Synthesis of novel 18 β ‐ glycyrrhetinic piperazine amides displaying significant in vitro and in vivo antibacterial activities against intractable plant bacterial diseases

2020 ◽  
Vol 76 (9) ◽  
pp. 2959-2971
Author(s):  
Meng Xiang ◽  
Ying‐Lian Song ◽  
Jin Ji ◽  
Xiang Zhou ◽  
Li‐Wei Liu ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
Bacterial Diseases

scholarly journals Novel 1,3,4-Oxadiazole Derivatives Containing a Cinnamic Acid Moiety as Potential Bactericide for Rice Bacterial Diseases

2019 ◽  
Vol 20 (5) ◽  
pp. 1020 ◽  
Author(s):  
Shaobo Wang ◽  
Xiuhai Gan ◽  
Yanju Wang ◽  
Shaoyuan Li ◽  
Chongfen Yi ◽  
...  
Keyword(s):  
Cinnamic Acid ◽  
Predictive Ability ◽  
Antibacterial Activities ◽  
Leaf Blight ◽  
Bacterial Leaf Blight ◽  
Acid Moiety ◽  
Bacterial Diseases ◽  
Oxadiazole Derivatives

Rice bacterial leaf blight and leaf streak are two important bacterial diseases of rice, which can result in yield loss. Currently, effective antimicrobials for rice bacterial diseases are still lacking. Thus, to develop highly effective and low-risk bactericides, 31 novel 1,3,4-oxadiazole derivatives containing a cinnamic acid moiety were designed and synthesized. Bioassay results demonstrated that all compounds exhibited good antibacterial activities in vitro. Significantly, compounds 5r and 5t showed excellent antibacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc), with the 50% effective concentration (EC50) values of 0.58 and 0.34, and 0.44 and 0.20 μg/mL, respectively. These compounds were much better than thiodiazole copper (123.10 and 161.52 μg/mL) and bismerthiazol (85.66 and 110.96 μg/mL). Moreover, compound 5t had better protective and curative activities against rice bacterial leaf blight and leaf streak than thiodiazole copper and bismerthiazol in vivo. Simultaneously, the in vivo efficacy of the compounds was demonstrated by real-time quantitative PCR to quantify bacterial titers. In addition, a three-dimensional quantitative structure–activity relationship model was created and presented good predictive ability. This work provides support for 1,3,4-oxadiazole derivatives containing a cinnamic acid moiety as a potential new bactericide for rice bacterial diseases.

scholarly journals Synthesis of N-Methylmorpholinium Derivatives Possessing a 1,3,4-Oxadiazole Core as Feasible Antibacterial Agents against Plant Bacterial Diseases

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xinxin Tuo ◽  
Jie Yang ◽  
Yedong Zhang ◽  
Peiyi Wang
Keyword(s):  
Quaternary Ammonium ◽  
Phytophthora Cinnamomi ◽  
Good Control ◽  
Antibacterial Activities ◽  
Strong Interactions ◽  
Microscopy Imaging ◽  
Bacterial Diseases ◽  
Phytotoxicity Test

To develop a kind of quaternary ammonium compounds that can safely apply in agriculture for managing the plant bacterial diseases, herein, a series of N-methylmorpholinium derivatives possessing a classical 1,3,4-oxadiazole core were prepared and the antibacterial activities both in vitro and in vivo were screened. Bioassay results revealed that compounds 3l and 3i showed the strongest antibacterial activity toward pathogens Xanthomonas oryzae pv. oryzae and X. axonopodis pv. citri with the lowest EC50 values of 1.40 and 0.90 μg/mL, respectively. Phytotoxicity test trials indicated that target compounds bearing a bulky N-methylmorpholinium pendant are safe for plants. The following in vivo bioassays showed that compound 3l could control the rice bacterial blight disease, thereby affording good control efficiencies of 55.95% (curative activity) and 53.09% (protective activity) at the dose of 200 μg/mL. Preliminary antibacterial mechanism studies suggested that target compounds had strong interactions with the cell membrane of bacteria via scanning electron microscopy imaging. Additionally, this kind of framework also displayed certain antifungal activity toward Fusarium oxysporum and Phytophthora cinnamomi. Given the above privileged characteristics, this kind of 1,3,4-oxadiazole-tailored N-methylmorpholinium derivatives could stimulate the design of safe quaternary ammonium bactericides for controlling plant bacterial diseases.

scholarly journals In Vitro and In Vivo Antibacterial Activities of DW-224a, a New Fluoronaphthyridone

2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
The Other ◽  
Vitro Activity ◽  
Gram Negative Bacteria ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.

In vitro and in vivo Antibacterial Activities of S-1090, a New Oral Cephalosporin, in the Fields of Obstetrics and Gynecology

Chemotherapy ◽  
1998 ◽  
Vol 44 (3) ◽  
pp. 153-156 ◽  
Author(s):  
Hiroshige Mikamo ◽  
Kyoko Kawazoe ◽  
Yasumasa Sato ◽  
Koji Izumi ◽  
Teruhiko Tamaya
Keyword(s):  
Antibacterial Activities ◽  
Obstetrics And Gynecology ◽  
Oral Cephalosporin

scholarly journals Uncovering and Engineering a Mini-Regulatory Network of the TetR-Family Regulator SACE_0303 for Yield Improvement of Erythromycin in Saccharopolyspora erythraea

2021 ◽  
Vol 9 ◽  
Author(s):  
Ying Liu ◽  
Sabir Khan ◽  
Panpan Wu ◽  
Bowen Li ◽  
Lanlan Liu ◽  
...  
Keyword(s):  
Regulatory Network ◽  
Target Genes ◽  
Antibacterial Activities ◽  
Saccharopolyspora Erythraea ◽  
High Yield ◽  
Yield Strain ◽  
Yield Improvement ◽  
Erythromycin Production

Erythromycins produced by Saccharopolyspora erythraea have broad-spectrum antibacterial activities. Recently, several TetR-family transcriptional regulators (TFRs) were identified to control erythromycin production by multiplex control modes; however, their regulatory network remains poorly understood. In this study, we report a novel TFR, SACE_0303, positively correlated with erythromycin production in Sac. erythraea. It directly represses its adjacent gene SACE_0304 encoding a MarR-family regulator and indirectly stimulates the erythromycin biosynthetic gene eryAI and resistance gene ermE. SACE_0304 negatively regulates erythromycin biosynthesis by directly inhibiting SACE_0303 as well as eryAI and indirectly repressing ermE. Then, the SACE_0303 binding site within the SACE_0303-SACE_0304 intergenic region was defined. Through genome scanning combined with in vivo and in vitro experiments, three additional SACE_0303 target genes (SACE_2467 encoding cation-transporting ATPase, SACE_3156 encoding a large transcriptional regulator, SACE_5222 encoding α-ketoglutarate permease) were identified and proved to negatively affect erythromycin production. Finally, by coupling CRISPRi-based repression of those three targets with SACE_0304 deletion and SACE_0303 overexpression, we performed stepwise engineering of the SACE_0303-mediated mini-regulatory network in a high-yield strain, resulting in enhanced erythromycin production by 67%. In conclusion, the present study uncovered the regulatory network of a novel TFR for control of erythromycin production and provides a multiplex tactic to facilitate the engineering of industrial actinomycetes for yield improvement of antibiotics.

scholarly journals SCE-963, a New Broad-Spectrum Cephalosporin: In Vitro and In Vivo Antibacterial Activities

1978 ◽  
Vol 14 (4) ◽  
pp. 557-568 ◽  
Author(s):  
K. Tsuchiya ◽  
M. Kida ◽  
M. Kondo ◽  
H. Ono ◽  
M. Takeuchi ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Antibacterial Activities

scholarly journals Characterization of Novel Antimicrobial Peptoids

1999 ◽  
Vol 43 (6) ◽  
pp. 1429-1434 ◽  
Author(s):  
Bob Goodson ◽  
Anton Ehrhardt ◽  
Simon Ng ◽  
John Nuss ◽  
Kirk Johnson ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
Membrane Disruption ◽  
Infection Model ◽  
Gram Negative Bacteria ◽  
Positional Isomers ◽  
Bacterial Growth Inhibition ◽  
Alpha Carbon

ABSTRACT Peptoids differ from peptides in that peptoids are composed of N-substituted rather than alpha-carbon-substituted glycine units. In this paper we report the in vitro and in vivo antibacterial activities of several antibacterial peptoids discovered by screening combinatorial chemistry libraries for bacterial growth inhibition. In vitro, the peptoid CHIR29498 and some of its analogues were active in the range of 3 to 12 μg/ml against a panel of gram-positive and gram-negative bacteria which included isolates which were resistant to known antibiotics. Peptoid antimicrobial activity againstStaphylococcus aureus was rapid, bactericidal, and independent of protein synthesis. β-Galactosidase and propidium iodide leakage assays indicated that the membrane is the most likely target of activity. Positional isomers of an active peptoid were also active, consistent with a mode of action, such as membrane disruption, that does not require a specific fit between the molecule and its target. In vivo, CHIR29498 protected S. aureus-infected mice in a simple infection model.

scholarly journals Pharmacodynamic Analysis of the Activity of Quinupristin-Dalfopristin against Vancomycin-ResistantEnterococcus faecium with Differing MBCs via Time-Kill-Curve and Postantibiotic Effect Methods

1998 ◽  
Vol 42 (9) ◽  
pp. 2188-2192 ◽  
Author(s):  
Jeffrey R. Aeschlimann ◽  
Michael J. Rybak
Keyword(s):  
Antibacterial Activities ◽  
Water Soluble ◽  
Postantibiotic Effect ◽  
Curve Method ◽  
Highly Correlated ◽  
Kill Curve ◽  
The Individual ◽  
Time Kill

ABSTRACT Quinupristin-dalfopristin (Q-D) is a new water-soluble, semisynthetic antibiotic that is derived from natural streptogramins and that is combined in a 30:70 ratio. A number of studies have described the pharmacodynamic properties of this drug, but most have investigated only staphylococci or streptococci. We evaluated the relationship between Q-D, quinupristin (Q), and/or dalfopristin (D) susceptibility parameters and antibacterial activities against 22 clinical isolates of vancomycin-resistant Enterococcus faecium (VREF) by using the concentration-time-kill-curve method and by measuring postantibiotic effects. Q-D, Q, and D MICs and minimum bactericidal concentrations (MBCs) ranged from 0.125 to 1 and 0.25 to 64, 8 to 512 and >512, and 2 to 8 and 8 to 512 μg/ml, respectively. There were no significant relationships between susceptibilities to the individual components and the susceptibilities to the Q-D combination product. In the time-kill-curves studies, Q-D at a concentration of 6 μg/ml was at least bacteriostatic against all VREF tested. There was increased activity against more susceptible isolates when the isolates were grouped either by Q-D MBCs or by Q MICs. By multivariate regression analyses, the percent change in the inoculum from that at the baseline was significantly correlated with the Q MIC (R = 0.74; P = 0.008) and the Q-D concentration-to-MBC ratio (R = 0.58;P = 0.02) and was inversely correlated with the Q-D MBC-to-MIC ratio (R = 0.68; P = 0.003). A strong correlation existed between the killing rate and the Q-D concentration-to-MBC ratio (R = 0.99;P < 0.0001). Time to 99.9% killing was best correlated with the Q-D MBC (R = 0.96;P < 0.0001). The postantibiotic effect ranged from 0.2 to 3.2 h and was highly correlated with the Q-D concentration-to-MBC ratio (R = 0.96;P < 0.0001) and was less highly correlated with the Q MIC (R = 0.42; P = 0.04). Further study of these relationships with in vitro or in vivo infection models that simulate Q-D pharmacokinetics should further define the utility of these pharmacodynamic parameters in the prediction of Q-D activity for the treatment of VREF infections in humans.

scholarly journals A COMPARATIVE STUDY OF ANTIMICROBIAL PROFILE HAVING BROAD SPECTRUM BACTERIOCINS AGAINST ANTIBIOTICS

2017 ◽  
Vol 10 (9) ◽  
pp. 44 ◽  
Author(s):  
Sabiha Imran ◽  
Twinkle Gupta ◽  
Aarti Arora ◽  
Nilanjan Das
Keyword(s):  
Broad Spectrum ◽  
Cationic Peptides ◽  
Promising Alternative ◽  
Bacterial Diseases ◽  
Adverse Side Effects ◽  
Experimental Systems ◽  
Improper Use ◽  
Physical And Chemical

  Bacteriocins are ribosomally synthesized antimicrobial peptides produced by microbes owned by different eubacterial taxonomic branches. Most of them are small cationic membrane-active compounds that form pores in the targeted cells, disrupting membrane possibilities, and triggering cell fatality. The availability of small cationic peptides with antimicrobial activity is a protection strategy found not only in bacteria but also in plants and animals. The antibiotics which have extensive applications in the treatment of various bacterial diseases have developed alarming resistance against them in many pathogens due to improper use besides this antibiotics have adverse side effects also. There are an extensive variety of bacteriocins made by different bacterial genera have promising alternative to antibiotics that needs to be further studied to show the no existence of undesirable effects, which must be performed both in vitro and in vivo experimental systems. Most of the bacteriocin have narrow spectrum of their activity and effective only on the related species. There is an urgent need for the identification of broad-spectrum bacteriocins isolated from the species from different habitats that can be effective against both Gram-positive and Gram-negative pathogens. In this review, we focus on the main physical and chemical characteristics of broad-spectrum bacteriocin and discuss their application as an alternative option to antibiotics.

scholarly journals Antibacterial activities of Camellia sinensis plant extracts against uropathogenic E. coli in vitro and in vivo

2020 ◽  
Vol 14 (6) ◽  
pp. 147-155
Author(s):  
J. N. Agbom ◽  
O. Ogbu ◽  
I. R. Iroha ◽  
I. B. Moses ◽  
A. L. Onuora ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Plant Extracts ◽  
Antibacterial Activities ◽  
E Coli
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