quinazoline as antimicrobials

A series of nine 2,3-disubstituted-quinazolin-4(3 H )-one derived Schiff bases and their three Cu(II) complexes was prepared and tested for their antimicrobial activities against reference strains Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212 and resistant clinical isolates of methicillin-resistant S. aureus (MRSA) and vancomycin-resistant E. faecalis (VRE). All the substances were tested in vitro against Mycobacterium tuberculosis H37 Ra ATCC 25177, M. kansasii DSM 44162 and M. smegmatis ATCC 700084...

Antimicrobial resistance has emerged as a covert global health crisis, posing a significant threat to humanity. If left unaddressed, it is poised to become the foremost cause of mortality worldwide. Among the multitude of resistant bacterial pathogens, Pseudomonas aeruginosa, a Gram-negative, facultative bacterium, has been responsible for mild to deadly infections. It is now enlisted as a global critical priority pathogen by WHO. Urgent measures are required to combat this formidable pathogen, necessitating the development of novel anti-pseudomonal drugs...

Adhatoda or Justicia is one of the biggest and complex genera of the Acanthaceae family. Adhatoda vasica is commonly known as 'Adosa'. It is an ayurvedic medicine with a medicinal history of more than a thousand years in India. Traditionally, it is used to treat cough, asthma, phlegm, bleeding hemorrhoids, for both adults and youth. This plant possesses antiarthritis, antiseptic, antimicrobial, anti-tuberculosis, anti-inflammatory and abortifacient properties. Alkaloids are the major phytoconstituents present in the plant in the form of pyrrolo-quinazoline derivatives viz vasicine, vasicinone, vasicinol, adhatodine, adhatodinine, adhavasinone and anisotine etc...

A total of 35 new quinazolinone derivatives bearing the 1,2,4-triazolo[3,4- b ][1,3,4]thiadiazole scaffold and the 4-piperidinyl linker were designed, prepared, and assessed for their antibacterial and antifungal activities. Among these derivatives, the chemical structure of compound F5 was clearly verified via single-crystal X-ray diffraction analysis. The experimental results revealed that some of the compounds displayed good even excellent inhibitory effects toward the tested phytopathogenic bacteria. For instance, compound F33 was capable of strongly inhibiting Xanthomonas oryzae pv...

The Mycobacterium abscessus drug development pipeline is poorly populated, with particularly few validated target-lead couples to initiate de novo drug discovery. Trimethoprim, an inhibitor of dihydrofolate reductase (DHFR) used for the treatment of a range of bacterial infections, is not active against M. abscessus . Thus, evidence that M. abscessus DHFR is vulnerable to pharmacological intervention with a small molecule inhibitor is lacking. Here, we show that the pyrrolo-quinazoline PQD-1, previously identified as a DHFR inhibitor active against Mycobacterium tuberculosis , exerts whole cell activity against M...

Drug resistance to commercially available antimalarials is a major obstacle in malaria control and elimination, creating the need to find new antiparasitic compounds with novel mechanisms of action. The success of kinase inhibitors for oncological treatments has paved the way for the exploitation of protein kinases as drug targets in various diseases, including malaria. Casein kinases are ubiquitous serine/threonine kinases involved in a wide range of cellular processes such as mitotic checkpoint signaling, DNA damage response, and circadian rhythm...

Introduction: Quinazolin-4(3 H )-one derivatives have attracted considerable attention in the pharmacological profiling of therapeutic drug targets. The present article reveals the development of arylidene-based quinazolin-4(3 H )-one motifs as potential antimicrobial drug candidates. Methods: The synthetic pathway was initiated through thermal cyclization of acetic anhydride on anthranilic acid to produce 2-methyl-4H-3,1-benzoxazan-4-one 1, which (upon condensation with hydrazine hydrate) gave 3-amino-2-methylquinazolin-4(3 H )-one 2...

Pseudomonas aeruginosa (PA), one of the ESKAPE pathogens, is an opportunistic Gram-negative bacterium responsible for nosocomial infections in humans but also for infections in patients affected by AIDS, cancer, or cystic fibrosis (CF). Treatment of PA infections in CF patients is a global healthcare problem due to the ability of PA to gain antibiotic tolerance through biofilm formation. Anti-virulence compounds represent a promising approach as adjuvant therapy, which could reduce or eliminate the pathogenicity of PA without impacting its growth...

A straightforward and high yielding synthetic approach is employed to synthesize the novel 1H-1,2,3-triazole tethered pyrazolo[5,1-b]quinazoline hybrids 7(a-t) as new antimicrobial agents with two pharmacophore in the effective two step synthesis. The first step is the four component one-pot synthesis of highly functionalized pyrazolo[5,1-b]quinazolines 5(a-j) catalysed by TBAB, with the advantages of an environmentally benign reaction, high yielding, quick reaction time, and operational simplicity. In the subsequent stage, CuSO4 /NaAsc system was employed to synthesize the 1H-1,2,3-triazole tethered pyrazolo[1,5-b]quinazoline hybrids as 1H-1,2,3-triazoles are the structures of great diversity and importance in diverse therapeutics containing numerous biological activities...

The treatment of many bacterial diseases remains a significant problem due to the increasing antibiotic resistance of their infectious agents. Among others, this is related to Staphylococcus aureus , especially methicillin-resistant S. aureus (MRSA) and Mycobacterium tuberculosis . In the present article, we report on antibacterial compounds with activity against both S. aureus and MRSA. A straightforward approach to 2-(1 H -indol-3-yl)quinazolin-4(3 H )-one and their analogues was developed. Their structural and functional relationships were also considered...

Metal-organic frameworks (MOFs) offered excellent catalytic activity due to their superior porosity, and high densities of catalytic sites in remarkable specific surfaces. In this research, we prepared a magnetic MOF nanocomposite and investigated the advantages of MOF as a catalyst. The multi-functional catalyst was prepared in five steps including (1) preparation of cobalt ferrite nanoparticles (CoFe2 O4 ), (2) surface modification of cobalt ferrite using tetraethyl orthosilicate, (3) surface functionalization using 3-aminopropyl triethoxysilane, (4) preparation of MOF-5, (5) preparation of CoFe2 O4 @SiO2 -NH2 @MOF-5 nanocomposite...

Drug resistance is rising to alarming levels, constituting one of the major threats to global health. The overexpression of efflux pumps and the formation of biofilms constitute two of the most common resistance mechanisms, favoring the virulence of bacteria. Therefore, the research and development of effective antimicrobial agents that can also counteract resistance mechanisms are extremely important. Pyrazino[2,1- b ]quinazoline-3,6-diones, from marine and terrestrial organisms and simpler synthetic analogues, were recently disclosed by us as having relevant antimicrobial properties...

BACKGROUND: To discover more efficient antimicrobial agents in agriculture, a series of new quinazoline derivatives bearing both sulfonate ester and piperidine-4-carboxamide moieties were synthesized and assessed for their antimicrobial effects. RESULTS: All of the target compounds were fully characterized by 1 H NMR , 13 C NMR, and high-resolution mass spectra, and compound III-6 containing a 3-bromophenyl substituent was clearly confirmed via single-crystal X-ray diffraction analysis...

Antimicrobial resistance is a never-ending challenge, which should be considered seriously, especially when using unprescribed "over-the-counter" drugs. The synthesis and investigation of novel biologically active substances is among the directions to overcome this problem. Hence, 18 novel 5,6-dihydrotetrazolo[1,5-c]quinazolines were synthesized, their identity, purity, and structure were elucidated by elemental analysis, IR, LC-MS, 1 Н, and 13 C NMR spectra. According to the computational estimation, 15 substances were found to be of toxicity Class V, two of Class IV, and only one of Class II...

Despite low temperatures, poor nutrient levels and high pressure, microorganisms thrive in deep-sea environments of polar regions. The adaptability to such extreme environments renders deep-sea microorganisms an encouraging source of novel, bioactive secondary metabolites. In this study, we isolated 77 microorganisms collected by a remotely operated vehicle from the seafloor in the Fram Strait, Arctic Ocean (depth of 2454 m). Thirty-two bacteria and six fungal strains that represented the phylogenetic diversity of the isolates were cultured using an One-Strain-Many-Compounds (OSMAC) approach...

Antimicrobial resistance (AMR) is one of ten global public health threats facing humanity. This created the need to identify and develop effective inhibitors as antimicrobial agents. In this respect, quinazolin-2,4-dione hybrids bearing N-heterocyclic cores such as pyrrolidine-2,5-dione, pyrazole and oxadiazole and/or bioactive scaffolds such as hydrazone, amide, sulfonamide, azomethine, and thiourea linkage are described for design, synthesis, antibacterial investigation, and in silico studies. The characterization of the target compounds was accomplished by elemental analysis and various spectroscopic data like FT-IR, 1 H-NMR, 13 C-NMR and MS...

Microbial infections remain a worldwide leading cause of death, despite the evolution of a large number of new antibiotics every year. Currently, several bacteria have developed resistance against antibiotics drugs which remain a major issue in antibiotics drug discovery. This review provides detailed information about antimicrobial and antifungal agent synthesis belonging to the pyrazoles scaffold. We reassemble the results obtained from several studies to characterize the importance of heteroatom nuclei in many synthetic products...

Sulfonamides, with the general formula R-SO2NR1R2, have attracted great attention since the early discovery of sulfonamide-containing antibacterial drugs. The combinations of certain sulfonamides and other drug molecules to form sulfonamide hybrids are being used to develop novel formulations with greater effectiveness and in a huge range of therapeutic applications such as antimicrobial, antifungal, anti-inflammatory, antitubercular, antiviral, antidiabetic, antiproliferative, carbonic anhydrase inhibitor, antimalarial, anticancer and other medicinal agents...

In this paper, we report on the design and synthesis of a novel series of quinazoline-2,4(1 H ,3 H )-dione derivatives as fluoroquinolone-like inhibitors of bacterial gyrase and DNA topoisomerase IV to identify and develop antimicrobial agents to prevent bacterial resistance problems. Their structures were confirmed using spectroscopic analyses (IR, NMR, and EI-MS). The novel quinazoline-2,4(1 H ,3 H )-dione derivatives were evaluated for their antimicrobial activities against Gram-positive and Gram-negative bacterial strains using the Agar well diffusion method to study the antimicrobial activities and compared them with the standard drugs...

In the last decade, quinazoline was one of the most explored scaffolds by researchers around the globe in medicinal chemistry. Its unique structural features provide a wide range of substitutions on nitrogen and carbonyl groups. In the current situation of COVID-19, hydroxychloroquine an antimalarial drug of the quinoline category was used for the treatment of severe infections. Various substitution patterns, hybrids, and conjugates of quinazoline have been developed and studied for various pharmacological activities like anticancer, anti-inflammatory, antimalarial, antitubercular, etc...