tetracycline and ethyl-acetate

Increasing prevalence of antibiotic resistance has led research to focus on discovering new antimicrobial agents derived from the marine biome. Although ample studies have investigated sponges for their bioactive metabolites with promising prospects in drug discovery, the potentiating effects of sponge extracts on antibiotics still remains to be expounded. The present study aimed to investigate the antibacterial capacity of seven tropical sponges collected from Mauritian waters and their modulatory effect in association with three conventional antibiotics namely chloramphenicol, ampicillin and tetracycline. Disc diffusion assay was used to determine the inhibition zone diameter (IZD) of the sponge total crude extracts (CE), hexane (HF), ethyl acetate (EAF) and aqueous (AF) fractions against nine standard bacterial isolates whereas broth microdilution method was used to determine their minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs) and antibiotic potentiating activity of the most active sponge extract. MIC values of the sponge extracts ranged from 0.039 to 1.25mg/mL. Extracts from Neopetrosia exigua rich in beta-sitosterol and cholesterol displayed the widest activity spectrum against the 9 tested bacterial isolates whilst the best antibacterial profile was observed by its EAF particularly against Staphylococcus aureus and Bacillus cereus with MIC and MBC values of 0.039mg/mL and 0.078mg/mL, respectively. The greatest antibiotic potentiating effect was obtained with the EAF of N. exigua (MIC/2) and ampicillin combination against S. aureus. These findings suggest that the antibacterial properties of the tested marine sponge extracts may provide an alternative and complementary strategy to manage bacterial infections.

Topics: Acetates; Ampicillin; Animals; Anti-Bacterial Agents; Aquatic Organisms; Biological Products; Chloramphenicol; Disk Diffusion Antimicrobial Tests; Drug Agonism; Drug Discovery; Drug Resistance, Bacterial; Gram-Negative Bacteria; Gram-Positive Bacteria; Indian Ocean; Mauritius; Microbial Sensitivity Tests; Porifera; Sitosterols; Solvents; Tetracycline

To explore a scientific idea, this study was examined for evaluation of antimicrobial potency using root, leaf and stem of ethyl acetate and chloroform extracts of C. infortunatum (Verbenaceae) due to randomly use in traditional medicine to cure common ailments such as intestinal disorder, diarrhea, tuberculosis and respiratory problems etc.. The in vitro application was carried out by using disc diffusion, micro broth dilution and serial dilution techniques against clinically important life threatening organisms.. All the extracts showed significant inhibitory activity over the bacteria and fungus comparable to the standard drug tetracycline and fluconazole. The maximum average diameter zone of inhibition was recorded to bacterial strains against B. megaterium, S. typhi, K. pneumoniae and to fungi against A. niger and C. albicans. The MIC values of ethyl acetate and chloroform root extract were determined 64 µg/ml to B. subtilis, and K. pneumoniae; to S.-β-haemolyticus and S. typhi for ethyl acetate extracts, 128 µg/ml to S. aureus, and E. coli for both ethyl acetate and chloroform root extracts but only S. typhi and S.-β-haemolyticus for chloroform extract.. The findings evidently appear promising antibacterial and antifungal properties of C. infortunatum against antagonistic pathogens. Leaf possess quite potent activity than root and stem specially root extract > leaf extract > stem extract. One of the more significant achievements of this study to follows and covers the most recent and important patents WO2009075290 (2009) which deals on yeast having immunopotentiating effect and food or feed. This study serves as basis for further research to lead compounds to be isolated so that may be as a template for the implications of these results for bioactivity and drug discovery potential of herbal products are discussed.

Topics: Acetates; Anti-Bacterial Agents; Antifungal Agents; Chloroform; Clerodendrum; Fluconazole; Microbial Sensitivity Tests; Patents as Topic; Plant Extracts; Plant Leaves; Plant Roots; Plant Stems; Tetracycline

Tetracycline is a widely used broad spectrum antibiotic. A derivative of tetracycline was synthesized by methylation (-CH3) of the phenolic hydroxyl group, with the use of diazomethane (CH2N2). A methyl ether group is then formed from the reaction with diazomethane, which replaces the hydroxyl group. The newly formed derivative has reduced hydrogen bonding capability relative to the unmodified tetracycline. An infrared spectra shows the appearance of the ether group on the derivative and the Log P calculations indicate that the derivative has increased lipophilic tendency. The Lipophilic Substituent Constant calculated for the tetracycline derivative is 0.46, indicating a lipophilic substituent. The tetracycline derivative was soluble in aqueous solvents and was stable for more than five weeks when stored at < or = 0 degrees C. The derivative was placed in tissue culture utilizing Luria-Bertani (LB) media, at a concentration of 12.0 microg/mL and inhibited the growth of E. coli (XL-1 blue) from 15% to 20% within the initial sixteen hours.

Topics: Acetates; Anti-Bacterial Agents; Cells, Cultured; Diazomethane; Drug Stability; Escherichia coli; Ether; Growth Inhibitors; Methylation; Solubility; Species Specificity; Tetracycline; Tetracycline Resistance

Bacterial resistance to antibiotics is a significant problem in medical care facilities, causing increased fatalities due to infection. The present study demonstrates that antibiotic structures can be selectively altered in a manner that revives their ability to inhibit bacterial growth. The antibiotic tetracycline was ethylated at the position of the phenolic hydroxy group with the use of diazoethane, forming an ethyl ether functional group. This derivative was dissolved in Luria-Bertani (LB) agar medium, then placed in tissue culture for screening against a tetracycline-resistant bacterial strain. The growth of this bacterial strain, designated XL1-Blue, was inhibited by the ethylated form of tetracycline. The procedure for synthesizing ethylated tetracycline utilizes diazoethane and is presented with the molecular structures and IR spectra. The ethylated form of tetracycline was stable at -20 degrees C for many weeks, and was soluble in LB agar plate medium. Ethylated tetracycline induced growth inhibition of XL1-Blue bacteria within the first 24 h of incubation. The level of bacterial growth inhibition was greater than 30%. Calculation of the partition coefficient, log P, was accomplished and indicates that ethylated tetracycline has an increased lipophilic tendency relative to unmodified tetracycline, and therefore has greater solubility in lipid bilayers.

Topics: Acetates; Alkylation; Anti-Bacterial Agents; Diazonium Compounds; Escherichia coli; Ether; Tetracycline; Tetracycline Resistance; Tetracyclines