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Brazilian Medicinal Plant Extracts with Antimicrobial Action Against Microorganisms that Cause Foodborne Diseases
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
Luiza Helena da Silva Martins, Sabrina Baleixo da Silva, Carissa Michelle Goltara Bichara, Johnnat Rocha Allan de Oliveira, Adilson Ferreira Santos Filho, Rafaela Cristina Barata Alves, Andrea Komesu, Mahendra Rai
Studies have shown the significant action of flavonoids as topoisomerase inhibitors, contributing to their antimicrobial activity. According to Plaper et al. (2003), DNA gyrase is defined as an essential enzyme so that DNA replication can be performed, being exclusive to prokaryotes, and an attractive target for drugs with antimicrobial action. Quercetin, apigenin and sakuranet are flavonoids capable of inhibiting Helicobacter pylori 3-hydroxyacyl ACP dehydrase (Zhang et al. 2008). Eleven flavanones with different configurations of hydroxyl groups were evaluated to verify the antimicrobial activity on E. faecalis (Jeong et al. 2009) and many were shown to be efficient, mainly being naringenin and taxifolin. Mori et al. (1987) reported that some flavonoids can affect the DNA of microorganisms, and act in the inhibition of bacterial nucleic acid synthesis. They noted that the incubation with epigallocatechin gallate, myricetin and robinetin resulted in the reduction of DNA, RNA and protein synthesis by Proteus vulgaris and S. aureus.
Heterocyclic Drugs from Plants
Published in Rohit Dutt, Anil K. Sharma, Raj K. Keservani, Vandana Garg, Promising Drug Molecules of Natural Origin, 2020
Debasish Bandyopadhyay, Valeria Garcia, Felipe Gonzalez
Ciprofloxacin and fluconazole are antibiotics that are frequently used to treat bacterial and fungal infections respectively. Ciprofloxacin (Figure 8.13) is an antibiotic belong to the fluoroquinolone class of antibiotics (Ciprofloxacin, 2018). The primary mechanism is the inhibition of bacterial DNA gyrase (Campoli et al., 1988). The drug has demonstrated higher potency than other fluoroquinolones (Lebel, 1988). It is also prescribed in treating pneumonia, gonorrhea, typhoid, infectious diarrhea, skin infection, bone, joint, abdomen, prostate, bronchitis, urinary tract, and skin infections. Ciprofloxacin is taken orally but it some cases intravenous administration is preferred (Campoli et al., 1988; Ciprofloxacin, 2018).
Role of Plant-Based Bioflavonoids in Combating Tuberculosis
Published in Megh R. Goyal, Durgesh Nandini Chauhan, Assessment of Medicinal Plants for Human Health, 2020
Alka Pawar, Yatendra Kumar Satija
Fluoroquinolones were discovered in the year 1965 as a derivative in the purification of the Chloroquine—an antimalarial drug. It mainly inhibits the type II topoisomerase/DNA gyrase enzyme of MTB. The DNA gyrase consists of subunits A and B, coded via gyr genes. Resistance of fluoroquinolones mainly occurs due to mutation in gyrA or gyrB genes.78
Discovery of N-quinazolinone-4-hydroxy-2-quinolone-3-carboxamides as DNA gyrase B-targeted antibacterial agents
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Wenjie Xue, Yaling Wang, Xu Lian, Xueyao Li, Jing Pang, Johannes Kirchmair, Kebin Wu, Zunsheng Han, Xuefu You, Hongmin Zhang, Jie Xia, Song Wu
Bacterial DNA gyrase B subunit (GyrB) is a promising target for discovery and development of a new class of antibiotics.8 As an indispensable component of DNA gyrase (A2B2), GyrB binds ATP at the ATPase domain and catalyses ATP hydrolysis; it provides energy for DNA supercoiling.9 When the GyrB inhibitor novobiocin was approved for clinical use (cf. Figure 1), antibiotics with the same mode of action were considered as promising therapeutics for the treatment of bacterial infections.7 Since the decline of novobiocin in 1960s due to its toxicity and low efficacy, several diverse GyrB inhibitors have been discovered, e.g. ethyl ureas,10 pyrazolopyridones,11 pyrrolamides,12 and quercetin diacylglycosides.13 Unfortunately, none of these have been approved. Two compounds, i.e. SPR720 (ethyl ureas)14 and DS-2969b (pyrrolamides),15 are in phase I clinical trials (cf. Figure 1), but the clinical outcomes of these chemotypes are also unpredictable. Therefore, the identification of diverse structures as GyrB inhibitors is still necessary.
Tryptanthrin, a potential biofilm inhibitor against toxigenic Vibrio cholerae, modulating the global quorum sensing regulator, LuxO
Published in Biofouling, 2019
Lekshmi Narendrakumar, Mary Theresa, Sivakumar Krishnankutty Chandrika, Sabu Thomas
Quinolone antibiotics act upon the DNA gyrase and the topoisomerase recognized to participate in DNA synthesis. A recent outbreak of strains of V. cholerae has been reported to acquire mutations in the gyrA (DNA gyrase) and parC (topoisomerase) genes, thus acquiring resistance. A desirable approach to be followed to tackle the growing antibiotic resistance of bacteria is to combine novel anti-biofilm compounds with conventionally used antibiotics. Such combinatorial therapy would resuscitate the potency of the antibiotics, conjoining beneficially to treat otherwise hardy infectious diseases. Tryptanthrin showed a synergistic action with ciprofloxacin at concentrations of 1 µg ml−1 and 2 µg ml−1 (FIC value 0.3279 ± 0.04 and 0.5002 ± 0.007 respectively). However, tryptanthrin in combination with nalidixic acid presented indifferent action with a FIC value of 1.5633 ± 0.032. and antagonistic action at higher concentrations (FIC value = 12.5690 ± 0.009). The synergistic studies thus revealed that tryptanthrin could re-sensitize ciprofloxacin resistant V. cholerae. This would be an encompassment since V. cholerae resistant to flouroquinoloes has been a major issue since 1995 (Mukhopadhyay et al. 1998; Divya et al. 2014).
Ozenoxacin: a review of preclinical and clinical efficacy
Published in Expert Review of Anti-infective Therapy, 2019
Jordi Vila, Adelaide A Hebert, Antonio Torrelo, Yuly López, Marta Tato, María García-Castillo, Rafael Cantón
Quinolones act by inhibiting the enzymes DNA gyrase and topoisomerase IV, both of which are involved in bacterial DNA synthesis [28]. DNA gyrase catalyzes the negative supercoiling of DNA, and thus plays an important role in the replication and transcription of DNA, and in organization of the chromosome [29]. The main function of topoisomerase IV is to decatenate the two daughter molecules of DNA after replication [30]. Both enzymes are tetrameric: DNA gyrase consists of two A subunits (GyrA, encoded by the gyrA gene) and two B subunits (GyrB, encoded by the gyrB gene); topoisomerase IV also has two A subunits (ParC or GrlA, the latter in S. aureus, encoded by the parC or grlA genes) and two B subunits (ParE or GrlB, the latter in S. aureus, encoded by the parE or grlB genes) [28]. Some quinolones (e.g. levofloxacin and ciprofloxacin) act preferentially against topoisomerase IV over DNA gyrase [31].