Design and synthesis of new antifungals based on N- un-substituted azoles as 14α demethylase inhibitor

Author(s):  
Asghar Davood ◽  
Aneseh Rahimi ◽  
Maryam Iman ◽  
Parisa Azerang ◽  
Soroush Sardari ◽  
...  

Objective(s): Azole antifungal agents, which are widely used as antifungal antibiotics, inhibit cytochrome P450 sterol 14α-demethylase (CYP51). Nearly all azole antifungal agents are N-substituted azoles. In addition, an azolylphenalkyl pharmacophore is uniquely shared by all azole antifungals. Due to importance of nitrogen atom of azoles (N-3 of imidazole and N-4 of triazole) in coordination with heme in the binding site of the enzyme, here a group of N- un-substituted azoles in which both of nitrogen is un-substituted was reported. Materials and Methods: Designed compounds were synthesized by reaction of imidazole-4-carboxaldehyde with appropriate arylamines and subsequently reduced to desired amine derivatives. Antifungal activity against Candida albicans and Saccharomyces cervisiae were done using a broth micro-dilution assay. Docking studies were done using AutoDock. Results: Antimicrobial evaluation revealed that some of these compounds exhibited moderate antimicrobial activities against tested pathogenic fungi, wherein compound 3, 7 and 8 were potent. Docking studies propose that all of the prepared azoles interacted with 14α-DM, wherein azole-heme coordination play main role in drug-receptor interaction. Conclusion: Our results offer some useful references in order to molecular design performance or modification of this series of compounds as a lead compound to discover new and potent antimicrobial agents.

Author(s):  
KOSARAJU LAHARI ◽  
RAJA SUNDARARAJAN

Objective: Isatins have emerged as antimicrobial agents due to their broad spectrum of in vitro and in vivo antimicrobial activities. In addition, thiazolidinone also reported to possess various biological activities particularly antimicrobial activity. Due to the importance, we planned to synthesize compounds with isatin functionality coupled with thiazolidinone as possible antitubercular and antimicrobial agents which could furnish better therapeutic results. Methods: In vitro Mycobacterium tuberculosis method and agar streak dilution test are used to estimate antitubercular and antimicrobial potency of title analogs, respectively. Minimum inhibitory concentration of entire title compounds was determined against all tested microorganism such as M. tuberculosis, four Gram-positive, three Gram-negative bacteria, and two fungi. Results: A series of new thiazolidinone substituted Schiff and Mannich bases of 5-nitroisatins were designed and synthesized by a multistep synthesis from isatin. Structures of synthesized compounds are characterized using Fourier-transform infrared, proton nuclear magnetic resonance, mass spectroscopy, and bases of elemental analysis. Mild to good antitubercular and antimicrobial activity was showed by synthesized 5-nitroisatin analogs. The relationship between the biological activity and the functional group variation of the tested compounds was discussed. Conclusion: 3-(4-(3-(4-Aminophenyl)-4-oxothiazolidin-2-yl)phenylimino)-1-((dimethyl amino)methyl)-5-nitroindolin-2-one 6 and 3-(4-(3- (2-aminophenyl)-4-oxothiazolidin-2-yl)phenylimino)-1-((dimethylamino)methyl)-5-nitroindolin-2-one 13 were found to be the most potent compounds of this series which might be extended as a novel class of antimicrobial agents.


Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4363
Author(s):  
Wei Gao ◽  
Xiaotian Li ◽  
Da Ren ◽  
Susu Sun ◽  
Jingqian Huo ◽  
...  

Protoporphyrinogen oxidase (PPO) has been identified as one of the most promising targets for herbicide discovery. A series of novel phthalimide derivatives were designed by molecular docking studies targeting the crystal structure of mitochondrial PPO from tobacco (mtPPO, PDB: 1SEZ) by using Flumioxazin as a lead, after which the derivatives were synthesized and characterized, and their herbicidal activities were subsequently evaluated. The herbicidal bioassay results showed that compounds such as 3a (2-(4-bromo-2,6-difluorophenyl) isoindoline-1,3-dione), 3d (methyl 2-(4-chloro-1,3-dioxoisoindolin-2-yl)-5-fluorobenzoate), 3g (4-chloro-2-(5-methylisoxazol-3-yl) isoindoline-1,3-dione), 3j (4-chloro-2-(thiophen-2-ylmethyl) isoindoline-1,3-dione) and 3r (2-(4-bromo-2,6-difluorophenyl)-4-fluoroisoindoline-1,3-dione) had good herbicidal activities; among them, 3a showed excellent herbicidal efficacy against A. retroflexus and B. campestris via the small cup method and via pre-emergence and post-emergence spray treatments. The efficacy was comparable to that of the commercial herbicides Flumioxazin, Atrazine, and Chlortoluron. Further, the enzyme activity assay results suggest that the mode of action of compound 3a involves the inhibition of the PPO enzyme, and 3a showed better inhibitory activity against PPO than did Flumioxazin. These results indicate that our molecular design strategy contributes to the development of novel promising PPO inhibitors.


2014 ◽  
Vol 68 (3) ◽  
Author(s):  
Jaiprakash Biradar ◽  
Parveen Rajesab ◽  
B. Sasidhar

AbstractA novel and convenient synthesis of thiopheno-4-thiazolidinyl indole analogues is presented (IVa-IVi), with the aim of obtaining biologically active compounds. 3,5-disubstituted indol-2-carboxyhydrazides (Ia-If) were allowed to react with 3-acetyl-2,5-dichlorothiophene (II) to yield the corresponding 3,5-disubstituted indol-2-carbohydrazides (IIIa-IIIf). The pre-formed indolecarbohydrazides (IIIa-IIIf) were allowed to react with 2-mercaptoacetic acid or 2-mercaptopropanoic acid to produce thiopheno-4-thiazolidinylindoles (IVa-IVi). This reaction protocol affords a simple, eco-friendly, non-hazardous, easier preparation and high yields. The antioxidant (free radical scavenging, total antioxidant capacity and ferric-reducing antioxidant power) and antimicrobial activities of the synthesised compounds were evaluated. The structures and purity of the products were confirmed by their IR, 1H NMR, 13C NMR and mass spectral and analytical data. Most of the compounds tested showed very significant scavenging, antioxidant and antimicrobial activities. Compounds containing electron donor group (CH3) at the fifth position of indole exhibit an excellent ferric-reducing activity. The present study suggests that compounds IIIa-IIIb, IIIf, IVa-IVc, IVf-IVi, may serve as promising lead scaffolds for antioxidant and antimicrobial agents.


2021 ◽  
Vol 18 (5) ◽  
pp. 1101-1108
Author(s):  
Abdulsalam A.M. Alkhaldi ◽  
Mohamed A. Abdelgawad ◽  
Bahaa G.M. Youssif ◽  
Ahmed O. El-Gendy ◽  
Harry P. De Koning

Purpose: To synthesize new triazole derivatives in order to overcome the problem of side effects of antimicrobial agents and microbial resistance, while broadening the spectrum of antimicrobial activity. Methods: The starting triazole, compound 1, was prepared through click chemistry and reacted with chloroacetyl chloride to yield compound II. Triazole 1 was reacted with acids and aldehydes to produce oxadiazole (III) and azomethine (IV) which cyclized in acetic anhydride to give a new acetylated oxadiazole (V). Minimum inhibitory concentration (MIC) and resorufin assays were used for antibacterial and anti-parasitic screening, respectively. Compounds II and IVb were subjected to molecular docking studies using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) Molecular Operating Environment (MOE) program. Results: Novel oxazole-triazole derivative (III) showed high activity against Pseudomonas aeruginosa and moderate activity against Staphylococcus epidermidis, whereas compound IVc showed moderate activity against Staphylococcus epidermidis. Chloro-acetyl-triazole II and 2-hydroxyphenyl-triazole Schiff base (Ivb) showed pronounced activity against the kinetoplastid parasites, Leishmania major, Leishmania mexicana and Trypanosoma brucei. Conclusion: The new synthesized triazoles represent a new antimicrobial scaffold and identifies potential new lead compounds for follow-up and for further mechanistic studies.


2020 ◽  
Vol 16 (8) ◽  
pp. 1242-1248
Author(s):  
Ravi K. Nishad ◽  
Karuna S. Shukla ◽  
Pooja A. Chawla

Background: An upsurge in the number of antibiotic-resistant microbial infections has warranted the discovery and development of new antibiotics. This is a matter of great concern for effective therapy for a search of novel antimicrobial agents. Literature has a number of reports of involvement of oxidative stress due to an imbalance between the generation and neutralization of free radicals in many diseases. Heterocyclic compounds have been involved in the treatment of various disorders. Benzothiazole is one such heterocyclic nucleus having benzene ring merged with the thiazole ring. Among the various substitutions possible in this nucleus, substitutions at position-2 have already been reported with potential bioactivities. Thus, different substituted compounds have been synthesized which could serve as antimicrobials and antioxidants. Methods: Benzothiazole derivatives (B1-B7) were synthesized by two-step reactions and the structures were confirmed through infrared, mass and NMR spectroscopy. The compounds were evaluated for in vitro antioxidant and antimicrobial activities using standard methods. Results: The results of antibacterial and antifungal activity showed that compound B4 exhibited maximum activity against all the tested strains of microorganisms with the zone of inhibition 17.1-18.5 mm and MIC value 1.1-1.5 μg/mL. Compound B5 exhibited potent antioxidant activity. Conclusion: The compounds substituted with halogen on the aryl ring showed increased antimicrobial activity as seen in the case of compound B4 (6-fluoro). The compounds substituted with a hydroxyl group (B5) exhibited good antioxidant activity.


2019 ◽  
Vol 20 (18) ◽  
pp. 4564 ◽  
Author(s):  
Kai-Wei Tang ◽  
Shih-Chun Yang ◽  
Chih-Hua Tseng

Staphylococcus aureus resistance to current antibiotics has become the greatest global challenge facing public health. The development of new antimicrobial agents is urgent and important and is needed to provide additional therapeutic options. In our previous study, we found out that pterostilbene exhibited potent antibacterial activity, especially against methicillin-resistant Staphylococcus aureus (MRSA). According to previous studies, 1,2,3-triazole, with the characteristic of increasing the interaction with the target readily and enhancing water solubility, were widely used in the approved anti-bacterial drugs. Therefore, these results attract our interest to use the structure of pterostilbene as a scaffold for the hybrid 1,2,3-triazole moiety to develop a novel anti-MRSA infection agent. In this study, we demonstrated the design and synthesis of a series of triazolylpterostilbene derivatives. Among these compounds, compound 4d exhibited the most potent anti-MRSA activity with a minimum inhibitory concentration (MIC) value of 1.2–2.4 μg/mL and a minimum bactericidal concentration (MBC) value of 19.5–39 μg/mL. The structure–activity relationship and antibacterial mechanism were investigated in this study. Molecular docking studies were carried out to verify and rationalize the biological results. In this study, the results confirmed that our design could successfully increase the inhibitory activity and specificity against MRSA. Compound 4d could be used as a candidate for anti-bacterial agents and in depth vivo studies should be further investigated.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rizk E. Khidre ◽  
Ibrahim Ali M. Radini

AbstractA novel series of substituted 4,6-dimethyl-2-oxo-1-(thiazol-2-ylamino)-1,2-dihydropyridine-3-carbonitrile derivatives 6, 9, 13, 15, and 17 was synthesized in a good to excellent yield from the reaction of 1-(3-cyano-4,6-dimethyl-2-oxopyridin-1(2H)-yl)thiourea with 2-oxo-N'-arylpropanehydrazonoyl chloride, chloroacetone, α-bromoketones, ethyl chloroacetate, and 2,3-dichloroquinoxaline, respectively. The potential DNA gyrase inhibitory activity was examined using in silico molecular docking simulation. The novel thiazoles exhibit dock score values between − 6.4 and − 9.2 kcal/mol and they were screened for their antimicrobial activities. Compound 13a shown good antibacterial activities with MIC ranged from 93.7–46.9 μg/mL, in addition, it shown good antifungal activities with MIC ranged from 7.8 and 5.8 μg/mL.


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