as well as neuroprotective and anticancer agents. Besides, due to their straightforward preparation and intrinsic chemical reactivity, steroidal arylidene derivatives are important synthetic intermediates for the preparation of other compounds, particularly bearing heterocyclic systems. In fact, starting from arylidenesteroids, it was possible to develop bioactive steroidal pyrazolines, pyrazoles, pyrimidines, pyridines, spiro-pyrrolidines, amongst others. Most of these products have also been studied as anti-inflammatory and anticancer agents, as well as 5α-reductase and aromatase inhibitors. This work aims to provide a comprehensive overview of steroidal arylidene derivatives described in the literature, highlighting their bioactivities and importance as synthetic intermediates for other pharmacologically active compounds.

Activation of Nrf2 signaling pathway by natural and synthetic chalcones: a therapeutic road map for oxidative stress

Introduction:Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway plays a key role in diverse gene expressions responsible for protection against oxidative stress and xenobiotics. Chalcones with a common chemical scaffold of 1,3-diaryl-2- propen-1-one, are abundantly present in nature with a wide variety of pharmacological properties. This review will discuss the interactions of natural and synthetic chalcones with Nrf2 signaling.Areas covered:Chalcones are reportedly found to activate Nrf2 signaling pathway, expression of Nrf2-regulated antioxidant genes, induce cytoprotective proteins and upregulate multidrug resistance-associated proteins. Chalcones being soft electrophiles are less prone to hostile off-target effects and unlikely to induce carcinogenicity and mutagenicity. Furthermore, their low toxicity, structural diversity, feasibility in structural reorganization and the presence of α,β-unsaturated carbonyl group which makes them suitable drug candidates targeting Nrf2-dependent diseases.Expert opinion:Nrf2-Keap1 signaling pathway plays a central role in redox signaling. However, available therapeutic agents for Nrf2 activation have limited practical applications due to their associated risks, relatively low efficacy and bioavailability. The designing and fabrication of new chemical entities with chalcone scaffold-based Michael acceptor mechanism should be aimed as potential therapeutic Nrf2 activators to target oxidative stress and inflammation-mediated diseases such as atherosclerosis, Parkinson's disease and many more.

Multi-Component One-Pot Assisted Synthesis, Anti-bacterial Capabilities, and Scanning Electron Microscopy of Novel Corticosteroid Thiopyran

BACKGROUND

Corticosteroids are an important group of polycyclic compounds having a wide range of pharmacological and physiological properties. Thiopyran derivatives are important building blocks of many biologically active compounds.

OBJECTIVE

Keeping in mind the wide range of applications of corticosteroids and thiopyran, herein we intend to develop a simple and efficient strategy to synthesize steroidal thiopyran derivatives starting with different commercially available corticosteroids and study their biological properties.

MATERIALS AND METHODS

To achieve our aim, we employed a one-pot multi-component synthesis of steroidal thiopyran derivatives by the reaction of corticosteroids, malononitrile, and carbon disulphide in the presence of triethylamine as a catalyst.

RESULTS AND DISCUSSION

An array of novel thiopyran compounds was obtained with the highest product yield using Et₃N. Scanning electron microscopy analysis manifested agglomeration pertaining to brick-shaped crystals of corticosteroid thiopyran. Synthesized compounds were also found to be active as anti-bacterial agents.

CONCLUSION

We describe a facile one-pot multi-component synthesis of corticosteroid thiopyran derivatives, which are found to possess anti-bacterial activity. Excellent yields of the products, simple work-up, easily available starting materials, and non-chromatographic purification are some of the main advantages of this protocol.

Discovery of novel steroidal-chalcone hybrids with potent and selective activity against triple-negative breast cancer

A series of novel steroidal-chalcone derivates were designed and synthesized based on the molecular hybridization strategy and further evaluated for their growth inhibitory activity against three human cancer cell lines. The MTT results indicated that most compounds were apparently more sensitive to human breast cancer cells MDA-MB-231. Compounds 8 and 18 exerted the best cytotoxic activity against triple-negative MDA-MB-231 cells with the IC₅₀ values of 0.42 μM and 0.52 μM respectively, which were 23-fold increase or more compared with 5-Fu. Further mechanism studies demonstrated that compound 8 could induce cells apoptosis through regulating Bcl-2/Bax proteins and activating caspase-3 signaling pathway. Moreover, compound 8 could upregulate the cellular ROS levels which accelerated the apoptosis of MDA-MB-231 cells. In addition, interestingly, cell cycle assay showed that compound 8 could arrest MDA-MB-231 cells at S phase but not commonly anticipated G2/M phase. These evidences fully confirmed that compound 8 could be a potential candidate that deserves further development as an antitumor agent against triple-negative breast cancer.

Unsubstituted Oximes as Potential Therapeutic Agents

Oximes, which are highly bioactive molecules, have versatile uses in the medical sector and have been indicated to possess biological activity. Certain oximes exist in nature in plants and animals, but they are also obtained by chemical synthesis. Oximes are known for their anti-inflammatory, antimicrobial, antioxidant and anticancer activities. Moreover, they are therapeutic agents against organophosphate (OP) poisoning. Two oximes are already commonly used in therapy. Due to these abilities, new oxime compounds have been synthesized, and their biological activity has been verified. Often, modification of carbonyl compounds into oximes leads to increased activity. Nevertheless, in some cases, oxime activity is connected to the activity of the substrate. Recent works have revealed that new oxime compounds can demonstrate such functions and thus are considered to be potential drugs for pathogenic diseases, as adjuvant therapy in various types of cancer and inflammation and as potential next-generation drugs against OP poisoning.

A Nature-Inspired Design Yields a New Class of Steroids Against Trypanosomatids

Chagas disease and Leishmaniasis are neglected endemic protozoan diseases recognized as public health problems by the World Health Organization. These diseases affect millions of people around the world however, efficient and low-cost treatments are not available. Different steroid molecules with antimicrobial and antiparasitic activity were isolated from diverse organisms (ticks, plants, fungi). These molecules have complex structures that make de novo synthesis extremely difficult. In this work, we designed new and simpler compounds with antiparasitic potential inspired in natural steroids and synthesized a series of nineteen steroidal arylideneketones and thiazolidenehydrazines. We explored their biological activity against Leishmania infantum, Leishmania amazonensis, and Trypanosoma cruzi in vitro and in vivo. We also assayed their genotoxicity and acute toxicity in vitro and in mice. The best compound, a steroidal thiosemicarbazone compound 8 (ID_1260) was active in vitro (IC₅₀ 200 nM) and in vivo (60% infection reduction at 50 mg/kg) in Leishmania and T. cruzi. It also has low toxicity in vitro and in vivo (LD₅₀ >2000 mg/kg) and no genotoxic effects, being a promising compound for anti-trypanosomatid drug development.

Chalcone derivatives and their antibacterial activities: Current development

The increase in antibiotic resistance due to various factors has encouraged the look for novel compounds which are active against multidrug-resistant pathogens. In this framework, chalcone-based compounds showed a diversity of pharmacological properties, and its derivatives possess a high degree of structural diversity, and it is helpful for the discovery of new therapeutic agents. The growing resistance to antibiotics worldwide has endangered their efficacy. This has led to a surging interest in the discovery of new antibacterial agents. Thus, there is an urgent need for new antibacterial drug candidates with increased strength, new targets, low cost, superior pharmacokinetic properties, and minimum side effects. The present review concluded and focuses on the recent developments in the area of medicinal chemistry to explore the diverse chemical structures of potent antibacterial agents and also describes its structure-activity relationships studies. The various synthetic structures leading to this class of neutral protective compound is common and additional structural optimization is promising for potential drug discovery and development.

New cholic acid analogs: synthesis and 17β-hydroxydehydrogenase (17β-HSD) inhibition activity

The 17β-hydroxysteroid dehydrogenase (17β-HSD) enzyme family is involved in the biosynthesis of active steroids and its inhibition constitutes an interesting approach for treating estrogen-, androgen-dependent cancers and osteoporosis. In this study, a new series of cholic acid analogs was designed with the goal of improving the biological activity as 17β-HSD1 and 17β-HSD2 inhibitors. To this end, 23-cholyl amides 4–7, 3-O-p-toluenesulfonyl-23-cholyl amides 10–12, 23-cholyl-carbohydrazide 14, carbothioamide analog 15, and 23-cholyl-acylhydrazone derivatives 18–22 were synthesized from cholic acid (3) via coupling, sulfonation and substitution reactions. Basic treatment of keto group of 5 with p-bromoaniline afforded 8, meanwhile acidic treatment of 3 with thiosemicarbazide furnished the 23-cholyl-thiadiazole derivative 16. The synthesized compounds were evaluated for their inhibition activity against 17β-HSD1 and 17β-HSD2, and were found inactive at 1.0 μm concentration (inhibition <10%). However, the steroids 12, 21 and 22 showed inhibition of 21.1, 23.9 and 21.3%, respectively, against 17β-HSD2 at the same concentration. Therefore, these steroidal analogs can be further structurally modified to optimize their inhibition activity against 17β-HSD2 for the development of potential therapeutics.

Haemolytic activity of formyl- and acetyl-derivatives of bile acids and their gramine salts

Bile acids (lithocholic: LCA, deoxycholic: DCA and cholic: CA) and their formyl- and acetyl-derivatives can be used as starting material in chemical synthesis of compounds with different biological activity strongly depended on their chemical structures. Our previous studies showed that biological activity of bile acids salts with gramine toward human erythrocytes was significantly different from the activity of bile acids alone. Moreover, gramine effectively modified the membrane perturbing activity of other steroids. As a continuation of our work, the haemolytic activity of formyl- and acetyl-substituet bile acids as well as their gramine salts was studied in vitro. The structures of new compounds were confirmed by spectral (NMR, FT-IR) analysis, mass spectrometry (ESI-MS) as well as PM5 semiempirical methods. The results shown that the haemolytic activity of formyl- and acetyl-LCA and DCA was significantly higher in comparison with their native forms at the whole concentration range. At high concentration, formyl derivative of CA was as effective as LCA and DCA derivatives whereas at lower concentration its haemolytic activity was at the level of original acid. The acetyl-CA was not active as membrane perturbing agents. Furthermore, gramine significantly decreased the membrane-perturbing activity of hydrophobic bile acids derivatives. The results obtained with the cellular system are in line with physicochemical calculation.

Synthesis of novel 4'-acylamino modified 21E-benzylidene steroidal derivatives and their cytotoxic activities

A series of 4'-acylamino modified Δ^1,4-pregnadien-21E-benzylidene-3,20-dione derivatives (6a-v) was synthesized from the commercially available progesterone (1). These title compounds were evaluated for their toxicity against brine shrimp (Artemia salina) and cytotoxic activities against two human cancer cell lines (HeLa and MCF-7). The results revealed that compound 6f exhibited promising in vitro cytotoxic activity to the two cancer cell lines and the nature of acylamino functional group in the benzylidene moiety had a significant influence on cytotoxicity.

Efficient three-component one-pot synthesis of steroidal polysubstituted anilines

An efficient and practical base-promoted cascade reaction has been developed to access steroidal polysubstituted anilines from simple precursors. The protocol reported herein achieved the formation of a benzene ring as well as three continuous C-C bonds in a single operation. The reaction mechanism was proposed on the basis of the key intermediate obtained. Besides, this method could be potentially employed for the synthesis of biphenyl compounds. The adjacent amine and nitrile groups existed in the final products have the potential for late stage functionalization, which would provide efficient access to steroidal compound collections with structural diversity and complexity.

Synthesis of conjugated bile acids/azastilbenes as potential antioxidant and photoprotective agents

A series of 14 bile acids/azastilbenes conjugates (1a-g and 2a-g) was prepared through the condensation of bile amides (1 and 2) and aromatic aldehydes. The newly synthesized conjugates were evaluated in vitro for their antioxidant and photoprotective activities. Six compounds (1, 1a, 1b, 2, 2a and 2b) showed promising antioxidant activity with IC50 values of 19.60-31.83 μg mL(-1). The synthesized compounds presented a varied photoprotection profile, with the SPF ranging from 2 to 9. Among the 16 compounds tested for the protection against UVB sunrays, 3 compounds (2c, 2e and 2g) presented more significant protection than resveratrol and the free azastilbene 3; while the UVAPF increased from 2 in resveratrol and 5 in 3 to 5-11 in the majority of the conjugates.

Evaluation of antimicrobial activity of glycinate and carbonate derivatives of cholesterol: Synthesis and characterization

A series of glycinate and carbonate derivatives of cholesterol (4a–t) were synthesized, characterized and assessed for their in vitro antimicrobial activity. Our results revealed that the compounds exerted inhibitory activities against gram-negative bacteria and fungi.

Synthesis, characterization and antitumor activities of some steroidal derivatives with side chain of 17-hydrazone aromatic heterocycle

Here a series of dehydroepiandrosterone-17-hydrazone and estrone-17-hydrazone derivatives possessing various aromatic heterocycle structures in 17-side chain of their steroidal nucleus were synthesized and their structures were evaluated. The antiproliferative activity of synthesized compounds against some cancer cells was investigated. The results have demonstrated that some dehydroepiandrosterone-17-hydrazone derivatives show distinct antiproliferative activity against some cancer cells through inducing cancer cell apoptosis, and compound 8 with a quinoline structure in 17-side chain displays excellent antiproliferative activity in vitro against SGC 7901 cancer cell (human gastric carcinoma) with an IC50 value of 1 μM. In addition, estrone-17-hydrazone derivatives having a key feature of indole group in the structure showed a special obvious cytotoxicity against HeLa cells, but almost inactive against other cells. The information obtained from the studies is valuable for the design of novel steroidal chemotherapeutic drugs.

Synthesis and characterization of steroidal heterocyclic compounds, DNA condensation and molecular docking studies and their in vitro anticancer and acetylcholinesterase inhibition activities

A facile and efficient approach for the synthesis of steroidal heterocyclic compounds (4–12) has been performed. Furthermore, these newly synthesized compounds were evaluated for their various biological activities.

Anadenanthera colubrina (Vell.) Brenan produces steroidal substances that are active against Alternaria alternata (Fr.) Keissler and that may bind to oxysterol-binding proteins

BACKGROUND

In previous studies, the extract from Anadenanthera colubrina was active against Alternaria alternata in vitro and reduced the disease caused by this fungus on Murcott tangor fruits to levels that have been obtained using commercial fungicides. Therefore, the goal of the present work was to isolate and identify the active substances in this extract and identify in silico their protein target in the fungus.

RESULTS

The bioguided fractionation of the methanol extract from the fruits of A. colubrina resulted in the isolation of β-sitosterol and β-sitosteryl linoleate, which had minimal inhibitory concentrations (MICs) of 250 and 500 µg mL(-1) , respectively, against A. alternata. Under the same conditions, the MICs for two commercial fungicides were 1250 and 19 µg mL(-1) . In silico studies showed that these steroidal substances bind well to oxysterol-binding proteins from Saccharomyces cerevisiae.

CONCLUSION

β-Sitosterol and β-sitosteryl linoleate, produced by A. colubrina, are active against A. alternata. In silico studies suggest that these substances may act by binding to oxysterol-binding proteins. Therefore, both substances and these proteins have potential use in the development of new steroidal structures and analogues to control the disease caused by A. alternata.

Synthesis and biological evaluation of novel C6-cyclo secondary amine substituted purine steroid-nucleosides analogues

Novel C6-cyclo secondary amine substituted purine steroid-nucleoside analogues (2-9) were efficiently synthesized through displacement of the C6 chloro on the purine ring of series 1 with versatile cyclic secondary amines, including pyrrolidines, piperidine, morpholine, and piperazines. All the newly-synthesized compounds were evaluated for their anticancer activity in vitro against Hela, PC-3 and MCF-7 cell lines. Among them, compounds 5c and 6b exhibited significant cytotoxicity on PC-3 cell lines.

Design, synthesis and biological evaluation of novel steroidal spiro-oxindoles as potent antiproliferative agents

Two series of novel steroidal spiro-pyrrolidinyl oxindoles 3a-t and 6a-c were designed and synthesized from dehydroepiandrosterone using the 1,3-dipolar cycloaddition as the key step and further evaluated for their antiproliferative activities for four human cancer cell lines (MGC-803, EC109, SMMC-7721 and MCF-7). This protocol achieved the formation of two CC bonds, one CN bond and the creation of one new five-membered pyrrolidine ring and three contiguous stereocenters in a single operation. Biological evaluation showed that these synthesized steroidal spiro-pyrrolidinyl oxindoles possessed moderate to good antiproliferative activities against the tested cell lines and some of them were more potent than 5-Fu. Particularly, compound 3g showed good antiproliferative activity against SMMC-7721 (IC50=0.71μM). Steroid dimer 6b showed improved antiproliferative activities against SMMC-7721 and MCF-7 with the IC50 values of 4.30 and 2.06μM, respectively. Flow cytometry analysis demonstrated that compound 3n caused the cellular early apoptosis and cell cycle arrest at G2/M phase in a concentration- and time-dependent manner. [Corrected]

Synthesis and anticancer activity of novel C6-piperazine substituted purine steroid-nucleosides analogues

Novel C6-piperazine substituted purine nucleoside analogues (2-9) bearing a modified pyranose-like D ring of the 4-azasteroid moiety were efficiently synthesized through nucleophilic substitution at C6 position of the steroid-nucleoside precursors (1) with versatile piperazines. All newly-synthesized compounds were evaluated for their anticancer activity in vitro against Hela, PC-3 and MCF-7 cell lines. Among them, compounds 8b and 9b exhibited significant cytotoxicity on PC-3 cell lines.

The Knoevenagel reactions of pregnenolone with cyanomethylene reagents: synthesis of thiophene, thieno[2,3-b]pyridine, thieno[3,2-d]isoxazole derivatives of pregnenolone and their in vitro cytotoxicity towards tumor and normal cell lines

The reaction of pregnenolone with either 2-aminoprop-1-ene-1,1,3-tricarbonitrile or 3-oxo-3-phenylpropanenitrile gave the Knoevenagel condensation products 3 and 6, respectively. Separation of the E and Z isomeric compounds of 3 and 6 together with their structure elucidation were carried out. Some chemical transformations of the latter products were carried out and the cytotoxicity of the newly obtained products was evaluated against some cancer cell lines and a human normal cell line. The results indicated that compounds 15, 17a, 18 and 20e among the tested compounds showed the highest cytotoxicity against the cancer cell lines.

Novel Regulatory Mechanisms of Pathogenicity and Virulence to Combat MDR in Candida albicans

Continuous deployment of antifungals in treating infections caused by dimorphic opportunistic pathogen Candida albicans has led to the emergence of drug resistance resulting in cross-resistance to many unrelated drugs, a phenomenon termed multidrug resistance (MDR). Despite the current understanding of major factors which contribute to MDR mechanisms, there are many lines of evidence suggesting that it is a complex interplay of multiple factors which may be contributed by still unknown mechanisms. Coincidentally with the increased usage of antifungal drugs, the number of reports for antifungal drug resistance has also increased which further highlights the need for understanding novel molecular mechanisms which can be explored to combat MDR, namely, ROS, iron, hypoxia, lipids, morphogenesis, and transcriptional and signaling networks. Considering the worrying evolution of MDR and significance of C. albicans being the most prevalent human fungal pathogen, this review summarizes these new regulatory mechanisms which could be exploited to prevent MDR development in C. albicans as established from recent studies.